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  1. Petrography and mineralogy of new lunar meteorite MIL090036

    Institute of Scientific and Technical Information of China (English)

    XIE Lanfang; CHEN Hongyi; MIAO Bingkui; XIA Zhipeng; YAO Jie

    2014-01-01

    MIL090036 is a previously unknown meteorite (a feldspathic lunar breccia) that was discovered in Antarctica. The detailed petrography and mineralogy of this meteorite forms the subject of this paper. It has a typical clastic texture that consists of various types of rock debris (e.g. anorthosite, gabbroic anorthosite, gabbro, regolith breccia, troctolite, microporphyritic crystalline impact melt and compound clasts), mineral crystal fragments (e.g. pyroxenes, plagioclase, olivine and ilmenite) and feldspathic glass clasts. The ifne-grained recrystallized minerals and mineral clasts are cemented together in a glassy groundmass. The anorthite content of plagioclase in the gabbro (An81-83) and anorthosite (An88-93) both have relatively low calcium content compared to those from other breccias (An90-98). The pyroxene composition (Fs12-35 Wo3-44 En22-79) in the rock debris, crystal mineral clasts and anorthositic glass clasts are relatively iron-deifcient compared to those from gabbro debris with melt glass (Fs37-65 Wo10-29 En21-49) and groundmass (Fs18-69 Wo3-45 En14-50). In contrast, the pyroxene grains in the gabbroic anorthosite display a narrow compositional range (Fs24-27 Wo7-14 En59-69). Olivine grains in mineral fragments and the groundmass have a wider compositional range (Fo57-79) than those in the rock debris (Fo67-77). The Fe/Mn ratio in olivine is in the range of 47 to 83 (average 76) and 76 to 112 (average 73) in pyroxenes, and hence classify within the lunar ifeld. The characteristics of texture, mineral assemblage and compositions suggest that MIL090036 possibly originated from a region beyond that of the Apollo and Luna samples. Further study of MIL090036 is therefore likely to lead to a better understanding of the geological processes on the Moon and the chemical composition of the lunar crust.

  2. Chemical Mineralogy, Geochemical Characterization and Petrography of the Cambumbia Stock, Northern Andes, South America, Colombia

    Science.gov (United States)

    Rojas Lequerica, Salvador; María Jaramillo Mejía, José; Concha Perdomo, Ana Elena; Jimenez Quintero, Camilo

    2013-04-01

    The Cambumbia Stock is located on the western flank of the Central Cordillera of the northern Andes, South America. The goals of this study were to characterize the mineral chemistry, the geochemical composition and the petrography of the Cambumbia igneous body and to establish its petrogenesis. We collected 41 samples, selected 28 for thin section petrographic analysis, 14 for whole rock elementary chemical determination by ICP-MS and 4 for chemical mineralogy by LA-ICP(JEOL JXA-8200). Petrographically the samples were classified as 30 % hornblende-gabbro, 30% pyroxene-gabbros, 10% diorites, 10% olivine-gabbro, 7% gabbronorites, 7% tonalities and 3% norite, 3% wehrlite, the rock varies from medium to coarse hipidiomorfic and holocristaline texture, with local microporfiritic texture. Spot elemental chemical analysis of the some minerals in 4 samples show the range of the major elemental composition is plagioclase (labradorite), clinopyroxene (augite), horblende (magnesiohornblende), olivine (fayalite())Chemical mineralogy shows the variety of minerals in this rock, essential minerals correspond to bytownite, augite, magnesio-honblende, fallaite and titanite. We conclude base on the SiO2 Vs Total Alkalis graph that the samples correspond to the sub-alkaline series with low K content, mainly in the calc-alkaline series. By using the SiO2 vs TiO2, Th/Yb vs Ta/Yb and Zr/117-Th-Nb/16 diagrams it was determined that these rocks were generated in two geotectonic environments: one type MOR (extension) and other island arc (subduction, compression). Recently, a U/Pb age was obtained by the Universidad de Caldas in zircon in 2009 (not published data), yielded an age of 233.41 ± 3.4 Ma (Carnian - Upper Triassic). Petrographic geochemical and geochronology comparisons between the rocks of Cambumbia Stock and Diorite and Gabbro El Pueblito (located about 25 km to the north-west) and with U/Pb age 231 ± 8 may postulate a possible genetic link between them. These ages are

  3. Ceramic petrography, mineralogy and typology of Eneolithic pottery from Krašnja, Slovenia

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    Andreja Žibrat Gašparič

    2014-12-01

    Full Text Available In this article, we present newly excavated Eneolithic pottery from the site at Krašnja near Lukovica in central Slovenia. The material was AMS 14C dated and is contemporaneous with archaeological sites from the Ljubljansko barje region in Slovenia. The vessels were reconstructed and then various types of pots, dishes, cups, and beakers were analysed using petrography and the X-ray diffraction method. Additionally, the clay remains of walls and the floor of an Eneolithic kiln excavated at the site were also analysed. The results show that Eneolithic potters used different fab- rics to make vessels, and mostly one recipe with added calcite. The raw source material probably came from a nearby valley to the south of the site at Krašnja.

  4. Petrography, mineralogy, and chemistry of calcite-silica deposits at Exile Hill, Nevada, compared with local spring deposits

    Energy Technology Data Exchange (ETDEWEB)

    Vaniman, D.T.; Chipera, S.J.; Bish, D.L.

    1995-12-01

    Chemical, mineralogic, and petrographic analyses of siliceous calcretes from Exile Hill east of Yucca Mountain, Nevada, indicate that pedogenic processes alone account for the formation of the calcretes. These calcretes have been interpreted by some observers as evidence of seismically triggered eruptions of deep water. Such an origin could have important consequences if Yucca Mountain is developed as an unsaturated site for the disposal of high-level nuclear waste. At odds with this hypothesis are the absence of features that should be present at fault-fed springs (e.g., fissure-ridge mounds with microterraces) and the preservation within root casts of delicate pedogenic microfossils, such as calcified filaments and needle-fiber calcites. Mineral-chemical evidence of pedogenic origin is found in heavy-mineral concentrations, reflected in Fe and Sc enrichments. These concentrations, which occur in the most massive of the vein calcretes, require derivation of detritus from a mixture of weathered and eolian materials that occur in the overlying B soil horizons, as opposed to direct incorporation of adjacent unweathered bedrock. Carbonate and silica abundances and accumulation rates are well within the scope of pedogenic processes. Calcium is derived from rainwater or eolian sources, whereas silica is derived in part by dissolution of local volcanic glasses or from dissolution of unstable silica minerals that are abundant in the local tuffs. In contrast with local deposits that are of spring or seep origin, the siliceous calcretes at Yucca Mountain are pedogenic in origin as well as evolution and provide no evidence in support of conjectured spring activity.

  5. Petrography of gypsum-bearing facies of the Codó Formation (Late Aptian, Northern Brazil

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    Jackson D.S. Paz

    2006-09-01

    Full Text Available An original and detailed study focusing the petrography of evaporites from the Late Aptian deposits exposed in the eastern and southern São Luís-Grajaú Basin is presented herein, with the attempt of distinguishing between primary and secondary evaporites, and reconstructing their post-depositional evolution. Seven evaporites phases were recognized: 1. chevron gypsum; 2. nodular to lensoidal gypsum or anhydrite; 3. fibrous to acicular gypsum; 4. mosaic gypsum; 5. brecciated gypsum or gypsarenite; 6. pseudo-nodular anhydrite or gypsum; and 7. rosettes of gypsum. The three first phases of gypsum display petrographic characteristics that conform to a primary nature. The fibrous to acicular and mosaic gypsum were formed by replacement of primary gypsum, but their origin took place during the eodiagenesis, still under influence of the depositional setting. These gypsum morphologies are closely related to the laminated evaporites, serving to demonstrate that their formation was related to replacements that did not affect the primary sedimentary structures. The pseudo-nodular anhydrite or gypsum seems to have originated by mobilization of sulfate-rich fluids during burial, probably related to halokinesis. The rosettes of gypsum, which intercept all the other gypsum varieties, represent the latest phase of evaporite formation in the study area, resulting from either intrastratal waters or surface waters during weathering.Neste trabalho, é apresentado um estudo original e detalhado enfocando os aspectos petrográficos dos evaporitos de depósitos aptianos superiores expostos no sul e leste da Bacia de São Luís-Grajaú. O objetivo é o estabelecimento de critérios que permitam distinguir entre evaporitos primários e secundários, além da reconstrução de sua evolução pós-deposicional. Sete fases de evaporitos foram reconhecidas: 1. gipsita em chevron; 2. gipsita ou anidrita nodular a lenticular; 3. gipsita fibrosa a acicular; 4. gipsita em

  6. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20112225Du Guangpeng(Shanghai Jianqiao College,Shanghai 201319,China);Fan Jianliang Characteristics of Raman Spectral of Calcite Group Minerals(Journal of Mineralogy and Petrology,ISSN1001 - 6872, CN51-1143/TD,30(4),2010,p.32-35, 2illus.,2tables,6refs.)

  7. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20130742 Huang Dubin (School of Geoscience and Surveying Engineering , China University of Mining and Technology , Beijing 100083 , China); Guan Xinbang Study on the Minera-logical Features of Chloritoid in Hongmiaoling Formation of Dongshan , Tanzhesi , West Beijing , China (Acta Mineralogica Sinica , ISSN1000-4734 , CN52-1045/P

  8. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20152310 Hao Penghao(National Defense Key Discipline Lab.of Nuclear Waste and Environmental Safety,Southwest University of Science and Technology,Mianyang 621010,China);Lu Xirui Structural Evolvement and the Capability of Resistance toγ-Ray Irradiation on Zircon Originated from the North Qaidam(Journal of Mineralogy and Petrology,

  9. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>20080144 Ma Guohua(Southwest University of Science and Technology,Mianyang 621002,China);Peng Tongjiang A Study of Chrysotile Asbestos Nanotube Synthesized by Hydrothermal Reaction(Journal of Mineralogy and Petrology,ISSN1001-6872,CN51-1143/TD,27(1),2007,p.40-45,2 illus.,2 photos,11 refs.)

  10. Clay fraction mineralogy of a Cambisol in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Anastacio, A. S.; Fabris, J. D., E-mail: jdfabris@ufmg.br [Federal University of Minas Gerais, Campus - Pampulha, Department of Chemistry (Brazil); Stucki, J. W. [Department of Natural Resources and Environmental Sciences (United States); Coelho, F. S.; Pinto, I. V. [Federal University of Minas Gerais, Campus - Pampulha, Department of Chemistry (Brazil); Viana, J. H. M. [Embrapa Milho e Sorgo (Brazil)

    2005-11-15

    Clay minerals having a 2:1 (tetrahedral:octahedral sheet) structure may be found in strongly weathering soils only if the local pedo-climatic environment prevents them from further weathering to other minerals such as iron oxides. The clay minerals impart important chemical properties to soils, in part by virtue of changes in the redox state of iron in their crystal structures. Knowing the chemical nature of soil clays is a first step in evaluating their potential reactivity with other soil constituents and processes, such as the chemical decomposition of organic substrates to be potentially used in environmental remediation. The purpose of this work was to characterize the iron oxides and iron-bearing clay minerals from a B horizon of a Cambisol developed on tuffite in the State of Minas Gerais, Brazil, using chemical analysis, powder X-ray diffraction, Moessbauer spectroscopy, and thermal analysis. The iron oxides of this NaOH-treated clay-fraction were found to contain mainly maghemite ({gamma}Fe{sub 2}O{sub 3}) and superparamagnetic goethite ({alpha}FeOOH). Kaolinite (Al{sub 2}Si{sub 2}O{sub 5}(OH){sub 4}), smectite, and minor portions of anatase (TiO{sub 2}) were identified in the CBD-treated sample.

  11. Integrating petrography, mineralogy and hydrochemistry to constrain the influence and distribution of groundwater contributions to baseflow in poorly productive aquifers: insights from Gortinlieve catchment, Co. Donegal, NW Ireland.

    Science.gov (United States)

    Caulfield, John; Chelliah, Merlyn; Comte, Jean-Christophe; Cassidy, Rachel; Flynn, Raymond

    2014-12-01

    Identifying groundwater contributions to baseflow forms an essential part of surface water body characterisation. The Gortinlieve catchment (5 km(2)) comprises a headwater stream network of the Carrigans River, itself a tributary of the River Foyle, NW Ireland. The bedrock comprises poorly productive metasediments that are characterised by fracture porosity. We present the findings of a multi-disciplinary study that integrates new hydrochemical and mineralogical investigations with existing hydraulic, geophysical and structural data to identify the scales of groundwater flow and the nature of groundwater/bedrock interaction (chemical denudation). At the catchment scale, the development of deep weathering profiles is controlled by NE-SW regional scale fracture zones associated with mountain building during the Grampian orogeny. In-situ chemical denudation of mineral phases is controlled by micro- to meso-scale fractures related to Alpine compression during Palaeocene to Oligocene times. The alteration of primary muscovite, chlorite (clinochlore) and albite along the surfaces of these small-scale fractures has resulted in the precipitation of illite, montmorillonite and illite-montmorillonite clay admixtures. The interconnected but discontinuous nature of these small-scale structures highlights the role of larger scale faults and fissures in the supply and transportation of weathering solutions to/from the sites of mineral weathering. The dissolution of primarily mineral phases releases the major ions Mg, Ca and HCO3 that are shown to subsequently form the chemical makeup of groundwaters. Borehole groundwater and stream baseflow hydrochemical data are used to constrain the depths of groundwater flow pathways influencing the chemistry of surface waters throughout the stream profile. The results show that it is predominantly the lower part of the catchment, which receives inputs from catchment/regional scale groundwater flow, that is found to contribute to the

  12. Petrography and Metamorphism of the Metasedimentary Country-Rocks of the Jacurici Valley Chromitite-Hosting Mafic-Ultramafic Complexes, Bahia, Northeastern Brazil

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    Eliane A. Del Lama

    2001-11-01

    Full Text Available This paper deal with on the metasedimentary country-rocks of the chromite-bearing ultramafic rocks that occur in the “Jacurici River Valley Chromium District” northeastern Bahia, Brazil. This region presents a complex geologic-petrologic framework of rocks that were intensely deformed, metamorphosed and transformed by metasomatic processes, making it difficult to interpret their volutionary/metamorphic record. Although the metasedimentary country rocks have also been affected by such processes, it is possible to distinguish evidence of a previous high-grade metamorphism that affected them. Thermobarometric data for the observed mineralogical associations indicate P-T conditions around 750-800ºC and 7-8 kb for the metamorphic peak, based mainly on the presence of olivine in marbles and the cordierite-garnet-sillimanitespinel association in aluminous gneisses.

  13. 一块新发现月球陨石MIL090036的岩相学和矿物学%PETROGRAPHY AND MINERALOGY OF A NEW LUNAR METEORITE MIL 090036

    Institute of Scientific and Technical Information of China (English)

    谢兰芳; 缪秉魁; 陈宏毅; 夏志鹏; 姚杰

    2013-01-01

    MIL090036是一块在南极新发现的月球陨石,属于斜长岩质月球角砾岩。本文对这块陨石开展详细的岩石学、矿物学特征观察与研究。 MIL090036月球陨石具有典型的碎屑结构。碎屑包括岩屑、矿屑和玻屑。岩屑类型有斜长岩岩屑、辉长质斜长岩岩屑、辉长岩岩屑、风化角砾岩岩屑、橄长岩岩屑、微斑熔融角砾岩岩屑、复合角砾岩岩屑等;矿屑有辉石、斜长石、橄榄石、钛铁矿等;玻屑主要为长石质。基质由玻璃质、重结晶的细粒矿物和矿屑胶结组成。辉长岩岩屑中的斜长石( An81-83)和斜长岩中的斜长石( An88-93)较其他碎屑中的斜长石( An90-98)贫钙。岩屑、矿屑和长石质玻屑中的辉石相对贫铁( Fs 12-35 Wo3-44 En22-79),而含玻璃质的辉长岩岩屑中的辉石( Fs37-65 Wo10-29 En21-49)与基质中的辉石( Fs18-69 Wo3-45 En14-50)相对富铁。辉长岩质斜长岩中辉石成分变化范围最小( Fs24-27 Wo7-14 En59-69)。矿屑橄榄石和分布于基质中的橄榄石铁镁含量(Fo57-79)相对岩屑中的橄榄石(Fo67-77)变化范围大。橄榄石Fe/Mn比值为47-83(平均76)、辉石Fe/Mn比值为76-112(平均73),都与月球橄榄石和月球辉石一致。岩石结构、矿物模式组合和化学成分等特征表明MIL090036是来自Apollo和Luna采样范围外的样品。对MIL090036的矿物学、岩石学和化学成分的进一步研究将丰富我们对月表物质组成和演化的认识。%MIL090036 is a newly found meteorite that belongs to a feldspathic lunar breccia .The detailed petrography and mineralogy of this meteorite are investigated in this paper .It has a typical breccia texture that consists of lithic , mineral and glass clasts .The rock types of the lithic clasts are anorthosite , gabbroic anorthosite , gabbro , regolith breccia, troctolite, microporphyritic crystalline impact melt , and compound clasts

  14. Spectral analysis for the mineralogical characterization of planosols in NE Brazil

    Science.gov (United States)

    Costa, Diego; Souza, Deorgia; Rocha, Washington

    2016-04-01

    This paper aims to conduct a spectral characterization in two soil profiles located in the northeast of Brazil proposing relations between the pedogenetic evolution and the environmental settings generated from the characteristics of Planosols analyzed and the presence of minerals identified by spectral pattern obtained in a laboratory. The methodological procedures were divided into the characterization of the study area, theoretical framework, field work with sampling, sample preparation, measurement in the laboratory, processing of spectral data, analysis and interpretation of results and a vegetation index calculation for aid in the environmental characterization. It is possible to see that: i) both profiles have similar spectral characterized patterns; ii) the horizons A and E show higher reflectance compared with B and C; iii) Minerals 2: 1 and 1: 1, such as montmorillonite and kaolinite can be identified; iv) Planosols are fragile to erosion. In both profiles, the C horizon less weathered and B horizon iluvial show intense absorption bands at 1400nm, 1900nm and 2200nm. These absorption bands indicate the existence of mineralogy 2: 1 on the horizons of the soils analyzed. In both profiles were found small peaks absorption in 2265nm, corresponding to gibbsite. The occurrence of this type of mineral is more common in highly weathered soils or old surfaces of erosion, which is reflected in small intensities of absorption observed in this analysis since these are of little-weathered soils of the Brazilian semiarid region. Spectral analysis and morphology described in the two profiles show difficulties for the growth of vegetation, which is consistent with NDVI values found, ranging from -0.32 to 0.61with a predominance of 0.19. These factors lead to the intensification of erosion. Erosion is characterized as one of the main indicators of environmental degradation, causing loss of important elements of the soil, which creates consequently a reduction in fertility

  15. Geology, petrography and geochemistry of the A-type granites from the Morro Redondo Complex (PR-SC, southern Brazil, Graciosa Province

    Directory of Open Access Journals (Sweden)

    FREDERICO C.J. VILALVA

    2014-03-01

    Full Text Available The Morro Redondo Complex is one of the most important occurrences of the Graciosa A-type Province, southern Brazil. It consists of the Papanduva and Quiriri granitic plutons and a contemporaneous bimodal volcanic association. The Papanduva Pluton includes massive and deformed peralkaline alkali-feldspar granites with Na-Ca and Na-amphiboles and clinopyroxenes. The deformed types are the most evolved rocks in the province and carry rare ‘agpaitic’ minerals, some being described for the first time in granites from Brazil. The larger Quiriri Pluton comprises massive, slightly peraluminous, biotite syeno- and monzogranites with rare Ca-amphibole. Biotite compositions are relatively homogeneous, whereas sodic amphiboles and clinopyroxenes show increasing Na and Fe3+ evolving paths. The Morro Redondo granites are ferroan, with high SiO2, alkalis and HFSE contents; the peralkaline types registering the highest fe#. LILE and HFSE abundances increase with the agpaitic index and the most evolved are HHP granites, with radiogenic heat production up to 5.7 µWm–3. Geothermobarometric estimates indicate emplacement under low pressures (∼100 MPa, at temperatures up to 850-800 °C, and relatively reduced (QFM and oxidized (+1 REPLACE_LT ΔQFM REPLACE_LT +3 environments for the Papanduva and Quiriri Plutons, respectively. In both cases, melts evolved to relatively high oxidation states upon crystallization progress.

  16. Mineralogy and Oxygen Isotope Compositions of an Unusual Hibonite-Perovskite Refractory Inclusion from Allende

    Science.gov (United States)

    Keller, L. P.; Snead, C.; Rahman, Z.; McKeegan, K. D.

    2012-01-01

    Hibonite-rich Ca- and Al-rich inclusions (CAIs) are among the earliest formed solids that condensed in the early nebula. We discovered an unusual refractory inclusion from the Allende CV3 chondrite (SHAL) containing an approx 500 micron long single crystal of hibonite and co-existing coarse-grained perovskite. The mineralogy and petrography of SHAL show strong similarities to some FUN inclusions, especially HAL. Here we report on the mineralogy, petrography, mineral chemistry and oxygen isotopic compositions in SHAL.

  17. Talc mineralisation associated with soft hematite ore, Gongo Soco deposit, Minas Gerais, Brazil: petrography, mineral chemistry and boron-isotope composition of tourmaline

    Science.gov (United States)

    Cabral, Alexandre Raphael; Wiedenbeck, Michael; Rios, Francisco Javier; Seabra Gomes, Antônio Augusto; Rocha Filho, Orlando Garcia; Jones, Richard David

    2012-04-01

    Talc mineralisation occurs as hematite-talc schist between soft hematite ore and dolomitic itabirite at Gongo Soco, Quadrilátero Ferrífero of Minas Gerais, Brazil. The hematite-talc schist and soft hematite have a prominent tectonic foliation of tabular hematite. Tabular hematite without preferential orientation is superimposed on the tectonic foliation. The talcose schist is enriched in F and has a constant Fe/S ratio. Electron-microprobe analyses indicate trace amounts of S in different generations of hematite. The whole-rock Fe/S ratio possibly represents sulfate S from hematite-hosted fluid inclusions. Fluid inclusions in foliation-overprinting hematite and chlorite geothermometry from talcose rocks suggest, respectively, temperatures from mass spectrometry, vary from -20‰ to -12‰ δ11B. This compositional isotopic range and the tourmaline chemical composition suggest a meta-evaporitic origin. A non-marine evaporitic setting is the most likely source of acidic, highly oxidising fluids, which resulted in the abundant F-bearing talc and the presence of otherwise immobile Ti in hematite. Oxidising brines were channelled along shear zones and converted dolomitic itabirite into the Gongo Soco soft hematite and the talc mineralisation. The latter is envisaged as the hydrothermal wall-rock alteration of dolomitic itabirite, which gave rise to the soft hematite ore.

  18. 国内18块普通球粒陨石的岩石矿物学研究∗%Petrography and Mineralogy of 18 Newly Recovered Ordinary Chondrites in China

    Institute of Scientific and Technical Information of China (English)

    李少林; 徐伟彪

    2015-01-01

    Petrology and mineralogy of 18 newly recovered ordinary chondrites in China are reported in this paper. Fifteen meteorites were found in Xinjiang, among which 13 meteorites were found in the Lop Nur desert, and the other 2 meteorites were found in Kumtag and Aksai Chin, respectively. Three other meteorites are observed falls in Xining, Fuhe, and Dongyang, respectively. All meteorites are equilibrated ordi-nary chondrites with 8 H group and 10 L group meteorites. Their petrographic types vary from 4 to 6 in the L group meteorites, with most being type 5, while all H group meteorites are classified as type 5. The features of shock metamorphism of most mete-orites are moderate though a few have features of≥S4 stage. Most Lop Nur meteorites underwent intense weathering with only two of which have weathering degree of W1 and W2. Both Kumtag and Aksai Chin meteorite have a weathering degree of W2. The newly discovered tens of meteorites in the gobi deserts east to the Taklimakan Desert indicate that this region may become an important dense meteorite collection area in Eurasia.%描述了国内收集的18块普通球粒陨石的岩石矿物学特征,其中13块为新疆罗布泊地区的发现型陨石,1块为新疆库姆塔格地区的发现型陨石(Kumtag),1块为新疆阿克赛钦地区的发现型陨石(Aksai Chin),另外3块分别为降落于青海省西宁市(Xining)、湖北省随州市(Fuhe)以及浙江省东阳市(Dongyang)内的降落型陨石.18块陨石均属于平衡型普通球粒陨石,其中H群8块(全部为H5), L群10块(1块L4,7块L5,2块L6).18块陨石所受冲击变质作用较弱,以S2、S3程度居多.大多数罗布泊陨石经历了较强的风化作用,仅有2块风化程度较低,分别为W1和W2, Kumtag与Aksai Chin陨石风化程度均为W2.在新疆塔克拉玛干沙漠东部的戈壁荒漠区发现的大量陨石表明该区域可能是欧亚地区重要的陨石富集区.

  19. Mineralogical characterization of diamonds from Roosevelt Indigenous Reserve, Brazil, using non-destructive methods

    Science.gov (United States)

    Borges, M. P. A. C.; Moura, M. A.; Lenharo, S. L. R.; Smith, C. B.; Araujo, D. P.

    2016-11-01

    In this study, 660 diamonds from Igarapé Lajes Diggings (Roosevelt and Aripuanã Park indigenous areas), in Amazonian craton, Rondônia State, Brazil, were investigated. Their morphological, optical and surface characteristics were described using optical and scanning electron microscopy (SEM), cathodoluminescence (CL) and infrared spectroscopy (FTIR). The results demonstrated a predominance of resorbed crystals with many surface corrosion features, generally colorless, and led to the identification of four distinct groups: G1, G2, G3 and G4. Group G1 presents features of secondary sources while G2 and G4 show only primary features, some of which are not described in literature. Group G3 is similar to the other groups, however, is composed of less resorbed specimens with primary octahedral morphology relatively well preserved, indicating shorter time of exposure to dissolution effects. Cathodoluminescence in G2 is attributed to features of plastic deformation and to low contents of nitrogen (< 100 ppm, Type II) and high aggregation (IaB). G4 shows homogeneous blue CL, high contents of nitrogen (700 to 1000 ppm) and intermediate aggregation (IaAB). G1 presents luminescence influenced by radiation effects and populations with N contents and aggregation in the same ranges of G2 and G4, suggesting that the primary sources of the three groups can be the same. The relationship of nitrogen content versus aggregation state indicates higher temperatures of formation for G2 and lower for G4. The obtained data suggests that diamonds of G2 originated in sublithospheric mantle as has also been reported in nearby deposits (Machado River and Juína). The employed techniques were also effective in distinguishing diamonds from Roosevelt Reserve and from other localities, indicating that they could be used for improvement of certification procedures of diamonds of unknown origin.

  20. Provenance and sedimentary environments of the Proterozoic São Roque Group, SE-Brazil: Contributions from petrography, geochemistry and Sm-Nd isotopic systematics of metasedimentary rocks

    Science.gov (United States)

    Henrique-Pinto, R.; Janasi, V. A.; Tassinari, C. C. G.; Carvalho, B. B.; Cioffi, C. R.; Stríkis, N. M.

    2015-11-01

    The Proterozoic metasedimentary sequences exposed in the São Roque Domain (Apiaí Terrane, Ribeira Belt, southeast Brazil) consist of metasandstones and meta-felspathic wackes with some volcanic layers of within-plate geochemical signature (Boturuna Formation), a passive margin turbidite sequence of metawackes and metamudstones (Piragibu Formation), and volcano-sedimentary sequences with MORB-like basalts (Serra do Itaberaba Group; Pirapora do Bom Jesus Formation). A combination of zircon provenance studies in metasandstones, whole-rock geochemistry and Sm-Nd isotopic systematics in metamudstones was used to understand the provenance and tectonic significance of these sequences, and their implications to the evolution of the Precambrian crust in the region. Whole-rock geochemistry of metamudstones, dominantly from the Piragibu Formation, points to largely granitic sources (as indicated for instance by LREE-rich moderately fractionated REE patterns and subtle negative Eu anomalies) with some mafic contribution (responding for higher contents of Fe2O3, MgO, V, and Cr) and were subject to moderate weathering (CIA - 51 to 85). Sm-Nd isotope data show three main peaks of Nd TDM ages at ca. 1.9, 2.1 and 2.4 Ga; the younger ages define an upper limit for the deposition of the unit, and reflect greater contributions from sources younger than the >2.1 Ga basement. The coincident age peaks of Nd TDM and U-Pb detrital zircons at 2.1-2.2 Ga and 2.4-2.5 Ga, combined with the possible presence of a small amount of zircons derived from mafic (gabbroid) sources with the same ages, as indicated by a parallel LA-ICPMS U-Pb dating study in metapsammites, are suggestive that these were major periods of crustal growth in the sources involving not only crust recycling but also some juvenile addition. A derivation from similar older Proterozoic sources deposited in a passive margin basin is consistent with the main sedimentary sequences in the São Roque Domain being broadly coeval and

  1. Mineralogy and petrograghy of some tin, lithium and beryllium bearing albite-pegmatites near Doade, Galicia, Spain

    NARCIS (Netherlands)

    Hensen, B.J.

    1967-01-01

    The petrography and mineralogy of some Hercynian albite-pegmatites near Doade, Galicia, Spain is described. The mineral assemblage consists of albite, K-feldspar, quartz, muscovite, spodumene, petalite, cassiterite, beryl, columbitetantalite, montebrasite, apatite, eosphorite-childrenite, zircon, to

  2. Chemical and mineralogical characterization of elbaites from the Alto Quixaba pegmatite, Seridó province, NE Brazil

    Directory of Open Access Journals (Sweden)

    Ana C.M. Ferreira

    2005-12-01

    Full Text Available The Alto Quixaba pegmatite, Seridó region, northeastern Brazil, is a 60º/80ºSW-trending subvertical dike discordantly intruded into biotite schists of the Upper Neoproterozoic Seridó Formation. It has three distinct mineralogical and textural zones, besides a replacement body that cuts the pegmatite at its central portion and in which occur, among other gem minerals, colored elbaites. Elbaites usually occur as prismatic crystals, elongate according to the c-axis, with rounded faces and striations parallel to this axis. Optically, crystals are uniaxial negative with strong pleochroism; refractive index extraordinary axis = 1.619-1.622 and ordinary axis = 1.639-1.643, birefringence between 0.019 and 0.021, average relative density of 3.07, and the following unit cell parameters: ao = 15.845 Å, co = 7.085 Å and V = 1540.476 Å. There is alkali deficiency in the X site of 12-17%. The elbaites are relatively enriched in MnO (1.69 to 2.87% and ZnO (up to 2.98%.O pegmatito Alto Quixaba na região do Seridó, nordeste do Brasil, é um corpo subvertical de direção 60°/80°SW intrudindo discordante biotita xistos da Formação Seridó. Apresenta três zonas distintas em termos de mineralogia e textura, al��m de uma zona de alteração em forma de dique na qual ocorre, entre outros minerais-gema, elbaítas coloridas. As elbaítas ocorrem como cristais prismáticos alongados de acordo com o eixo C, com faces arredondadas e estrias paralelas a esse eixo. Os cristais são uniaxiais negativos e apresentam forte pleocroísmo; índices de refração nE = 1,619-1,622 e nO = 1.639-1.643, birrefrigência entre 0,019 e 0,021, densidade relativa de 3,07, e os parâmetros seguintes da célula unitária: ao = 15,845 Å, co = 7,085 Å e V = 1540,476 Å. O sítio X apresenta deficiência em álcalis entre 12 e 17%. As elbaítas são relativamente ricas em MnO (1,69 a 2,87% e ZnO (até 2,98%.

  3. 西南天山东德沟橄榄岩的岩相学、矿物学演化特征及其地质意义%Petrography, mineralogy and the evolution of peridotites from the Dongdegou, southwestern Tianshan and its geological significance

    Institute of Scientific and Technical Information of China (English)

    孔凡梅; 李旭平; 吴苏; 李守军; 徐衍明

    2013-01-01

    Peridotites of the Dongdegou are located at the northern of the orogenic belt between the Tarim plate and the Yili-central Tianshan plate, southwestern Tianshan, China, and are generally metasomatized by hydrous melt or fluid. The main minerals in the rocks are olivine, spinel, orthopyroxene, amphibole, phlogopite and diopside. Studies suggested that compositions of olivine and orthopyroxene are similar to those from mantle wedge peridotite, and the primary chromian spinel carries characteristics of mantle wedge above subduction zone peridotites, whiles secondary green spinels form later in granulite/amphibolite facies. Comprehensive analyses of petrography, mineralogy and mineral assemblage provide insight into a very complicated evolutional history of the peridotites from the Dongdegou. In generally, after the formation of peridotites, they experienced early mantle metasomatism, retrogressive metamorphism of granulite/amphibolite facies and finally followed by an episode of serpentinization. The peridotites from the Dongdegou were considered formed at mantle environment at temperature of 915 ~ 961 ℃ , and the mantle metasomatism may be under PT conditions of 770 ~900℃ , 10 ~ 18kbar. The features of the peridotite, such as lower TiO2 in both whole rock composition and in spinel minerals, and mineral assemblages, imply that the rocks has been cooled effectively by fluid released from the subducted slab, and are most likely to be the fragments of peridotite from SSZ volcanic arc environment.%中国西南天山东德橄榄岩出露于天山伊犁-中天山板块和塔里木板块碰撞造山带北缘,普遍经历了复杂多期的含水流体(熔体)交代作用.主要矿物为橄榄石、斜方辉石、尖晶石、角闪石、金云母和单斜辉石,研究发现,橄榄石和斜方辉石与地幔楔橄榄岩中橄榄石和斜方辉石成份相近,原生铬尖晶石具有SSZ环境橄榄岩的特征,次生绿色尖晶石形成于麻粒岩相-角闪相

  4. Geochemistry and mineralogy of recent sediments of Guanabara Bay (NE sector and its major rivers - Rio de Janeiro State - Brazil

    Directory of Open Access Journals (Sweden)

    FARIA MARCIA DE MELO

    2001-01-01

    Full Text Available Geochemical and clay mineralogical studies of bottom sediments collected along the Macacu and Caceribu rivers and Guanabara Bay were carried out in order to investigate the relationship between major source areas and recent sediments of the bay. Clay mineralogy includes different groups with selective distribution conditioned by geomorphic features and depositional settings. Micaceous clay minerals are abundant near parent rock in the upper course, whereas kaolinite derived from varied sources is gradually concentrated towards the estuary. In the Guanabara Bay, kaolinite accumulates near river mouths, while micaceous clay minerals are converted into mixed layers in the estuary. Analyses of heavy metal contents reveal higher levels of Zn and Cu in sediments of the bay than in river sediments. Profiles along rivers indicate a downstream decrease of heavy metals, whereas in the bay geochemical trends display greater variations. In general river mouth sediments present the lowest concentrations. At the north and east of Paquetá Island anomalous areas with the highest heavy metal contents occur. Cu tends to concentrate in < 2mum grain-size fraction and indicates an association with micaceous clay minerals in the upper river course. However, Cu retention seems to be further controlled by other components of bottom sediments due to changes in physical and chemical conditions of the estuarine environment. Zn shows unstable behavior along the rivers and concentrates in the bay. Pb displays small variations from river to bay sediments, and accumulates mainly in the < 63mum grain-size fraction without any association with clay mineral. Geoaccumulation indexes of Cu, Pb and Zn classify the study area as unpolluted in both studied rivers and in the NE sector of the bay, though the enrichment factors are higher in the bay. The study does not indicate those rivers as major sources of heavy metal pollution to the bay.

  5. Point of zero salt effect: Relationships with clay mineralogy of representative soils of the S(a)o Paulo State, Brazil

    Institute of Scientific and Technical Information of China (English)

    M. E. ALVES; A. LAVORENTI

    2005-01-01

    The point of zero salt effect (PZSE) is the soil pH value at which the magnitude of the variable surface charges is not changed due to variations in the ionic concentration of the soil solution. This property influences not only electrochemical phenomena occurring at the solid-solution interface but also the flocculation degree of the soil particles. In this study we investigated the relationships between the clay mineralogy and the PZSE values of representative soils of the Sao Paulo State, Brazil. The results confirmed the usefulness of the difference between the soil pH values measured in 1 mol L-1 KCl (pHKC1) and in water (pHH2O) (2 pHKC1 - pHH2O) for estimating the PZSE of tropical soils, except for the ones rich in exchangeable Al; furthermore, the △pH index (pHKCI - pHH2O) was highly correlated with the difference between the PZSE and pHH2O values, reiterating the △pH utility for estimating both the signal and the magnitude of the net surface charge of tropical soils. Finally, correlation and multiple regression analyses showed that the PZSE value of weathered non-allophanic tropical soils tends to increase and to equal the soil pH due to the weathering-induced kaolinite destabilization and concomitant Fe- and Al-oxide accumulation.

  6. Mineralogical and textural evidences of melt transfer in a granulite from the Paleoproterozoic Itabuna-Salvador-Curaça belt (Salvador da Bahia, Brazil)

    Science.gov (United States)

    Goncalves, Philippe; Santos de Souza, Jailma; Barbosa, Johildo; Bourque, Hugo; Floess, David

    2014-05-01

    In pelitic rocks, the effect of melt transfer (loss and/or gain) on phase relations can be successfully predicted via phase equilibrium modeling and more particularly using pseudosections with bulk composition as a variable (e.g. White et al., 2001). One of the most obvious effect of melt loss is the dehydration of the rock that limits further melting and favors the preservation of peak metamorphic assemblage. However, in most cases, melt loss has a limited effect that can be hardly seen mineralogically. Indeed, composition of phases like garnet, cordierite or plagioclase, that are first-order metamorphic phase, will not be affected significantly by melt loss. Therefore, evidences of melt extraction must be evidenced texturally. The goal of this contribution is to present an example where both mineralogical and textural evidences of melt extraction have been inferred. The studied sample is a pelitic granulite from the Paleoproterozoic Itabuna-Salvador-Curaça belt (Salvador da Bahia, Brazil). It is located in the city of Salvador da Bahia, next to the Farol da Bara. Structurally, it is located in a steeply deeping high strain zone that could have play a major role on the segregation and transfer of melt. The gneissic foliation is marked by a compositional banding with centimer-wide quartzo-feldspathic leucosomes in a garnet-bearing granulite. Leucosomes are almost systematically surrounded by a darker layer that is quartz-undersaturated and enriched in spinel and primatic sillimanite. This silica undersaturation is interpreted as the effect of extreme melt extraction and was modeled using phase diagram section. An interesting feature of the rock is that garnet grain size decreases and the number of garnet grains increases in the melanosome away from the leucosome. Furthermore, the type, amount and shape of inclusions in garnet, chemical composition and zoning in garnet also varies greatly and continuously across the gneissic foliation. Texturally, the presence of

  7. Ore mineralogy of the Serra Pelada Au-Pd-Pt deposit, Carajás, Brazil and implications for ore-forming processes

    Science.gov (United States)

    Berni, Gabriel V.; Heinrich, Christoph A.; Lobato, Lydia M.; Wall, Vic

    2016-08-01

    Serra Pelada is a world-class hydrothermal Au-Pd-Pt deposit located at the eastern border of the Amazon craton, northern Brazil. The rocks at Serra Pelada have experienced intense tropical weathering for about 70 Ma, but drill core samples preserve the primary mineralogy and hydrothermal alteration features, with extreme grades of Au, Pd and Pt individually reaching hundreds of parts per million (ppm) by weight. Mineralization at Serra Pelada occurs in hydrothermally altered metasiltstones and dolomitic metasandstones at the hinge zone of a recumbent syncline, comprising zones of hematite, chlorite-carbon, argillic, and siliceous alteration. The main hydrothermal gangue minerals are quartz, kaolinite, sericite, amesite, hematite, monazite, florencite and variable amounts of highly reflective carbonaceous matter. Hydrothermal carbon input is evident from precipitated carbon occurring along crenulation planes and veinlets associated with the precious metals. Ore and accessory minerals include a variety of sulphide, selenide, arsenide, sulphate and oxide minerals, including gold with variable metal contents, palladian gold, fischesserite, sudovikovite, sperrylite, selenian braggite, isomertieite, mertieite-II and secondary Au-Pt-Pd alloys. The composition of fischesserite varies from the ideal formula (Ag3AuSe2) towards a more Ag-rich composition, indicating a disordered solid solution form that is stable only above 260 °C, consistent with the high thermal maturity of associated carbonaceous matter approaching graphite. Primary ore and gangue minerals at Serra Pelada comprise a suite of elements that are best transported in oxidising conditions and precipitated upon reduction. This suggests that fluid mixing between a highly oxidised (metal carrier) and a reduced fluid was a key process for high-grade noble metal precipitation at Serra Pelada.

  8. Process mineralogy IX

    Energy Technology Data Exchange (ETDEWEB)

    Petruk, W.; Hagni, R.D.; Pignolet-Brandom, S.; Hausen, D.M. (eds.) (Canada Centre for Mineral and Energy Technology, Ottawa, ON (Canada))

    1990-01-01

    54 papers are presented under the headings: keynote address; process mineralogy applications to mineral processing; process mineralogy applications to gold; process mineralogy applications to pyrometallurgy and hydrometallurgy; process mineralogy applications to environment and health; and process mineralogy applications to synthetic materials. Subject and author indexes are provided. Three papers have been abstracted separately.

  9. Mineralogical characterization of quarry fines from Tracuateua city, state of Para, Brazil; Caracterizacao mineralogica dos finos de pedreira do municipio de Tracuateua-PA

    Energy Technology Data Exchange (ETDEWEB)

    Costa, J.H.B. da; Negrao, R.C.; Angelica, R.S., E-mail: jhcosta@ig.com.br [Instituto Federal de Educacao, Ciencia e Tecnologia do Para (IFPA), Belem, PA (Brazil). Departamento de Recursos Naturais. Coordenacao de Mineracao; Universidade Federal do Para (UFPA), Belem, PA (Brazil). Instituto de Geociencias

    2011-07-01

    The aim of this study was to characterize the mineralogy quarry fines samples for its reuse and thus contributing to mitigate the environmental impact caused by this waste. In order to achieve the results, samples were collected and prepared for assays and identification of the mineralogical phases present in the quarry fines from the samples. X-ray diffraction and optical microscopy techniques were used. The quarry of fines characterization was based on qualitatively identification the minerals present in the samples. It was detected the presence of quartz, muscovite and feldspar (albite and microclinite) by x-ray diffraction technique and microscopic and macroscopic observations. Moreover, the size distribution was determined, and the samples presented a medium to fine size (ranging from 9,5 mm to 0,075 mm) and the grains presented an irregular and angular shapes. (author)

  10. Mineralogical characterization of the argillaceous material from the Municipality of Santa Barbara, Para, Brazil; Caracterizacao mineralogica de material argiloso proveniente do municipio de Santa Barbara, Para, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrando, E.A., E-mail: edemarino@ufpa.b [Universidade Federal do Para (UFPA), Maraba, PA (Brazil). Fac. de Engenharia de Materiais. Lab. de Materiais Ceramicos; Sheller, T.; Angelica, R.S. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Fac. de Geologia. Inst. de Geociencias; Neves, R.S. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Fac. de Engenharia Quimica. Inst. de Tecnologia

    2009-07-01

    In the present work were investigated mineralogical phases in a material with argillaceous characteristic of the region of Genipauba, Santa Barbara, State of Para. Characterization of the collected sample was performed by X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetric analysis (TG) and infrared spectroscopy (IR). The results of the assays indicate the presence of the clay minerals like kaolinite and muscovite, as well as minerals as quartz and anatase. (author)

  11. Mineralogical characterization of historical portuguese wall tiles of Sao Luis, Maranhao, Brazil; Caracterizacao mineralogica de azulejos portugueses do Centro Historico de Sao Luis do Maranhao

    Energy Technology Data Exchange (ETDEWEB)

    Rivas Mercury, J.M.; Vasconcelos, N.S.L.S.; Cabral, A.A., E-mail: rivascefetma@gmail.co [Instituto Federal de Educacao, Ciencia e Tecnologia do Maranhao (IFMA), Sao Luis, MA (Brazil). Programa de Mestrado em Engenharia de Materiais; Pereira, D.J. Costa [Centro de Criatividade Odylo Costa Filho (SECMA), Sao Luis, MA (Brazil). Centro Historico; Angelica, R.S. [Universidade Federal do Para (CG/UFPA), Belem, PA (Brazil). Inst. de Geociencias

    2010-07-01

    Portuguese wall tiles from centuries, XVII, XVIII and XIX, found in Sao Luis Maranhao has been studied by X-ray diffraction, in order to interpret the possible raw material and burning temperature. The mineral phases, Quartz, Wollastonite, Calcite and Gehlenite were identified in all samples. Based on the results it is possible to affirm that the main raw materials used to manufacture this materials was probably mixtures of kaolinite clay and calcite. Based on the mineralogical information it was also possible to state that burning temperature of this wall tiles was lower than 1000 deg C. (author)

  12. Chemical, mineralogical and ceramic properties of clays from Northern Santa Catarina, Brazil; Caracterizaco fisico-quimica de argilas da regiao norte de Santa Catarina

    Energy Technology Data Exchange (ETDEWEB)

    Correia, S.L.; Bloot, E.L.; Folgueras, M.V., E-mail: sivaldo@joinville.udesc.b [Universidade do Estado de Santa Catarina (UDESC/CCT), Joinville, SC (Brazil). Centro de Ciencias Tecnologicas; Hotza, D. [Universidade Federal de Santa Catarina (UFSC/EQA), Florianopolis, SC (Brazil). Dept. de Engenharia Quimica

    2009-07-01

    Clay materials crop out in the northern Santa Catarina mining district were investigated in order to assess their potential in the ceramic industry. Four different clays (A, B, C and D) were selected. Their chemical composition was obtained by Xray fluorescence and their mineralogy by X-ray diffraction, coupled with numerical rational analysis. Their thermal behaviour was studied by differential thermal analysis. Technological testing consisted in a simulation of the industrial processing performed at a laboratory scale. The test pieces were obtained by pressing and fired in the range of 850-1200 deg C. In each case their technological properties were studied. The main mineralogical phases detected were kaolinite, quartz and mica. Hematite and feldspars may be present in the clays. The clays show two groups of particle sizes almost equally frequent in the range of 1 to 60 {mu}m. The northern Santa Catarina clays are suitable for the production of bricks and earthenware in the 900- 1100 deg C range. (author)

  13. Mineralogia de um Argissolo Vermelho-Amarelo da zona úmida costeira do Estado de Pernambuco Mineralogy of an Ultisol in the coastal humid zone of Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Júlio Guilherme da Costa Lima

    2008-04-01

    álise dos resultados permite concluir que o Argissolo estudado é autóctone, bem desenvolvido e altamente intemperizado devido às condições de clima, relevo e vegetação, apresentando baixa reserva potencial mineral de nutrientes para as plantas.Soil mineralogy is an important tool to study and understand soil genesis and soil physical and chemical behavior. Furthermore, soil mineralogy is used as diagnostic criterion to define soil classes in the Brazilian System of Soil Classification and provides information on the potential soil mineral reserve of plant nutrients. In this context, this study presents the mineralogical characterization of gravel, fine and coarse sand fractions (under a binocular lens and petrographic microscope, and of the silt and clay fractions (by X ray diffraction of all soil horizons, and the petrographic study of the parent rock, aiming to understand the mineralogical evolution of a typical Ultisol of the Coastal Humid Zone of Pernambuco State. The coarse fractions of the studied Ultisol are formed, essentially, by angular shaped quartz (> 95 %, demonstrating the absence of transported materials during soil formation. Rock fragments (formed by quartz, feldspars and opaque minerals, feldspars and biotite, with more evident weathering in the surface horizons, were also observed and are mineralogically compatible with the parent rock. The silt fraction is composed by micas, feldspars, quartz and kaolinite. Chlorite is only observed in the deeper horizons. The clay fraction has the same mineralogy as observed for the silt fraction, and still there are interstratified minerals in the bottom horizons. The parent rock is biotite-gneiss of medium granulometry, formed by feldspars (plagioclase, perthite and microcline, quartz and biotite, with epidotes, zircon and opaque minerals as accessory minerals. The results showed that the studied Ultisol is autochthonous and highly weathered, due to the humid tropical climatic conditions, and has a very low

  14. Brazil.

    Science.gov (United States)

    1985-09-01

    Brazil's population in 1985 was 135 million, with an annual growth rate (1982) of 2.3%. The infant mortality rate (1981) was 92/1000, and life expectancy stood at 62.8 years. 76% of the adult population was literate. Brazil is a federal republic which recognizes 5 political parties. 55% of the population is Portuguese, Italian, German, Japanese, African, or American Indian; 38% is white. Of the work force of 50 million, 35% are engaged in agriculture, 25% work in industry, and 40% are employed in services. Trade union membership totals 6 million. The agricultural sector accounts for 12% of the GDP and 40% of exports. Brazil is largely self-sufficient in terms of food. The GDP was US$218 billion in 1984, with an annual growth rate of 4%. Per capita GDP was US$1645. Brazil's power, transportation, and communications systems have improved greatly in recent years, providing a base for economic development. High inflation rates have been a persistent problem.

  15. The integration of physical rock properties, mineralogy and geochemistry for the exploration of large zinc silicate deposits: A case study of the Vazante zinc deposits, Minas Gerais, Brazil

    Science.gov (United States)

    McGladrey, Alexandra J.; Olivo, Gema Ribeiro; Silva, Adalene Moreira; Oliveira, Gustavo Diniz; Neto, Basilio Botura; Perrouty, Stéphane

    2017-01-01

    The Vazante deposit, which is the world's largest zinc silicate deposit, occurs in brecciated dolomite and comprises mainly willemite with various proportions of hematite, Fe-carbonate, minor franklinite and magnetite. Exploration for this type of deposit is more challenging than zinc sulfide deposits, as they do not exhibit similar geophysical anomalies. To improve the application of geophysical surveys to the exploration of hypogene silicate zinc deposits, data from 475 samples were investigated from drill holes representative of the various types of ore and host rocks as well as barren zones of known geophysical anomalies in the Vazante District. Lithogeochemical and mineralogical (optical, SEM and MLA) data were integrated with physical rock properties (density, magnetic susceptibility and Ksbnd Usbnd Th gamma-ray spectrometry) to assist in exploring for this type of deposit. The most distinct physical property of the ore is density, compared with the host rocks due to high proportion of denser minerals (hematite and willemite). However, barren hematite breccias also have high densities. The zinc ore and hematite breccias yielded higher magnetic susceptibilities than the surrounding host rocks, with the highest values associated with greater proportions of franklinite and magnetite. The density and magnetic susceptibility contrasts are a result of hydrothermal fluids interacting with and altering the carbonate host rocks. Zinc ore also yielded elevated U concentrations relative to the various host rocks, yielding higher gamma-ray spectrometric values. The results of this investigation indicate that an integration of magnetic, gravimetric and radiometric surveys would be required to identify zinc silicate ore zones.

  16. Mineralogia, química e estabilidade de agregados do tamanho de silte de solos da Região Sudeste do Brasil Mineralogy, chemistry and stability of silt-size aggregates of soils from the Southeast Region of Brazil

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Tadeu Vitorino

    2003-01-01

    Full Text Available Com o objetivo de avaliar a relação da composição mineralógica e química do solo com a estabilidade de agregados do tamanho de silte, foram realizados estudos utilizando-se amostras de horizontes A e B de diversos solos da Região Sudeste do Brasil. Amostras de TFSA foram dispersas a 12.000 rpm por 20 minutos e a fração silte foi separada por esgotamento da fração argila, constituindo-se na fração denominada pseudo-silte, a qual foi sonificada, separando-se a fração argila desagregada (por sifonamento da fração silte propriamente dita. Estudos de correlação mostraram que as composições mineralógica e química dos solos têm efeito marcante na dispersão de argila, com reflexos na fração silte. Maiores teores de gibbsita refletem em maior estabilidade dos agregados do tamanho de silte ao passo que a caulinita proporciona efeito inverso. As formas de Al determinadas na fração pseudo-silte estão associadas à maior dificuldade de dispersão da fração argila dos solos.The objective of this work was to evaluate the relationship of soil mineralogical and chemical composition with stability of silt-size aggregates. The studies were carried out using samples of A and B horizons of some soils from the Southeast Region of Brazil. Fine-earth samples were dispersed at 12,000 rpm during 20 minutes and the silt fraction was separated through clay fraction drain, constituting the fraction named pseudo-silt, which was sonificated, separating the desegregated clay fraction (by sonication from the properly named silt fraction. Correlation analyses showed that the soil mineralogical and chemical compositions have marked influence upon clay dispersion, with reflections on the silt fraction. Higher amounts of gibbsite reflect in higher stability of silt-size aggregates, while the kaolinite promotes inverse effect. The Al forms determined on the pseudo-silt fraction are associated with higher difficult of dispersion of clay fraction of

  17. Major soil classes of the metropolitan region of Curitiba (PR, Brazil: I - mineralogical characterization of the sand, silt and clay fractions

    Directory of Open Access Journals (Sweden)

    Ana Christina Duarte Pires

    2007-03-01

    Full Text Available The aim of this work was to evaluate the mineralogical and chemical characteristics of most representative soils of the Region of Curitiba, Paraná State. Samples were collected at different depths. The results showed: (a the quartz was the only identified mineral at the silt and sand fractions. The dominant clay mineral was Kaolinite, with contents ranging from 676.7 to 820.8 g kg-1. The gibbsite was also an important constituent of the most weathered horizons and the hematite and goethite contents were low, mainly in the Histosol; (b at the C horizon of the Inceptisol, high intensity of vermiculite/smectite reflections were detected (X-ray diffraction, justifying the high capacity of expansion and contraction, normally showed for this soil horizon; (c was observed a good relation between pedogenetic degree and crystallographic mineral characteristics.Devido a grande importância dos minerais, notadamente aqueles da fração argila, sobre o planejamento de uso e sobre os impactos das atividades antrópicas, estudos detalhados da composição dos solos das regiões metropolitanas são imprescindíveis. Para avaliar as características mineralógicas e químicas de solos mais representativos da Região Metropolitana de Curitiba, estado do Paraná, foram coletadas amostras das classes Organossolo, Latossolo e Cambissolo, em diferentes profundidades. As frações areia, silte e argila foram estudadas por difratometria de Raios-X (DRX e a fração mais fina foi submetida a análise térmica e extrações químicas com oxalato de amônio (OA, ditionito-citrato-bicarbonato (DCB e solução de NaOH 5 mol L-1 fervente. As características cristalográficas da hematita (Hm, goethita (Gt, gibbsita (Gb e caulinita (Ct foram determinadas por DRX. Os resultados permitiram concluir que: (a o quartzo foi o único mineral identificado nas frações areia e silte. Na fração argila, verificou-se o predomínio de Ct, com teores variando de 661,7 a 820,8 g kg-1

  18. Mineralogical and Geochemical Investigations in the Perm State University (1916 – 2016

    Directory of Open Access Journals (Sweden)

    R. G. Iblaminov

    2016-09-01

    Full Text Available The history of foundation and development of mineralogical and geochemical sciences on the Mineralogy and Petrography Department of the Perm State University for 100 years is presented. The achievements in the alluvial mineralogy and nanomineralogy are characterised. Relationship of development in the area of geochemical research on early stage with the European scientific school is discussed. The next stage is characterized by transition to investigations of trace elements and usage of the modern analytic base for environmental geochemistry. Petrographic and lithologic investigations have become the base for paleotectonic reconstruction of the Western Urals area. The study of distribution of mineral resources has been conducted on the base of specific minerageodynamic concept. The principles of minerageodinamic investigation of oil and gas basins, and methodology of reservoir study using modern technology were developed. The contribution of individual scientists in development in different scientific areas is illustrated.

  19. Ore Petrography Using Optical Image Analysis: Application to Zaruma-Portovelo Deposit (Ecuador

    Directory of Open Access Journals (Sweden)

    Edgar Berrezueta

    2016-06-01

    Full Text Available Optical image analysis (OIA supporting microscopic observation can be applied to improve ore mineral characterization of ore deposits, providing accurate and representative numerical support to petrographic studies, on the polished section scale. In this paper, we present an experimental application of an automated mineral quantification process on polished sections from Zaruma-Portovelo intermediate sulfidation epithermal deposit (Ecuador using multispectral and color images. Minerals under study were gold, sphalerite, chalcopyrite, galena, pyrite, pyrrhotite, bornite, hematite, chalcocite, pentlandite, covellite, tetrahedrite and native bismuth. The aim of the study was to quantify the ore minerals visible in polished section through OIA and, mainly, to show a detailed description of the methodology implemented. Automated ore identification and determination of geometric parameters predictive of geometallurgical behavior, such as grade, grain size or liberation, have been successfully performed. The results show that automated identification and quantification of ore mineral images are possible through multispectral and color image analysis. Therefore, the optical image analysis method could be a consistent automated mineralogical alternative to carry on detailed ore petrography.

  20. Petrography and Geochemistry of Lunar Meteorite Miller Range 13317

    Science.gov (United States)

    Zeigler, R. A.; Korotev, R. L.

    2016-01-01

    Miller Range (MIL) 13317 is a 32-g lunar meteorite collected during the 2013-2014 ANSMET (Antarctic Search for Meteorites) field season. It was initially described as having 25% black fusion crust covering a light- to dark-grey matrix, with numerous clasts ranging in size up to 1 cm; it was tenta-tively classified as a lunar anorthositic breccia. Here we present the petrography and geochemistry of MIL 13317, and examine possible pairing relationships with previously described lunar meteorites.

  1. Mineralogy and Microstructures of Shock-Induced Melt Veins in Chondrites

    Science.gov (United States)

    Sharp, Thomas G.

    2000-01-01

    The applicability of phase equilibrium data to the interpretation of shock-induced melt veins can only be tested by a detailed study of melt- vein mineralogy to see how high-pressure assemblages vary as a function of shock conditions inferred from other indicators. We have used transmission electron microscopy (TEM), analytical electron microscopy (AEM), scanning electron microscopy (SEM), electron microprobe analysis (EMA) and optical petrography to characterize the mineralogy, microstructures, and compositions of melt veins and associated high-pressure minerals in shocked chondrites and SNC meteorites. In the processes, we have gained a better understanding of what melt veining can tell us about shock conditions and we have discovered new mineral phases in chondritic and SNC meteorites.

  2. Combustion char morphology related to combustion temperature and coal petrography

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, P.; Petersen, H.I.; Thomsen, E. [Geological Survey of Denmark, Copenhagen (Denmark)

    1996-07-01

    Chars produced from different reactors were found to lack consistency of morphological charactersitics. Therefore, the morphology of chars sampled from various laboratory-scale reactors operating at temperatures from 800 to {gt} 1400{degree}C, together with chars collected directly in the flame zone in a full-scale pulverised fuel combustion experiment, was examined. A coal and coal blend dominated by vitrinite-rich microlithotypes together with four coals dominated by inertinite-rich microlithotypes were used to produce the combustion chars. Char samples produced at temperatures above {approximately} 1300{degree}C have a morphotype composition very similar to the composition of the full-scale char samples, whereas the morphotype compositions of those produced at {approximately} 1550{degree}C or lower are significantly different. Correlation between coal petrography and char morphology and determination of char reactivity should thus be attempted only using chars produced at temperatures comparable with those for the intended use of the coal. A clear distinction between the high-temperature char samples (burnout 50-60wt% daf) emerges which is related mainly to the parent coal petrography and probably secondarily to the rank. Vitrite, clarite and vitrinertie V may be correlated with the porous tenuisphere and crassisphere morphotypes, whereas inertite, durite, vitrinertite I, duroclarite and charodurite may be correlated with the crassinetwork-mixed-network-mixed morphotype group. 29 refs., 7 figs., 7 tabs.

  3. Environmental Mineralogical Materials

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Basic properties, including surface absorption, porous filtration, ion exchange, heat effect and chemical solubility of environmental mineralogical materials, are widely applied to the pollution prevention environment improvement. The pollunian prevenition environmenr means the quality improvement of surface water, groundwater, river, lake and ground reservoir: the improvement of soil, the disposal of nuclear waste, the purification of domestic sewage, the collection of smoke and dust and the treatment of waste water. The prospective investigation and utilization of environmental mineralogical materials have been dealt with in more detail by the author of this paper with emphases on the prevention and control of soil contamination by heavy metals, on the quality im provement and treatment of surface water and groundwater,and on the collection of smoke and dust arising from burning coals.

  4. Comparison among chemical, mineralogical and physical analysis from alluvial clays from counties of Southwest of Minas Gerais state (Brazil); Comparacao entre as analises quimicas, mineralogicas e tecnologicas das argilas aluvionares de alguns municipios do sudoeste de Minas Gerais

    Energy Technology Data Exchange (ETDEWEB)

    Gaspar Junior, L.A., E-mail: lineo.gaspar@unifal-mg.edu.br [Universidade Federal de Alfenas (UNIALFENAS), MG (Brazil). Instituto de Ciencias da Natureza; Varajao, A.F.D.C. [Universidade Federal de Ouro Preto (UFOP), MG (Brazil). Escola de Minas; Souza, M.H.O. [Universidade Federal de Uberlandia (UFU), MG (Brazil). Departamento de Geografia; Moreno, M.M.T. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Rio Claro, SP (Brazil). Departamento de Petrologia e Metalogenia

    2011-07-01

    The studied area is located in the southwestern portion of Minas Gerais State, encompassing the counties of Alfenas, Areado, Machado, Poco Fundo, Campestre, Serrania, Monte Belo, Bandeira do Sul, Botelhos and Cabo Verde. This region is dominated by strongly weathered pre-cambrian rocks in association with colluvial-alluvial sediments. The present work consisted in a comparison among the mineralogical (X-Ray Diffraction), textural (Laser Granulometry), chemical (X-Ray Fluorescence) and technological (mechanical resistance, water absorption, etc, made in specimen tests) properties of the clays collected on potteries located in these counties. The mineralogical and chemical analysis displayed the kaolinitic nature of the clays from this region, showing also small amount of interlayered clays and large amount of quartz. The best results of physical analysis were obtained for clays from the counties of Cabo Verde and Monte Belo due to the presence of lower values of SiO{sub 2} (quartz) associated with a finer particle size distribution. (author)

  5. Syngenetic and diagenetic features of evaporite-lutite successions of the Ipubi Formation, Araripe Basin, Santana do Cariri, NE Brazil

    Science.gov (United States)

    do Nascimento, Daniel Rodrigues, Jr.; da Silva Filho, Wellington Ferreira; Freire, José Gervásio, Jr.; dos Santos, Felipe Holanda

    2016-12-01

    The Ipubi Formation in the Araripe Basin (Northeast Brazil) has evaporite-lutite successions rich in gypsum, a mineral of great regional economic relevance, a highlighted stratigraphic mark, and also a natural boundary for underlying successions potentially analogous to "Pre-Salt" hydrocarbon reservoirs of the Brazilian coastal basins. In this study, syngenetic and diagenetic aspects of the Ipubi Formation at Santana do Cariri (Ceará State) were investigated by means of facies analysis, petrography, and mineralogical/chemical analyses of evaporites and shales. The results show that the contact relationship between evaporites and marly shales, without signs of subaerial exposure and laterally adjacent, was associated with shallow, calm and somewhat anoxic waterbodies, locally salt-supersaturated (brines) but under seasonal variations of water levels. This scenario could have shared place with hydrothermal phenomena in a playa lake depositional system. Regarding diagenesis, although there is evidence supporting pseudomorphic replacement of gypsum by anhydrite, the burial of the Ipubi Formation would have been limited due to the frequent occurrence of gypsum without any trace of chemical replacement.

  6. Petrography and chemistry of basalts from the Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    concentrations, together with variable relations of P2O3, TiO2, Ni and Cr with MgO indicate a process of fractional crystallisation of a primary magma. Chemically and mineralogically these rocks have a closer affinity to those of the other parts of the Mid...

  7. Journal of Mineralogical and Petrological Sciences

    Science.gov (United States)

    Official journal of Japan Association of Mineralogical Sciences (JAMS), focusing on mineralogical and petrological sciences and their related fields. Journal of Mineralogical and Petrological Sciences (JMPS) is the successor journal to both “Journal of Mineralogy, Petrology and Economic Geology” and “Mineralogical Journal”. Journal of Mineralogical and Petrological Sciences (JMPS) is indexed in the ISI database (Thomson Reuters), the Science Citation Index-Expanded, Current Contents/Physical, Chemical & Earth Sciences, and ISI Alerting Services.

  8. Petrography and geochronology (U/Pb-Sm/Nd) the Passagem Granite, Pensamiento Granitoid Complex, Paragua Terrane, SW Amazon Craton, Mato Grosso, Brazil; Petrologia e geocronologia (U/Pb-Sm/Nd) do Granito Passagem, Complexo Granitoide Pensamiento, SW do Craton Amazonico (MT)

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Gisely Carmo de, E-mail: giselycarmo@hotmail.co [Universidade Federal de Mato Grosso (ICET/UFMT), Cuiaba, MT (Brazil). Inst. de Ciencias Exatas e da Terra. Programa de Pos-Graduacao em Geociencias; Sousa, Maria Zelia Aguiar de, E-mail: mzaguiar@terra.com.b [Universidade Federal de Mato Grosso(ICET/UFMT), Cuiaba, MT (Brazil). Inst. de Ciencias Exatas e da Terra. Dept. de Recursos Minerais; Ruiz, Amarildo Salina; Matos, Joao Batista de, E-mail: asruiz@gmail.co, E-mail: jmatos@cpd.ufmt.b [Universidade Federal de Mato Grosso (ICET/UFMT), Cuiaba, MT (Brazil). Inst. de Ciencias Exatas e da Terra. Dept. de Geologia Geral

    2010-09-15

    The Passagem granite includes stocks, plugs and dikes located in the Ricardo Franco hill - Vila Bela da Santissima Trindade region - state of Mato Grosso, central Brazil. The Passagem Granite is included in the Paragua terrane - SW Amazonian Craton. It consists of isotropic monzogranite, sienogranite and more rarely granodiorites with leucocratic dark gray to white color. These rocks range from hypidomorphic inequigranular to xenomorphic texture, fine to medium grained. Biotite is the only primary mafic present as essential phase and characterize an expanded slightly acid sequence formed by a sub-alkaline magmatism of high-potassium calc-alkaline, slightly peraluminous composition from arc magmatic tectonic environment during a post-collisional period. Mechanism of fractional crystallization of plagioclase, biotite, titanite, apatite and zircon associated with simultaneous crustal assimilation are suggested for the evolution of these rocks. The results support the hypothesis of a post-collisional magmatism in the Paragua terrane at 1284 +- 20 Ma corresponding to the crystallization age of the Passagem granite. This paper propose that Passagem Granite represents as an extension in Brazilian terrane of the Pensamiento Granitoid Complex. (author)

  9. United Arab Emirates limestones: impact of petrography on thermal behavior

    Science.gov (United States)

    Alaabed, Sulaiman; Soltan, Abdel Monem; Abdelghany, Osman; Amin, Bahaa Eldin Mahmoud; El Tokhi, Mohamed; Khaleel, Abbas; Musalim, Abdullah

    2014-12-01

    The thermal behavior of selected limestones from representative localities of the United Arab Emirates is investigated for their suitability for soft-burnt lime production. The limestone samples were collected from the Ghalilah, Musandam, Shauiba, Muthaymimah, Dammam and Asmari formations. The samples were characterized for petrography, mineral and chemical composition, together with physico-mechanical characteristics. Investigative methods included transmitted light microscopy (TLM), cathodoluminescence (CLM) and scanning electron microscopy (SEM), as well as X-ray micro-tomography (μ-CT), XRD, XRF and Archimedes method. The limestone samples were fired in an electrical muffle furnace for 0.25, 0.5, 1 and 2 hours at 800, 900, 1,000 and 1,100 °C. After firing the lime grains were tested to determine their hydration rate and microfabric. The Ghalilah and Musandam limes show the lowest and highest maximum hydration rates, respectively, due mainly to the impure nature of the former, and the smaller lime crystallites and dominance of post-calcination micro-cracks of the latter. The Dammam and Asmari limes preserve a "ghost" microfabric of the original limestone. Higher allochem contents impose lower activation energy requirements for calcination, which implies earlier calcination of the allochems. The Musandam, Shauiba and Muthaymimah limestones may be useful for the production of reactive soft-burnt lime under the applied firing conditions, however, the Dammam and Asmari limestones need more advanced calcination conditions than the applied ones. The Ghalilah limestone was found to be unsuitable for the production of lime.

  10. The Blue Angel. I - The mineralogy and petrogenesis of a hibonite inclusion from the Murchison meteorite

    Science.gov (United States)

    Armstrong, J. T.; Meeker, G. P.; Huneke, J. C.; Wasserburg, G. J.

    1982-01-01

    Results are presented of a mineralogical and petrological examination of a relatively large hibonite-containing inclusion in the Murchison chondrite called the Blue Angel. Mechanisms of formation and modification of hibonite-rich inclusions are investigated. Evidence is found that modifying processes occurred before the inclusion was incorporated into its present location, which indicates a sequence of aqueous and metamorphic alteration followed by disruption and relithification of the protometeoritic material. The mineral chemistry and petrography of the Blue Angel is consistent with a three stage formation history, and extensive alteration of Ca-Al-rich inclusions may have occurred by aqueous alteration and thermal metamorphism followed by explosive mixing processes on a parent body.

  11. Petrography and petrogenesis of some Indian basaltic achondrites derived from the HED parent body: Insights from electron microprobe analyses

    Indian Academy of Sciences (India)

    Rajesh K Srivastava

    2013-06-01

    Three Indian achondrites, viz., Bholghati howardite, Lohawat howardite and Pipliya Kalan eucrite and two other achondrites, viz., Bé ré ba eucrite and Johnstown diogenite are studied for their petrography and mineral chemistry. All these achondrites are derived from the HED parent body. Both Bholghati and Lohawat howardites are polymict breccias and contain pieces of eucrites and diaogenites (lithic clasts), pyroxene and minor olivine as mineral clasts, and small proportion of ilmenite and pure iron metal. Eucrite clasts are noncumulate basaltic in nature, whereas diogenite clasts are mostly composed of orthopyroxene with minor clinopyroxene and anorthite. Both howardite samples contain orthopyroxene, pigeonite and augite. Notable characteristics observed in Lohawat howardite include crystallization of orthoenstatite first at a high-temperature followed by ferrosilite, pigeonite olivine and augite from a basaltic melt. Piplia Kalan eucrite is noncumulate, unbrecciated and basaltic in nature and display ophitic/sub-ophitic or hypidiomorphic textures. It contains ∼60% pyroxenes (clinoenstatite and pigeonite) and ∼40% plagioclase feldspars (bytownite to anorthite). The observed mineralogy in the Piplia Kalan eucrite suggests its crystallization from a high-temperature basaltic melt crystallized at low pressure. Two other achondrite samples, viz., Bé ré ba eucrite and Johnstown diogenite are also studied. The Bé ré ba eucrite shows cumulate nature which is probably formed by small-degree melts of ilmenitebearing gabbro, whereas the Johnstown diogenite crystallized from a slow cooling of a Ca-poor basaltic melt derived from cumulates formed from the magma ocean, similar to the origin of the noncumulate eucrites.

  12. Evolução geoquímica e mineralógica em perfis de alteração sobre rochas serpentinizadas no sudoeste de Minas Gerais Geochemical and mineralogical evolution in alteration profiles on serpentinized rocks in southwestern Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Pablo Vidal-Torrado

    2007-10-01

    Full Text Available Estudou-se a evolução geoquímica e mineralógica em três perfis distintos de alteração de rochas serpentinizadas que ocorrem nas imediações dos municípios de Alpinópolis e Fortaleza de Minas, no sudoeste do Estado de Minas Gerais, sob regimes de umidade e de temperatura údico e térmico, respectivamente. Nas condições atuais, o grau de evolução química e mineralógica é moderado em relação ao desenvolvido sobre outros tipos de rochas básicas e ultrabásicas da mesma área, caracterizando-se por uma importante perda de Na e Mg e, em menor proporção, de Ca e Si. O Al (localmente também o Fe é o elemento menos móvel dos sistemas. O K é escasso no material de origem e nas zonas de alteração, e ocorre enriquecimento desse elemento nos horizontes superficiais por aporte externo. Os minerais primários mais facilmente intemperizáveis, como o talco, a tremolita e a clorita trioctaédrica, são abundantes ainda na fração argila desses solos tropicais com composição mineralógica pouco comum, mas são todos termodinamicamente instáveis. Do ponto de vista geoquímico, o processo de alteração atual pode ser definido como uma bissialitização, que pode coincidir com ferruginização, com formação de minerais trioctaédricos secundários por transformação direta de estrutura e também por neoformação, todos coexistindo com os minerais primários residuais. No entanto, as fases de maior evolução, em volumes com drenagem mais eficiente, tendem à monossialitização, com formação de caulinitas de diferentes graus de cristalinidade. A assembléia mineralógica existente evidencia a metaestabilidade e o caráter incipiente do sistema pedogenético.The geochemical and mineralogical evolution was studied in three different alteration profiles of ultramafic (serpentine rocks near Alpinópolis and Fortaleza de Minas, in southwestern Minas Gerais State (Brazil. Soil moisture and temperature regimes are udic and thermic

  13. Mineralogical Studies Related to Endemic Diseases in Rural P. R. China

    Science.gov (United States)

    Belkin, H. E.; Zheng, B.; Finkelman, R. B.

    2003-12-01

    Domestic combustion of coal for heating and cooking is mostly confined to the world's developing countries and probably involves about 1 billion persons in China, India, Indonesia, and Africa. Various endemic diseases affecting millions of people involving arsenic, selenium, and fluorine poisoning have been associated with domestic coal combustion in rural China. We have investigated the relationship between mineralized coals (and stone coals) and disease occurrences in Guizhou and Hubei Provinces. The mineralogy of the coals has been studied by a wide variety of techniques, including optical petrography, scanning electron microscopy, electron microprobe analysis, ion probe, Synchrotron XANES-EXAFS, and Raman spectroscopy. Arsenic enrichment (up to 3 weight percent) in Upper Permian Longtan Formation coals, southwestern Guizhou Province, occurs in both 3+ and 5+ valence states. Arsenic occurs in arsenopyrite, pyrite, Al-phosphate, scorodite, Fe-oxides, and as an organically-bound species. Fluorine poisoning, much more widespread than arsenic-poisoning, is related to burning F-rich coals and F-rich clays as admixtures. Mineralogical and chemical analysis suggests that the clays contain the fluorine probably substituting for the hydroxyl group. Localized selenium poisoning in Hubei Province is related to Se-rich stone coals. The selenium occurs as a native element and in rare mandarinoite. In these three cases, knowledge of the paragenesis and mineralogy of the element enrichment in coal was vital to help understand and mitigate the endemic diseases. For the situation concerning arsenic and selenium poisoning, suspect coals have been identified and mining from these deposits has been curtailed. Fluorine has been a much more difficult problem for the local public health officials as both the coal and clay in the burning admixture can contain high fluorine. Regional geochemical and mineralogical studies will help to define coal and clay with low fluorine, suitable for

  14. Petrography and geochemistry of the Pedra Dourada Granulite, southeastern Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Kassia de Souza Medeiros Marinho

    Full Text Available Abstract The Pedra Dourada Granulite (PDG occurs at the southeastern portion of the Araçuaí Belt, north of the town of Ponte Nova. It comprises bodies up to 45 km2 inserted into amphibolite-facies gneisses of the Mantiqueira Complex. Motivated by the discrepancy of metamorphic grade with surrounding rocks, this paper presents results of the petrographic and geochemical investigation of the PDG. The unit is comprised of meta-igneous and metasedimentary rocks. Meta-igneous rocks dominate and include felsic granulites (biotite ± garnet-bearing and orthopyroxene-bearing and subordinate mafic granulites. Metasedimentary rocks are aluminous granulites with Al-rich mineral assemblages (garnet, sillimanite, spinel. Geochemical data show that most of felsic protoliths are peraluminous rocks including granites, granodiorites and diorites of calc-alkaline character, chemically similar to granitoids of convergent tectonic settings. Mafic protoliths are metaluminous rocks comprised of gabbros and subordinate diorites of tholeiitic affinity, compositionally similar to plate margin basalts. Aluminous protoliths may be peraluminous pelitic rocks and wackes, analogous to sediments from convergent environments. The mineral assemblages indicate that these rocks were metamorphosed under medium-P granulite-facies conditions. Coronitic garnet textures suggest a near-isobaric cooling (IBC-path after metamorphic peak.

  15. Mineralogia e cristalografia da fração argila de horizontes coesos de solos nos tabuleiros costeiros Crystallography and mineralogy of the clay fraction of hardsetting horizons in soils of coastal tablelands in Brazil

    Directory of Open Access Journals (Sweden)

    Neyde Fabíola Balarezo Giarola

    2009-02-01

    -related physical and chemical factors, but an influence of mineralogical and crystallographic properties of clay minerals was also suggested by some researchers. In this study we tested the possibility that clay fraction of hardsetting horizons of soils from the Barreiras sediments of Coastal Tablelands are predominantly kaolinitic and highly crystalline and organized, which can favor a face-to-face arrangement of the crystals. The purpose of this study was to evaluate the crystallographic and mineralogical characteristics of clay minerals in hardsetting soil horizons from the sediment group Barreiras and their contribution to the hardsetting character. One non-hardsetting and five hardsetting horizons were studied along the coastal tableland. A kaolinite sample with high crystallinity degree was also included as reference. All profiles were analyzed for taxonomic classification and location of the horizons of interest. Organic matter and oxides were removed from the samples of the selected horizons. After soil dispersion, the clay fraction was individualized, treated and examined by X-ray diffraction (XRD to determine the minerals and structure degree of order/disorder, according to the method described by Plançon & Zacarie (1990. The degree of structural organization of the kaolinites of the hardsetting and non-hardsetting horizons was similar to and lower than the kaolinite used as reference. Results indicated that the hardsetting behavior of the studied soils could not be explained by clay packaging.

  16. Application of automated image analysis to coal petrography

    Science.gov (United States)

    Chao, E.C.T.; Minkin, J.A.; Thompson, C.L.

    1982-01-01

    content M. The volume percentage of each component present is indicated by a subscript. For example, a lithologic unit was determined megascopically to have the composition (V)13(I)1(S)1(X1)83(X2)2. After microscopic analysis of the mixed phases, this composition was expressed as (V)13(I)1(S)1(V63E19I14M4)83(V67E11I13M9)2. Finally, these data were combined in a description of the bulk composition as V67E16I13M3S1. An AIAS can also analyze textural characteristics and can be used for quick and reliable determination of rank (reflectance). Our AIAS is completely software based and incorporates a television (TV) camera that has optimum response characteristics in the range of reflectance less than 5%, making it particularly suitable for coal studies. Analysis of the digitized signal from the TV camera is controlled by a microprocessor having a resolution of 64 gray levels between full illumination and dark current. The processed image is reconverted for display on a TV monitor screen, on which selection of phases or features to be analyzed is readily controlled and edited by the operator through use of a lightpen. We expect that automated image analysis, because it can rapidly provide a large amount of pertinent information, will play a major role in the advancement of coal petrography. ?? 1982.

  17. Atributos químicos, mineralógicos e micromorfológicos de horizontes coesos de latossolos e argissolos dos tabuleiros costeiros do estado de Alagoas Mineralogy and micromorphology of cohesive horizons in oxisols and ultisols of the coastal tablelands of Alagoas, Brazil

    Directory of Open Access Journals (Sweden)

    José de Almeida Lima Neto

    2010-04-01

    importance, the formation of these horizons has not been fully explained. The objective of this study was a chemical, mineralogical and micromorphological characterization of cohesive soils of the Coastal Tablelands in Northeast Brazil, to understand their pedogenesis and identify properties for the definition of the cohesive character by the Brazilian System of Soil Classification. The following four soil profiles were morphologically characterized: a Yellow Argisol (Ultisol, a Gray Argisol (Ultisol and two Yellow Latosols (Oxisols. Samples from cohesive and non cohesive horizons were taken for chemical analysis of Fe, Al and Si extracted by DCD, oxalate, CaCl2 and hot water, mineralogy by X ray diffraction, and micromorphological characterization. The Fe contents in the soils were low and kaolinite with a moderate to high degree of structural disorder predominated in all studied soil horizons. No increase in Al and Si extracted by DCB and oxalate was observed in the cohesive horizons, indicating the absence of cementation in its genesis. Results of the mineralogical and micromorphological characterization suggest two distinct phases in the genesis of the cohesive character. The first step was determined by clay illuviation, clogging the soil pores, and later iron loss, destroying the soil structure and resulting in a direct adjustment with kaolinite particles.

  18. Alterações na mineralogia de um argissolo do Rio Grande do Sul submetido à fertilização potássica Potassium fertilization affecting the mineralogy of a rhodic acrisol in Rio Grande do Sul - Brazil

    Directory of Open Access Journals (Sweden)

    Edson Campanhola Bortoluzzi

    2005-06-01

    Full Text Available As mudanças mineralógicas de solos cultivados e submetidos à fertilização potássica ainda são pouco conhecidas em regiões de clima subtropical úmido. Para que estas sejam avaliadas, amostras de solo foram coletadas, na profundidade de 0-10 cm, em um experimento realizado desde 1991 no campo experimental do Departamento de Solos da Universidade Federal de Santa Maria, com e sem fertilização potássica. Adicionalmente, foi coletada uma amostra de solo sob campo nativo em área ao lado do experimento. As amostras foram submetidas às análises de K total, K não-trocável, K trocável com extração simples, extrações sucessivas e à difratometria de raios X. Os difratogramas de raios X foram obtidos sobre amostras de solo e argila saturadas com Ca2+, com posterior modelagem matemática, e indicaram a presença de feldspato, ilita, interestratificados do tipo ilita-esmectita, dentre outros. Após o segundo ano do início do experimento, os teores de K trocável estabilizaram-se em 30 e 90 mg kg-1 para o solo que recebeu 0 e 90 kg ha-1 ano-1 de K2O, respectivamente. A adição de 90 kg ha-1 ano-1 de K2O manteve maior proporção dos argilominerais do tipo ilita e do tipo ilita-esmectita interestratificado na fração menor que 2 µm que sem a adição de K2O. Com o cultivo, independentemente da dose de fertilização potássica recebida, as fases ilita e ilita-esmectita tenderam a diminuir sua proporção relativa em detrimento da fase vermiculita hidróxi-Al entrecamadas.Changes in soil mineralogical properties in humid subtropical regions due to potassic fertilizer practices are so far poorly understood. The main objective of this study was to compare the changes in soil minerals and the consequences on K+ release. Soil samples (depth of 0-10 cm were collected over eleven years from areas with and without K fertilization and from a nearby natural grassy vegetation site on the Campus of the Federal University of Santa Maria. The K

  19. Cretaceous to Quaternary Siliciclastic Sediments of the Tarfaya Basin, Marginal Atlantic, SW Morocco Petrography, Geochemistry, Provenance, Climate and Weathering

    OpenAIRE

    Ali, Sajid

    2012-01-01

    This dissertation is prepared to attain the doctorate under the title "Cretaceous to Quaternary Siliciclastic Sediments of the Tarfaya Basin, Marginal Atlantic, SW Morocco Petrography, Geochemistry, Provenance, Climate and Weathering".

  20. Petrography and geochemistry characteristics of the lower Cretaceous Muling Formation from the Laoheishan Basin, Northeast China: implications for provenance and tectonic setting

    Science.gov (United States)

    Song, Yu; Liu, Zhaojun; Meng, Qingtao; Wang, Yimeng; Zheng, Guodong; Xu, Yinbo

    2016-10-01

    The petrography, mineralogy and geochemistry of sedimentary rocks from the lower Cretaceous Muling Formation (K1ml) in the Laoheishan basin, northeast (NE) China are studied to determine the weathering intensity, provenance and tectonic setting of the source region. Petrographic data indicate the average quartz-feldspar-lithic fragments (QFL) of the sandstone is Q = 63 %, F = 22 %, and L = 15 %. Lithic fragments mainly contain volcanic clasts that derived from surrounding basement. X-ray diffraction (XRD) data reveal abundant clay and detrital minerals (e.g. quartz), as well as minor calcite in the fine-grained sediments. The Hf contents and element concentration ratios such as Al2O3/TiO2, Co/Th, La/Sc, and La/Th are comparable to sediments derived from felsic and intermediate igneous rocks. The strong genetic relationship with the igneous rocks from the northwest and northeast areas provides evidence that the sediments of the Muling Formation (K1ml) in the Laoheishan basin have been derived from this area. The chemical index of alteration (CIA) and index of chemical variability (ICV) reveal an intensive weathering in the source region of the sediments. The multidimensional tectonic discrimination diagrams indicate that the source rocks of K1ml are mainly derived from the collision system. However, they may also comprise sediments derived from the continental rift system. The results are consistent with the geology of the study area.

  1. Petrography, Geochemistry and Petrogenesis of Volcanic Rocks, NW Ghonabad, Iran

    Directory of Open Access Journals (Sweden)

    Sedigheh Zirjanizadeh

    2016-07-01

    Full Text Available Introduction The study area is located in NW Gonabad, Razavi Khorasan Province, northern Lut block and eastern Iran north of the Lut Block. Magmatism in NW Gonabad produced plutonic and volcanic rock associations with varying geochemical compositions. These rocks are related to the Cenozoic magmatic rocks in Iran and belong to the Lut Block volcanic–plutonic belt. In this study, petrogenesis of volcanic units in northwest Gonabad was investigated. The volcanic rocks are andesites/trachyandesites, rhyolites, dacites/ rhyodacites and pyroclastics.These rocks show porphyritic, trachytic and embayed textures in phenocrysts with plagioclase, sanidine and quartz (most notably in dacite and rhyolite, hornblende and rare biotite. The most important alteration zones are propylitic, silicification and argillic.Four kaolinite- bearing clay deposits have been located in areas affectedby hydrothermal alteration of Eocene rhyolite, dacite and rhyodacite. Analytical techniques Five samples were analyzed for major elements by wavelength dispersive X-ray fluorescence (XRF and six samples were analyzed for trace elements using inductively coupled plasma-mass spectrometry (ICP-MS in the Acme Laboratories, Vancouver (Canada.Sr and Nd isotopic compositions were determined for four whole-rock samples at the Laboratório de GeologiaIsotópica da Universidade de Aveiro, Portugal. Results Petrography. The rocks in this area are consist of trachyte, andesite/ trachyandesite, dacite/ rhyodacite, principally as ignimbrites and soft tuff. The textures of phenocrysts are mainly porphyritic, glomerophyric, trachytic and embayed textures in plagioclase, hornblende and biotite. The groundmasses consist of plagioclase and fine-grainedcrystals of hornblende. Plagioclase phenocrysts and microlitesare by far the most abundant textures in andesite - trachyandesites (>25% and in size from 0.01 to 0.1mm. Euhedral to subhedral hornblende phenocrysts areabundant (3-5%and 0.1 to 0

  2. Mineralogy and trace-element geochemistry of the high-grade iron ores of the Águas Claras Mine and comparison with the Capão Xavier and Tamanduá iron ore deposits, Quadrilátero Ferrífero, Brazil

    Science.gov (United States)

    Spier, Carlos Alberto; de Oliveira, Sonia Maria Barros; Rosière, Carlos Alberto; Ardisson, José Domingos

    2008-02-01

    Several major iron deposits occur in the Quadrilátero Ferrífero (QF), southeastern region of Brazil, where metamorphosed and heterogeneously deformed banded iron formation (BIF) of the Cauê Formation, regionally called itabirite, was transformed into high- (Fe >64%) and low-grade (30% < Fe < 64%) hematite ores. Based on their mineralogical composition, three major types of itabirites occur in the QF: siliceous, dolomitic, and amphibolitic itabirite. Unlike other mines in the QF, the Águas Claras Mine contained mainly high-grade ores hosted within dolomitic itabirite. Two distinct types of high-grade ore occurred at the mine: soft and hard. The soft ore was the most abundant and represented more than 85% of the total ore mined until it was mined out in 2002. Soft and hard ores consist essentially of hematite, occurring as martite, anhedral to granular/tabular hematite and, locally, specularite. Gangue minerals are rare, consisting of dolomite, sericite, chlorite, and apatite in the hard and soft ores, and Mn-oxides and ferrihydrite in the soft ore where they are concentrated within porous bands. Chemical analyses show that hard and soft ores consist almost entirely of Fe2O3, with a higher amount of detrimental impurities, especially MnO, in the soft ore. Both hard and soft ores are depleted in trace elements. The high-grade ores at the Águas Claras Mine have at least a dual origin, involving hypogene and supergene processes. The occurrence of the hard, massive high-grade ore within “fresh” dolomitic itabirite is evidence of its hypogene origin. Despite the contention about the origin of the dolomitic itabirite (if this rock is a carbonate-rich facies of the Cauê Formation or a hematite-carbonate precursor of the soft high-grade ore), mineralogical and geochemical features of the soft high-grade ore indicate that it was formed by leaching of dolomite from the dolomitic itabirite by meteoric water. The comparison of the Águas Claras, Capão Xavier and

  3. Caracterização química e mineralógica de agregados de diferentes classes de tamanho de Latossolos Bruno e Vermelho localizados no estado do Paraná Chemical and mineralogical characterization of the different structure size classes of Red-Yellow and Dusky Red Latosols in Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Vander de Freitas Melo

    2008-02-01

    Full Text Available O teor e a forma dos minerais da fração argila são determinantes na definição da morfologia dos agregados do solo. Objetivando estudar a mineralogia da fração argila e as propriedades químicas de diferentes classes de agregados de Latossolos (Latossolo Bruno Ácrico húmico - LBd e Latossolo Vermelho Distroférrico húmico - LVdf originados de rochas basálticas no Estado do Paraná, coletaram-se amostras indeformadas em diferentes profundidades (horizontes Bw1 e Bw2 em perfis de solos localizados em duas toposseqüências (quatro perfis no LBd e três no LVdf. Após secagem e separação das amostras indeformadas em seis classes de agregados (2-4; 1-2; 0,5-1; 0,25-0,5; 0,105-0,25; The content and shap of clay minerals are important in the definition of soil structure morphology. To evaluate the clay mineralogy and chemical properties of different aggregate size-classes of Latosols (Red-Yellow - LBd and Dusky Red - LVdf derived from basalt in the state of Paraná, Brazil, soil samples of the Bw1 and Bw2 horizons were collected in four LBd and three LVdf profiles, distributed across two distinct toposequences. Dried and undisturbed soil samples were separated into six size-classes (2-4; 1-2; 0.5-1; 0.25-0.5; 0.105-0.25; < 0.105 mm and the soluble Si in 0,5 mol L-1 acetic acid and exchangeable K, Ca, Mg and Al contents were determined. The clay fraction extracted from each aggregate size-class was investigated by X-ray diffraction, thermal analysis and chemical analysis. The content of exchangeable elements did not vary among the aggregate size-classes in the Bw1 and Bw2 horizons for Red-Yellow and Dusky Red Latosol profiles. In spite of the high and continuous weathering of these soils the mineralogical characteristics of the aggregate clay fraction were not homogenized. The highest variation in the mineral contents, according to the aggregate size class, was observed for the profile in the highest position of the LBd toposequence; the

  4. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20150124Ji Liming(Key Laboratory of Petroleum Resources Research of Gansu Province,Lanzhou 730000,China);Ma Xiangxian Relationship between Methane Adsorption Capacity of Clay Minerals and Micropore Volume(Natural Gas Geoscience,ISSN1672-1926,CN62-1177/TE,25(2),2014,p.141-152,7illus.,4tables,21refs.)Key words:clay minerals The pore size,surface area and methane adsorption isotherm of clay-rich rocks are measured.Clay minerals mainly contain micropore of 3~100nm,and have two main in-

  5. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20090143 Cao Ke (Research Center for Tibeten Plateau Geology, School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China); Li Xianghui Cretaceous Clay Minerals and Paleoclimate in Sichuan Basin (Acta Geologica Sinica, ISSN0001-5717, CN11-1951, 82(1), 2008, p.115-123, 3 illus., 3 tables, 30 refs., with English abstract)

  6. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20090867 Chen Quanli(Gemmological Institute, China University of Geosciences, Wuhan 430074,China);Qi Lijian Thermal Property of the Apatite Pseudomorphic Turquoise(Earth Science,ISSN1000-2383, CN42-1233/P,33(3),2008,p.416-422, 6 illus.,1 table,11 refs.)

  7. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110079 Ding Kuiying(Weifang Entry-Exit Inspection and Quarantine Bureau of the People’s Republic of China,Weifang 261041,China);Zhu Maoxu The Effect of Low Molecular Weight Organic Acids to Phosphate Adsorption by Hydroxyaluminum/Iron-Montmorillonite Complexes(Acta Mineralogica Sinica,ISSN1000-4734,CN52-1045/P,30(1),2010,p.56-62,4 illus.,3 tables,13 refs.)Key words:organic acids,montmorillonit

  8. Development of a Multi-functional Physical Model Testing System for Deep Coal Petrography Engineering

    Science.gov (United States)

    Lu, Yiyu; Wang, Haiyang; Xia, Binwei; Li, Xiaohong; Ge, Zhaolong; Tang, JiRen

    2017-02-01

    Physical model testing is an important research tool for coal petrography engineering as it can solve many difficult problems associated with high risks and requiring long time periods to investigate with field studies. However, the accuracy of physical model tests can be reduced by problems with testing equipment, such as small model specimen size, poor airtightness and insufficient stress and pressure loading ability. To study the problems of coal petrography engineering in complicated stress environments, especially those in fluid-solid coupling, we designed and developed a multi-functional physical model testing system. The entire testing system consists of several specific sub-systems: loading, specimen shaping and installation, data monitoring and acquisition, pumping and gas injection, excavation simulating. The testing system can simulate complicated stress environments of coal-rock mass, and it can also be used to study the characteristics of strength-deformation, seepage-rheology and instability-failure under the conditions of gas-solid coupling and gas-liquid-solid multi-phase coupling. A load-unload experiment of air pressure and three-dimensional stress was conducted using the testing system. The experiment verified major technical indicators such as the loading capacity, sealing pressure and test precision, as well as operational stability of the testing system. The strain fields within the model specimen are well distributed and approximately linear with the stress. The stress of the specimen surface is approximately well distributed, and the specimen is subjected to uniform stresses. The testing system meets the requirements of the design parameters and has great potential significance to help reveal the scientific laws and inherent mechanisms of coal petrography engineering.

  9. Application of organic petrography in North American shale petroleum systems: A review

    Science.gov (United States)

    Hackley, Paul C.; Cardott, Brian J.

    2016-01-01

    Organic petrography via incident light microscopy has broad application to shale petroleum systems, including delineation of thermal maturity windows and determination of organo-facies. Incident light microscopy allows practitioners the ability to identify various types of organic components and demonstrates that solid bitumen is the dominant organic matter occurring in shale plays of peak oil and gas window thermal maturity, whereas oil-prone Type I/II kerogens have converted to hydrocarbons and are not present. High magnification SEM observation of an interconnected organic porosity occurring in the solid bitumen of thermally mature shale reservoirs has enabled major advances in our understanding of hydrocarbon migration and storage in shale, but suffers from inability to confirm the type of organic matter present. Herein we review organic petrography applications in the North American shale plays through discussion of incident light photographic examples. In the first part of the manuscript we provide basic practical information on the measurement of organic reflectance and outline fluorescence microscopy and other petrographic approaches to the determination of thermal maturity. In the second half of the paper we discuss applications of organic petrography and SEM in all of the major shale petroleum systems in North America including tight oil plays such as the Bakken, Eagle Ford and Niobrara, and shale gas and condensate plays including the Barnett, Duvernay, Haynesville-Bossier, Marcellus, Utica, and Woodford, among others. Our review suggests systematic research employing correlative high resolution imaging techniques and in situ geochemical probing is needed to better document hydrocarbon storage, migration and wettability properties of solid bitumen at the pressure and temperature conditions of shale reservoirs.

  10. Phobos surface spectra mineralogical modeling

    Science.gov (United States)

    Pajola, M.; Lazzarin, M.; Dalle Ore, C. M.; Cruikshank, D. P.; Roush, T. L.; Pendleton, Y.; Bertini, I.; Magrin, S.; Carli, C.; La Forgia, F.; Barbieri, C.

    2014-04-01

    A mineralogical model composed of a mixture of Tagish Lake meteorite (TL) and Pyroxene Glass (PM80) was presented in [1] to explain the surface reflectance of Phobos from 0.25 to 4.0 μm. The positive results we obtained, when comparing the OSIRIS data [2] extended in wavelength to include the [3,4] spectra, forced us to perform a wider comparison between our TL-PM80 model and the CRISM and OMEGA Phobos spectra presented in [5]. Such spectra cover three different regions of interest (ROIs) situated in the Phobos sub-Mars hemisphere: the interior of the Stickney crater, its eastern rim, and its proximity terrain southeast of the Reldresal crater. We decided to vary the percentage mixture of the components of our model (80% TL, 20% PM80), between pure TL and pure PM80, by means of the radiative transfer code based on the [6] formulation of the slab approximation. Once this spectral range was derived, see Fig. 1, we attempted to compare it with the [5] spectra between 0.4 and 2.6 μm, i.e. below the thermal emitted radiation, to see if any spectral match was possible. We observed that CRISM scaled spectra above 1.10 μm fall within pure Tagish Lake composition and the [1] model. The CRISM data below 1.10 μm present more discrepancies with our models, in particular for the Stickney's rim spectrum. Nevertheless the TL and PM80 components seem to be good mineralogical candidates on Phobos. We performed the same analysis with the OMEGA data and, again, we found out that the Stickney's rim spectrum lies out of our model range, while the two remaining spectra still lie between pure TL and 80% TL - 20% PM80, but indicating that a different, more complicated mixture is expected in order to explain properly both the spectral trend and the possible absorption bands located above 2.0 μm. Within this analysis, we point out that a big fraction of TL material (modeled pure or present with a minimum percentage of 80% mixed together with 20% PM80) seems to explain Phobos spectral

  11. Petrography and Physicomechanical Properties of Rocks from the Ambela Granitic Complex, NW Pakistan

    Directory of Open Access Journals (Sweden)

    Mohammad Arif

    2013-01-01

    Full Text Available Petrography and physicomechanical properties of alkali granites, alkali quartz syenite, and nepheline syenite from Ambela, NW Pakistan, have been investigated. Whereas the alkali quartz syenite and most of the alkali granites are megaporphyritic, the nepheline syenite and some of the alkali granites are microporphyritic. Their phenocryst shape and size and abundance of groundmass are also different. The values of unconfined compressive strength (UCS are the lowest and highest for megaporphyritic alkali granite and alkali quartz syenite, respectively. However, all the four rock types are moderately strong. Correspondingly, their specific gravity and water absorption values are within the permissible range for use as construction material. The UCS for the alkali quartz syenite is the highest, most probably because (i it has roughly equal amounts of phenocryst and groundmass, (ii it displays maximum size contrast between phenocryst and groundmass, (iii its phenocrysts are highly irregular, and (iv it contains substantial amounts of quartz.

  12. Mineralization and leaching process in the Jian copper deposit, northeastern Fars province: Application of petrography and stable isotopes

    Directory of Open Access Journals (Sweden)

    Farid Moore

    2015-04-01

    Full Text Available Introduction One of the first principles in the formation of a reserve is mineralogical, construction and mineral textures studies and investigation of paragenetic relations in the ore minerals. In addition, to petrographic studies, isotopic investigates have wide applications in economic geology. In general, copper isotope variability in primary (high temperature mineralization forms a tight cluster, in contrast to secondary mineralization, which has a much larger isotope range. A distinct pattern of heavier copper isotope signatures is evident in supergene samples, and a lighter signature characterizes the leached cap and oxidation-zone minerals. This relationship has been used to understand oxidation–reduction processes (Hoefs, 2009. Also for a better understanding of the origin of the Jian Cu deposit, this research focuses on the origin and composition of the fluid and elucidation of its evolution during the mineralization process. In order to achieve this end, field observations, vein petrography, microthermometry of fluid inclusions and stable isotope analyses of veins and minerals were investigated. The present study also compares high and low temperature sulfide samples in an attempt to document and explain diagnostic δ65Cu ranges in minerals from the Jian deposit. Materials and methods The samples were taken from different depths to measure Cu isotope variations within each reservoir. Mineralogical composition was determined using X-ray diffractometry. In addition, chromatographic separation was carried out on all samples (except for native Cu samples in a clean lab and was conducted as outlined in Mathur et al. (Mathur et al., 2009. These samples were measured into a Multicollector Inductively-Coupled-Plasma Mass Spectrometer (MC-ICPMS, the Micro mass Isoprobe at the University of Arizona in low resolution mode using a microconcentric nebulizer to increase sensitivity for the samples with lower concentrations of copper. Preparation

  13. Gold process mineralogy: Objectives, techniques, and applications

    Science.gov (United States)

    Zhou, Joe Y.; Cabri, Louis J.

    2004-07-01

    The extractive metallurgy of gold is largely driven by mineralogical factors such as gold particle size; association with other minerals; coatings; presence of cyanicides, oxygen consumers, and preg-robbers; presence of refractory gold minerals; and locking of submicroscopic gold in sulfide and sulfarsenide mineral structures. Gold process mineralogy addresses all issues related to gold ore processing by the detailed study of an ore or a mill product. The methodology is widely used as a predictive tool in feasibility studies and during the process development stage, and as a trouble-shooting tool for mineral processing and hydrometallurgical operations.

  14. Petrography and mineral chemistry of carbonatites and mica-rich rocks from the Araxa Complex (Alto Paranaiba Province, Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Traversa, Gianbosco; Morbidelli, Lucio; Ronca, Sara [Roma Univ. (Italy). Dipt. di Scienze della Terra; Gomes, Celso B.; Ruberti, Excelso [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias].E-mail: cgomes@usp.br; Brotzu, Piero [Napoli Univ. (Italy). Dipt. di Scienze della Terra; Buraglini, Nicoletta [Catania Univ. (Italy). Dipt. di Scienza della Terra; Principato, Maria Speranza [Milano Univ. (Italy). Dipt. di Scienza della Terra

    2001-03-01

    The Araxa complex (16 km{sup 2}) comprises carbonatites forming a central core and a complex network of concentric and radial dykes as well as small veins; additionally, it includes mica-rich rocks, phoscorities and lamprophyres. Fenites also occur and rare represented by Proterozoic quartzites and schists of the Araxa Group. The petrographic study of 130 borehole samples indicates that the complex is basically made up by two rock-types, carbonatites and mica-rich rocks, and subordinately by a third unit of hybrid composition. Carbonatites range chemically in composition, the most abundant type being magnesio-carbonatites. Dolomite and calcite correspond to the chief constituents, but other carbonate phases, including the Ce-group RE minerals, are also recognized. phosphates and oxides are widespread accessories whereas silicate minerals consist of olivine, clinopyroxene, mica and amphibole. Mica-rich rocks are represented by abundant glimmeritic rocks and scare cumulitic phlogopite-, olivine-and diopside-bearing pyroxenites. Hybrid rocks mainly contain phlogopite and tetraferriphlopite as cumulus and intercumulus phases, respectively; carbonate minerals may also be found. Chemical data indicate that the carbonatities are strongly enriched in REE and have lower contents of Nb, Zr, V, Cr, Ni and Rb compared to the mica-rich rocks. The higher K, Nb and Zr contents of the latter rocks are believed to be related to metasomatic processes (glimmeritization) of the pyroxenites. Similar REE patterns for carbonatites and mica-rich rocks seem to suggest that they are related to a single parental magma, possibly of ijolitic composition. Steep LREE/HREE fractionation and high {sigma}REE content of some carbonatite samples would be explained by hydrothermal and supergenic processes. (author)

  15. Virtual Petrography (ViP) - A virtual microscope for the geosciences

    Science.gov (United States)

    Virgo, Simon; Heup, Torsten; Urai, Janos L.; Berlage, Thomas

    2016-04-01

    Virtual Microscopy has advanced in recent years to a powerful versatile tool in the life sciences with many applications in research and teaching. We present the first virtual microscopy platform especially designed for geoscience applications. It was developed in a collaboration between RWTH Aachen University and Fraunhofer FIT under consideration of the demands of modern petrography. The system consists of a fully automated polarisation microscope that can scan entire thin sections in very high resolution under various polarisation and illumination conditions to capture and digitise all information that could be extracted from the section with classical polarised microscopy. The data is processed to extract the polarisation behaviour of each pixel as continuous functions that are fitted for each pixel based on images taken under different polarisation angles. This information is stored in a newly developed format that allows fast access and offers a very good degree of compression. The datasets can be viewed with a virtual microscopy software (TileViewer) that is easy to operate and allows fluent zooming and browsing through the thin section as well as rotation of the polarisers and switching between illumination conditions. The viewer software is platform independent and requires no special hardware, rather it operates well on a standard laptop. Besides navigation and image adjustments the TileViewer Software offers the possibility to create annotations, visualise the data based on certain characteristics (for example extinction direction), and offers a basic module for image segmentation. For further analysis the data can be exported to Matlab, ArcGis or other image analysis environments. The information density of each dataset (including the extinction behaviour) and the high resolution over very large continuous areas allows for new methods of automated and semi-automated analysis that was not possible before with single image acquisition and analysis

  16. Silicate mineralogy at the surface of Mercury

    Science.gov (United States)

    Namur, Olivier; Charlier, Bernard

    2017-01-01

    NASA's MESSENGER spacecraft has revealed geochemical diversity across Mercury's volcanic crust. Near-infrared to ultraviolet spectra and images have provided evidence for the Fe2+-poor nature of silicate minerals, magnesium sulfide minerals in hollows and a darkening component attributed to graphite, but existing spectral data is insufficient to build a mineralogical map for the planet. Here we investigate the mineralogical variability of silicates in Mercury's crust using crystallization experiments on magmas with compositions and under reducing conditions expected for Mercury. We find a common crystallization sequence consisting of olivine, plagioclase, pyroxenes and tridymite for all magmas tested. Depending on the cooling rate, we suggest that lavas on Mercury are either fully crystallized or made of a glassy matrix with phenocrysts. Combining the experimental results with geochemical mapping, we can identify several mineralogical provinces: the Northern Volcanic Plains and Smooth Plains, dominated by plagioclase, the High-Mg province, strongly dominated by forsterite, and the Intermediate Plains, comprised of forsterite, plagioclase and enstatite. This implies a temporal evolution of the mineralogy from the oldest lavas, dominated by mafic minerals, to the youngest lavas, dominated by plagioclase, consistent with progressive shallowing and decreasing degree of mantle melting over time.

  17. SITE-94. Mineralogy of the Aespoe site

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Karin [Chalmers Univ. of Technology, Goeteborg (Sweden). Technical Environmental Planning

    1996-12-01

    The water composition has several impacts on the repository. It will influence the behaviour of the engineered materials (e.g. corrosion). It may also determine the possible solubility and speciation of released radionuclides. It also acts as a transport medium for the released elements. The groundwater composition and the potential development of the composition due to the presence of the repository as well as due to external variations is thus an important issue in a safety analysis. The development of the groundwater composition is strongly dependent on reactions with the minerals present in water bearing fractures. Here equilibrium chemistry may be of importance, but also reaction kinetics is important to the long-term behaviour. Within the SITE-94 project, a safety analysis is performed for the conditions at the Aespoe site. The mineralogy of the area has been evaluated from drill cores at various places at the site. In this report a recommendation for selection of mineralogy to be used in geochemical modelling of the repository is given. Calcite and iron containing minerals dominate the fracture filling mineralogy at the Aespoe site. Some typical fracture filling mineralogies may be identified in the fractures: epidote, chlorite, calcite, hematite, some illite/smectite + quartz, fluorite, pyrite and goethite. In addition to these a number of minor minerals are found in the fractures. Uncertainties in the fracture filling data may be due to problems when taking out the drill cores. Drilling water may remove important clay minerals and sealed fractures may be reopened mechanically and treated as water conducting fractures. The problem of determining the variability of the mineralogy along the flow paths also remains. This problem will never be solved when the investigation is performed by drilling investigation holes

  18. Petrography and Geochemistry of Peridotite Xenoliths from Hannuoba and Significance for Lithospheric Mantle Evolution

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The compositions of the whole rocks and trace elements of minerals in peridotites can reflect the characteristics of the lithospheric mantle. The nature and evolution of the Cenozoic lithospheric mantle beneath Hannuoba (汉诺坝), located on the north edge of the intra-North China orogenic belt,are discussed based on the in-situ LAM-ICPMS detected trace element compositions of clinopyroxenes in the Hannuoba peridotitic xenoliths combined with detailed petrography and geochemistry studies. The Hannuoba lithospheric mantle was formed by different partial meltings of the primitive mantle. Most of the samples reflect the partial melting degree of lower than 5% with a few samples of 15%-20%.Major element compositions of the whole rocks and geochemical compositions of clinopyroxenes reveal the coexistence of both fertile and depleted mantle underneath the Hannuoba region during the Cenozoic.This was probably caused by the asthenospheric mantle replacing the aged craton mantle through erosion,intermingling and modification. Our conclusion is further supported by the existence of both carbonatitic magmatic material and silicate melt/fluid metasomatism as magnified by the trace elements of the clinopyroxenes from the Hannuoba lithospheric mantle.

  19. On the Relationship between Cosmic Ray Exposure Ages and Petrography of CM Chondrites

    Science.gov (United States)

    Takenouchi, A.; Zolensky, M. E.; Nishiizumi, K.; Caffee, M.; Velbel, M. A.; Ross, K.; Zolensky, A.; Lee, L.; Imae, N.; Yamaguchi, A.; Mikouchi, T.

    2014-01-01

    Carbonaceous (C) chondrites are potentially the most primitive among chondrites because they mostly escaped thermal metamorphism that affected the other chondrite groups. C chondrites are chemically distinguished from other chondrites by their high Mg/Si ratios and refractory elements, and have experienced various degrees of aqueous alteration. They are subdivided into eight subgroups (CI, CM, CO, CV, CK, CR, CB and CH) based on major element and oxygen isotopic ratios. Their elemental ratios vary over a wide range, in contrast to those of ordinary and enstatite chondrites which are relatively uniform. It is critical to know how many separate bodies are represented by the C chondrites. In this study we defined 4 distinct cosmic-ray exposure (CRE) age groups of CMs and systematically characterized the petrography in each of the 4 CRE age groups to determine whether the groups have significant petrographic differences with such differences probably reflecting different parent body (asteroid) geological processing, or multiple original bodies. We have reported the results of a preliminary grouping at the NIPR Symp. in 2013 [3], however, we revised the grouping and here report our new results.

  20. Mineralogy and geochemistry of the older (> 40 ka) ignimbrites on the Campanian Plain, southern Italy

    Science.gov (United States)

    Belkin, H. E.; Rolandi, G.; Jackson, J. C.; Cannatelli, C.; Doherty, A. L.; Petrosino, P.; De Vivo, B.

    2016-09-01

    The Campanian Plain in southern Italy has been volcanically active for at least the last 300 ka. The Campanian Ignimbrite (CI) erupted at 39.3 ka, has a volume of ≥ 310 km3 and a great areal extent. However, significant, but scattered deposits of older ignimbrites underlie the CI and document a long history of volcanism. We examined the mineralogy and geochemistry of 11 older ignimbrite strata by optical petrography, electron microprobe, scanning electron microscope, X-ray diffraction, and various whole-rock geochemical techniques. We have analyzed strata at Durazzano (116.1 ka), Moschiano (184.7 ka), Seiano Valley (245.9 and 289.6 ka), and Taurano - Acqua Feconia (157.4, 183.8, 205.6, and 210.4 ka) that have been previously dated on unaltered sanidine. The older ignimbrites are highly altered with loss on ignition (LOI) that ranges from 17 to 8 wt%. Whole-rock compositions reflect variable element mobility during weathering; e.g., CaO is enriched and Na2O depleted relative to hydration. X-ray diffraction identified major chabazite, kaolinite, and illite alteration products in some samples. Rhabdophane-(Nd), usually intergrown with chabazite and Mn-carbonate, indicates that some LREE were also mobilized during weathering. The phenocryst mineralogy is typical for Campanian Plain (CP) magmas and consists of plagioclase (An88 Ab11 Or1 to An32 Ab63 Or5), potassium feldspar (Or40 Ab57 An3 to Or79 Ab18 An3), biotite (TiO2 = ~ 4-7 wt%, BaO = up to 2 wt%, F = up to 2 wt%), diopside (Ca47Mg47Fe6 to Ca48Mg29Fe23), and titaniferous magnetite. Relatively immobile trace elements Zr, Hf, Th, Ta, V, and Nb were used to investigate element abundance and ratio compared to the Campanian Ignimbrite and other CP magmas. Zr/Hf of the older ignimbrites is similar to that of the CI, but Ta is depleted relative to Th and V is enriched compared to CI. Th/Ta and Nb/V distributions for most of the older ignimbrites are similar to those in the Neapolitan Yellow Tuff with the exception of

  1. Petrography, Mineral Chemistry and Geothermobarometry of Andalusite- Bearing Schists North of Azna (Northern Sanandaj-Sirjan Zone, Iran

    Directory of Open Access Journals (Sweden)

    Karim Abdollahi Silabi

    2016-07-01

    deformation that hasproduced the current morphologyof the Sanandaj-Sirjan zone (Shabanian Borujeni, 2008. In this paper we focused on petrography and mineral chemistry and thermodynamic conditions of the metapelites. Materials and methods The chemical compositions of minerals were determined by a CAMECA SX100 electron microprobe (EMP at Universität Stuttgart (Germany. The instrument is equipped with five wavelength dispersive spectrometers. The beam current and acceleration voltage were 15 nA and 15 kV, respectively. v Discussion and Results The Azna regional metamorphic rocks include quartz-feldspar schists, mica schists, andalusite-bearing schists and quartzites. The Azna metapelites are schists, containing quartz, feldspars, andalusite, muscovite, biotite, muscovite, chlorite and garnet, in variable proportions, characterized byporphyroblastic and lepidoblastic textures. Based on mineralogy, minerals of these rocks contain andalusite, garnet, feldspar, muscovite, biotite, quartz and chlorite. Microprobe analyses show that the mineral compositions are as follows: White micas in the andalusite-bearing schists are muscovite, plagioclases are albite-oligoclase, garnets are almandine-spessartine with weak chemical zoning and biotites are siderophylite-annite. Based on geothermobarometry, these rocks formed in the hornblende-hornfels facies and the low pressure part of the amphibolite facies,with temperatures about 562-692 °C and pressures1.07-4.12 kbar. After the regional metamorphism of these rocks,granitoidintrusions causedthermal metamorphism of these rocks and the formation of andalusite-bearing schists. Acknowledgments The authors wish to thank the Office of Graduate Studies of the University of Isfahan for their support. We also thank Prof. Hans-JoachimMassonne, who played major roles during the microprobe analysis of minerals at the InstitutfürMineralogie und Kristallchemie, Universität Stuttgart (Germany. References Aghanabati, A., 2004. Geology of Iran. Geological

  2. Petrography and mineral chemistry of wehrlites in contact zone of gabbro intrusions and mantle peridotites of the Naein ophiolite

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    Farhad Ghaseminejad

    2014-10-01

    , banded meta-chert, and succession of schist and marble (Davoudzadeh, 1972; Jabbari, 1997; Pirnia Naeini, 2006; Torabi, 2012; Shirdashtzadeh, 2006. In this ophiolite, the leucogabbro intrusions crosscut all other rock units. Materials and Methods Mineralogical analyses were conducted by wavelength-dispersive EPMA (JEOL JXA-8800R at the Cooperative Centre of Kanazawa University (Japan. The analyses were performed under an accelerating voltage of 15 kV and a beam current of 15 nA. JEOL software using ZAF corrections was employed for data reduction. Natural and synthetic minerals of known composition are used as standards. The Fe3+ content in minerals was estimated by assuming mineral stoichiometry. Results In the contact zone of leucogabbros and mantle peridotites of the Naein ophiolite, wehrlite and olivine clinopyroxenite are formed. Rock-forming minerals of these wehrlites are olivine (chrysolite, clinopyroxene (diopside, Cr-spinel, serpentine, amphibole (tremolite and tremolitic hornblende, epidote and magnetite. Comparison of mineral chemistry of olivine, clinopyroxene and chromian spinel in wehrlites and mantle peridotites indicate that chemical composition of clinopyroxene and olivine in these rocks are different, but chemistry of Cr-spinels in harzburgite and wehrlite are nearly same. Discussion According to the resistance of Cr-spinel against the metamorphism and alteration, it can be concluded that the wehrlites in contact zone of gabbros and mantle peridotites are formed at the expense of harzburgite. Olivine and clinopyroxene of wehrlites are formed by serpentine metamorphism and interaction of serpentine and calcium of gabbro, respectively. Field study of the research area shows that the leucogabbro intrudes the harzburgite. This research shows that after the serpentinization of mantle harzburgite, the gabbro intrusions crosscut the serpentinized peridotites, and wehrlite and olivine clinopyroxenite formed in the contact zone. Acknowledgements The authors thank

  3. Mineralogy and Surface Composition of Asteroids

    CERN Document Server

    Reddy, Vishnu; Thomas, Cristina A; Moskovitz, Nicholas A; Burbine, Thomas H

    2015-01-01

    Methods to constrain the surface mineralogy of asteroids have seen considerable development during the last decade with advancement in laboratory spectral calibrations and validation of our interpretive methodologies by spacecraft rendezvous missions. This has enabled the accurate identification of several meteorite parent bodies in the main asteroid belt and helped constrain the mineral chemistries and abundances in ordinary chondrites and basaltic achondrites. With better quantification of spectral effects due to temperature, phase angle, and grain size, systematic discrepancies due to non-compositional factors can now be virtually eliminated for mafic silicate-bearing asteroids. Interpretation of spectrally featureless asteroids remains a challenge. This paper presents a review of all mineralogical interpretive tools currently in use and outlines procedures for their application.

  4. Mineralogical Evolution in Extreme Debris Disks

    Science.gov (United States)

    Su, Kate

    2015-10-01

    Young (10-200 Myr), luminous (fractional luminosity on the order of 1.E-2) extreme debris disks provide a unique opportunity to explore exo-asteriod and exo-planetesimal collisions during the oligarchic and chaotic phases of terrestrial planet-building. We propose to obtain low-resolution grism spectra of four extreme debris disks to document and characterize the mineralogy changes in the mid-IR region where strong peaks originating from silica and forsterite dust can be easily identified. The proposed observations will supplement our on-going warm Spitzer monitoring program studying disk variability at 3.6 and 4.5 microns, provide immediate insights on the long-term mineralogical evolution in comparison with the existing Spitzer IRS spectra, and will bridge to similar studies that JWST will provide in the near future.

  5. An unpublished text of Jovellanos about mineralogy

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    Jorge ORDAZ GARGALLO

    2012-02-01

    Full Text Available An unpublished manuscript of Gaspar Melchor de Jovellanos about the history of mineralogy, written during his captivity in Bellver Castle (Palma de Mallorca is presented and analyzed. In this writing the importance of the chemical knowledge as a source of other branches of science and its applications in different fields of agriculture, mining and industry is considered. The author made a historical synthesis reviewing the men of science that contributed in a great extent to the advance of the chemistry and mineralogy. The text clearly supports the new contributions of Lavoisier and other supporters of experimentation as a scientific method, which agrees with Jovellanos’ ideas about the development of the «useful» sciences for the progress of the countries.

  6. An unpublished text of Jovellanos about mineralogy

    OpenAIRE

    Ordaz Gargallo, Jorge; Gutiérrez Claverol, Manuel; De Lorenzo Álvarez, Elena

    2012-01-01

    An unpublished manuscript of Gaspar Melchor de Jovellanos about the history of mineralogy, written during his captivity in Bellver Castle (Palma de Mallorca) is presented and analyzed. In this writing the importance of the chemical knowledge as a source of other branches of science and its applications in different fields of agriculture, mining and industry is considered. The author made a historical synthesis reviewing the men of science that contributed in a great extent to the advance of t...

  7. Observations on the palynology, petrography and geochemistry of the Western Kentucky number 4 coal bed

    Science.gov (United States)

    Eble, C.F.; Greb, S.F.; Williams, D.A.; Hower, J.C.

    1999-01-01

    Eight bench-column samples of the Western Kentucky Number 4 coal bed, collected from an area along the southern margin of the Western Kentucky Coal Field, were analyzed palynologically, petrographically, and geochemically to document both temporal and spatial variability among these parameters. The Western Kentucky Number 4 coal occurs near the top of the Tradewater Formation, is of Early Desmoinesian age, and is correlative with the lower part of the Allegheny Formation of the Appalachian Basin, and Late Bolsovian strata of western Europe. Palynologically, the coal is co-dominated by spores that were produced by lycopod trees (Lycospora and Granasporites medius) and tree ferns. Thin-walled tree fern spores (Punctatisporites minutus, P. minutus, P. rotundus) are more abundant than thick-walled forms (Laevigatosporites globosus, P. granifer). Calamitean spores (Calamospora and Laevigatosporites spp.) are locally abundant as is cordaitean pollen (Florinites). Small fern (Granulatisporites) and small lycopod spores (Densosporites, Cirratriradites, Endosporites and Anacanthotriletes spinosus) are present, but occur in minor amounts. Temporal changes in palynomorph composition occur, but are not uniform between columns. Spatial variability among columns is also evident. Petrographically, the coal is dominated by vitrinite macerals, with telinite and telocollinite generally occurring more commonly than desmocollinite and gelocollinite. Basal benches typically contain high percentages of vitrinite; middle benches usually contain higher percentages of liptinite and inertinite. In about half the studied columns, the terminal coal benches show a slight increase in vitrinite. In the study area, the petrography of the Western Kentucky Number 4 coal is more uniform than the palynology. Ash yields and total sulfur contents are temporally uniform in some columns, but variable in others. In the latter case, higher percentages of ash and sulfur occur at the base of the bed and

  8. X-ray computed microtomography integrated to petrography for the three-dimensional study of rock porosity; A microtomografia computadorizada de raios x integrada a petrografia no estudo tridimensional de porosidade em rochas

    Energy Technology Data Exchange (ETDEWEB)

    Reis Neto, Joss Manoel dos; Fiori, Alberto Pio; Lopes, Angela Pacheco; Pinto-Coelho, Cristina Valle; Vasconcellos, Eleonora Maria Gouvea; Silva, Gabriel Fischer da [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Geologia; Marchese, Clarice; Secchi, Rodrigo, E-mail: jmreis@ufpr.br, E-mail: fiori@ufpr.br, E-mail: angelalopes@ufpr.br, E-mail: cristinavpc@ufpr.br, E-mail: eleonora@ufpr.br, E-mail: fischergab@hotmail.com, E-mail: clamarchese@hotmail.com, E-mail: rosecchi@yahoo.com.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Geologia. Lab. de Analise de Minerais e Rochas

    2011-09-15

    The porosity contained in rocks is object of study by geoscientists due to the various genetic implications of these features. However, what have been motivating the search for new analytical techniques to study pores are the petrophysical analyses. The experimental techniques for porosity analysis, such as mercury or gas injection, allow a quantitative approach, but do not allow the visualization of the porous framework. Petrographic analysis by optical microscopy allows the visualization and quantification of intergranular pores, but it is restricted to the two-dimensional space and quantifications are less representative. Technological advances in X-ray computed microtomography (micro-CT) allowed three-dimensional analysis of pore geometry in microscale, in addition to automated volume measurements. The analyses of marble, quartzite, sandstone and dolomite breccia represented in this work and performed under the Project Falhas/ PETROBRAS/UFPR, show the shape, size, connectivity, tortuosity, pore volume and distribution in these rocks, demonstrating the differences in the rocks' porous frameworks. The integration of micro-CT to petrography allows the identification of mineral phases with attenuation of contrasting X-rays, placing the incidence of porosity in the mineralogical context in three dimensions, in addition to the contribution to the consistency of the method. Although the resolution is limited in the X-ray microtomography that was used (the Skyscan model 1172), which does not reach the smallest pore size of some rocks, the integration of both techniques provides new information, of extreme importance for the research about micro-features related to the pores in rocks, helping in genetic interpretations and significantly contributing for the analyses of reservoirs. (author)

  9. Petrography and Diagenesis of Palaeocene -Eocene Sandstones in the Siri Canyon, Danish North Sea

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari

    small differences in textural and compositional properties, and the lack of depositional structures in deep-water sandstones, the distinction between "in situ" and injected or remobilised sandstones is often indistinct.   Large scale heavy mineral sorting (in 10 m thick units) is observed in several...... of zeolites, pore water chemistry, composition of mineralogical precursors and the host sediments. This study demonstrates also the diagenetic evolution glaucony-rich deep-water sandstones from the Rau-1A well in the Siri Canyon, Danish North Sea.  The major diagenetic phases in the studied well.......  It was transformed to chlorite with depth.    A second phase chlorite is distinguished by its morphology and slightly different diffraction pattern.  It fills the porosity and reduced permeability in the upper marginal part of the reservoir, which had preserved porosity and permeability due to microquartz...

  10. Topographical mineralogy of the Bamble sector, south Norway

    NARCIS (Netherlands)

    Nijland, T.G.; Zwaan, J.C.; Touret, L.

    1998-01-01

    The Bamble sector of southern Norway is a classic high grade metamorphic gneiss region, which provided specimens to many mineralogical collections all over the world. The topographical mineralogy of this area is described and reviewed. All minerals known to occur in the area are listed according to

  11. Adsorção de fósforo, superfície específica e atributos mineralógicos em solos desenvolvidos de rochas vulcânicas do Alto Paranaíba (MG Phosphorus adsorption, specific surface, and mineralogical attributes of soils developed from volcanic rocks from the Upper Paranaíba, MG (Brazil

    Directory of Open Access Journals (Sweden)

    F. C. Rolim Neto

    2004-12-01

    Cambissolos mostraram variações grandes nos atributos químicos, mineralógicos e na CMAF, em virtude da natureza diversificada de materiais de origem e do menor grau de intemperismo.Despite relatively high levels of total P, most deeply-weathered tropical soils have very low levels of available P due to the low solubility of most P forms found in these soils. In this research we studied P adsorption of soils, some of which were rich in apatite, developed from basic to ultrabasic volcanic rocks in the Upper Paranaíba region of Minas Gerais State, in relation to the specific surface and clay mineralogy. Samples of eleven B horizons from representative Latosols (Oxisols and Cambisols (Inceptisols were used. Standard chemical, physical, and mineralogical characterizations were realized, as well as the determination of maximum P adsorption capacity (PMAC, specific surface (SS by the BET-N2 and indirect methods, and the quantification of individual clay minerals by allocation. The sum of the SS values obtained by the indirect method for each mineral overestimated the results, compared with the SS values obtained by the BET-N2 method for the total clay fraction. Among the studied Latosols, exhibiting varying textures and basic-alkaline to ultrabasic parent materials, the proportion and surface area of gibbsite and goethite appeared closely related to P adsorption. The range of PMAC values for the fine earth (< 2 mm fraction was also consistent with values reported in literature, although the Red-Yellow Latosol derived from ultrabasic rock (fine earth PMAC = 2.98 mg g-1 and PMACclay = 4.38 mg g-1 was similar to values of alophanic subtropical soils derived from volcanic ash. The PMACclay values were greater in the Cambisols derived from ultrabasic volcanics (4.32 and 5.52 than in those derived from tuffites (3.16 mg g-1. Al-isomorphic substitution in goethites was found to be higher than in hematites. In contrast to the Latosols, the Cambisols presented larger variations in

  12. Spotlight: Brazil.

    Science.gov (United States)

    Carter, M

    1996-08-01

    Brazil is South America's largest country and home to nearly half of the continent's people. Despite solid economic growth, Brazil has one of the world's widest income disparities. In the early 1990s, nearly 40% of urban and 66% of rural Brazilians lived in poverty. The streets of Brazil's cities are home to a large population of street children. Although it is difficult to estimate, 10 million children and youths may be either homeless or making a meager living off of the streets. Street children may be linked to prostitution and drugs and be the targets or perpetrators of violence. Child labor is an issue in Brazil. Today an estimated 30% of rural children and 9% of urban children ages 10-13 work in the formal economy. In some rural areas, 60% of workers are ages 5-17. Child labor also contributes to Brazil's relatively low educational attainment levels. UNICEF estimates that around 1990 only 1/3 of all Brazilian children continued on to secondary school, compared to 74% and 47%, respectively, for the Latin America and Caribbean regions. Immunization rates among Brazil's children are rising but still lag slightly behind regional averages. The mortality rate for children under age 5 decreased dramatically from 181 deaths for every 1000 live births in 1960 to 61/1000 in 1994. During the same time period, the average number of children born to a woman during her lifetime dropped from 6.2 to 2.8. This fertility decline is related in part to increased access to and acceptance of family planning. Contraceptive prevalence, including traditional and modern methods, is around 66%, with female sterilization and the pill being the most popular methods. Brazil's abortion rates are high, despite laws limiting access to abortion services. One estimate suggests that about 30% of all pregnancies are terminated through abortion each year.

  13. Surface chemistry and mineralogy. [of planet Mars

    Science.gov (United States)

    Banin, A.; Clark, B. C.; Waenke, H.

    1992-01-01

    The accumulated knowledge on the chemistry and mineralogy of Martian surface materials is reviewed. Pertinent information obtained by direct analyses of the soil on Mars by the Viking Landers, by remote sensing of Mars from flyby and orbiting spacecraft, by telescopic observations from earth, and through detailed analyses of the SNC meteorites presumed to be Martian rocks are summarized and analyzed. A compositional model for Mars soil, giving selected average elemental concentrations of major and trace elements, is suggested. It is proposed that the fine surface materials on Mars are a multicomponent mixture of weathered and nonweathered minerals. Smectite clays, silicate mineraloids similar to palagonite, and scapolite are suggested as possible major candidate components among the weathered minerals.

  14. Stable NRM and mineralogy in Allende - Chondrules

    Science.gov (United States)

    Wasilewski, P. J.; Saralker, C.

    The main objective of the present investigation is related to a description of the magnetic and mineralogic contrasts between chondrules which have a natural remanent magnetization (NRM) vector that is ultrastable during alternating field (AF) demagnetization, and those which have unstable NRM vectors when subjected to the same treatment. The results presented in the present investigation together with new magnetic results from Allende listed in a summary provided by Wasilewski (1981) are used as a basis to argue that the stable NRM in Allende was acquired during a sulfidation event. Attention is given to magnetic phases in Allende, experimental results obtained in magnetic studies conducted with 20 chondrules, and a magnetization model for Allende.

  15. Mineralogy and geochemistry of the Jurassic coals from the Gheshlagh mine, Eastern Alborz

    Directory of Open Access Journals (Sweden)

    Gholam Hossein Shamanian

    2015-10-01

    Full Text Available Introduction The Alborz structural zone in northern Iran is the host of a number of important coal deposits. The Gheshlagh coal mine is one of them, which is located 35 km southeast of Azadshahr. Coal bearing strata in the Gheshlagh mining district occur in the middle part of the Lower Jurassic Shemshak Formation which consists mainly of shales, siltstones and sandstones. The Geshlagh coals have a low sulfur content and a low ash yield. The ash content of coal and its geochemical character depends on the environment of deposition and subsequent geological history (Yazdi and Esmaeilnia, 2004. The purpose of this study was to investigate the texural and mineralogical characteristcs of the Ghashlagh coals and to identify the geochemistry of the major and trace elements and their relationship to specific mineralogical components. These results are necessary to improve the understanding of coal characterization and to relate the mineralogy of different materials to their potential for producing acidic or alkaline mine waters associated with mining and preparation processes. Materials and methods About 20 samples were collected from the main coal seams. These samples were taken from fresh faces of the mine to avoid weathered surfaces and get fresh samples. The petrography of the samples was carried out by the conventional microscopic methods at the Golestan University. Mineralogical analyses were done by a X-ray diffractometer equipped with a CuKα tube and monochrometer (XRD Philips PW 1800 at the Kansaran Binaloud Company. The coal samples were initially crushed to less than 200 μm and homogenized. Then, 50 g from each sample was heated to 525 oC according to the United States Geological Survey procedure(Bullock et al., 2002. The concentration of the major and trace elements in the resulting ash samples was determined using a wavelength Xray fluorescence spectrometer (XRF Philips PW1480 at the Kansaran Binaloud Company. Results The Coal

  16. Clay mineralogy in agrochernozems of western Ukraine

    Science.gov (United States)

    Papish, I. Ya.; Chizhikova, N. P.; Poznyak, S. P.; Varlamov, E. B.

    2016-10-01

    The mineralogy of clay fractions separated from deep low-humus deep-gleyic loamy typical agrochernozems on loess-like loams of the Upper Bug and Dniester uplands in the Central Russian loess province of Ukraine consists of complex disordered interstratifications with the segregation of mica- and smectite-type layers (hereafter, smectite phase), tri- and dioctahedral hydromicas, kaolinite, and chlorite. The distribution of the clay fraction is uniform. The proportions of the layered silicates vary significantly within the profile: a decrease in the content of the smectite phase and a relative increase in the content of hydromicas up the soil profile are recorded. In the upper horizons, the contents of kaolinite and chlorite increase, and some amounts of fine quartz, potassium feldspars, and plagioclases are observed. This tendency is observed in agrochernozems developed on the both Upper Bug and Dniester uplands. The differences include the larger amounts of quartz, potassium feldspars, and plagioclases in the clay material of the Upper Bug Upland, while the contents of the smectite phase in the soil profiles of the areas considered are similar. An analogous mineral association is noted in podzolized agrochernozems on loess-like deposits in the Cis-Carpathian region of the Southern Russian loess province developed on the Prut-Dniester and Syan-Dniester uplands. The distribution of particle-size fractions and the mineralogy of the clay fraction indicate the lithogenic heterogeneity of the soil-forming substrate. When the drifts change, the mineral association of the soils developed within the loess-like deposits gives place to minerals dominated by individual smectite with some mica-smectite inter stratifications, hydromicas, and chlorite.

  17. The ceramic artifacts in archaeological black earth (terra preta from lower Amazon region, Brazil: mineralogy Artefatos cerâmicos em sítios arqueológios com terra preta na região do baixo Amazonas, Brasil: mineralogia

    Directory of Open Access Journals (Sweden)

    Marcondes Lima da Costa

    2004-01-01

    Full Text Available Several archaeological black earth (ABE sites occur in the Amazon region. They contain fragments of ceramic artifacts, which are very important for the archaeological purpose. In order to improve the archaeological study in the region we carried out a detailed mineralogical and chemical study of the fragments of ceramic artifacts found in the two ABE sites of Cachoeira-Porteira, in the Lower Amazon Region. Their ceramics comprise the following tempers: cauixi, cariapé, sand, sand +feldspars, crushed ceramic and so on and are composed of quartz, clay equivalent material (mainly burned kaolinite, feldspars, hematite, goethite, maghemite, phosphates, anatase, and minerals of Mn and Ba. Cauixi and cariapé, siliceous organic compounds, were found too. The mineralogical composition and the morphology of their grains indicate a saprolite (clayey material rich on quartz derived from fine-grained felsic igneous rocks or sedimentary rocks as source material for ceramic artifacts, where silica-rich components such cauixi, cariapé and/or sand (feldspar and rock fragments were intentionally added to them. The high content of (Al,Fe-phosphates, amorphous to low crystalline, must be product of the contact between the clayey matrix of pottery wall and the hot aqueous solution formed during the daily cooking of animal foods (main source of phosphor. The phosphate crystallization took place during the discharge of the potteries put together with waste of organic material from animal and vegetal origin, and leaving to the formation of the ABE-soil profile.Sítios arqueológicos com Terra Preta, denominados de Terra Preta de Índio ou ainda Terra Preta Arqueológica (TPA são muito freqüentes na Amazônia. As TPA geralmente contém fragmentos de vasos cerâmicos, por vezes abundantes, além de líticos, que são materiais de grande importância para os estudos arqueológicos. Para consubstanciar esses estudos, realizou-se pesquisas mineralógicas e químicas em

  18. Mineralogia, micromorfologia e gênese de solos planossólicos do Sertão do Araripe, estado de Pernambuco Mineralogy, micromorphology and genesis of soils with stagnic properties from Sertão of Araripe, Pernambuco State, Brazil

    Directory of Open Access Journals (Sweden)

    L. B. Oliveira

    2004-08-01

    muitos argilãs de iluviação, e a ausência de características que evidenciem mobilização de argila do Bt precedente revelam uma paleopedogênese para o solo. Estes resultados indicam que os solos foram desenvolvidos em duas etapas. As rochas do embasamento cristalino sofreram uma primeira pedogênese, da qual o marco atual de evidência é a camada de litofragmentos, em sua maioria arestados, que ocorre no topo do B plânico, e que foi, provavelmente, acumulada pela erosão diferencial, formando um pavimento desértico. Posteriormente, os solos foram recobertos por camadas de sedimentos intemperizados, relacionados com a Chapada do Araripe, que se misturaram, em proporções variadas, ao material já edafizado das rochas do embasamento. Estes materiais estão, desde sua deposição, sendo retrabalhados pelos processos pedogenéticos atuais.The objective of the present study was to characterize the mineralogy and micromorphology of soils with stagnic properties from the micro region of Araripina, in the Sertão Zone of Pernambuco State aiming to improve the understanding of their properties and pedogenic processes. Up to now, these soils have been poorly studied. They are characterized by the presence of a solodic or natric B horizon underlying a normal argic B horizon. Three representative soil profiles were selected in Ouricuri County. According to the World Reference Base for Soil Resources they are classified as: Natric Stagnic Sesquisol (profile 1; Solodic Stagnic Lixisol (profile 2, and Plinthic Stagnic Lixisol (profile 3. The mineralogy of the coarse fractions was determined macroscopically or by using a binocular magnifying lens, while the silt and clay fractions were analyzed by X-ray diffraction. Selected horizons were micromorphologically described based on thin soil sections. The sand fraction of the studied soils is essentially composed by quartz, but feldspars and micas were also detected in the 2Btbn horizons. The silt fraction contains mostly quartz

  19. Teores de metais pesados e caracterização mineralógica de solos do Cemitério Municipal de Santa Cândida, Curitiba (PR Heavy metal contents and mineralogical characterization of soils from the Santa Cândida Municipal Cemetery, in Curitiba (PR, brazil

    Directory of Open Access Journals (Sweden)

    Yara Jurema Barros

    2008-08-01

    , em parte determinadas pelo material de origem, não apresentaram relação de causa e efeito com metais pesados nas áreas estudadas.The metal pieces of coffins, such as handles and adornments, are considered the main source of soil heavy metal contamination. Other sources of pollutants are the products used in the body embalming, wood preservatives and fluids released from body decomposition. The purpose of this study was to investigate the clay fraction mineralogy and heavy metal contents of soils from Santa Cândida Municipal Cemetery, in Curitiba (PR, and estimate the contamination risk. The samples were collected at three depths (0-20, 20-80 and 80-120 cm at seven selected points, representing two parent materials (granite/gneiss and claystone and two burial modalities (unmarked graves and mausoleum area. The clay fraction was studied by X ray diffractometry and thermal analysis, and Fe and Al contents were determined, after acid ammonium oxalate (amorphous Fe and Al oxides and sodium citrate-bicarbonate-dithionite (crystalline Fe oxides extractions, by atomic absorption spectroscopy (AAS. The total and exchangeable heavy metal contents were determined by AAS, after sample digestion with concentrated HF and BaCl2 1 mol L-1 solution, respectively. The predominance of kaolinite and occurrence of vermiculite with Al-hydroxy interlayers and smectite determined the high values of soil CEC. Heavy metal contents were higher in the mausoleum area, where the highest Cr and Pb contents were found (516.3 and 260.2 mg kg-1, respectively. The lower metal contamination in the area of unmarked graves may be attributed to simpler burial practices, with less potential heavy metal sources, such as wood preservatives and metal parts of coffins. No cause-effect relation was observed between the chemical and mineralogical soil characteristics, in part determined by the parent material, and the heavy metal contents in the studied area.

  20. Petrography and geochemistry of Paleocene-Eocene limestones in the Ching-dar syncline, eastern Iran

    Institute of Scientific and Technical Information of China (English)

    S. Halimeh Hashemi Azizi; Gholamreza Mirab Shabestari; Ahmadreza Khazaei

    2014-01-01

    The Ching-dar syncline is located to the west of the city of Birjand, in the east of Iran. The ca. 500 m thick studied section at the eastern flank of the syncline contains a sequence of almost continuous shallow-marine limestones that exhibit no major sedimentary breaks or evidence for volcanic activity. Skeletal grains consist of large benthic foraminifera and green algae whereas non-skeletal grains are mostly peloids and intraclasts. They were deposited on a shallow-marine carbonate ramp. The limestones have undergone extensive diagenetic processes with varying intensities, the most important of which are micritization, cementation, compaction (chemical and mechanical), internal filling and stylolitization. Chemical analysis of the limestone samples revealed high calcium and low magnesium content. Major and minor element values were used to determine the original carbonate mineralogy of these lime-stones. Petrographic evidence and elemental values indicate that calcite was the original carbonate mineral in the limestones of the Ching-dar syncline. The elemental composition of the Ching-dar car-bonates also demonstrates that they have stabilized in a meteoric phreatic environment. Variation of Sr/Ca vs. Mn values suggests that diagenetic alteration occurred in an open geochemical system.

  1. Automated Quantitative Rare Earth Elements Mineralogy by Scanning Electron Microscopy

    Science.gov (United States)

    Sindern, Sven; Meyer, F. Michael

    2016-09-01

    Increasing industrial demand of rare earth elements (REEs) stems from the central role they play for advanced technologies and the accelerating move away from carbon-based fuels. However, REE production is often hampered by the chemical, mineralogical as well as textural complexity of the ores with a need for better understanding of their salient properties. This is not only essential for in-depth genetic interpretations but also for a robust assessment of ore quality and economic viability. The design of energy and cost-efficient processing of REE ores depends heavily on information about REE element deportment that can be made available employing automated quantitative process mineralogy. Quantitative mineralogy assigns numeric values to compositional and textural properties of mineral matter. Scanning electron microscopy (SEM) combined with a suitable software package for acquisition of backscatter electron and X-ray signals, phase assignment and image analysis is one of the most efficient tools for quantitative mineralogy. The four different SEM-based automated quantitative mineralogy systems, i.e. FEI QEMSCAN and MLA, Tescan TIMA and Zeiss Mineralogic Mining, which are commercially available, are briefly characterized. Using examples of quantitative REE mineralogy, this chapter illustrates capabilities and limitations of automated SEM-based systems. Chemical variability of REE minerals and analytical uncertainty can reduce performance of phase assignment. This is shown for the REE phases parisite and synchysite. In another example from a monazite REE deposit, the quantitative mineralogical parameters surface roughness and mineral association derived from image analysis are applied for automated discrimination of apatite formed in a breakdown reaction of monazite and apatite formed by metamorphism prior to monazite breakdown. SEM-based automated mineralogy fulfils all requirements for characterization of complex unconventional REE ores that will become

  2. Mineralogia e química dos sedimentos de fundo do médio e baixo Madeira e de seus principais tributários: Amazonas - Brasil Mineralogy and chemistry of bottom sediments of the middle and lower Madeira River and its main tributaries: Amazonas - Brazil

    Directory of Open Access Journals (Sweden)

    Maria Mireide Andrade Queiroz

    2011-01-01

    Full Text Available O objetivo deste trabalho foi investigar a variação composicional e mineralógica dos sedimentos de fundo transportados pelos grandes rios da Amazônia, com nascentes nos Andes provenientes de rochas cratônicas. O estudo foi realizado com base em análises granulométricas, mineralógicas e químicas, incluindo isótopos de Pb, no rio Madeira e seus tributários. O conjunto de dados mostra que os sedimentos de fundo do rio Madeira são granulométrica, mineralógica e quimicamente distintos de seus principais tributários. Os sedimentos do rio Madeira são mais arenosos; têm maior quantidade de quartzo; menor conteúdo de Al2O3, Fe2O3, K2O, MgO, Na2O, PF, TiO2, P2O5, MnO e elementos-traço; e a maturidade aumenta de montante para jusante. Dentre os sedimentos dos tributários, os rios Machado e secundariamente o rio Marmelos são os que mais se aproximam da composição dos sedimentos do rio Madeira, enquanto que o Jamari com sedimentos com maior proporção de TiO2, Zr, Y, Nb, Ga, Hf, U, Ta e ETR, é o mais distinto. Apesar do ambiente de intenso intemperismo e erosão, em condições tropicais úmidas, a que estão submetidas as rochas drenadas pela bacia do rio Madeira, os valores das razões Th/Co, Th/Pb, Th/Yb, Al/Pb, Zr/Co e a composição isotópica de Pb indicam fontes distintas para os sedimentos de fundo estudados. Os sedimentos do rio Madeira são provenientes, principalmente, de rochas máficas, enquanto que os sedimentos de seus tributários têm como fonte essencialmente rochas félsicas.This study reports the granulometric, mineralogic and chemical analyses, including Pb isotope, carried out on the bottom sediments of the Madeira River, whose headwaters are in the Andes Mountain, and its tributaries that come from the cratonic region, in order to investigate the compositional variation of the sediments transported by the major rivers of the Amazon. The analytical data show that the bottom sediments of the Madeira River have

  3. Mineralogical, chemical, and physical properties of the regolith overlying crystalline rocks, Fairfax County, Virginia: a preliminary report

    Science.gov (United States)

    Leo, Gerhard W.; Pavich, M.J.; Obermeier, Stephen F.

    1977-01-01

    Undisturbed cores of saprolite developed on crystalline rocks of the Piedmont Province in Fairfax County, Virginia have been obtained using a combination of Shelby tubes, Denison sampler, and modified diamond core-drilling. The principal purpose of the core study is to correlate variations in chemistry, mineralogy and texture with engineering properties throughout the weathering profile. Coring sites were chosen to obtain a maximum depth of weathering on diverse lithologies. The rocks investigated include pelitic schist, metagraywacke, granite, diabase and serpentinite. Four to twelve samples per core were selected, depending on thickness of 1) the weathering profile (from about 1 m in serpentinite to more than 30 m in pelitic schist) and on 2) megascopic changes in saprolite character for analysis of petrography, texture, clay mineralogy andd major element chemistry. Shear strength and compressibility were determined on corresponding segments of core. Standard penetration tests were performed adjacent to coring sites to evaluate engineering properties in situ. Geochemical changes of saprolite developed from each rock type follow predictable trends from fresh rock to soil profile, with relative Increases in Si, Ti, Al, Fe3+ and H20; variable K; and relative loss of Fe 2+, Mg, Ca, and Na. These variations are more pronounced in the weathering profiles over mafic and ultramafic rocks than metagraywacke. Clay minerals in granite, schist and metagraywacke saprolite are kaolinite, dioctahedral vermiculite, interlayered micavermiculite, and minor illite. Gibbsite is locally developed in near-surface samples of schist. Standard penetration test data for the upper 7 m of saprolite over schist and metagraywacke suggest alternations between stronger and weaker horizons than probably reflect variations in lithology including the presence of quartz lenses. Results for granite saprolite are most consistent but indicate lower strength. Shear strength increases fairly regularly

  4. Geochemical and Mineralogical Proxies for characterizing Tsunami and Paleotsunami Deposits

    Science.gov (United States)

    Löwhagen, L.; Jankaew, K.; Kylander, M. E.; Skelton, A.; Wohlfarth, B.

    2015-12-01

    In this study we show how geochemistry and mineralogy can be used to correlate between previously dated tsunami and paleotsunami deposits in western Thailand. We do this based on cores from three parallel swales along a transect from the shoreline inland. Stratigraphy, together with geochemical and mineralogical analyses was used to correlate between tsunami and paleotsunami layers at these sites. Using element biplots (Ti-Zr, Ti-Y and Zr-Y) and mineralogical constraints, source signatures of each of the tsunami and paleotsunami layers were used to correlate between sand layers representing the 2004 tsunami and sand layers representing at least three paleotsunamis. Based on our correlations between these swales, we predict different inundation distances and directions for these paleotsunamis. Our study shows that a combination of geochemical and mineralogical analysis provides a powerful tool for correlation between tsunami and paleotsunami layers.

  5. Olivine-dominated Asteroids: Mineralogy and Origin

    CERN Document Server

    Sanchez, Juan A; Kelley, Michael S; Cloutis, Edward A; Bottke, William F; Nesvorný, David; Lucas, Michael P; Hardersen, Paul S; Gaffey, Michael J; Abell, Paul A; Corre, Lucille Le

    2013-01-01

    Olivine-dominated asteroids are a rare type of objects formed either in nebular processes or through magmatic differentiation. The analysis of meteorite samples suggest that at least 100 parent bodies in the main belt experienced partial or complete melting and differentiation before being disrupted. However, only a few olivine-dominated asteroids, representative of the mantle of disrupted differentiated bodies, are known to exist. Due to the paucity of these objects in the main belt their origin and evolution have been a matter of great debate over the years. In this work we present a detailed mineralogical analysis of twelve olivine-dominated asteroids. Within our sample we distinguish two classes, one that we call pure-olivine asteroids and another referred to as olivine-rich asteroids. For the pure-olivine asteroids the olivine chemistry was found to range from ~ Fo49 to Fo70, consistent with the values measured for brachinites and R chondrites. In the case of the olivine-rich asteroids we determined thei...

  6. Magnetic mineralogy of the Mercurian lithosphere

    Science.gov (United States)

    Strauss, B. E.; Feinberg, J. M.; Johnson, C. L.

    2016-11-01

    Mercury and Earth are the only inner solar system planets with active, internally generated dynamo magnetic fields. The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission recently detected magnetic fields on Mercury that are consistent with lithospheric magnetization. We investigate the physical and chemical environment of Mercury's lithosphere, past and present, to establish the conditions under which magnetization may have been acquired and modified. Three factors are particularly crucial to the determination of crustal composition and iron mineralogy: redox conditions in the planet's crust and mantle, the iron content of the lithosphere, and, for any remanent magnetization, the temperature profile of the lithosphere and its evolution over time. We explore potential mechanisms for remanence acquisition and alteration on Mercury, whose surface environment is both hot and highly reducing. The long-term thermal history of Mercury's crust plays an important role in the longevity of any remanent crustal magnetization, which may be subject to remagnetization through thermal, viscous, and shock mechanisms. This thermal and compositional framework is used both to constrain plausible candidate minerals that could carry magnetic remanence on Mercury and to evaluate their capacity to acquire and retain sufficient magnetization to be detectable from satellite orbit. We propose that iron metal and its alloys are likely to be the dominant contributors to induced and remanent magnetization in Mercury's lithosphere, with additional contributions from iron silicides, sulfides, and carbides.

  7. The mineralogy of ordinary chondrites and implications for asteroid spectrophotometry

    Science.gov (United States)

    Mcsween, Harry Y., Jr.; Bennett, Marvin E., III; Jarosewich, Eugene

    1991-01-01

    Published data from bulk chemical analyses of 94 ordinary chondrites are compiled in a table of normative mineralogy and discussed in detail. Significant variations in olivine, pyroxene, and metal abundance ratios are found within each chondrite class and attributed to redox processes superimposed on initial differences in metal/silicate ratios. The use of the diagrams constructed here to predict the mineralogic characteristics of asteroids on the basis of spectrophotometric observations is suggested.

  8. Revised mineralogic summary of Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Bish, D.L.; Chipera, S.J.

    1989-03-01

    We have evaluated three-dimensional mineral distribution at Yucca Mountain, Nevada, using quantitative x-ray powder diffraction analysis. All data were obtained on core cuttings, or sidewall samples obtained from drill holes at and around Yucca Mountain. Previously published data are included with corrections, together with new data for several drill holes. The new data presented in this report used the internal standard method of quantitative analysis, which yields results of high precision for the phases commonly found in Yucca Mountain tuffs including opal-CT and glass. Mineralogical trends with depth previously noted are clearly shown by these new data. Glass occurrence is restricted almost without exception to above the present-day static water level (SWL), although glass has been identified below the SWL in partially zeolitized tuffs. Silica phases undergo well-defined transitions with depth, with tridymite and cristobalite occurring only above the SWL, opal-CT occurring with clinoptilolite-mordenite tuffs, and quartz most abundant below the SWL. Smectite occurs in small amounts in most samples but is enriched in two distinct zones. These zones are at the top of the vitric nonwelded base of the Tiva Canyon Member and at the top of the basal vitrophyre of the Topopah Spring Member. Our data support the presence of several zones of mordenite and clinoptilolite-heulandite as shown previously. New data on several deep clinoptililite-heulandite samples coexisting with analcime show that they are heulandite. Phillipsite has not been found in any Yucca Mountain samples, but erionite and chabazite have been found once in fractures. 21 refs., 17 figs.

  9. Mineralogical characterization of clays used in the structural ceramic industry in west of S. Paulo State, Brazil Caracterização mineralógica de argilas usadas na indústria de cerâmica estrutural no oeste do estado de S. Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    S. R. Teixeira

    2001-12-01

    Full Text Available Plasticity and the grain-size distribution of the raw material used to make structural bricks and roof tiles are very important to the production process. These two parameters and the mineral composition will define the quality and properties of the final product: color, mechanical resistance, water absorption, cracks, swell and shrink during drying and firing the ceramic pieces etc. In the Brazilian ceramic industry it is very common to mix together two or more different kinds of raw material to achieve the ceramic mass with the desired grain-size distribution. The objective of this work was to characterize the raw material collected at the floodplains of the Paraná and Paranapanema Rivers and the ceramic mass used by the ceramic industry in western São Paulo State, Brazil. Particle size distribution, organic matter and X-ray diffraction were used to study this material. The textural analysis indicates that the raw materials have the clay fraction ranging from 38.2% to 66.3%, the silt from 22.2% to 49.7% and the sand from 3.1% to 34.1%. The results indicate that all mixed raw materials have more clay in its composition than would be necessary. The organic matter ranges from 5 to 7%. All samples have kaolinite and many of them have smectites, HIV and mica. Gibbsite, iron and titanium oxides, and quartz are also identified. One of the samples (yellow is rich in goethite.A plasticidade e a granulometria da massa cerâmica são dois parâmetros importantes para o processo de produção de tijolos e telhas. Estes dois parâmetros e a composição mineralógica definirão a qualidade e propriedades (cor, resistência mecânica, absorção de água, trincas, mudanças nas dimensões durante a secagem e queima, etc. do produto final. Na indústria cerâmica brasileira é comum misturar dois ou mais tipos de "barro" para se obter a massa cerâmica com a granulometria e plasticidade desejada. O objetivo deste trabalho foi caracterizar a matéria prima

  10. Petrography, diagenesis and geotechnical properties of the El-Rufuf Formation (Thebes Group), El-Kharga Oasis, Egypt

    Science.gov (United States)

    Bashed, M. A.; Sediek, K. N.

    1997-10-01

    The El-Rufuf Formation (Thebes Group) outcrops widely in Egypt. It is quarried as an ornamental building stone and used as slabs in walls and floors. It is also important in foundation construction. The geotechnical behaviour of these rocks is commonly related to stratigraphical position, controlled by their petrography and textural and diagenetic features. The El-Rufuf Formation of Naqb Assiut, El-Kharga Oasis, consists of 63 m of micritic and neomorphosed limestones which are marly at the base. Microfacies analysis of these limestones indicates an inner to middle shelf open marine environment. The most common diagenetic features are neomorphism, silicification, dissolution and stylolites. There are clear relationships between the measured compressive strength of rocks and the facies and diagenetic features. Neomorphic sparry limestone has the lowest compressive strength, while cherty biomicritic limestone shows the highest values. Micritic and biomicritic limestones show intermediate values. Some anisotropism of compressive strength values is recorded in the stylolitic limestones and in the foliated marly part of the formation. The present study reveals that the El-Rufuf limestones, according to Deere's (1968) classification, are low to medium strength rocks with low modulus ratios (DL-CL), while the marly parts of the formation are low strength rocks with low modulus ratios (EL). The rocks of the marly part of the El-Rufuf Formation are unstable with regard to water and therefore have a zero softness coefficient.

  11. What does the fine-scale petrography of IDPs reveal about grain formation and evolution in the early solar system?

    Science.gov (United States)

    Bradley, John

    1994-01-01

    The 'pyroxene' interplanetary dust particles (IDP's) may be the best samples for investigation of primordial grain-forming reactions because they appear to have experienced negligible post-accretional alteration. They are likely to continue to yield information about gas-to-solid condensation and other grain-forming reactions that may have occurred either in the solar nebular or presolar interstellar environments. An immediate challenge lies in understanding the nanometer-scale petrography of the ultrafine-grained aggregates in 'pyroxene' IDP's. Whether these aggregates contain components from diverse grain-forming environments may ultimately be answered by systematic petrographic studies using electron microscopes capable of high spatial resolution microanalysis. It may be more difficult to decipher evidence of grain formation and evolution in 'olivine' and 'layer silicate' IDP's because they appear to have experienced post-accretional alteration. Most of the studied 'olivine' IDPs have been subjected to heating and equilibration, perhaps during atmospheric entry, while the 'layer silicate' IDP's have experienced aqueous alteration.

  12. Diagenetic Mineralogy at Gale Crater, Mars

    Science.gov (United States)

    Vaniman, David; Blake, David; Bristow, Thomas F.; Chipera, Steve; Gellert, Ralf; Ming, Douglas; Morris, Richard; Rampe, E. B.; Rapin, William

    2015-01-01

    Three years into exploration of sediments in Gale crater on Mars, the Mars Science Laboratory rover Curiosity has provided data on several modes and episodes of diagenetic mineral formation. Curiosity determines mineralogy principally by X-ray diffraction (XRD), but with supporting data from thermal-release profiles of volatiles, bulk chemistry, passive spectroscopy, and laser-induced breakdown spectra of targeted spots. Mudstones at Yellowknife Bay, within the landing ellipse, contain approximately 20% phyllosilicate that we interpret as authigenic smectite formed by basalt weathering in relatively dilute water, with associated formation of authigenic magnetite as in experiments by Tosca and Hurowitz [Goldschmidt 2014]. Varied interlayer spacing of the smectite, collapsed at approximately 10 A or expanded at approximately 13.2 A, is evidence of localized diagenesis that may include partial intercalation of metal-hydroxyl groups in the approximately 13.2 A material. Subsequent sampling of stratigraphically higher Windjana sandstone revealed sediment with multiple sources, possible concentration of detrital magnetite, and minimal abundance of diagenetic minerals. Most recent sampling has been of lower strata at Mount Sharp, where diagenesis is widespread and varied. Here XRD shows that hematite first becomes abundant and products of diagenesis include jarosite and cristobalite. In addition, bulk chemistry identifies Mg-sulfate concretions that may be amorphous or crystalline. Throughout Curiosity's traverse, later diagenetic fractures (and rarer nodules) of mm to dm scale are common and surprisingly constant and simple in Ca-sulfate composition. Other sulfates (Mg,Fe) appear to be absent in this later diagenetic cycle, and circumneutral solutions are indicated. Equally surprising is the rarity of gypsum and common occurrence of bassanite and anhydrite. Bassanite, rare on Earth, plays a major role at this location on Mars. Dehydration of gypsum to bassanite in the

  13. Mineralogy and Microbial Survival During Carbon Sequestration

    Science.gov (United States)

    Santillan, E. U.; Gilbert, K.; Bennett, P.

    2010-12-01

    When CO2 is sequestered in deep saline aquifers, a region of high dissolved CO2 surrounds the supercritical CO2 plume. While microbial life will doubtless be perturbed as a result of the CO2 injection, survival may be possible in the region of high dissolved CO2. Mineralogy of the aquifer may influence which microorganisms survive by providing substrates for lithotrophic microbes and determining the competitiveness of microbes in the subsurface. Iron-rich minerals like hematite, for example, provide a terminal electron acceptor for dissimilatory iron reducing bacteria (DIRB) that is essential for their respiration. Mineral dissolution may also provide toxicity for microbes providing increased concentration of toxic elements like Al in groundwater as a result of feldspar or clay dissolution. We investigated, Shewanella oneidensis MR-1, a model DIRB, grown in the presence of representative minerals found in deep saline aquifers including carbonate minerals, silicate minerals, and clays. Cultures were subjected to 20 to 25 atm of CO2 at 30° C for 2 to 8 hours in modified Parr reactors. Cultures were plated to determine viability after CO2 stress and imaged using environmental scanning electron microscopy (ESEM). Preliminary results show that MR-1 grown in the presence of dolomite and subjected to 20 atm of CO2 for 2 hours results in decreased viability in comparison to cells grown with hematite or no minerals present. This suggests there is selective toxicity with dolomite, possibly due to an increase in dissolved Mg. Additionally, ESEM imaging revealed a change in cell morphology from plump rods to thin, pointy cells after incubating in CO2 for 8 hours at 25 atm. This change in cell morphology may be the result of cell damage due to CO2 stress. This material is based upon work supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic

  14. Novel Visualization Approaches in Environmental Mineralogy

    Science.gov (United States)

    Anderson, C. D.; Lopano, C. L.; Hummer, D. R.; Heaney, P. J.; Post, J. E.; Kubicki, J. D.; Sofo, J. O.

    2006-05-01

    Communicating the complexities of atomic scale reactions between minerals and fluids is fraught with intrinsic challenges. For example, an increasing number of techniques are now available for the interrogation of dynamical processes at the mineral-fluid interface. However, the time-dependent behavior of atomic interactions between a solid and a liquid is often not adequately captured by two-dimensional line drawings or images. At the same time, the necessity for describing these reactions to general audiences is growing more urgent, as funding agencies are amplifying their encouragement to scientists to reach across disciplines and to justify their studies to public audiences. To overcome the shortcomings of traditional graphical representations, the Center for Environmental Kinetics Analysis is creating three-dimensional visualizations of experimental and simulated mineral reactions. These visualizations are then displayed on a stereo 3D projection system called the GeoWall. Made possible (and affordable) by recent improvements in computer and data projector technology, the GeoWall system uses a combination of computer software and hardware, polarizing filters and polarizing glasses, to present visualizations in true 3D. The three-dimensional views greatly improve comprehension of complex multidimensional data, and animations of time series foster better understanding of the underlying processes. The visualizations also offer an effective means to communicate the complexities of environmental mineralogy to colleagues, students and the public. Here we present three different kinds of datasets that demonstrate the effectiveness of the GeoWall in clarifying complex environmental reactions at the atomic scale. First, a time-resolved series of diffraction patterns obtained during the hydrothermal synthesis of metal oxide phases from precursor solutions can be viewed as a surface with interactive controls for peak scaling and color mapping. Second, the results of

  15. Microstructure, porosity and mineralogy around fractures in Olkiluoto bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Kuva, J. (ed.); Myllys, M.; Timonen, J. [Jyvaeskylae Univ. (Finland); Kelokaski, M.; Ikonen, J.; Siitari-Kauppi, M. [Helsinki Univ. (Finland); Lindberg, A. [Geological Survey of Finland, Espoo (Finland); Aaltonen, I.

    2012-01-15

    3D distributions of minerals and porosities were determined for samples that included waterconducting fractures. The analysis of these samples was performed using conventional petrography methods, electron microscopy, C-14-PMMA porosity analysis and X-ray tomography. While X-ray tomography proved to be a very useful method when determining the inner structure of the samples, combining tomography results with those obtained by other methods turned out to be difficult without very careful sample preparation design. It seems that the properties of rock around a water-conducting fracture depend on so many uncorrelated factors that no clear pattern emerged even for rock samples with a given type of fracture. We can conclude, however, that a combination of different analysis methods can be useful and used to infer novel structural information about alteration zones adjacent to fracture surfaces. (orig.)

  16. Fall, mineralogy and chemistry of Nathdwara H6 chondrite

    Institute of Scientific and Technical Information of China (English)

    V. Agarwal; G. Parthasarathy; M.S. Sisodia; N. Bhandari

    2014-01-01

    We report here for the first time the composition and mineralogical studies on a new meteorite, which fell in Dhayala ki Chappar (24º58'N, 73º48'27'' E) 5 km NW of Nathdwara in south Rajasthan, India, on Dec. 25th, 2012. Mineralogical and compositional studies were carried out on a representative piece of the Nathdwara meteorite sample. The mineralogical composition of the meteorite has been found to be olivine (42-45 vol.%), feldspar (10-15 vol.%), orthopyroxene (23-25 vol.%), troilite (6-8 vol.%), and titanium bearing minerals (6-8 vol.%). Our investigations show that the Nathdwara meteorite belongs to H6 group of ordinary chondrites.

  17. Fall, mineralogy and chemistry of Nathdwara H6 chondrite

    Directory of Open Access Journals (Sweden)

    V. Agarwal

    2014-05-01

    Full Text Available We report here for the first time the composition and mineralogical studies on a new meteorite, which fell in Dhayala ki Chappar (24°58′N, 73°48′27″E 5 km NW of Nathdwara in south Rajasthan, India, on Dec. 25th, 2012. Mineralogical and compositional studies were carried out on a representative piece of the Nathdwara meteorite sample. The mineralogical composition of the meteorite has been found to be olivine (42−45 vol.%, feldspar (10−15 vol.%, orthopyroxene (23−25 vol.%, troilite (6−8 vol.%, and titanium bearing minerals (6−8 vol.%. Our investigations show that the Nathdwara meteorite belongs to H6 group of ordinary chondrites.

  18. Mineralogy of the Culebra Dolomite Member of the Rustler Formation

    Energy Technology Data Exchange (ETDEWEB)

    Sewards, T.; Williams, M.L.; Keil, K. (New Mexico Univ., Albuquerque, NM (USA))

    1991-03-01

    This report characterizes the mineralogy of the Culebra Member of the Rustler Formation based on studies of samples from cores of eight boreholes surrounding the WIPP repository. This investigation has three main goals: to obtain accurate modal compositions of all the samples selected; to investigate both the lateral and vertical variation of the mineralogy of the Culebra unit; and, to characterize water-bearing fracture surfaces in particular detail. The Culebra Dolomite member of the Rustler Formation is mineralogically and texturally heterogeneous, both vertically and horizontally. Although the predominant mineral is dolomite, important constituents of the formation are clay, quartz, gypsum, and calcite. Trace minerals include halite, phyllosilicates of metamorphic origin, feldspar, and pyrite. 24 refs., 90 figs., 27 tabs.

  19. Petrography and petrology of Quaternary volcanic rocks from Ghezel Ghaleh, northwest Qorveh

    Directory of Open Access Journals (Sweden)

    Alireza Bajelan

    2014-10-01

    disequilibrium textures in the minerals (zoned state, solution and twinning shows a magmatic contamination in mixing volcanic mass. References Aldanmaz, E., Koprubasi, N.O., Gurer, F., Kaymakci, N. and Gournaud, A., 2006. geochemical constraints on the Cenozoic, OIB-type alkaline volcanic rocks of NW Turkey: implications for mantle sources and melting processes. Lithos, 86 (1–2 pp. 50–76. De La Roche, H., Leterrier, J., Grand claude, P. and Marchel, M., 1980. A classification of volcanic and plutonic rocks using R1-R2 diagrams and major elements, it’s relationships with current nomenclature. Chemical Geology, 29(1-4: 183–210. Hirschman, M., 1998. Origin of the transgressive granophyres in the layered series of the Skaergaard intrusion, East Greenland. In: D.J. Geist and C.M. White (Editors.. Journal of Volcanology and Geothermal Research, 52(1-3: 185–207. Irvine, T.N. and Baragar, W.R.A., 1971. A guide to chemical classification of the common volcanic rocks. Canadian Journal of Earth Sciences, 5(8: 448– 523. Moein Vaziri, H., 1997. The history of magmatism in Iran. Tehran University Press, Tehran, 440 pp. (in Persian Moein Vaziri, H. and Aminsobhani, A., 1985. Study of young volcanic region being involved in –Qorveh- Takab. Tehran University Press, Tehran, 350 pp. (in Persian Pearce, J.A. and Cann, J.R., 1973. Tectonic setting of basaltic volcanic rocks determind using traceelements analysis. Earth and Planetary Science Letters, 19(2: 290– 300. Pearce, J.A. and Norry, M.J., 1979. Petrogenetic implications of Ti, Zr, Y and Nb variation in volcanic rocks. Contributions to Mineralogy and Petrology, 69(1: 33– 47. Shelley, D. (Translated by Mohamadzadeh, F., 1993. Igneous and metamorphic rocks under the microscope, classification, textures, microstructures and mineral preferred-orientations. Chapman and Hall, Unwin, London, 445 pp.

  20. Ceramic raw materials from the State of Maranhão, Brazil. Part 1: chemical and mineralogical characterization and technological properties of clays from São Luis, Rosário, Pinheiro and Mirinzal Matérias-primas cerâmicas do Estado do Maranhão. Parte 1: caracterização químico-mineralógica e propriedades tecnológicas de argilas dos municípios de São Luís, Rosário, Pinheiro e Mirinzal

    Directory of Open Access Journals (Sweden)

    José Manuel Rivas Mercury

    2012-12-01

    Full Text Available This work involved the characterization of clays collected in the municipalities of São Luis, Rosário, Pinheiro and Mirinzal (state of Maranhão, Brazil, based on specific mass, specific surface area, cation exchange capacity (CEC, particle size distribution, X-ray diffraction (XRD, differential thermal analysis (DTA, thermogravimetric analysis (TG-DTA and Atterberg limits. Technological tests for ceramic applications were also carried out on compacts pressed under 20 MPa and heat-treated at 850, 950, 1050, 1150 and 1250ºC. Our results indicated that two of the clays composed of kaolinite, quartz, and anatase with high plasticity limits, have excellent properties and can be used in the whiteware industry. The other ones are red-firing clays and have a mineralogical composition of quartz, kaolin, feldspar, montmorillonite, hematite and goethite. The latter showed low and moderate values of plasticity, which makes them suitable for the production of heavy clay products.Nesse trabalho, foram caracterizadas algumas argilas coletadas nos municípios de São Luís, Rosário, Pinheiro e Mirinzal. A caracterização foi realizada através dos ensaios de difração de raios X, massa específica real, capacidade de troca de cátions (CTC, área superficial, distribuição granulométrica, análise química, análise térmica (TG-DTA e limites de Atterberg. Ensaios tecnológicos de retração linear, antes e após a queima, absorção de água e tensão de ruptura a flexão, em três pontos, foram realizados em corpos de prova prensados uniaxialmente a 20 MPa e tratados termicamente em 850, 950, 1050, 1150 e 1250ºC. Os resultados obtidos permitiram identificar duas argilas de queima branca, constituídas de quartzo, caolim, feldspato e anatásio, com excelentes propriedades para uso em cerâmica branca. As restantes são queima vermelha e possuem composição mineralógica de quartzo, caolim, feldspato, montmorilonita, hematita e goetita. Estas

  1. MINERALOGICAL FEATURES OF ULTRAMAFIC HYPOXENOLITHS IN ALKALI-RICH PORPHYRY

    Institute of Scientific and Technical Information of China (English)

    LIU Xianfan; YANG Zhengxi; LIU Jiaduo; ZHANG Chengjiang; WU Dechao; LI Youguo

    2003-01-01

    Ultramafic hypoxenoliths found in the alkali-rich porphyry in the Liuhe Village, Heqing, Yunnan,China, are of great significance in understanding the origin and evolution of the porphyry. This paper discusses the mineralogical features of the hypoxenoliths. It shows that the xenoliths are characterized by the upper mantle rocks modified to certain extent by the enriched mantle fluid metasomatism in the mantle environment, with the enriched mantle property of Iow-degree partial melting. This constitutes the important mineralogical evidence for the petrogenesis and mineralization of alkali-rich porphyry.

  2. Notas de mineralogía parte I

    OpenAIRE

    Henao Vásquez, Martha

    1987-01-01

    Resumen: El presente trabajo, llamado "Notas de mineralogía, parte I", es un resumen y recopilación de temas de varios textos, notas y de la misma experiencia docente. Existen dos razones que motivan la elaboración de estas notas, y son: en primer lugar, un requisito parcial para la promoción a la categoría de Profesor Asistente de la Facultad de Ciencias, Universidad Nacional, y en segundo, por ser la mineralogía una asignatura esencial en programas tales como geología, ingeniería de geol...

  3. Mineralogy: a modern approach to teaching a traditional discipline

    Science.gov (United States)

    Cook, G. W.

    2011-12-01

    Mineralogy has traditionally been a primary component in undergraduate geoscience curriculum. In recent years, there has been a trend in which mineralogy and petrology have been combined into Earth Materials courses. This is unfortunate as these disciplines each have much to offer students, and content once considered essential is eliminated out of necessity. Mineralogy is still fundamental to students' understanding of the Earth and Earth processes. Using a modern approach to time-honored concepts, I teach a quarter-long Introductory Mineralogy class offered through the Scripps Institution of Oceanography at the University of California, San Diego. Student evaluations of this course unequivocally indicate a high degree of learning and interest in the material, confirming that mineralogy continues to be a valuable class into the 21st century. While much of the content remains similar to what has been taught over the last century, my strategy involves a well-balanced approach to old and new. The first third of the course is background including the relevance of mineralogy, crystal chemistry, and crystallography; the second third of the course is systematic mineralogy using the Dana system; the last third of the course is devoted to understanding optical mineralogy, using modern analytical equipment such as XRD and SEM, and learning to use the petrographic microscope. Throughout the quarter, a strong emphasis is placed on the importance of hand-sample identification. Field work, traditionally not emphasized in mineralogy courses, has been re-introduced to the curriculum. I use modern technology to facilitate and support student learning. A lecture-based approach is employed with carefully crafted and organized PowerPoint presentations. PowerPoint lectures can be effective and highly engaging. The key is to ensure that the lectures are not overly reliant on text, instead relying on diagrams, charts, photos, and embedded media such as 3-D animations (ex. to teach

  4. Augen gneisses versus Augen gneisses from the Jaguaribeana Belt, northeastern region from Brazil: stratigraphy, geochemistry and U-Pb ages; Augen gnaisses versus Augen gnaisses da faixa Jaguaribeana, NE do Brasil: estratigrafia, geoquimica e idades U-Pb

    Energy Technology Data Exchange (ETDEWEB)

    Sa, Jaziel Martins; Silva, Elvis Roberto da [Rio Grande do Norte Univ., Natal, RN (Brazil). Dept. de Geologia; Bertrand, Jean Michel [Savoie Univ., 73 - Chambery (France). Lab. de Geodynamique; Leterrier, Jacques [Centre National de la Recherche Scientifique (CNRS), 54 - Nancy (France). Centre de Recherches Petrographiques et Geochimiques

    1997-12-31

    The Jaguaribeana Belt is located at Borborema Province, Ceara State, Brazil and this study aims to present Uranium-Lead (U-Pb) data and the augen gneisses petrographic and geochemical study of the Jaguaribe Belt, and to realize comparisons between these and the augen gneisses from the Oros Belt. It describes the geological characteristics of this region, the augen gneisses petrography and geochemical data and the U-Pb method results for a discussion about the augen gneisses from the Oros and Jaguaribe Belt 10 refs., 6 figs.

  5. Fluid Inclusion Petrography:A Discussion%流体包裹体岩相学的一些问题探讨

    Institute of Scientific and Technical Information of China (English)

    卢焕章

    2014-01-01

    Petrographic microscopy of a rock and mineral sample is the first and at same time essential step of any fluid inclusion study. Fluid inclusion is a paleogeofluid trapped in minerals. To distinguish the primary and secondary fluid inclusions is an essential step, then a proper interpretation of fluid inclusions can be made only when textural relationship between fluid inclusion and the host mineral and rock are considered. This is the major subject for fluid inclusion petrography. A few methods to describe the essential part of fluid inclusion petrography are included.%流体包裹体岩相学是流体包裹体研究的基础和前提。在流体包裹体研究过程中,我们十分重视和强调选择什么样的流体包裹体去做测温和分析。在流体色裹体岩相学中区分原生和次生包裹体十分重要。只有选择了原生流体包裹体后才能进行显微测温学和流体包裹体成分分析。这种选择包裹体的过程(或步骤),确定流体包裹体的分类以及在显微镜下观察流体包裹体捕获后的変化,是流体包裹体岩相学(Fluid inclusion petrography)最主要的内容。本文叙述流体包裹体岩相学的内容和区分原生和次生流体包裹体的一些实例和方法,阐述了流体包裹体与主矿物之关系。

  6. Applied Mineralogy: A Critical Review and 5-Year Plan for Its Strategic Use within Teck

    OpenAIRE

    Nichola Ann McKay

    2015-01-01

    A strategic business case analysis and five-year plan are presented here for the Teck Applied Mineralogy group in Trail, British Columbia. Applied mineralogy is a key technical competency for Teck Resources that adds value in the fields of process mineralogy supporting optimization at the mining operations, and in ore characterization supporting evaluation of greenfield and brownfield properties. This 2016-2020 business plan for the applied mineralogy group is cognisant of the current mining ...

  7. Mineralogy and geochemistry of bauxite and bentonite deposits from Mozambique

    NARCIS (Netherlands)

    Dos Muchangos, A.C.

    2000-01-01

    Results of mineralogical and geochemical studies of bauxites, kaolinitic clays and bentoniteS from Mozambique are presented in this thesis. The bauxite and kaolinitic clay deposits in Penhalonga area (in the central western part of Mozambique) are associated with Precambrian magmatic rocks and the b

  8. Models as an Aid to Courses in Crystallography and Mineralogy.

    Science.gov (United States)

    Brady, K. T.

    1983-01-01

    Three models used in teaching crystallography/mineralogy at the University of Technology (Papua, New Guinea) are described. These include stereographic projection model, optical indicatrix models for Istropic/Anisotropic minerals, and model showing effect of anisotropic minerals under crossed polars. Photographs of the models are also included.…

  9. Environmental factors of urinary stones mineralogy, Khouzestan Province, Iran

    Science.gov (United States)

    Zarasvandi, Alireza; Carranza, E. J. M.; Heidari, Majid; Mousapour, Esmaeil

    2014-09-01

    Urinary stone diseases in the Khouzestan province (southwest Iran) are growing in number and it required extensive studies on various factors of the urinary stones formation in this province. In this research, in addition to distribution of urinary stones in different areas of province, the role of bioenvironmental (race), climate (temperature) and geology (water hardness) factors in urinary stones diversity has been studied. Mineralogical studied using X-ray diffraction showed that uricite and whewellite are the most frequency mineral phases. Struvite, Cystine, hydroxyapatite, weddellite, and Niahite can be observed as urinary stones, too. These data show that the urinary stone in the Khouzestan province can divide into 7 groups: calcium oxalate, phosphate, calcium oxalate/ phosphate, Urate, Urate/calcium, Urate/calcium oxalate/phosphate, Cystine/calcium oxalate. Also the results which attained from temperature effect investigation on the mineralogy of urinary stones, confirms that from Mediterranean sub-humid climates (northeastern area) to warm and dry climates (south and southwest area), calcium oxalate stones and urate stones concentration decreases and increases respectively. Comparison of data related to the drinking water hardness and mineralogy of urinary stones in different areas of Khouzestan province show that the combination of drinking water (especially water hardness) affects mineralogy of urinary stones in some areas (such az Ramhormoz and Hendijan). Finally, the data suggest that frequency of calcium oxalate in women is more than that of men. Moreover, there is direct relationship between the age (>45 years) and the increase in frequency of Urate minerals.

  10. Variations in the Fe mineralogy of bright Martian soil

    Science.gov (United States)

    Murchie, Scott; Mustard, John; Erard, Stephane; Geissler, Paul; Singer, Robert

    1993-01-01

    Bright regions on Mars are interpreted as 'soil' derived by chemical alteration of crustal rocks, whose main pigmentary component is ferric oxide or oxyhydroxide. The mineralogy and mineralogic variability of ferric iron are important evidence for the evolution of Martian soil: mineralogy of ferric phases is sensitive to chemical conditions in their genetic environments, and the spatial distributions of different ferric phases would record a history of both chemical environments and physical mixing. Reflectance spectroscopic studies provide several types of evidence that discriminate possible pigmentary phases, including the position of a crystal field absorption near 0.9 microns and position and strengths of absorptions in the UV-visible wavelength region. Recent telescopic spectra and laboratory measurements of Mars soil analogs suggest that spectral features of bright soil can be explained based on a single pigmentary phase, hematite (alpha-Fe2O3), occurring in both 'nanophase' and more crystalline forms. Here we report on a systematic investigation of Martian bright regions using ISM imaging spectrometer data, in which we examined spatial variations in the position and shape of the approximately 0.9 microns absorption. We found both local and regional heterogeneities that indicate differences in Fe mineralogy. These results demonstrate that bright soils do not represent a single lithology that has been homogenized by eolian mixing, and suggest that weathering of soils in different geologic settings has followed different physical and chemical pathways.

  11. Mineralogy and geochemistry of density-separated Greek lignite fractions

    NARCIS (Netherlands)

    Iordanidis, A.; Doesburg, van J.D.J.

    2006-01-01

    In this study, lignite samples were collected from the Ptolemais region, northern Greece, homogenized, crushed to less than I nun, and separated in three density fractions using heavy media. The mineralogical investigation of the density fractions showed a predominance of pyrite in the light fractio

  12. Petrography and mineral chemistry of carbonatites and mica-rich rocks from the Araxá complex (Alto Paranaíba Province, Brazil

    Directory of Open Access Journals (Sweden)

    GIANBOSCO TRAVERSA

    2001-03-01

    Full Text Available The Araxá complex (16 km² comprises carbonatites forming a central core and a complex network of concentric and radial dykes as well as small veins; additionally, it includes mica-rich rocks, phoscorites and lamprophyres. Fenites also occur and are represented by Proterozoic quartzites and schists of the Araxá Group. The petrographic study of 130 borehole samples indicates that the complex is basically made up by two rock-types, carbonatites and mica-rich rocks, and subordinately by a third unit of hybrid composition. Carbonatites range chemically in composition, the most abundant type being magnesiocarbonatites. Dolomite and calcite correspond to the chief constituents, but other carbonate phases, including the Ce-group RE minerals, are also recognized. Phosphates and oxides are widespread accessories whereas silicate minerals consist of olivine, clinopyroxene, mica and amphibole. Mica-rich rocks are represented by abundant glimmeritic rocks and scarce cumulitic phlogopite-, olivine- and diopside-bearing pyroxenites. Hybrid rocks mainly contain phlogopite and tetraferriphlogopite as cumulus and intercumulus phases, respectively; carbonate minerals may also be found. Chemical data indicate that the carbonatites are strongly enriched in REE and have lower contents of Nb, Zr, V, Cr, Ni and Rb compared to the mica-rich rocks. The higher K, Nb and Zr contents of the latter rocks are believed to be related to metasomatic processes (glimmeritization of the pyroxenites. Similar REE patterns for carbonatites and mica-rich rocks seem to suggest that they are related to a single parental magma, possibly of ijolitic composition. Steep LREE/HREE fractionation and high sigmaREE content of some carbonatite samples would be explained by hydrothermal and supergenic processes.O complexo de Araxá (16 km² é constituído por carbonatitos na forma de um núcleo central e de complexa rede de diques concêntricos e radiais, além de pequenos veios; adicionalmente, ele contém rochas ricas em mica, foscoritos e lamprófiros. Fenitos também ocorrem e estão representados principalmente por quartzitos e xistos proterozóicos do Grupo Araxá. O estudo petrográfico de 130 amostras de testemunhos de sondagem indica que o complexo reúne basicamente dois tipos litológicos, carbonatitos e rochas ricas em mica, e, subordinadamente, um terceiro de composição híbrida. Carbonatitos apresentam composição química variável e têm magnésiocarbonatitos como o tipo mais abundante. Dolomita e calcita são os seus principais constituintes, mas outras fases carbonáticas, incluindo as pertencentes ao grupo dos carbonatos ricos em ETR, são também reconhecidas. Fosfatos e óxidos diversos caracterizam os acessórios mais comuns enquanto que os minerais silicáticos consistem de representantes dos grupos da olivina, clinopiroxênio, mica e anfibólio. As rochas ricas em mica reúnem abundantes glimmeritos e escassos piroxenitos cumuláticos portadores de quantidades variáveis de flogopita, olivina e diopsídio. As rochas híbridas contêm principalmente flogopita e tetraferriflogopita, respectivamente, como fases cumulus e intercumulus; minerais carbonáticos podem também estar presentes. Dados químicos indicam que os carbonatitos são fortemente enriquecidos em ETR e possuem teores mais baixos em Nb, Zr, V, Cr, Ni e Rb em relação às rochas mais ricas em mica. As concentrações mais altas em K, Nb e Zr dessas últimas poderiam ser atribuídas a processos metassomáticos (glimeritização que teriam afetado os piroxenitos. O comportamento similar dos ETR nos carbonatitos e nas rochas ricas em mica parece sugestivo de que essas litologias estão relacionadas a um mesmo magma parental, possivelmente de composição ijolítica. O pronunciado fracionamento ETRL/ETRP e os elevados teores em ETR de algumas amostras de carbonatitos poderiam estar ligados a processos de natureza hidrotermal ou mesmo supergênicos.

  13. Petrography and geochemistry of Oligocene bituminous coal from the Jiu Valley, Petrosani basin (southern Carpathian Mountains), Romania

    Energy Technology Data Exchange (ETDEWEB)

    Belkin, Harvey E.; Tewalt, Susan J. [U.S. Geological Survey, 956 National Center, Reston, VA 20192 (United States); Hower, James C. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); Stucker, J.D. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); University of Kentucky Department of Earth and Environmental Sciences, Lexington, KY 40506 (United States); O' Keefe, Jennifer M.K. [Morehead State University, Morehead, KY, 40351 (United States); Tatu, Calin A. [University of Medicine and Pharmacy, Department of Immunology, Clinical Laboratory No. 1, Pta. E. Murgu No. 2, RO-1900 Timisoara (Romania); Buia, Grigore [University of Petrosani, Department of Geology, University St. 20, RO-2675 Petrosani (Romania)

    2010-05-01

    Belt samples of Oligocene (Chattian) bituminous coal from 10 underground mines located in the Jiu Valley, Hunedoara County, Petrosani basin, Romania, have been examined and analyzed for proximate and ultimate analysis, major-, minor- and trace-element chemistry, organic petrography, and vitrinite reflectance. The mineral chemistry and mode of occurrence of trace elements also have been investigated using SEM and electron microprobe techniques. Twenty coal beds occur in the Jiu Valley and most of the samples are from bed no. 3, the most productive bed of the Dilja-Uricani Formation of Oligocene age. The Petrosani basin, oriented SW-NE, is 48-km long, 10-km wide at the eastern part and 2-km wide at the western part. The coal mines are distributed along the center of the valley generally following the Jiu de Vest River. Reflectance measurements indicate that the rank of the coals ranges from high-volatile B to high-volatile A bituminous. Overall, rank decreases from the southwest to the northeast. In bed no. 3, R{sub max} varies from 0.75% in the northeast to 0.93% in the southwest. Although, most Oligocene coals in Romania and adjacent countries are lignite in rank, the Jiu Valley bituminous coals have been affected by regional metamorphism and attending hydrothermal fluids related to the Alpine orogenic event. The coals are all dominated by vitrinite; resinite and funginite are important minor macerals in most of the coals. Pyrite and carbonate generally dominate the mineral assemblages with carbonate more abundant in the northwest. Siderite occurs as nodules and masses within the macerals (generally vitrinite). Dolomite and calcite occur as fracture fillings, plant-cell fillings, and in other authigenic forms. Late-stage fracture fillings are siderite, dolomite, calcite, and ankerite. In one instance, two populations of siderite ({proportional_to} 35 and {proportional_to} 45 wt.% FeO) plus ankerite fill a large fracture. Late-stage pyrite framboid alteration is Ni

  14. Biochemical Education in Brazil.

    Science.gov (United States)

    Vella, F.

    1988-01-01

    Described are discussions held concerning the problems of biochemical education in Brazil at a meeting of the Sociedade Brazileira de Bioquimica in April 1988. Also discussed are other visits that were made to universities in Brazil. Three major recommendations to improve the state of biochemistry education in Brazil are presented. (CW)

  15. Polishing surgical metal pieces, granulomatosis and mineralogical analysis.

    Science.gov (United States)

    Catinon, Mickaël; Chemarin, C; Roux, E; Cavalin, C; Rosental, P-A; Thivolet-Bejui, F; Vincent, M

    2016-08-01

    This report describes the case of a 44-year-old man with pulmonary nodules whose histological analysis initially suggested tuberculosis. The Mycobacterium tuberculosis (MT) culture was negative and a questionnaire revealed a professional activity of brushing and polishing surgical instruments without any protection for 7 years.  A mineralogical analysis by optical and electron microscopy was performed on both a healthy lung tissue biopsy and a lung nodule in a paraffin block. Electron microscopy analysis revealed the presence of metal particles (iron oxide, titanium oxide, aluminum oxide and steel) in both samples. This study suggests that mineralogical analysis combined with a questionnaire on dust exposure could help redirect the diagnosis of a dust-related disease.

  16. Fracture mineralogy of the Forsmark site. SDM-Site Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Sandstroem, Bjoern (Dept. of Earth Sciences, Univ. of Goeteborg (Sweden)); Tullborg, Eva-Lena (Terralogica AB, Graabo (Sweden)); Smellie, John (Conterra AB, Luleaa (Sweden)); MacKenzie, Angus B. (SUERC, Scottish Enterprise Technology Park, East Kilbride (United Kingdom)); Suksi, Juhani (Dept. of Chemistry, Univ. of Helsinki, Helsinki (Finland))

    2008-08-15

    Detailed investigations of the fracture mineralogy and altered wall rock have been carried out as part of the site characterisation programme between 2003 and 2007 at Forsmark. The results have been published in a number of P-reports and in contributions to scientific journals. This report summarises and evaluates the data obtained during the detailed fracture mineralogical studies. The report includes descriptions of the identified fracture minerals and their chemical composition. A sequence of fracture mineralisations has been distinguished and provides information of the low to moderate temperature (brittle) geological and hydrogeological evolution at the site. Special focus has been paid to the chemical and stable isotopic composition of calcite to obtain palaeohydrogeological information. Chemical analyses of bulk fracture filling material have been carried out to identify possible sinks for certain elements and also to reveal the presence of minor phases rich in certain elements which have not been possible to detect by X-ray diffraction (XRD). Statistical analysis of the mineralogy in fractures outside deformation zones (i.e. within fracture domains FFM01, FFM02, FFM03 and FFM06) have been carried out concerning variation of fracture mineral distribution at depth and in different fracture domains. Uranium contents and uranium-series isotopes have been analysed on fracture coating material from hydraulically conductive fractures. Such analyses are also available from the groundwaters and the results are combined in order to reveal recent (< 1 Ma) removal/deposition of uranium in the fracture system. The redox conditions in the fracture system have been evaluated based on mineralogical and chemical indicators as well as Moessbauer analyses

  17. Mineralogy and cooling history of magnesian lunar granulite 67415

    Science.gov (United States)

    Takeda, Hiroshi; Miyamoto, Masamichi

    1993-01-01

    Apollo granulite 67415 was investigated by mineralogical techniques to gain better understanding of cooling histories of lunar granulities. Cooling rates were estimated from chemical zoning of olivines in magnesian granulitic clasts by computer simulation of diffusion processes. The cooling rate of 10 deg C/yr obtained is compatible with a model of the granulite formation, in which the impact deposit was cooled from high temperature or annealed, at the depth of about 25 m beneath the surface.

  18. Mineralogical and geological study of quaternary deposits and weathering profiles

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gi Young; Lee, Bong Ho [Andong National Univ., Andong (Korea, Republic of)

    2004-01-15

    Movement history of a quaternary reverse fault cutting marine terrace deposit and tertiary bentonite in the Yangnammyon, Gyoungju city was studied by the mineralogical and microtextural analysis of the fault clays and weathered terrace deposits. Two types of fault clays were identified as greenish gray before the deposition of the marine terrace deposits and reddish brown after deposition. Greenish gray fault clay is composed mostly of smectite probably powdered from bentonite showing at least two events of movement from microtextures. After the bentonite was covered by quaternary marine gravel deposits, the reverse fault was reactivated cutting marine gravel deposits to form open spaces along the fault plane which allowed the hydrological infiltration of soil particles and deposition of clays in deep subsurface. The reddish brown 'fault' clays enclosed the fragments of dark brown ultrafine varved clay, proving two events of faulting, and slicken sides bisecting reddish brown clays suggest another faulting event in the final stage. Mineralogical and microtextural analysis of the fault clay show total five events of faulting, which had not been recognized even by thorough conventional paleoseismological investigation using trench, highlighting the importance of microtextural and mineralogical analysis in paleoseismology.

  19. Martian Surface Mineralogy from Rovers with Spirit, Opportunity, and Curiosity

    Science.gov (United States)

    Morris, Richard V.

    2016-01-01

    Beginning in 2004, NASA has landed three well-instrumented rovers on the equatorial martian surface. The Spirit rover landed in Gusev crater in early January, 2004, and the Opportunity rover landed on the opposite side of Mars at Meridian Planum 21 days later. The Curiosity rover landed in Gale crater to the west of Gusev crater in August, 2012. Both Opportunity and Curiosity are currently operational. The twin rovers Spirit and Opportunity carried Mossbauer spectrometers to determine the oxidation state of iron and its mineralogical composition. The Curiosity rover has an X-ray diffraction instrument for identification and quantification of crystalline materials including clay minerals. Instrument suites on all three rovers are capable of distinguishing primary rock-forming minerals like olivine, pyroxene and magnetite and products of aqueous alteration in including amorphous iron oxides, hematite, goethite, sulfates, and clay minerals. The oxidation state of iron ranges from that typical for unweathered rocks and soils to nearly completely oxidized (weathered) rocks and soils as products of aqueous and acid-sulfate alteration. The in situ rover mineralogy also serves as ground-truth for orbital observations, and orbital mineralogical inferences are used for evaluating and planning rover exploration.

  20. Deciphering the depositional environment of the laminated Crato fossil beds (Early Cretaceous, Araripe Basin, North-eastern Brazil)

    DEFF Research Database (Denmark)

    Heimhofer, Ulrich; Ariztegui, Daniel; Lenniger, Marc

    2010-01-01

    The laminated limestones of the Early Cretaceous Crato Formation of the Araripe Basin (North-eastern Brazil) are world-famous for their exceptionally well-preserved and taxonomically diverse fossil fauna and flora. Whereas the fossil biota has received considerable attention, only a few studies...... bedded, pale to dark lamination. To obtain information on palaeoenvironmental conditions, sample slabs derived from three local stratigraphic sections within the Araripe Basin were studied using high-resolution multiproxy techniques including detailed logging, petrography, mu-XRF scanning and stable......-poor meteoric water source and support a continental freshwater setting for the Nova Olinda Member. The delta C-13 values, which are comparatively rich in C-13 (between -0.1 and +1.9 parts per thousand), are interpreted to reflect reduced throughflow of water in a restricted basin, promoting...

  1. Manaus, Brazil

    Science.gov (United States)

    2002-01-01

    The junctions of the Amazon and the Rio Negro Rivers at Manaus, Brazil. The Rio Negro flows 2300 km from Columbia, and is the dark current forming the north side of the river. It gets its color from the high tannin content in the water. The Amazon is sediment laden, appearing brown in this simulated natural color image. Manaus is the capital of Amazonas state, and has a population in excess of one million. The ASTER image covers an area of 60 x 45 km. This image was acquired on July 16, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA's Earth Science Enterprise, a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system.The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface

  2. An unpublished text of Jovellanos about mineralogy Notas inéditas de Jovellanos sobre mineralogía

    OpenAIRE

    Ordaz Gargallo, Jorge; Gutiérrez Claverol, Manuel; De Lorenzo Álvarez, Elena

    2012-01-01

    An unpublished manuscript of Gaspar Melchor de Jovellanos about the history of mineralogy, written during his captivity in Bellver Castle (Palma de Mallorca) is presented and analyzed. In this writing the importance of the chemical knowledge as a source of other branches of science and its applications in different fields of agriculture, mining and industry is considered. The author made a historical synthesis reviewing the men of science that contributed in a great extent to the advance of t...

  3. An unpublished text of Jovellanos about mineralogy Notas inéditas de Jovellanos sobre mineralogía

    Directory of Open Access Journals (Sweden)

    Jorge ORDAZ GARGALLO

    2012-01-01

    Full Text Available An unpublished manuscript of Gaspar Melchor de Jovellanos about the history of mineralogy, written during his captivity in Bellver Castle (Palma de Mallorca is presented and analyzed. In this writing the importance of the chemical knowledge as a source of other branches of science and its applications in different fields of agriculture, mining and industry is considered. The author made a historical synthesis reviewing the men of science that contributed in a great extent to the advance of the chemistry and mineralogy. The text clearly supports the new contributions of Lavoisier and other supporters of experimentation as a scientific method, which agrees with Jovellanos’ ideas about the development of the «useful» sciences for the progress of the countries.Se presenta y analiza un manuscrito inédito de Gaspar Melchor de Jovellanos sobre la historia de la mineralogía, que redactó durante su cautiverio en el Castillo de Bellver (Palma de Mallorca. En el escrito considera de gran importancia los conocimientos químicos como fuente de otras ramas del saber científico y sus aplicaciones en distintos ámbitos de la agricultura, minería e industria. El autor hace una síntesis histórica repasando los hombres de ciencia que en mayor medida contribuyeron al avance de la química y la mineralogía. El texto apoya claramente las nuevas aportaciones de Lavoisier y otros químicos partidarios de la experimentación como método científico, y es acorde con las ideas de Jovellanos acerca del cultivo de las ciencias «útiles» para el progreso de los pueblos.

  4. Chemical characterization, nano-particle mineralogy and particle size distribution of basalt dust wastes

    Energy Technology Data Exchange (ETDEWEB)

    Dalmora, Adilson C. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Institute for Environmental Assessment and Water Studies (IDÆA), Spanish National Research Council (CSIC), C/Jordi Girona 18-26, 08034 Barcelona (Spain); Ramos, Claudete G.; Oliveira, Marcos L.S. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Teixeira, Elba C. [Fundação Estadual de Proteção Ambiental Henrique Luis Roessler, Porto Alegre, RS (Brazil); Kautzmann, Rubens M.; Taffarel, Silvio R. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Brum, Irineu A.S. de [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Gonçalves, 9500. Bairro Agronomia. CEP: 91501-970 Porto Alegre, RS (Brazil); and others

    2016-01-01

    Understanding the geochemistry of basalt alteration is central to the study of agriculture systems. Various nano-minerals play an important role in the mobilization of contaminants and their subsequent uptake by plants. We present a new analytical experimental approach in combination with an integrated analytical protocol designed to study basalt alteration processes. Recently, throughout the world, ultra-fine and nano-particles derived from basalt dust wastes (BDW) during “stonemeal” soil fertilizer application have been of great concern for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the Nova Prata mining district in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/Energy Dispersive Spectroscopy (EDS)/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM/EDS), and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO{sub 2}, Al{sub 2}O{sub 3}, and Fe{sub 2}O{sub 3,} with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition, we have identified a number of trace metals such as Cd, Cu, Cr, and Zn, that are preferentially concentrated into the finer, inhalable, dust fraction and, thus, could present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano

  5. Chemical and mineralogical changes in a Brazilian Rhodic Paleudult under different land use and managements

    Directory of Open Access Journals (Sweden)

    Jessé Rodrigo Fink

    2014-08-01

    Full Text Available Changes in land use and management can affect the dynamic equilibrium of soil systems and induce chemical and mineralogical alterations. This study was based on two long-term experiments (10 and 27 years to evaluate soil used for no-tillage maize cultivation, with and without poultry litter application (NTPL and NTM, and with grazed native pasture fertilized with cattle droppings (GrP, on the chemical and mineralogical characteristics of a Rhodic Paleudult in Southern Brazil, in comparison with the same soil under native grassland (NGr. In the four treatments, soil was sampled from the 0.0-2.5 and 2.5-5.0 cm layers. In the air-dried fine soil (ADFS fraction (∅ < 2 mm, chemical characteristics of solid and liquid phases and the specific surface area (SSA were evaluated. The clay fraction (∅ < 0.002 mm in the 0.0-2.5 cm layer was analyzed by X-ray diffraction (XRD after treatments for identification and characterization of 2:1 clay minerals. Animal waste application increased the total organic C concentration (COT and specific surface area (SSA in the 0.0-2.5 cm layer. In comparison to NGr, poultry litter application (NTPL increased the concentrations of Ca and CECpH7, while cattle droppings (GrP increased the P and K concentrations. In the soil solution, the concentration of dissolved organic C was positively related with COT levels. With regard to NGr, the soil use with crops (NTM and NTPL had practically no effect on the chemical elements in solution. On the other hand, the concentrations of most chemical elements in solution were higher in GrP, especially of Fe, Al and Si. The Fe and Al concentrations in the soil iron oxides were lower, indicating reductive/complexive dissolution of crystalline forms. The X-ray diffraction (XRD patterns of clay in the GrP environment showed a decrease in intensity and reflection area of the 2:1 clay minerals. This fact, along with the intensified Al and Si activity in soil solution indicate dissolution of

  6. Chemical characterization, nano-particle mineralogy and particle size distribution of basalt dust wastes.

    Science.gov (United States)

    Dalmora, Adilson C; Ramos, Claudete G; Oliveira, Marcos L S; Teixeira, Elba C; Kautzmann, Rubens M; Taffarel, Silvio R; de Brum, Irineu A S; Silva, Luis F O

    2016-01-01

    Understanding the geochemistry of basalt alteration is central to the study of agriculture systems. Various nano-minerals play an important role in the mobilization of contaminants and their subsequent uptake by plants. We present a new analytical experimental approach in combination with an integrated analytical protocol designed to study basalt alteration processes. Recently, throughout the world, ultra-fine and nano-particles derived from basalt dust wastes (BDW) during "stonemeal" soil fertilizer application have been of great concern for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the Nova Prata mining district in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/Energy Dispersive Spectroscopy (EDS)/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM/EDS), and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO2, Al2O3, and Fe2O3, with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition, we have identified a number of trace metals such as Cd, Cu, Cr, and Zn, that are preferentially concentrated into the finer, inhalable, dust fraction and, thus, could present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano-particle mineralogy and chemical composition in

  7. Petrography, Geochemistry and Proposed Genesis of Ordovician Oolitic Iron Formation Members of the Lashkarak Formation, Eastern Alborz

    Directory of Open Access Journals (Sweden)

    Mansoore Maghsoudloo Mahalli

    2016-07-01

    Full Text Available Introduction Oolitic iron formations are sedimentary rocks with >5 vol.% oolites and >15 wt.% iron, corresponding to 21.4 wt.% Fe2O3 (Young, 1989; Petranek and Van Houten, 1997; Mucke and Farshad, 2005. In Iran, new iron oolite-bearing members have been identified in the Lashkarak Formation (lower-middle Ordovician in the Abarsej, Dehmola and Simehkuh sections, eastern Alborz (Ghobadi Pour et al., 2011. At present, the mineralogy and geochemistry of these members are not known. Consequently, research reported here was conducted to reveal the mineralogical and geochemical characteristics of Ordovician oolitic iron formationmembers and to discuss their genesis and economic importance. Materials and Analyses Field geology and sampling was carried out to collect 25 samples from the ooliticiron formation members in the Abarsej, Dehmola and Simehkuh section in eastern Alborz. Samples were prepared for polished-thin sections (n=10, XRD analysis (n=15. Whole-rock chemical analysis (n=15 by XRF for major elements and by ICP-ES for trace elements was performed by laboratories at the SarCheshmeh copper mine complex, Kerman, Iran. One sample was analyzed by SEM at the Wales Museum, UK. Results Microscopic studies show that the oolitic iron formation members are hosted by carbonate argillite rocks. They are mainly composed of oolites rather than pisoliths (small bodies somewhat larger and more irregular than oolites, whereas oolites have mainly ellipsoidal forms and locally spherical shapes. Most (6 oolites show banding with a central core. Simple oolites without a core are scarce. Mineralogically, oolites are mainly chamositic and hematitic in composition; goethite, pyrite and glauconite occur in traces and siderite is absent. Quartz, calcite and zircon are accessory minerals which are present in the groundmass. Geochemically, TFeO % of the oolitic iron formation horizons ranges from 8 to 48 % with an average of 21%. The CaO content ranges from 2 to 37% and

  8. New rare cave minerals from the Perolas-Santana karst system (Sào Paulo State, Brazil.

    Directory of Open Access Journals (Sweden)

    Forti Paolo

    2000-01-01

    Full Text Available The Perolas-Santana karst system (Sào Paulo State, Brazil has been partially studied from the mineralogical point of view. The present paper will contribute to the knowledge of the minerals in these caves, describing the occurrence of euhedral celestite crystals and of a rather rare mineral for a cavern environment: lithiophorite. Thanks to these new discoveries the Perolas-Santana karst system becomes one of the most important in Brazil from a mineralogical point of view. Finally, the result of the chemical analyses carried out on this newly discovered Monoxyhydroxide put in evidence a zonation in the distribution of the different elements which may be related to several subsequent depositional events characterized by solutions with a chemical content variable in time.

  9. Mineralogy and geochemistry of atmospheric particulates in western Iran

    Science.gov (United States)

    Ahmady-Birgani, Hesam; Mirnejad, Hassan; Feiznia, Sadat; McQueen, Ken G.

    2015-10-01

    This study investigates the mineralogy and physico-chemical properties of atmospheric particulates collected at Abadan (southwestern Iran) near the Persian Gulf coast and Urmia (northwestern Iran) during ambient and dust events over 6 months (winter 2011; spring 2012). Particle sizes collected were: TSP (total suspended particulates); PM10 (particulates Al, Mg, Na, Cl, P, S, Ca, K, Fe, Ti, and Si, mostly reflecting calcite, quartz, aluminosilicates, clays, gypsum and halite. Additionally, As, Pb, Zn, Mn, Sc, Nd, W, Ce, La, Ba and Ni were detected in TSP, PM10 and PM2.5 samples collected during dust events.

  10. Mineralogy of dust deposited during the Harmattan season in Ghana

    DEFF Research Database (Denmark)

    He, Changling; Breuning-Madsen, Henrik; Awadzi, Theodore W.

    2007-01-01

    In Ghana, a dust-laden Harmattan wind blows from the Sahara in the period November to March. Some of the dust is trapped in the vegetation, in lakes and other inland waters, and a little on the bare land, whereas the rest of the dust is blown further away to the Ivory Coast or out into the Atlantic....... This conclusion is supported by the clay mineralogy of the samples. However, the pH of the dust is significantly higher than that of the local soils, indicating that a substantial amount of the dust comes from the Sahara....

  11. Notas de mineralogía: parte II

    OpenAIRE

    Henao Vásquez, Martha

    2001-01-01

    El presente trabajo se ha realizado con el propósito de contribuir a la formación mineralógica de los estudiantes que cursan la asignatura N.5140 Mineralogía, de los programas curriculares de ingeniería de minas y metalurgia. Se sintetizan en él los rasgos característicos y descripciones particulares de las especies minerales de mayor importancia y significado, tanto económico como petrográfico, que ayudan sustancialmente en su caracterización e identificación. El modelo descriptivo que...

  12. Iron mineralogy across the oxycline of a lignite mine lake

    OpenAIRE

    Miot, Jennyfer; Lu, Shipeng; Morin, Guillaume; Adra, Areej,; Benzerara, Karim; Küsel, Kirsten

    2016-01-01

    International audience; Iron-rich pelagic aggregates of microbial origin named “iron snow” are formed in the water column of some acidic lignite mine lakes. We investigated the evolution of Fe mineralogy across the oxycline of the Lusatian lake 77, Germany at two sampling sites differing by their pH and mixing profiles. The central basin (CB) of this lake shows a dimictic water regime with a non-permanent anoxic deep layer and a homogeneous acidic pH all over the water column (pH 3). In contr...

  13. Mineralogy and arsenic mobility in arsenic-rich Brazilian soils and sediments

    Science.gov (United States)

    de Mello, J.W.V.; Roy, W.R.; Talbott, J.L.; Stucki, J.W.

    2006-01-01

    Background. Soils and sediments in certain mining regions of Brazil contain an unusually large amount of arsenic (As), which raises concerns that mining could promote increased As mobility, and thereby increase the risks of contaminating water supplies. Objectives. The purpose of t his study was to identify the most important factors governing As mobility in sediments and soils near three gold-mining sites in the State of Minas Gerais, Brazil. Methods. Surface and sub-surface soil samples were collected at those sites and characterized by chemical and mineralogical analyses. Oxalate (Feo) and citrate-bicarbonate-dithionite (Fed) iron contents were determined by atomic absorption spectroscopy (AAS). Arsenic mobilization was measured after incubating the samples in a 2.5 mM CaCl2 solution under anaerobic conditions for 1, 28, 56, 84, or 112 days. The solution concentrations of As, Fe, and Mn were then measured by inductively coupled plasma-mass spectrometry (ICP-MS) and AAS, respectively. Results and Discussion. Results indicated that As mobilization is largely independent of both the total As and the Feo/Fed ratio of the solid phase. Soluble As is roughly controlled by the Fe (hydr)oxide content of the soil, but a closer examination of the data revealed the importance of other highly weathered clay minerals and organic matter. Large amounts of organic matter and a low iron oxide content should favor As leaching from soils and sediments. Under reducing conditions, As is mobilized by the reductive dissolution of Fe and/or Mn oxides. However, released As may be readsorbed depending on the sorptive properties of the soil. Gibbsite is particularly effective in adsorbing or readsorbing As, as is the remaining unreduced fraction of the iron (hydr)oxides. Conclusion and Outlook. In general, low soluble As is rel ated to the presence of gibbsite, a large amount of iron oxides, and a lack of organic matter in the solid phase. This has environmental significance because

  14. Mineralogical, chemical and toxicological characterization of urban air particles.

    Science.gov (United States)

    Čupr, Pavel; Flegrová, Zuzana; Franců, Juraj; Landlová, Linda; Klánová, Jana

    2013-04-01

    Systematic characterization of morphological, mineralogical, chemical and toxicological properties of various size fractions of the atmospheric particulate matter was a main focus of this study together with an assessment of the human health risks they pose. Even though near-ground atmospheric aerosols have been a subject of intensive research in recent years, data integrating chemical composition of particles and health risks are still scarce and the particle size aspect has not been properly addressed yet. Filling this gap, however, is necessary for reliable risk assessment. A high volume ambient air sampler equipped with a multi-stage cascade impactor was used for size specific particle collection, and all 6 fractions were a subject of detailed characterization of chemical (PAHs) and mineralogical composition of the particles, their mass size distribution and genotoxic potential of organic extracts. Finally, the risk level for inhalation exposure associated to the carcinogenic character of the studied PAHs has been assessed. The finest fraction (<0.45 μm) exhibited the highest mass, highest active surface, highest amount of associated PAHs and also highest direct and indirect genotoxic potentials in our model air sample. Risk assessment of inhalation scenario indicates the significant cancer risk values in PM 1.5 size fraction. This presented new approach proved to be a useful tool for human health risk assessment in the areas with significant levels of air dust concentration.

  15. Preliminary description of small block mineralogical features, data report

    Energy Technology Data Exchange (ETDEWEB)

    Glassley, W., LLNL

    1998-02-03

    The large block heater test, to be conducted at Fran Ridge (Lin et al., 1994), is designed to provide a database with which to test codes that simulate hydrological, geochemical, and geomechanical processes that may occur within the repository block. The geochemical processes that may occur include rock-water interaction within the matrix of fracture bounded blocks, and with the minerals that line fractures (see, for example, Buscheck and Nitao, 1992,1993ab, 1994; Glassley, 1993). As a first step in evaluating these interactions, characterization of the fractures, and of the matrix that is adjacent to those fractures, must be completed Characterization of the fractures and matrix before the large block test is started will allow a `baseline` set of data to be collected that will describe the properties of the large block prior to the test. After the test is completed, the block will be dismembered and characterization of the matrix and fractures will be repeated. Changes in matrix and fracture mineralogies will allow documentation of the mineralogical consequences of rock-water interaction resulting from heating of tuff under the conditions of the test.

  16. Coupling among Microbial Communities, Biogeochemistry, and Mineralogy across Biogeochemical Facies

    Energy Technology Data Exchange (ETDEWEB)

    Stegen, James C.; Konopka, Allan; McKinely, Jim; Murray, Christopher J.; Lin, Xueju; Miller, Micah D.; Kennedy, David W.; Miller, Erin A.; Resch, Charles T.; Fredrickson, Jim K.

    2016-07-29

    Physical properties of sediments are commonly used to define subsurface lithofacies and these same physical properties influence subsurface microbial communities. This suggests an (unexploited) opportunity to use the spatial distribution of facies to predict spatial variation in biogeochemically relevant microbial attributes. Here, we characterize three biogeochemical facies—oxidized, reduced, and transition—within one lithofacies and elucidate relationships among facies features and microbial community biomass, diversity, and community composition. Consistent with previous observations of biogeochemical hotspots at environmental transition zones, we find elevated biomass within a biogeochemical facies that occurred at the transition between oxidized and reduced biogeochemical facies. Microbial diversity—the number of microbial taxa—was lower within the reduced facies and was well-explained by a combination of pH and mineralogy. Null modeling revealed that microbial community composition was influenced by ecological selection imposed by redox state and mineralogy, possibly due to effects on nutrient availability or transport. As an illustrative case, we predict microbial biomass concentration across a three-dimensional spatial domain by coupling the spatial distribution of subsurface biogeochemical facies with biomass-facies relationships revealed here. We expect that merging such an approach with hydro-biogeochemical models will provide important constraints on simulated dynamics, thereby reducing uncertainty in model predictions.

  17. Temperature buffer test. Hydro-mechanical and chemical/ mineralogical characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias; Olsson, Siv; Dueck, Ann; Nilsson, Ulf; Karnland, Ola [Clay Technology AB, Lund (Sweden); Kiviranta, Leena; Kumpulainen, Sirpa [BandTech Oy, Helsinki (Finland); Linden, Johan [Aabo Akademi, Aabo (Finland)

    2012-01-15

    The Temperature Buffer Test (TBT) is a joint project between SKB/ANDRA and supported by ENRESA (modeling) and DBE (instrumentation), which aims at improving the understanding and to model the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test has been carried out in a KBS-3 deposition hole at Aspo HRL. It was installed during the spring of 2003. Two steel heaters (3 m long, 0.6 m diameter) and two buffer arrangements have been investigated: the lower heater was surrounded by rings of compacted Wyoming bentonite only, whereas the upper heater was surrounded by a composite barrier, with a sand shield between the heater and the bentonite. The test was dismantled and sampled during the winter of 2009/2010. This report presents the hydro-mechanical and chemical/mineralogical characterization program which was launched subsequent to the dismantling operation. The main goal has been to investigate if any significant differences could be observed between material from the field experiment and the reference material. The field samples were mainly taken from Ring 4 (located at the mid-section around the lower heater), in which the temperature in the innermost part reached 155 deg C. The following hydro-mechanical properties have been determined for the material (test technique within brackets): hydraulic conductivity (swelling pressure device), swelling pressure (swelling pressure device), unconfined compression strength (mechanical press), shear strength (triaxial cell) and retention properties (jar method). The following chemical/mineralogical properties (methods within brackets) were determined: anion analysis of water leachates (IC), chemical composition (ICP/AES+MS, EGA), cation exchange capacity (CEC, Cu-trien method) and exchangeable cations (exchange with NH4, ICPAES), mineralogical composition (XRD and FTIR), element distribution and microstructure (SEM and

  18. Zircon Geochronology (U-Pb, Petrography, Geochemistry and Radioisotopes of Bornaward Metarhyolites (Central Taknar Zone-Northwest of Bardaskan

    Directory of Open Access Journals (Sweden)

    Reza Monazzami Bagherzadeh

    2016-07-01

    Full Text Available Introduction The Bornaward area is located in the Northeastern Iran (in the Khorasan Razavi province 28 km northwest of the city of Bardaskan at 57˚ 46΄ to 57˚ 52΄ N latitude and 35˚ 21΄ to 35˚ 24΄E longitude. The Taknar structural zone, situated in the North central Iranian micro continent, is part of the Lut block (Forster, 1978. The Taknar zone is an allochthonous block bounded by the Darouneh and Taknar major faults. Much of this zone consists of metarhyolite-rhyodacite volcanic rocks, and rhyolitic tuff with interlayers of sandstone and dolomite (Taknar Formation. Analytical Results ICP-MS analysis of REE and minor elements of samples of the Bornaward metarhyolites was carried out at the ACME Laboratory in Vancouver, Canada. U-Pb dating of the metarhyolites was performed on isolated zircons in Crohn's Laser Lab, in Arizona (Gehrels et al., 2008. Measurement of Rb, Sr, Sm and Nd isotopes and (143Nd/144Ndi and (87Sr/86Sri ratios took place in the radioisotope laboratory of the University of Aveiro in Portugal. Petrography The volcanic rocks are porphyritic, commonly containing phenocrysts of orthoclase and rarely sanidine, quartz and intermediate plagioclase in a groundmass of fine-grained quartz and feldspar. An alteration has produced oriented needles of sericite and clay minerals, clusters of fine-grained green biotite and clots of epidote and chlorite. Geochemistry The compositions of the volcanic rocks are calc alkaline and high K- calc alkaline. The obtained Shand index (Al2O3/( CaO+Na2O+K2O is above 1.1, in the peraluminous S-type granite field (Chappell and White, 2001. Plotted on the TAS diagram (Middlemost, 1994, all the metarhyolite-rhyodacite samples are located in the sub-alkaline field and the majority fall into the rhyolite group. The metarhyolite-rhyodacites show enrichment of LREE with a moderately ascending pattern ((La/YbN=2.51-10.11 and La=46.45-145.48. Europium shows a negative anomaly (Eu/Eu*=0.23-0.71. U

  19. The Connection between the Properties of Elements and Compounds; Mineralogical-Crystallochemical Classification of Elements

    OpenAIRE

    Godovikov, Alexander A.; Hariya, Yu

    1987-01-01

    The described mineralogical-crystallochemical classification bears some similar features with geochemical classification of elements. This similarity emphasizes a greater importance in conforming the vast practical data on petrology. The present classification also bears some resemblance to the technical classification of elements by Berg (1929). The similarity seems logical since the mineralogical. crystallochemical classification of elements unites them on the basis of crystallochemical sim...

  20. Comparative mineralogical characteristics of red soils from South Bulgaria

    Directory of Open Access Journals (Sweden)

    Marlena Yaneva

    2015-01-01

    Full Text Available The present study aims to compare mineralogical composition of red soils, formed on marbles in South Bulgaria. We used mineralogical analysis of heavy and light mineral fraction in immersion under polarizing microscope and X-ray diffraction analysis of bulk sample and clay fraction. Three test polygons, located in South Bulgaria were examined: Petrovo, Nova Lovcha and Dobrostan, which are characterized with different latitude, altitude, and exposition. Three or more sites from each polygon were sampled and analyzed. The red soils are formed on white and gray calcite and calcite-dolomite marbles, impure silicate-rich marbles and only in one site – on marble breccias. We determined the following mineral phases in red soils: calcite, dolomite, quarts, and feldspars, mica, illite-type mica, illite, smectite, vermiculite-smectite, and kaolinite. Heavy minerals are represented by amphibole, titanite and epidote, and minor amounts of zircon, garnet, tourmaline, rutile, pyroxene, andalusite, kyanite, sillimanite and apatite. Opaque minerals are predominantly goethite and hematite. Plant tissue is abundant in light fraction from the uppermost soil horizons. Analyses of heavy mineral fraction show presence of metamorphic and igneous minerals which indicate participation of weathering products from other rock types in the nearby area. The types of heavy minerals in soils depend more on composition of parent rocks and geomorphic position than on climate type. Soils from Nova Lovcha show similar composition, but the quantity of goethite and hematite significantly increase in soil from plain. Typical high-metamorphic minerals as andalusite, kyanite and sillimanite present only in Nova Lovcha, while garnet dominates in Petrovo and opaque minerals - in Dobrostan. Red soils, formed on slopes, where erosion prevails over accumulation, contain more illite, smectite and vermiculite-smectite, and very few or no kaolinite, whereas the kaolinite is dominant in soils

  1. Roles of Mineralogical Phases in Aqueous Carbonation of Steelmaking Slag

    Directory of Open Access Journals (Sweden)

    Huining Zhang

    2016-05-01

    Full Text Available Mineralogical phases of steelmaking slags have significant influences on the carbonation of the slags. In this paper, the effects of temperature and reaction time on the conversion of calcium-related phases and the carbonation degree of a slag sample were studied. The experimental conditions were a liquid-to-solid ratio of 20 mL/g, a carbon dioxide flow rate of 1 L/min and a slag particle size of 38–75 μm. The results show that the optimum carbonation temperature and reaction time are 60 °C and 90 min, respectively, and calcite phase content is about 26.78% while the conversion rates of Ca3Al2O6, CaSiO3, Ca2SiO4 and free CaO are about 40%, 42.46%, 51% and 100%, respectively, and the carbon dioxide sequestration efficiency is about 170 g/kg slag.

  2. Mineralogy and geochemistry of soils from glass houses and solariums

    Science.gov (United States)

    Bulgariu, Dumitru; Filipov, Feodor; Rusu, Constantin; Bulgariu, Laura

    2010-05-01

    The experimental studies have been performed on soil samples from Copou-Iaşi, Bacău and Bârlad (România) glass houses. We have specially follow the aspects concerning to the distribution of occurrence forms, composition and structure of mineral and organic components, and the genetic correlations between these in conditions of soils from glass houses, respectively. The results regarding the distribution tendencies on profile and the correlations between mineral and organic components of studied soils have been correlated with the results of microscopic, spectral (IR and Raman) and X-ray diffraction studies, and with the results of thermodynamic modelling of mineral equilibriums and dynamics of pedogenesis processes, in conditions of soils from glass houses. The utilization of intensive cultivation technologies of vegetables in glass houses determined the degradation of morphological, physical and chemical characteristics of soils, by fast evolution of salted processes (salinization and / or sodization), compaction, carbonatation, eluviation-illuviation, frangipane formation, stagnogleization, gleization, etc. Under these conditions, at depth of 30-40 cm is formed a compact and impenetrable horizon with frangipane characteristics, expresses more or less. The aspects about the formation of frangipane horizon in soils from glasshouses are not yet sufficiently know. Whatever of the formation processes, the frangipane horizons determined a sever segregation in pedo-geochemical evolution of soils from glasshouses, with very important consequences on the agrochemical quality of these soils. The soils from glass houses are characterized by a very large variability of mineralogy and chemistry, which are traduced by intense modifications of superior horizons, in many cases there are conditions for the apparition of new pedogenetic horizons through new-pedogenesis processes. Under these conditions the definition of some general characteristics of soils from glasshouses is

  3. Mineralogical data on bat guano deposits from three Romanian caves

    Directory of Open Access Journals (Sweden)

    Alexandra Giurgiu

    2013-12-01

    Full Text Available Mineralogical studies performed on crusts, nodules and earthy masses from the Romanian caves Gaura cu Muscă, Gaura Haiducească and Peștera Zidită have revealed the presence of three different phosphate associations. The minerals have been identified by means of X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Five phosphates have been identified in the samples, with hydroxylapatite the only common mineral in all the three caves. Brushite, taranakite, leucophosphite and variscite are the other phosphates identified. Associated minerals include gypsum, calcite, quartz and illite-group minerals. Aside from differences in the lithology, the occurrences of the different phosphate minerals indicate variable pH and humidity conditions near or within the guano accumulations.

  4. Chemical and mineralogical characterizations of a copper converter slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A copper converter slag was examined chemically and mineralogically to determine its existing phases, in particular those containing Co and Cu. The slag consists predominantly of fayalite and magnetite, together with some glass,chalcocite, and metallic copper. Copper is entrapped in the slag mostly as chalcocite and metallic copper, as well as trace copper oxide. There was no indication of any independent Co mineral in the slag, but Co was found to be enriched in fayalite and megnetite as solid solution, although Co was detected in all the phases of the slag by SEM-EDX (scanning electron microscopy equipped with model EDAX-9100 energy dispersive spectrometer) and WDS (model WDX-2A X-ray wave-length dispersive spectrometer).

  5. Mineralogical effects on the detectability of the postperovskite boundary

    Energy Technology Data Exchange (ETDEWEB)

    Grocholski, Brent; Catalli, Krystle; Shim, Sang-Heon; Prakapenka, Vitali (MIT); (UC)

    2012-04-02

    The discovery of a phase transition in Mg-silicate perovskite (Pv) to postperovskite (pPv) at lowermost mantle pressure-temperature (P - T) conditions may provide an explanation for the discontinuous increase in shear wave velocity found in some regions at a depth range of 200 to 400 km above the core-mantle boundary, hereafter the D{double_prime} discontinuity. However, recent studies on binary and ternary systems showed that reasonable contents of Fe{sup 2+} and Al for pyrolite increase the thickness (width of the mixed phase region) of the Pv - pPv boundary (400-600 km) to much larger than the D{double_prime} discontinuity ({le} 70 km). These results challenge the assignment of the D{double_prime} discontinuity to the Pv - pPv boundary in pyrolite (homogenized mantle composition). Furthermore, the mineralogy and composition of rocks that can host a detectable Pv {yields} pPv boundary are still unknown. Here we report in situ measurements of the depths and thicknesses of the Pv {yields} pPv transition in multiphase systems (San Carlos olivine, pyrolitic, and midocean ridge basaltic compositions) at the P - T conditions of the lowermost mantle, searching for candidate rocks with a sharp Pv - pPv discontinuity. Whereas the pyrolitic mantle may not have a seismologically detectable Pv {yields} pPv transition due to the effect of Al, harzburgitic compositions have detectable transitions due to low Al content. In contrast, Al-rich basaltic compositions may have a detectable Pv - pPv boundary due to their distinct mineralogy. Therefore, the observation of the D{prime} discontinuity may be related to the Pv {yields} pPv transition in the differentiated oceanic lithosphere materials transported to the lowermost mantle by subducting slabs.

  6. Mineralogy of Selected Paddy Soils in Southeastern China

    Institute of Scientific and Technical Information of China (English)

    F.L.WANG; P.M.HUANG

    1997-01-01

    Limited information is available concerning the mineralogy of paddy soils in the southeastern China, Using chemical methods in conjunction with X-ray diffractometry,we studied the mineral composition of three paddy soils:Jinghua (paddy soil on Quaternary red clay),Fuyang (Hapl-percogenic loamy paddy soil),and Shaoxing(gleyic clayey paddy soil).All the soils contained quartz,mica,vermiculite,chlorite and kaolinite ,and the distribution of these minerals varied with soil prticle size fractions.The clay fraction of the Fuyang and Shaoxing soils aso contained smectite.Although X-ray data did not show the presence of smectite in the Jinghua soil,this mineral was identified by the chemical method.suggesting a transitional property of the mineral in the soil.Hydroxy-Al interlayered minerals were also present in the clay fraction.The amount of smectite in the soils was 31.6(Shaoxing),16.5(Fuyang),and 21.4(Jinghua)g kg-1;for vermiculite it was 33.3(Shaoxing),16.5(Fuyang),and 8.5(Jinghua) g kg-1,Smectite was only Found in the clay fraction,In contrast,amounts of vermiculite in soil particle size fractions were 3.0-11.4(sand), 2.1-6.0(coarse silt),4.6-18.9(medium silt),0.9-40.0(fine silt),and 17.0-108(clay)g kg-1,The amount of noncrystalline aluminosilicates in the soils in g kg-1 decreased in the order:Shaoxing(2.4)>Jinghua (1.9)>Fuyang(1.7).This study has provided useful mineralogical information that is fundamental in future development of management strategies of soils.

  7. Mineralogical effects on the detectability of the postperovskite boundary

    Science.gov (United States)

    Grocholski, Brent; Catalli, Krystle; Shim, Sang-Heon; Prakapenka, Vitali

    2016-03-01

    The discovery of a phase transition in Mg-silicate perovskite (Pv) to postperovskite (pPv) at lowermost mantle pressure-temperature (P - T) conditions may provide an explanation for the discontinuous increase in shear wave velocity found in some regions at a depth range of 200 to 400 km above the core-mantle boundary, hereafter the D'' discontinuity. However, recent studies on binary and ternary systems showed that reasonable contents of Fe2+ and Al for pyrolite increase the thickness (width of the mixed phase region) of the Pv - pPv boundary (400-600 km) to much larger than the D'' discontinuity (≤ 70 km). These results challenge the assignment of the D'' discontinuity to the Pv - pPv boundary in pyrolite (homogenized mantle composition). Furthermore, the mineralogy and composition of rocks that can host a detectable Pv → pPv boundary are still unknown. Here we report in situ measurements of the depths and thicknesses of the Pv → pPv transition in multiphase systems (San Carlos olivine, pyrolitic, and midocean ridge basaltic compositions) at the P - T conditions of the lowermost mantle, searching for candidate rocks with a sharp Pv - pPv discontinuity. Whereas the pyrolitic mantle may not have a seismologically detectable Pv → pPv transition due to the effect of Al, harzburgitic compositions have detectable transitions due to low Al content. In contrast, Al-rich basaltic compositions may have a detectable Pv - pPv boundary due to their distinct mineralogy. Therefore, the observation of the D'' discontinuity may be related to the Pv → pPv transition in the differentiated oceanic lithosphere materials transported to the lowermost mantle by subducting slabs.

  8. Seismogenic faulting in the Meruoca granite, NE Brazil, consistent with a local weak fracture zone

    Directory of Open Access Journals (Sweden)

    ANA CATARINA A. MOURA

    2014-12-01

    Full Text Available A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geological structures in the Meruoca granite. We carried out geological mapping in the epicentral area, analyzed the mineralogy of fault rocks, and compared the seismically-defined Riacho Fundo fault with geological data. We concluded that the seismically-defined fault coincides with ∼E–W-striking faults observed at outcrop scale and a swarm of Mesozoic basalt dikes. We propose that seismicity reactivated brittle structures in the Meruoca granite. Our study highlights the importance of geological mapping and mineralogical analysis in order to establish the relationships between geological structures and seismicity at a given area.

  9. Seismogenic faulting in the Meruoca granite, NE Brazil, consistent with a local weak fracture zone.

    Science.gov (United States)

    Moura, Ana Catarina A; De Oliveira, Paulo H S; Ferreira, Joaquim M; Bezerra, Francisco H R; Fuck, Reinhardt A; Do Nascimento, Aderson F

    2014-12-01

    A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geological structures in the Meruoca granite. We carried out geological mapping in the epicentral area, analyzed the mineralogy of fault rocks, and compared the seismically-defined Riacho Fundo fault with geological data. We concluded that the seismically-defined fault coincides with ∼E-W-striking faults observed at outcrop scale and a swarm of Mesozoic basalt dikes. We propose that seismicity reactivated brittle structures in the Meruoca granite. Our study highlights the importance of geological mapping and mineralogical analysis in order to establish the relationships between geological structures and seismicity at a given area.

  10. Brazil : Eradicating Child Labor in Brazil

    OpenAIRE

    World Bank

    2001-01-01

    The report reviews evidence of child labor in Brazil, and the Government's efforts to eradicate its worst forms, by examining background assessments of ongoing programs for its prevention. It seeks to identify promising strategies, addressing the needs of highly vulnerable children in urban areas, engaged in activities such as drug commerce, prostitution, or other dangerous activities. One...

  11. Automatic, exploratory mineralogical mapping of CRISM imagery using summary product signatures

    Science.gov (United States)

    Allender, Elyse; Stepinski, Tomasz F.

    2017-01-01

    Martian spectroscopic and mineralogical analysis is usually performed using Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) browse products - false color images which show the spatial distribution of absorption features at key wavelengths. This manual, time-consuming method is ill-suited for exploratory surveys of a large number of images - for such surveys an automatic methodology is needed. In this paper we propose a method for exploratory but fully automatic mineralogical mapping of CRISM images. In our approach pixels are characterized by vectors of CRISM summary product values instead of spectral functions, and mineralogical units are discovered using a clustering principle. Moreover, the rare class discovery algorithm DEMUD is used in place of a standard clustering algorithm to identify mineralogical units - enabling the identification of only scientifically interesting, possibly rare, mineralogical deposits. The method outputs a map for each site showing the spatial distribution of mineralogical units - areas characterized by similar mineralogy. It also provides, without using a spectral library, semantic labels for each unit. We envision our method as a focus-of-attention tool to facilitate fast exploratory surveys of a large number of images. An analyst needs only to examine manually regions within an image where our pipeline indicates the existence of mineral units of interest. In this paper the method for our computational pipeline is described in detail and its performance is evaluated using a sample of 20 CRISM images - the mineralogical content of which is known from manual analysis. We find that our pipeline identifies most deposits found through manual analysis as well as some additional deposits which were not targeted by those analyses. Overall, we conclude that our fully automatic mineralogical mapper works well for exploratory purposes. Thus, it adds a new, valuable functionality to existing tools for CRISM imagery analysis.

  12. Petrography and chemical evidence for multi-stage emplacement of western Buem volcanic rocks in the Dahomeyide orogenic belt, southeastern Ghana, West Africa

    Science.gov (United States)

    Nude, Prosper M.; Kwayisi, Daniel; Taki, Naa A.; Kutu, Jacob M.; Anani, Chris Y.; Banoeng-Yakubo, Bruce; Asiedu, Daniel K.

    2015-12-01

    The volcanic rocks of the Buem Structural Unit in the Dahomeyide orogenic belt of southeastern Ghana, constitute a unique assemblage among the monocyclic sedimentary formations of this structural unit. Representative volcanic rock samples were collected from the Asukawkaw, Bowiri-Odumase and Nkonya areas which form a roughly north-south trend. The volcanic rocks comprise spherulitic, amygdaloidal, vesicular, phyric and aphyric varieties. Whole rock geochemistry shows that these volcanic rocks exhibit both alkaline and subalkaline characteristics. The alkaline varieties are relatively enriched in REE and incompatible trace element concentrations, similar to OIB; the subalkaline varieties show E-MORB and N-MORB REE and incompatible element characteristics. The rocks have low La/Nb (<1), low K/Nb (<450) and high Nb/U (averagely 47.3) values, suggesting no significant effect of crustal contamination. The key characteristics of these volcanic rocks are the distinct petrography and geochemistry, shown from the three separate localities, which may suggest source fractionation at different depths or modes of emplacement. The association of volcanic rocks of OIB, E-MORB and N-MORB affinities, with no significant crustal contamination, may suggest mantle derived magma that may have been related to rifting event and eventual emplacement at the eastern passive margin of the West African Craton.

  13. Temperature buffer test. Hydro-mechanical and chemical/ mineralogical characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias; Olsson, Siv; Dueck, Ann; Nilsson, Ulf; Karnland, Ola [Clay Technology AB, Lund (Sweden); Kiviranta, Leena; Kumpulainen, Sirpa [BandTech Oy, Helsinki (Finland); Linden, Johan [Aabo Akademi, Aabo (Finland)

    2012-01-15

    The Temperature Buffer Test (TBT) is a joint project between SKB/ANDRA and supported by ENRESA (modeling) and DBE (instrumentation), which aims at improving the understanding and to model the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test has been carried out in a KBS-3 deposition hole at Aspo HRL. It was installed during the spring of 2003. Two steel heaters (3 m long, 0.6 m diameter) and two buffer arrangements have been investigated: the lower heater was surrounded by rings of compacted Wyoming bentonite only, whereas the upper heater was surrounded by a composite barrier, with a sand shield between the heater and the bentonite. The test was dismantled and sampled during the winter of 2009/2010. This report presents the hydro-mechanical and chemical/mineralogical characterization program which was launched subsequent to the dismantling operation. The main goal has been to investigate if any significant differences could be observed between material from the field experiment and the reference material. The field samples were mainly taken from Ring 4 (located at the mid-section around the lower heater), in which the temperature in the innermost part reached 155 deg C. The following hydro-mechanical properties have been determined for the material (test technique within brackets): hydraulic conductivity (swelling pressure device), swelling pressure (swelling pressure device), unconfined compression strength (mechanical press), shear strength (triaxial cell) and retention properties (jar method). The following chemical/mineralogical properties (methods within brackets) were determined: anion analysis of water leachates (IC), chemical composition (ICP/AES+MS, EGA), cation exchange capacity (CEC, Cu-trien method) and exchangeable cations (exchange with NH4, ICPAES), mineralogical composition (XRD and FTIR), element distribution and microstructure (SEM and

  14. Relationship between soil oxidizable carbon and physical, chemical and mineralogical properties of umbric ferralsols

    Directory of Open Access Journals (Sweden)

    Flávio Adriano Marques

    2011-02-01

    Full Text Available The occurrence of Umbric Ferralsols with thick umbric epipedons (> 100 cm thickness in humid Tropical and Subtropical areas is a paradox since the processes of organic matter decomposition in these environments are very efficient. Nevertheless, this soil type has been reported in areas in the Southeast and South of Brazil, and at some places in the Northeast. Aspects of the genesis and paleoenvironmental significance of these Ferralsols still need a better understanding. The processes that made the umbric horizons so thick and dark and contributed to the preservation of organic carbon (OC at considerable depths in these soils are of special interest. In this study, eight Ferralsols with a thick umbric horizon (UF under different vegetation types were sampled (tropical rain forest, tropical seasonal forest and savanna woodland and their macromorphological, physical, chemical and mineralogical properties studied to detect soil characteristics that could explain the preservation of high carbon amounts at considerable depths. The studied UF are clayey to very clayey, strongly acidic, dystrophic, and Al-saturated and charcoal fragments are often scattered in the soil matrix. Kaolinites are the main clay minerals in the A and B horizons, followed by abundant gibbsite and hydroxyl-interlayered vermiculite. The latter was only found in UFs derived from basalt rock in the South of the country. Total carbon (TC ranged from 5 to 101 g kg-1 in the umbric epipedon. Dichromate-oxidizable organic carbon represented nearly 75 % of TC in the thick A horizons, while non-oxidizable C, which includes recalcitrant C (e.g., charcoal, contributed to the remaining 25 % of TC. Carbon contents were not related to most of the inorganic soil variables studied, except for oxalate-extractable Al, which individually explained 69 % (P < 0.001 of the variability of TC in the umbric epipedon. Clay content was not suited as predictor of TC or of the other studied C forms. Bulk

  15. Preliminary Results on Magnetic Mineralogy and Elemental Composition of Meteorites from Geological Museum of Kazan University

    Science.gov (United States)

    Kuzina, D. M.; Nurgaliev, D. K.; Gareev, B. I.; Batalin, G. A.; Silantev, V. V.

    2016-08-01

    Thermomagnetic analysis (magnetic mineralogy) and Micro X-ray Fluorescence analysis (mapping) were made for collection of meteorites. As a result we have elements distribution on surface of meteorites and Fe-Ni presence in meteorites.

  16. X-Ray Diffraction and Fluorescence Instrument for Mineralogical Analysis at the Lunar Surface Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop LUNA, a compact and lightweight X-Ray Diffraction (XRD) / X-Ray Fluorescence (XRF) instrument for mineralogical analysis of regolith, rock...

  17. Geochemical and mineralogical maps for soils of the conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Geochemical and mineralogical maps along with a histogram, boxplot, and empirical cumulative distribution function plot for each element or mineral whose data are...

  18. X-Ray Diffraction and Fluorescence Instrument for Mineralogical Analysis at the Lunar Surface Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a compact and lightweight X-Ray Diffraction (XRD) / X-Ray Fluorescence (XRF) instrument for analysis of mineralogical composition of regolith,...

  19. Mineralogical Composition of the Mexican Ordinary Chondrite Type Meteorite: A Raman, Infrared and XRD Study

    Science.gov (United States)

    Ostrooumov, M.

    2016-08-01

    The Raman microprobe (RMP), infrared (IR) and XRD analysis have been applied to the examination of mineralogical composition of seven mexican meteorites: Aldama, Cosina, El Pozo, Escalon, Nuevo Mercurio,Pacula, Zapotitlan Salinas.

  20. Mineralogy and microstructure of sintered lignite coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Marina Ilic; Christopher Cheeseman; Christopher Sollars; Jonathan Knight [Faculty of Technology and Metallurgy, Belgrade (Yugoslavia)

    2003-02-01

    Lignite coal fly ash from the 'Nikola Tesla' power plant in Yugoslavia has been characterised, milled, compacted and sintered to form monolithic ceramic materials. The effect of firing at temperatures between 1130 and 1190{sup o}C on the density, water accessible porosity, mineralogy and microstructure of sintered samples is reported. This class C fly ash has an initial average particle size of 82 {mu}m and contains siliceous glass together with the crystalline phases quartz, anorthite, gehlenite, hematite and mullite. Milling the ash to an average particle size of 5.6 m, compacting and firing at 1170{sup o}C for 1 h produces materials with densities similar to clay-based ceramics that exhibit low water absorption. Sintering reduces the amount of glass, quartz, gehlenite and anhydrite, but increases formation of anorthite, mullite, hematite and cristobalite. SEM confirms the formation of a dense ceramic at 1170{sup o}C and indicates that pyroplastic effects cause pore formation and bloating at 1190{sup o}C. 23 refs., 6 figs., 2 tabs.

  1. Notes on Lithology, Mineralogy, and Production for Lunar Simulants

    Science.gov (United States)

    Rickman, D. L.; Stoeser, D. B.; Benzel, W. M.; Schrader, C. M.; Edmunson, J. E.

    2011-01-01

    The creation of lunar simulants requires a very broad range of specialized knowledge and information. This document covers several topic areas relevant to lithology, mineralogy, and processing of feedstock materials that are necessary components of the NASA lunar simulant effort. The naming schemes used for both terrestrial and lunar igneous rocks are discussed. The conflict between the International Union of Geological Sciences standard and lunar geology is noted. The rock types known as impactites are introduced. The discussion of lithology is followed by a brief synopsis of pyroxene, plagioclase, and olivine, which are the major mineral constituents of the lunar crust. The remainder of the text addresses processing of materials, particularly the need for separation of feedstock minerals. To illustrate this need, the text includes descriptions of two norite feedstocks for lunar simulants: the Stillwater Complex in Montana, United States, and the Bushveld Complex in South Africa. Magnetic mineral separations, completed by Hazen Research, Inc. and Eriez Manufacturing Co. for the simulant task, are discussed.

  2. Mineralogy of Pyroxene and Olivine in the Almahata Sitta Ureilite

    Science.gov (United States)

    Mikouchi, T.; Zolensky, M.; Takeda, H.; Hagiya, K.; Ohsumi, K; Satake, W.; Kurihara, T.; Dept. of Physics; Shaddad, M. H.

    2010-01-01

    The Almahata Sitta meteorite (hereafter "Alma") is the first example of a recovered asteroidal sample that fell to earth after detection still in the orbit (2008TC3 asteroid), and thus is critical to understand the relationship between meteorites and their asteroidal parent bodies [1]. Alma is a polymict ureilite showing a fine-grained brecciated texture with variable lithologies from black, porous to denser, white stones [1]. It is an anomalous ureilite because of wide compositional ranges of silicates with abundant pores often coated by vapor-deposit crystals [1]. Nevertheless, Alma has general similarities to all ureilites because of reduction textures of silicates suggestive of rapid cooling from high temperature as well as heterogeneous oxygen isotope compositions [e.g., 1-5]. Alma is especially unique because it spans the compositional range of known ureilites [1]. In this abstract we report detailed mineralogical and crystallographic investigations of two different fragments to further constrain its thermal history with regards to the nature of the ureilite parent body.

  3. Chemical, Mineralogical, and Morphological Properties of Steel Slag

    Directory of Open Access Journals (Sweden)

    Irem Zeynep Yildirim

    2011-01-01

    Full Text Available Steel slag is a byproduct of the steelmaking and steel refining processes. This paper provides an overview of the different types of steel slag that are generated from basic-oxygen-furnace (BOF steelmaking, electric-arc-furnace (EAF steelmaking, and ladle-furnace steel refining processes. The mineralogical and morphological properties of BOF and electric-arc-furnace-ladle [EAF(L] slag samples generated from two steel plants in Indiana were determined through X-Ray Diffraction (XRD analyses and Scanning Electron Microscopy (SEM studies. The XRD patterns of both BOF and EAF(L slag samples were very complex, with several overlapping peaks resulting from the many minerals present in these samples. The XRD analyses indicated the presence of free MgO and CaO in both the BOF and EAF(L slag samples. SEM micrographs showed that the majority of the sand-size steel slag particles had subangular to angular shapes. Very rough surface textures with distinct crystal structures were observed on the sand-size particles of BOF and EAF(L slag samples under SEM. The characteristics of the steel slag samples considered in this study are discussed in the context of a detailed review of steel slag properties.

  4. A geochemical and mineralogical approach to environmental protection

    Energy Technology Data Exchange (ETDEWEB)

    Memmi, I. [Siena Univ., Siena (Italy). Dipt. di Scienze della Terra; Hunziker, J.C. [UNIL BFSH-2 CH, Institut de Mineralogie, Lausanne (Switzerland); Panichi, C. [Consiglio Nazionale delle Ricerche, International Institute for Geothermal Research, Ghezzano, PI (Italy)

    2000-07-01

    Chemical pollution of the biospheric environment by human activity has become a problem of regional and global scale. There is no doubt that the contribution of geochemistry and mineralogy in defining the extent of this problem and estimating its long-term effects on life-forms is fundamental. Most of the environmental pollution problems arise from human activity associated with the exploitation and utilisation of the Earth's resources, involving minerals and fluids in some way. These problems include waste generated by mining activity, industrial, domestic, and nuclear waste. Particular problems can arise form the use of minerals and rocks in buildings and monuments. The relationship between minerals and human health represents a special case. Minerals can, on the one hand, create a problem; but, on the other hand, due to their peculiar structural properties of potentially hazardous and also useful minerals, capable of adsorbing or neutralizing any toxic, acid and undesirable components. Geochemistry can make important contributions in defining background concentrations, in mapping and accounting for dispersion patterns, in understanding the chemical interaction of pollutants with natural dissolved constituents and mineral matter, in estimating residence times and the extent to which geochemical processes will remove pollutants from the environment.

  5. Mineralogical characterization of airborne individual particulates in Beijing PM10

    Institute of Scientific and Technical Information of China (English)

    LU Sen-lin; SHAO Long-yi; WU Ming-hong; JIAO Zheng

    2006-01-01

    This work mainly focuses on the mineralogical study of particulate matter(PM10) in Beijing. Samples were collected on polycarbonate filter from April, 2002 to March, 2003 in Beijing urban area. Scanning electronic microscopy coupled with energy dispersive X-ray(SEM/EDX) was used to investigate individual mineral particles in Beijing PM10. 1454 individual mineral particulates from 48 samples were analysed by SEM/EDX. The results revealed that mineral particulates were complex and heterogeneous. 38kinds of minerals in PM10 were identified. The clay minerals, of annual average percentage of 30.1% , were the main composition among the identified minerals, and illite/smectite was the main composition in clay minerals, reaching up to 35%. Annual average percentage of quartz, calcite, compound particulates, carbonates were 13.5%, 10.9%, 11.95%, 10.31%, respectively. Annual average percentage less than 10% were gypsum, feldspar, dolomite, and so on. Fluorite, apatite, halite, barite and chloridize zinc (ZnCl2) were firstly identified in Beijing PM10. Sulfurization was found on surface of mineral particles, suggested extensive atmospheric reaction in air during summer.

  6. Petrography and hydric characterization of the quarry material of the varieties of Borriol Stone (Castellón

    Directory of Open Access Journals (Sweden)

    Ovejero, M.

    2005-06-01

    Full Text Available Borriol stone is one of the most widely used and well-known building materials in the Spanish province of Castellapn. It is a cretaceous limestone quarried in the El Abeller quarry, Borriol (Castellón. Since the seventeenth century it has been used in several historic buildings to be found both in the city of Castellaon and in nearby Valencia. Although it is commercially classified as a single rock type, two different lithologies or varieties can be distinguished in the Abeller outcrop; these represent vertical changes in the outcrop series andaré referred to in this paper as Ochre Borriol and Red Borriol. Petrographic, mineralogical and chemical studies were carried out, along with color determination. The stone s hydric parameters were obtained via the following tests: vacuum water absorption, free water absorption, desorption and capillary water absorption. Red Borriol is a reddish dolomitic grainstone with textures of dedolimitization. It is a low-porosity rock consisting mainly of calcite and dolomite, with quartz, illite, goethite and hematite as secondary minerals. As it has a low absorption coefficient, low capillarity index and rapid water desorption, it is expected to behave well under the action of weathering agents. Ochre Borriol is a yellowish packstonegrainstone with higher porosity. It is famed mainly of calcite and has less dolomite content than Red Borriol. Its accesory minerals are quartz, illite and goethite. It has a higher absorption coefficient and higher capillarity. Although it absorbs water more rapidly, its desorption is slower. As the hydric behavior of Ochre Borriol is less favorable, it is to be expected that its deterioration processes are encouraged by water circulation more than Red Borriol´sare.

    La "Piedra de Borriol" es uno de los materiales más utilizados y conocidos en la construcción de la provincia de Castellón que se han utilizado desde el siglo XVII como material de construcción en numerosos

  7. Mineralogical characteristic of rutile from Bonče, Republic of Macedonia

    OpenAIRE

    Sijakova-Ivanova, Tena; Boev, Blazo

    2014-01-01

    This paper gives mineralogical characteristic of rutile. Several samplesof rutile were collected for research by Scanning electron microscopy (SEM),coupled with an energy dispersive X-ray spectrometer (EDS) and X-raydiffraction (XRD). SEM is especially useful because it gives elemental,mineralogical and morphological data at the same time. X-ray diffraction(XRD) is known as the best method for the identification and quantification ofminerals The instrument used was a XRD Schimadzu 6100. Coppe...

  8. Skeletal mineralogy of coral recruits under high temperature and pCO2

    Directory of Open Access Journals (Sweden)

    T. Foster

    2016-03-01

    Our results show that elevated pCO2 alone is unlikely to drive changes in the skeletal mineralogy of young corals. Not having an ability to switch from aragonite to calcite precipitation may leave corals and ultimately coral reef ecosystems more susceptible to predicted ocean acidification. An important area for prospective research would be the investigation of the combined impact of high pCO2 and reduced Mg ∕ Ca ratio on coral skeletal mineralogy.

  9. Mineralogical and Thermal Analyses of a Bangle Shard from Harrappa, an Indus Valley Settlement in Pakistan

    CERN Document Server

    Kayani, Saheeb Ahmed

    2012-01-01

    In this research study we present initial results of a recent project in which mineralogical and thermal analysis were carried out on a terracotta bangle shard from Harrappa. We were surprised to find bentonite clay as the major constituent of the bangle shard. Also we have used knowledge of the mineralogical structure determined through X-ray diffraction and results of thermal analysis to predict value of firing temperature of the bangle shard.

  10. Zika: Why Brazil, Why Now

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_160251.html Zika: Why Brazil, Why Now Several factors -- including economics, climate and ... 5, 2016 THURSDAY, Aug. 4, 2016 (HealthDay News) -- Brazil, by a wide margin, has been the country ...

  11. Corporate Governance Country Assessment : Brazil

    OpenAIRE

    World Bank

    2005-01-01

    This report assesses Brazil's corporate governance policy framework. It highlights recent improvements in corporate governance regulation, makes policy recommendations, and provides investors with a benchmark against which to measure corporate governance in Brazil. It is an update of the 2005 corporate governance Report on the Observance of Standards and Codes (ROSC). Brazil's experience o...

  12. [A better Brazil].

    Science.gov (United States)

    Lesser, Jeffrey

    2014-01-01

    Many countries in the Americas describe themselves as "nations of immigrants." In the United States, the myth of the "promised land" suggests that foreigners better themselves upon arrival because the nation is intrinsically great. In Brazil, however, the relationship between immigration and national identity is different. Many intellectuals, politicians, and cultural and economic leaders saw (and see) immigrants as improving an imperfect nation that has been tainted by the history of Portuguese colonialism and African slavery. As a result, immigrants were often hailed as saviors because they modified and improved Brazil, not because they were improved by Brazil. This "improvement" took place through absorption, mixture and with the use of increasingly flexible racial and ethnic categories.

  13. Characterisation of dispersed organic matter from lower Palaeozoic metasedimentary rocks by organic petrography, X-ray diffraction and micro-Raman spectroscopy analyses

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, Alexandra; Noronha, Fernando [GIMEF-Departamento de Geologia e Centro de Geologia, Faculdade de Ciencias, Praca Gomes Teixeira, 4099-002 Porto (Portugal); Prieto, A. Carmelo [Departamento de Fisica de la Materia Condensada, Cristalografia y Mineralogia, Universidad de Valladolid, 47011 Valladolid (Spain)

    2005-06-22

    Dispersed organic matter (DOM) concentrates of C-rich rocks from areas with different metamorphic characteristics were studied by organic petrography, X-ray diffraction (XRD) and micro-Raman spectroscopy analysis. The concentrates contain several types of DOM with different morphologies, reflectance, X-ray diffraction and micro-Raman characteristics. Four different morphological types were identified in the two studied areas. The different types have different distributions and their reflectance is quite variable in the four types, with a dominance of the highest reflectance values in the DOM from the area with the highest metamorphic grade. XRD analyses of samples from the areas reveal the presence of fine graphite together with non-graphitised carbons. The Raman spectral profiles show the usual bands G (1582 cm{sup -1}) and D1 (1350 cm{sup -1}), on the first-order Raman spectrum, and S1 (2700 cm{sup -1}) on the second-order spectrum. Additional weaker bands, D2 (1620 cm{sup -1}), and more rarely D3 (1500 cm{sup -1}) and S2 (2900 cm{sup -1}), are present. These are characteristic for disordered carbons in the different types of DOM and in both studied areas. However, the Raman parameters (D1/G intensity area ratio and the frequency and width of G band) indicate variable degrees of organisation in all DOM types. The existence of different types of DOM with different degrees of ordering in the same lithologies and metamorphic grade seems to be related to different organic precursors, as they are graphitised to different extents under the same metamorphic conditions. However, in the same lithologies and metamorphic grade, the existence of various stages of graphitisation within the same type of DOM can only be explained though the interaction of DOM with the metamorphic fluids present in the rocks. The ordering graphitisation process may be due to the existence of metamorphic fluid circulation events with a variety of compositions.

  14. Scientific integrity in Brazil.

    Science.gov (United States)

    Lins, Liliane; Carvalho, Fernando Martins

    2014-09-01

    This article focuses on scientific integrity and the identification of predisposing factors to scientific misconduct in Brazil. Brazilian scientific production has increased in the last ten years, but the quality of the articles has decreased. Pressure on researchers and students for increasing scientific production may contribute to scientific misconduct. Cases of misconduct in science have been recently denounced in the country. Brazil has important institutions for controlling ethical and safety aspects of human research, but there is a lack of specific offices to investigate suspected cases of misconduct and policies to deal with scientific dishonesty.

  15. Clay mineralogy in different geomorphic surfaces in sugarcane areas

    Science.gov (United States)

    Camargo, L.; Marques, J., Jr.

    2012-04-01

    The crystallization of the oxides and hydroxides of iron and aluminum and kaolinite of clay fraction is the result of pedogenetic processes controlled by the relief. These minerals have influence on the physical and chemical attributes of soil and exhibit spatial dependence. The pattern of spatial distribution is influenced by forms of relief as the geomorphic surfaces. In this sense, the studies aimed at understanding the relationship between relief and the distribution pattern of the clay fraction attributes contribute to the delineation of specific areas of management in the field. The objective of this study was to evaluate the spatial distribution of oxides and hydroxides of iron and aluminum and kaolinite of clay fraction and its relationship with the physical and chemical attributes in different geomorphic surfaces. Soil samples were collected in a transect each 25 m (100 samples) and in the sides of the same (200 samples) as well as an area of 500 ha (1 sample each six hectare). Geomorphic surfaces (GS) in the transect were mapped in detail to support mapping the entire area. The soil samples were taken to the laboratory for chemical, physical, and mineralogical analysis, and the pattern of spatial distribution of soil attributes was obtained by statistics and geostatistics. The GS I is considered the oldest surface of the study area, with depositional character, and a slope ranging from 0 to 4%. GS II and III are considered to be eroded, and the surface II plan a gentle slope that extends from the edge of the surface until the beginning of I and III. The crystallographic characteristics of the oxides and hydroxides of iron and aluminum and kaolinite showed spatial dependence and the distribution pattern corresponding to the limits present of the GS in the field. Surfaces I and II showed the best environments to the degree of crystallinity of hematite and the surface III to the greatest degree of crystallinity of goethite agreeing to the pedoenvironment

  16. Timescales of carbon turnover in soils with mixed crystalline mineralogies

    Science.gov (United States)

    Khomo, Lesego; Trumbore, Susan; Bern, Carleton R.; Chadwick, Oliver A.

    2017-01-01

    Organic matter-mineral associations stabilize much of the carbon (C) stored globally in soils. Metastable short-range-order (SRO) minerals such as allophane and ferrihydrite provide one mechanism for long-term stabilization of organic matter in young soil. However, in soils with few SRO minerals and a predominance of crystalline aluminosilicate or Fe (and Al) oxyhydroxide, C turnover should be governed by chemisorption with those minerals. Here, we correlate mineral composition from soils containing small amounts of SRO minerals with mean turnover time (TT) of C estimated from radiocarbon (14C) in bulk soil, free light fraction and mineral-associated organic matter. We varied the mineral amount and composition by sampling ancient soils formed on different lithologies in arid to subhumid climates in Kruger National Park (KNP), South Africa. Mineral contents in bulk soils were assessed using chemical extractions to quantify Fe oxyhydroxides and SRO minerals. Because of our interest in the role of silicate clay mineralogy, particularly smectite (2 : 1) and kaolinite (1 : 1), we separately quantified the mineralogy of the clay-sized fraction using X-ray diffraction (XRD) and measured 14C on the same fraction. Density separation demonstrated that mineral associated C accounted for 40-70 % of bulk soil organic C in A and B1 horizons for granite, nephelinite and arid-zone gabbro soils, and > 80 % in other soils. Organic matter strongly associated with the isolated clay-sized fraction represented only 9-47 % of the bulk soil C. The mean TT of C strongly associated with the clay-sized fraction increased with the amount of smectite (2 : 1 clays); in samples with > 40 % smectite it averaged 1020 ± 460 years. The C not strongly associated with clay-sized minerals, including a combination of low-density C, the C associated with minerals of sizes between 2 µm and 2 cm (including Fe oxyhydroxides as coatings), and C removed from clay-sized material by 2 % hydrogen peroxide had

  17. Timescales of carbon turnover in soils with mixed crystalline mineralogies

    Science.gov (United States)

    Khomo, Lesego; Trumbore, Susan E.; Bern, Carleton R.; Chadwick, Oliver A.

    2017-01-01

    Organic matter–mineral associations stabilize much of the carbon (C) stored globally in soils. Metastable short-range-order (SRO) minerals such as allophane and ferrihydrite provide one mechanism for long-term stabilization of organic matter in young soil. However, in soils with few SRO minerals and a predominance of crystalline aluminosilicate or Fe (and Al) oxyhydroxide, C turnover should be governed by chemisorption with those minerals. Here, we correlate mineral composition from soils containing small amounts of SRO minerals with mean turnover time (TT) of C estimated from radiocarbon (14C) in bulk soil, free light fraction and mineral-associated organic matter. We varied the mineral amount and composition by sampling ancient soils formed on different lithologies in arid to subhumid climates in Kruger National Park (KNP), South Africa. Mineral contents in bulk soils were assessed using chemical extractions to quantify Fe oxyhydroxides and SRO minerals. Because of our interest in the role of silicate clay mineralogy, particularly smectite (2 : 1) and kaolinite (1 : 1), we separately quantified the mineralogy of the clay-sized fraction using X-ray diffraction (XRD) and measured 14C on the same fraction. Density separation demonstrated that mineral associated C accounted for 40–70 % of bulk soil organic C in A and B1 horizons for granite, nephelinite and arid-zone gabbro soils, and > 80 % in other soils. Organic matter strongly associated with the isolated clay-sized fraction represented only 9–47 % of the bulk soil C. The mean TT of C strongly associated with the clay-sized fraction increased with the amount of smectite (2 : 1 clays); in samples with > 40 % smectite it averaged 1020 ± 460 years. The C not strongly associated with clay-sized minerals, including a combination of low-density C, the C associated with minerals of sizes between 2 µm and 2 cm (including Fe oxyhydroxides as coatings), and C removed from clay

  18. Chemical-mineralogical characterisation of coarse recycled concrete aggregate.

    Science.gov (United States)

    Limbachiya, M C; Marrocchino, E; Koulouris, A

    2007-01-01

    The construction industry is now putting greater emphasis than ever before on increasing recycling and promoting more sustainable waste management practices. In keeping with this approach, many sectors of the industry have actively sought to encourage the use of recycled concrete aggregate (RCA) as an alternative to primary aggregates in concrete production. The results of a laboratory experimental programme aimed at establishing chemical and mineralogical characteristics of coarse RCA and its likely influence on concrete performance are reported in this paper. Commercially produced coarse RCA and natural aggregates (16-4 mm size fraction) were tested. Results of X-ray fluorescence (XRF) analyses showed that original source of RCA had a negligible effect on the major elements and a comparable chemical composition between recycled and natural aggregates. X-ray diffraction (XRD) analyses results indicated the presence of calcite, portlandite and minor peaks of muscovite/illite in recycled aggregates, although they were directly proportioned to their original composition. The influence of 30%, 50%, and 100% coarse RCA on the chemical composition of equal design strength concrete has been established, and its suitability for use in a concrete application has been assessed. In this work, coarse RCA was used as a direct replacement for natural gravel in concrete production. Test results indicated that up to 30% coarse RCA had no effect on the main three oxides (SiO2, Al2O3 and CaO) of concrete, but thereafter there was a marginal decrease in SiO2 and increase in Al2O3 and CaO contents with increase in RCA content in the mix, reflecting the original constituent's composition.

  19. East African magadi (trona): flouride concentration and mineralogical composition

    Science.gov (United States)

    Nielsen, Joan M.

    1999-08-01

    Magadi from Lake Magadi, Kenya, Lake Natron, Tanzania, Lake Katwe, Uganda, El-Atrun, Sudan and efflorescent crust from the soil surface (scooped magadi) from northern Tanzania have been analysed chemically to determine fluoride and carbonates concentrations and by X-ray diffraction to determine the mineralogical composition. Magadi from Lake Natron and Lake Magadi are found to be very similar consisting mainly of trona (CO 32- + HCO 3- > 10.4 meq [g magadi] -1) mixed with halite and either kogarkoite or villaumite, respectively, resulting in fluoride concentrations up to 8.7 mg F - [g magadi] -1. The scooped magadi is not as pure with respect to trona as the crystalline magadi, but the fluoride content is of same order of magnitude (0.23-5.1 mg F - [g magadi] -1). The scooped magadi consists of trona (CO 32- + HCO 3 = 3.5-9.5 meq [g magadi] -1) with different mixtures of halite, quartz, villiaumite, kogarkoite and thermonatrite. No fluoride containing minerals are identified in magadi from Uganda and Sudan, probably due to the very low fluoride concentrations of 0.02 and < O.24 mg (g magadi) -1, respectively, indicating that these samples are not contaminated with fluoride. The Sudanese magadi is a different mixture of trona, halite and quartz resulting in a variation in the carbonate concentration of 4.6-11.9 meq (g magadi) -1. The magadi from Lake Katwe consists of trona (CO 32- + HCO 3- = 7.0 meq [g magadi] -1) mixed with burkeite and halite.

  20. Mineralogy of iron microbial mats from Loihi Seamount

    Directory of Open Access Journals (Sweden)

    Brandy Marie Toner

    2012-04-01

    Full Text Available Extensive mats of Fe oxyhydroxides and associated Fe-oxidizing microbial organisms form in diverse geochemical settings – freshwater seeps to deep-sea vents – where ever opposing Fe(II-oxygen gradients prevail. The mineralogy, reactivity, and structural transformations of Fe oxyhydroxides precipitated from submarine hydrothermal fluids within microbial mats remains elusive in active and fossil systems. In response, a study of Fe microbial mat formation at the Loihi Seamount was conducted to describe the physical and chemical characteristics of Fe-phases using extended X-ray absorption fine structure spectroscopy, powder X-ray diffraction, synchrotron radiation X-ray total scattering, low-temperature magnetic measurements, and Mössbauer spectroscopy. Particle sizes of 3.5-4.6 nm were estimated from magnetism data, and coherent scattering domain sizes as small as 1.6 nm are indicated by pair distribution function (PDF analysis. Disorder in the nanostructured Fe-bearing phases results in limited intermediate-range structural order: less than that of standard 2-line ferrihydrite (Fh, except for the Pohaku site. The short-range ordered natural Fh (FhSRO phases were stable at 4 °C in the presence of oxygen for at least 1 year and during 400 oC treatment. The observed stability of the FhSRO is consistent with magnetic observations that point to non-interacting nanoparticles. PDF analyses of total scattering data provide further evidence for FhSRO particles with a poorly ordered silica coating. The presence of coated particles explains the small coherent scattering domain for the mat minerals, as well as the stability of the minerals over time and against heating. The mineral properties observed here provide a starting point from which progressively older and more extensively altered iron deposits may be examined, with the ultimate goal of improved interpretation of past biogeochemical conditions and diagenetic processes.

  1. Clay mineralogy and magnetic susceptibility of Oxisols in geomorphic surfaces

    Directory of Open Access Journals (Sweden)

    Livia Arantes Camargo

    2014-06-01

    Full Text Available Studies analyzing the variability of clay minerals and magnetic susceptibility provide data for the delineation of site-specific management areas since many of their attributes are important to agronomy and the environment. This study aimed to evaluate the spatial variability of clay minerals, magnetic susceptibility, adsorbed phosphorus and physical attributes in Oxisols of sandstones in different geomorphic surfaces. For that purpose, soil samples were collected every 25 m along a transect located within the area where the geomorphic surfaces were identified and mapped. The transect occupied the central portion of 500 ha, where it was also sampled for density purposes with one sample per six hectares. Soil samples were collected at a depth of 0.0-0.2 m. The results of the physical, chemical, mineralogical and magnetic susceptibility analyses were subjected to statistical and geostatistical analyses. The nature of the clay minerals and magnetic susceptibility was dependent on the variation of the soil parent material. High values of magnetic susceptibility were associated with the presence of maghemite and magnetite of coarse size. The spatial variability of crystallinity and the content of Fe oxides, as well as magnetic susceptibility, were dependent on the age of the geomorphic surfaces. The youngest surface had greater spatial variability of these attributes. The iron (goethite and hematite and aluminum (gibbsite oxides in the youngest geomorphic surface influenced the low values of soil density and high values of total pore volume, micropores and P adsorption. The characterization of the spatial variability of Fe oxides and susceptibility allowed for the delineation of homogeneous areas.

  2. Mineralogy and geochemistry of Bobov Dol coals, Bulgaria

    Energy Technology Data Exchange (ETDEWEB)

    Vassilev, S.V.; Yossifova, M.G.; Vassileva, C.G. (Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. of Applied Mineralogy)

    1994-10-01

    The mineralogy, elemental composition and modes of occurrence of 49 elements in nine composite samples of Bobov Dol high-ash coals were studied by optical microscopy, scanning and transmission electron microscopy, X-ray diffractometry and chemical analysis. The major minerals were quartz, kaolinite, illite, plagioclase and K-feldspar and the minor minerals and phases were pyrite, marcasite, siderite, calcite, dolomite, gypsum, muscovite, montmorillonite and volcanic glass. The accessory minerals include a wide variety of minerals, such as galena, pyrrhotite, magnetite, hematite, goethite, chromite, rutile, anatase, corundum, gibbsite, biotite, chlorite, zircon, enstatite, garnet, jarosite, alunite, barite, polyhalite, aragonite, ankerite, witherite, apatite, halite and sylvite. The modes of occurrence and some genetic peculiarities of the above-mentioned minerals are described. Thirty-three elements occurred in concentrations higher than the respective Clarke values; especially S, Rb, Nb, Hf, Zn, Cu, Pb, Mn, Ti and U. The concentration trends and modes of occurrence of the trace elements are also discussed. In decreasing order of significance, the trace elements probably occur as element-organic compounds, as impurities in the mineral constituents, as major components in the minerals, as major and impurity components in the inorganic amorphous constituents, and in the fluid constituents. The Bobov Dol coals have undergone complex syngetenic, diagenetic and epigenetic mineralization processes associated with hydrothermal and volcanic activities. These processes were also accompanied by intensive tectonic movements, and possibly, by a later change from continental to marine sedimentation in the area after burial of the coal. 38 refs., 1 fig., 6 tabs., 5 plates.

  3. Corrosion mineralogy of an 1800 Spanish piece of eight

    Energy Technology Data Exchange (ETDEWEB)

    Craig, J.R. [Virginia Polytechnic Inst. and State Univ., Dept. of Geological Sciences, Blacksburg, Virginia (United States); Callahan, J.E. [Appalachain State Univ., Dept. of Geology, Boone, North Carolina (United States); Kimbell, J.T. [Tavernier, Florida (United States); Solberg, T.N. [Virginia Polytechnic Inst. and State Univ., Dept. of Geological Sciences, Blacksburg, Virginia (United States)

    2002-04-01

    Spanish colonial eight real silver coins, commonly called Pieces of Eight, were used throughout the Spanish-speaking world for hundreds of years. We undertook a detailed mineralogical, textural, and chemical investigation of an 1800 Carlos IIII eight real coin recovered from the wreck of the Spanish frigate Santa Leocadia, which sank on the rocky shore of Ecuador on November 16, 1800, with a loss of more than 140 lives and of 2,100,000 pesos of gold and silver coins. The coin is a typical eight real piece, composed of about 90% Ag and 10% Cu. It was buried in elastic sediments beneath the oxidized zone, such that it reacted with sulfur released by sulfate-reducing bacteria. Consequently, the coin has been totally encapsulated in a mixture of sand, gravel, and shell fragments cemented by metal sulfides. The residual coin consists of silver with small interspersed micrometric grains of copper. Reaction of the dissolved metal with the bacterially generated diagenetic sulfur in the intergranular fluids resulted in extensive cementation of the sediment particles by Ag and Cu sulfides. In the 1-mm zone immediately adjacent to the coin, Cu-bearing acanthite occurs as concentric layers with intervening zones of sand and clay. Beyond this zone, acanthite formed from Ag dissolved from the coin occurs as a more or less continuous interstitial cement with local small islands of covellite, CuS. Copper also occurs as films of Cu carbonate on quartz grains, as isolated grains of jalpaite Ag{sub 3}CuS{sub 2}, stromeyerite AgCuS, mckinstryite (Ag,Cu){sub 2}S, and as atacamite Cu{sub 2}C1(OH){sub 3}, which rim and replace detrital carbonate grains. (author)

  4. Eand P opportunities in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Castilho, Marcelo [National Petroleum Agency of Brasil (Brazil)

    2011-07-01

    Brazil is one of the world's largest economies and the country also has significant heavy oil reserves. This report from the National Petroleum Agency of Brazil aims at presenting the situation of the oil and gas sector in Brazil in terms of resources, production, regulatory framework and opportunities for the future. Brazil has numerous sedimentary basins at its disposal, most of them being prospected by both national and foreign companies from all over the world. Brazil has over 14 billion barrels of proven reserves, its production is 2,1 MMBbl/d and heavy oil represents almost 40% of that production. The National Petroleum Agency of Brazil is responsible for the implementation of oil sector policy with the aims of maintaining self-sufficiency, implementing good practices in terms of health and safety, and increasing local content. This paper pointed out that Brazil has an important opportunity to enhance its energy sector through the development of heavy oil.

  5. Clay mineralogy, organic carbon burial, and redox evolution in Proterozoic oceans

    Science.gov (United States)

    Tosca, Nicholas J.; Johnston, David T.; Mushegian, Alexandra; Rothman, Daniel H.; Summons, Roger E.; Knoll, Andrew H.

    2010-03-01

    Clay minerals formed through chemical weathering have long been implicated in the burial of organic matter (OM), but because diagenesis and metamorphism commonly obscure the signature of weathering-derived clays in Precambrian rocks, clay mineralogy and its role in OM burial through much of geologic time remains incompletely understood. Here we have analyzed the mineralogy, geochemistry and total organic carbon (TOC) of organic rich shales deposited in late Archean to early Cambrian sedimentary basins. Across all samples we have quantified the contribution of 1 M and 1 Md illite polytypes, clay minerals formed by diagenetic transformation of smectite and/or kaolinite-rich weathering products. This mineralogical signal, together with corrected paleo-weathering indices, indicates that late Archean and Mesoproterozoic samples were moderately to intensely weathered. However, in late Neoproterozoic basins, 2 M1 illite/mica dominates clay mineralogy and paleo-weathering indices sharply decrease, consistent with an influx of chemically immature and relatively unweathered sediment. A late Neoproterozoic switch to micaceous clays is inconsistent with hypotheses for oxygen history that require an increased flux of weathering-derived clays (i.e., smectite or kaolinite) across the Precambrian-Cambrian boundary. Compared to previous studies, our XRD data display the same variation in Schultz Ratio across the late Neoproterozoic, but we show the cause to be micaceous clay and not pedogenic clay; paleo-weathering signals cannot be recovered from bulk mineralogy without this distinction. We find little evidence to support a link between these mineralogical variations and organic carbon in our samples and conclude that modal clay mineralogy cannot by itself explain an Ediacaran increase in atmospheric oxygen driven by enhanced OM burial.

  6. Chikungunya risk for Brazil

    Directory of Open Access Journals (Sweden)

    Raimunda do Socorro da Silva Azevedo

    2015-01-01

    Full Text Available This study aimed to show, based on the literature on the subject, the potential for dispersal and establishment of the chikungunya virus in Brazil. The chikungunya virus, a Togaviridae member of the genusAlphavirus, reached the Americas in 2013 and, the following year, more than a million cases were reported. In Brazil, indigenous transmission was registered in Amapa and Bahia States, even during the period of low rainfall, exposing the whole country to the risk of virus spreading. Brazil is historically infested by Ae. aegypti and Ae. albopictus, also dengue vectors. Chikungunya may spread, and it is important to take measures to prevent the virus from becoming endemic in the country. Adequate care for patients with chikungunya fever requires training general practitioners, rheumatologists, nurses, and experts in laboratory diagnosis. Up to November 2014, more than 1,000 cases of the virus were reported in Brazil. There is a need for experimental studies in animal models to understand the dynamics of infection and the pathogenesis as well as to identify pathophysiological mechanisms that may contribute to identifying effective drugs against the virus. Clinical trials are needed to identify the causal relationship between the virus and serious injuries observed in different organs and joints. In the absence of vaccines or effective drugs against the virus, currently the only way to prevent the disease is vector control, which will also reduce the number of cases of dengue fever.

  7. English Teaching Profile: Brazil.

    Science.gov (United States)

    British Council, London (England). English Language and Literature Div.

    This review of the status of English language instruction in Brazil provides an overview of the Brazilian geographic, historical, and political context and the role of English in the society in general and in the educational system. The following topics are covered: an outline of the status of English use and instruction in the educational system…

  8. Adult Education in Brazil.

    Science.gov (United States)

    Ministerio da Educacao e Cultura, Rio de Janeiro (Brazil).

    The status and goals of adult education programs in Brazil are discussed in this report. Supplemental systems such as the Brazilian Literacy Movement (Mobral) and their results are described and evaluated. Charts detailing the evolution of literacy are shown and priorities in education are suggested. The progress of other educational entities is…

  9. Mineralogy of Soils from Different Agroecological Regions of Bangladesh : Region 18–Young Meghna Estuarine Floodplain

    OpenAIRE

    Akter, Fouzia; Moslehuddin, Abu Zofar Md; Kader, Mohammed Abdul; Sarker, Md. Mosharaf Hossain; Mori, Yuki

    2015-01-01

    Bangladesh is consisting of 30 Agroecological Regions (AEZs) and the applied agricultural research has been conducted based on this. In context of the lack of enough information on mineralogy based on AEZs, an attempt has been taken to study the mineralogy of important soils from all AEZs of Bangladesh in order to provide basic information for applied research. As part of this attempt, the mineralogy of twenty four soils from three representative soil series (Ramgati, Hatiya and Silonia) of A...

  10. Textural patterns, mineralogy, and chemistry of sandstone-related Calçadinha chalcedony (Piauí, Brazil

    Directory of Open Access Journals (Sweden)

    Marcondes Lima da Costa

    Full Text Available ABSTRACT: Paleozoic sandstones of the Parnaíba Basin, in addition to hosting opal deposits, also have occurrences of chalcedonies with potential for mineral and ornamental handicrafts, in addition to assisting the understanding of the geological evolution of the basin. However, the chalcedonies were not investigated yet, and this study intended to fulfill this gap by the investigation of the chalcedonies of Calçadinha in Piauí. Fieldwork, microtexturals analysis, X-ray diffraction and scanning electron microscopy with energy dispersive spectrometry, chemical analysis, and gemological assessments were developed. Four distinct types of chalcedonies have been distinguished. They stand out for their well distribution of Fe and Mn dendrites, which involves opal nodules, and contains microcavities with well-formed microcrystalline quartz, nontronite, and palygorskite. The mesoscopic features of these chalcedonies and cabochon and free forms cutting show potential for use in mineral crafts and semi-jewels. As expected, the chalcedonies are dominated by high contents of SiO2, besides the low and variable contents of Al2O3, Fe2O3, MgO, and TiO2. Among trace elements that show high Ba contents, bound in barite, seem also to be a geochemical signature of the country sandstones in Parnaíba basin. These chalcedonies were formed during the partial solubilization of SiO2 of sandstones, which was promoted during their tectonic formation in faults and fractures zones.

  11. Mineralogy of the Santa Fe Tin deposit, Bolivia

    Science.gov (United States)

    Jiménez-Franco, Abigail; Alfonso, Pura; Canet, Carles; Garcia-Valles, Maite; Elvys Trujillo, Juan

    2014-05-01

    Santa Fe is a Sn-Zn-Pb-Ag ore deposit located in the Oruro district, Central Andean Tin Belt, Bolivia. Mineralization occurs in veins and disseminations. It is hosted in Silurian shales and greywackes. The sedimentary sequence is folded and unconformably covered by a volcanic complex of the Morococala Formation, mainly constituted by tuffs of Miocene age. A wide Nº40 shear zone and two systems of fracture are developed. A Nº40 fracture system, dipping 60ºW, which hosts Sn and Zn minerals, and other in the same direction but dipping 75ºE, which is related to Zn-Pb-Ag veins. The mineralization is associated to intrusive felsic magmatism. Although there are not intrusive rocks in Santa Fe, a dyke and the felsic San Pablo stock occur at a distance of about 10 km. In the present work we describe the geology and mineralogy of the Santa Fe deposit. X-ray diffraction, scanning electron microscopy and electron microprobe analyses were used to characterize the minerals. Veins are filled with quartz and an ore mineral assemblage of cassiterite, sulfides and sulfosalts. Cassiterite constitutes the earliest formed mineralization. Preliminar microprobe analyses indicate that it is nearly pure, with negligible contents in Nb and Ta. Rutile occurs as a late phase associated with a late generation of cassiterite. It forms thin neddle-like crystals. In addition, Sn is also present in sulfides as stannite, stannoidite and kësterite. Other sulfides are pyrrhotite, pyrite, arsenopyrite, galena, sphalerite, marchasite and argentite. Bismuthinite and berndite are found nin trace amounts. Sulfosalts include tetrahedrite, myarhyrite, boulangerite, jamesonite, franckeite, zinckenite, cilindrite and andorite. Associated with the mineralization, several phosphate minerals are found filling cavities and small fractures. The most abundant are monacite (Ce,La,Nd,Th)PO4 and plumbogummite (PbAl3(PO4)2(OH)5•(H2O)). Crandallite CaAl3(PO4)2(OH)5•(H2O) and vivianite (Fe3+(PO4)2•8(H2O)) also

  12. Mineralogy of two Cryosoils fromWestern Antarctica

    Science.gov (United States)

    Abakumov, E.; Sapega, V.

    2009-04-01

    Investigations of Antarctic Cryosoils are very urgent now in context of finishing of International Polar Year, assessment of soil resources on the Sixth Continent and prognosis of soil evolution and stability in changing climate. Two soils were investigated on two climatic regions of Western Antarcica. The first was in continental climate (station "Russkaya" 74.45 S., 136.48 W.) and the second in the sea-shore ecoclimatic region (station "Leningradskaya", 69.30 S., 159.23 E.). In first case soils were described as thin (max 3 cm) coarse gravel low humus content layer, presented by sporadical spots of Cryosoils on the debrises of gneises iwth permafrost on the depth about 30 cm. The second soil was located in three polypedons situated in micro depressions on the gneises and basalts rocks with permafros depth about 35 cm. Soils was identified as Cryosoils on gneises, the solum thickness is more than 10 cm. On the base of soil mineralogical study the following peculiarities of Antarctic soils were revealed: - initial parent materials consists of quarts, spates, byotyte, granate and augite, - the ratio of coarse to thin fraction (on the diameter 1 mm) was 90:1 and 80:2 in Russkaya nad Leningradskaya stations correspondingly, which shows that the weathering process is more expressed in sea-shore ecoclimatic region. - "iron films" formation on the surface of stones, this process mostly expressed on the northern exposed slopes, which have a good insolation. Iron films presented by hetite and pyrolisite and mostly expessed in Russkaya station with extra-arid climate, - clay minerals was presented by: smectite (K-Na and Ca-Mg types), illite, chlorite and kaolinite, with some portion of mixedlayer fraction These data shows that the weathering process in very intensive and simultaneously going with new clay and amorphous minerals formation, in both cases of continental and sea-shore climatic environments. That is why it is possible to conclude that main soil formation process

  13. Mineralogy and Petrology of Comet Wild 2 Nucleus Samples

    Energy Technology Data Exchange (ETDEWEB)

    Zolensky, M E; Zega, T J; Yano, H; Wirick, S; Westphal, A J; Weisberg, M K; Weber, I; Warren, J L; Velbel, M A; Tsuchiyama, A; Tsou, P; Toppani, A; Tomioka, N; Tomeoka, K; Teslich, N; Taheri, M; Susini, J; Stroud, R; Stephan, T; Stadermann, F J; Snead, C J; Simon, S B; Siminovici, A; See, T H; Robert, F; Rietmeijer, F M; Rao, W; Perronnet, M C; Papanastassiou, D A; Okudaira, K; Ohsumi, K; Ohnishi, I; Nakanura-Messenger, K; Nakamura, T; Mostefaoui, S; Mikouchi, T; Meibom, A; Matrajt, G; Marcus, M A; Leroux, H; Lemelle, L; Le, L; Lanzirotti, A; Langenhorst, F; Krot, A N; Keller, L P; Kearsley, A T; Joswiak, D; Jacob, D; Ishii, H; Harvey, R; Hagiya, K; Grossman, L; Graham, G A; Gounelle, M; Gillet, P; Genge, M J; Flynn, G; Ferrior, T; Fallon, S; Ebel, D S; Dai, Z R; Cordier, P; Chi, M; Butterworth, A L; Brownlee, D E; Bridges, J C; Brennan, S; Brearley, A; Bradley, J P; Bleuet, P; Bland, P A; Bastien, R

    2006-10-11

    The bulk of the Wild 2 samples appear to be weakly-constructed mixtures of nanometerscale grains with occasional much larger (>1{micro}m) ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal and accessory phases. The very wide range of olivine and low-Ca pyroxene compositions in Wild 2 require a wide range of formation conditions, probably reflecting different formation locations in the protoplanetary disk. The restricted compositional ranges of Fe-Ni sulfides, the wide range for silicates, and absence of hydrous phases indicate that Wild 2 experienced little or no aqueous alteration. Less abundant Wild 2 materials include a refractory particle, whose presence appears to require large-scale radial transport in the early protoplanetary disk. The nature of cometary solids is of fundamental importance to our understanding of the early solar nebula and protoplanetary history. Until now we have had to study comets from afar using spectroscopy, or settle for analyses of interplanetary dust particles (IDPs) of uncertain provenance. We report here mineralogical and petrographic analyses of particles derived directly from Comet Wild 2. All of the Wild 2 particles we have thus far examined have been modified in various ways by the capture process. All particles that may have been loose aggregates, ''traveling sand piles'', disaggregated into individual components with the larger, denser components penetrating more deeply into the aerogel. Individual grains experienced a wide range of heating effects that range from excellent preservation to melting (Fig. 1); such behavior was expected (1, 2 ,3). What is remarkable is the extreme variability of these modifications and the fact that severely modified and unmodified materials can be found within a micrometer of each other, requiring tremendous local temperature gradients. Fortunately, we have an internal gauge of impact collection heating. Fe-Ni sulfides are ubiquitous in the Wild 2 samples, are very

  14. Mineralogy of crater Haulani on dwarf planet Ceres

    Science.gov (United States)

    Tosi, Federico; Zambon, Francesca; Raponi, Andrea; De Sanctis, Maria Cristina; Ammannito, Eleonora; Capria, Maia Teresa; Giacomo Carrozzo, Filippo; Ciarniello, Mauro; Combe, Jean-Philippe; Formisano, Michelangelo; Hoffmann, Martin; Krohn, Katrin; Longobardo, Andrea; McFadden, Lucy Ann; Y McSween, Harry; Nathues, Andreas; Palomba, Ernesto; Pieters, Carle; Stephan, Katrin; Russell, Christopher T.; Raymond, Carol; Dawn/VIR Team

    2016-10-01

    On dwarf planet Ceres, several high-albedo units are visible at the local scale. Haulani crater, located in the equatorial quadrangle having the same name, is one of the notable bright units highlighted by the Dawn spacecraft since its first approach to Ceres in early 2015. Due to the images obtained by the Dawn Framing Camera, it was possible to reveal that Haulani's bright material displays a very small or even negative ("blue") spectral slope in the range from the visible to the near infrared light, which is a peculiar occurrence compared to the average surface of Ceres.Hyperspectral images returned by the Visible and InfraRed mapping spectrometer (VIR) onboard Dawn enabled a detailed mineralogical analysis of the Haulani crater area. Already at the spatial resolution of the Survey phase (~1.1 km/px), and even more so during HAMO (~0.38 km/px) and LAMO (~0.10 km/px) mission phases, Haulani crater shows considerable spectral variability. The spectral features centered at 2.7 and 3.06 µm, respectively indicative of the presence of hydrous minerals and ammoniated phyllosilicates, show a decrease of band depth in the floor and in the bright ejecta corresponding to the blue spectral slope. Spectral signatures at 3.4 and ~4 µm, indicative of carbonates, also show a moderate variability. Finally, Haulani shows the highest thermal contrast over the entire surface of Ceres, which may be linked to the albedo and texture of the material excavated by the impact, combined with its compactness in specific areas such as pitted terrain.The application of a spectral unmixing model on VIR data acquired in Survey and HAMO suggests that the observed spectral variations might be due to substantial differences in grain size, rather than to significant variations in composition. However, a comprehensive analysis shall include LAMO data acquired at higher pixel resolution.AcknowledgementsThis work is supported by the Italian Space Agency (ASI). VIR was funded and coordinated by the

  15. Optimization and Quality Control of Automated Quantitative Mineralogy Analysis for Acid Rock Drainage Prediction

    Directory of Open Access Journals (Sweden)

    Robert Pooler

    2017-01-01

    Full Text Available Low ore-grade waste samples from the Codelco Andina mine that were analyzed in an environmental and mineralogical test program for acid rock drainage prediction, revealed inconsistencies between the quantitative mineralogical data (QEMSCAN® and the results of geochemical characterizations by atomic absorption spectroscopy (AAS, LECO® furnace, and sequential extractions. For the QEMSCAN® results, biases were observed in the proportions of pyrite and calcium sulfate minerals detected. An analysis of the results indicated that the problems observed were likely associated with polished section preparation. Therefore, six different sample preparation protocols were tested and evaluated using three samples from the previous study. One of the methods, which involved particle size reduction and transverse section preparation, was identified as having the greatest potential for correcting the errors observed in the mineralogical analyses. Further, the biases in the quantities of calcium sulfate minerals detected were reduced through the use of ethylene glycol as a polishing lubricant. It is recommended that the sample preparation methodology described in this study be used in order to accurately quantify percentages of pyrite and calcium sulfate minerals in environmental mineralogical studies which use automated mineralogical analysis.

  16. Correlating Mineralogy and Amino Acid Contents of Milligram-Scale Murchison Carbonaceous Chondrite Samples

    Science.gov (United States)

    Burton, Aaron, S.; Berger, Eve L.; Locke, Darren R.; Elsila, Jamie E.; Glavin, Daniel P.; Dworkin, Jason P.

    2015-01-01

    Amino acids, the building blocks of proteins, have been found to be indigenous in most of the carbonaceous chondrite groups. The abundances of amino acids, as well as their structural, enantiomeric and isotopic compositions differ significantly among meteorites of different groups and petrologic types. This suggests that there is a link between parent-body conditions, mineralogy and the synthesis and preservation of amino acids (and likely other organic molecules). However, elucidating specific causes for the observed differences in amino acid composition has proven extremely challenging because samples analyzed for amino acids are typically much larger ((is) approximately 100 mg powders) than the scale at which meteorite heterogeneity is observed (sub mm-scale differences, (is) approximately 1-mg or smaller samples). Thus, the effects of differences in mineralogy on amino acid abundances could not be easily discerned. Recent advances in the sensitivity of instrumentation have made possible the analysis of smaller samples for amino acids, enabling a new approach to investigate the link between mineralogical con-text and amino acid compositions/abundances in meteorites. Through coordinated mineral separation, mineral characterization and highly sensitive amino acid analyses, we have performed preliminary investigations into the relationship between meteorite mineralogy and amino acid composition. By linking amino acid data to mineralogy, we have started to identify amino acid-bearing mineral phases in different carbonaceous meteorites. The methodology and results of analyses performed on the Murchison meteorite are presented here.

  17. Geochemical and mineralogical maps for soils of the conterminous United States

    Science.gov (United States)

    Smith, David B.; Cannon, William F.; Woodruff, Laurel G.; Solano, Federico; Ellefsen, Karl J.

    2014-01-01

    The U.S. Geological Survey began sampling in 2007 for a low-density (1 site per 1,600 square kilometers, 4,857 sites) geochemical and mineralogical survey of soils in the conterminous United States as part of the North American Soil Geochemical Landscapes Project. The sampling protocol for the national-scale survey included, at each site, a sample from a depth of 0 to 5 centimeters, a composite of the soil A horizon, and a deeper sample from the soil C horizon or, if the top of the C horizon was at a depth greater than 1 meter, a sample from a depth of approximately 80–100 centimeters. The elements by methods that yield the total or near-total elemental content. The major mineralogical components in the samples from the soil A and C horizons were determined by a quantitative X-ray diffraction method using Rietveld refinement. Sampling in the conterminous United States was completed in 2010, with chemical and mineralogical analyses completed in May 2013. The resulting data set provides an estimate of the abundance and spatial distribution of chemical elements and minerals in soils of the conterminous United States and represents a baseline for soil geochemistry and mineralogy against which future changes may be recognized and quantified. This report releases geochemical and mineralogical maps along with a histogram, boxplot, and empirical cumulative distribution function plot for each element or mineral.

  18. Influence of mineralogical and heavy metal composition on natural radionuclide concentrations in the river sediments.

    Science.gov (United States)

    Suresh, G; Ramasamy, V; Meenakshisundaram, V; Venkatachalapathy, R; Ponnusamy, V

    2011-10-01

    The natural radiation level has been determined for the sediment samples of the Ponnaiyar River with an aim of evaluating the radiation hazard. The mineralogical characterizations of the sediments have been carried out using the Fourier Transform Infrared (FTIR) spectroscopic technique. The relative distribution of major minerals is determined by calculating extinction coefficient. The concentration and spatial distribution of heavy metals (Pb, Cr, Cu, Zn and Ni) have been studied to understand the heavy metal contamination and its level of toxicity. To evaluate the potential toxicity, heavy metal concentrations are compared with different toxicological and geological reference values. The comparison results suggest that the present metals create an adverse effect on the aquatic ecosystems associated with this river. To assess the sediment contamination due to the studied heavy metals, the Pollution Load Index (PLI) is calculated. Multivariate Statistical analyses (Pearson Correlation, Cluster and Factor analysis) were carried out between the parameters obtained from radioactivity, mineralogical and geochemical analysis to know the existing relations. Obtained results showed that the effect of mineralogy on level of radioactivity should be significant. However, mineralogy effect on heavy metal composition in the sediments should be limited, indicating that other factors such as vicinity of the pollution sources are more important. Also, the influence of mineralogical characterization on level of radioactivity is significant, whereas the influence of the heavy metal composition on level of radioactivity should be limited.

  19. CCD-Based XRD/XRF for Determining Environmental Mineralogy on Mars

    Science.gov (United States)

    Vaniman, D. T.; Bish, D. L.; Blake, D. F.; Chipera, S. J.

    2000-01-01

    Health effects from Martian dusts will be a concern for any manned Mars missions. Nuisance dusts plagued the Apollo astronauts, but dusts of more hazardous mineralogy, in habitats occupied by Mars astronauts weakened by a long-duration mission, may be more than a nuisance. Chemical hazards in Martian regolith attributable to S, Cl, Br, Cd, and Pb are known or strongly suspected to be present, but terrestrial studies of the health effects of dusts indicate that accurate determination of mineralogy is a critical factor in evaluating inhalation hazards. Mineral inhalation hazards such as the Group-I carcinogenic zeolite erionite, which is demonstrated to cause mesothelioma, cannot be identified by chemical analysis alone. Studies of palagonite analogs raise the possibility that erionite may occur on Mars. In addition to health effects concerns, environmental mineralogy has significant importance in resource extraction, groundwater use, and sustained agriculture. The high sulfur and chlorine content of Martian regolith will affect all of these uses, but the nature of mineralogic reservoirs for S and Cl will determine their uptake and concentration in extracted groundwater and in agricultural applications of regolith. Wet chemistry experiments planned for the Mars Environmental Compatibility Assessment (MECA) will define some of the consequences of water/soil interaction, but an understanding of the mineralogic basis for water-rock reactions is needed to understand the mechanisms of reaction and to apply the results of a few experiments to larger scales and different conditions.

  20. Mineralogic Zonation Within the Tuff Confining Unit, Yucca Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Lance Prothro

    2005-09-01

    Recently acquired mineralogic data from drill hole samples in Yucca Flat show that the tuff confining unit (TCU) can be subdivided into three mineralogic zones based on the relative abundances of primary and secondary mineral assemblages. These zones are (1) an upper zone characterized by the abundance of the zeolite mineral clinoptilolite with lesser amounts of felsic and clay minerals; (2) a middle zone with felsic minerals dominant over clinoptilolite and clay minerals; and (3) a basal argillic zone where clay minerals are dominant over felsic minerals and clinoptilolite. Interpretation of the mineralogic data, along with lithologic, stratigraphic, and geophysical data from approximately 500 drill holes, reveals a three-layer mineralogic model for the TCU that shows all three zones are extensive beneath Yucca Flat. The mineralogic model will be used to subdivide the TCU in the Yucca Flat hydrostratigraphic framework model, resulting in a more accurate and versatile framework model. In addition, the identification of the type, quantity, and distribution of minerals within each TCU layer will permit modelers to better predict the spatial distribution and extent of contaminant transport from underground tests in Yucca Flat, at both the level of the hydrologic source term and the corrective action unit.

  1. Mineralogy, morphology and crystal-chemistry of the monazite from Catalao 1 (Goias, Brazil); Mineralogia, morfologia e cristaloquimica da monazita de Catalao 1 (Goias, Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Maria Cristina Motta de; Oliveira, Sonia Maria Barros de; Ferrari, Viviane Carillo [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias]. E-mails: mcristol@usp.br; vferrari@usp.br; Fontan, Francois; Parseval, Philippe de [Universite Paul Sabatier, Toulouse (France). Lab. Mineralogie et Cristallographie]. E-mails: fontan@cict.fr; parseval@insatlse.fr

    2004-03-15

    The Catalao alkaline carbonatite complex hosts a number of mineral resources including monazite. This mineral is a common accessory phase in two lithological units: carbonatite and silexite. Textural evidence suggest that monazite replaced carbonates in the carbonatite and crystallized simultaneously with quartz in the silexite. Monazite was resistant to the strong laterization that affected the massif, except for the incipient transformation into gorceixite or cerianite. In both carbonatite and silexite, monazite occurs as a complex aggregate of sub-micrometric crystals, showing unusual morphological and chemical characteristics. It contains Ca, Sr, and Ba in the A-site, and shows a certain degree of hydration indicated by ATD and IV data. Structural formulae calculated on the basis of sum of cations=1 show a moderate ionic deficiency in the anionic site. Rietveld refinement indicated poor crystallinity. Notwithstanding these peculiar characteristics, cell dimensions are similar to those of standard monazite. (author)

  2. Geochemical and mineralogical data for soils of the conterminous United States

    Science.gov (United States)

    Smith, David B.; Cannon, William F.; Woodruff, Laurel G.; Solano, Federico; Kilburn, James E.; Fey, David L.

    2013-01-01

    In 2007, the U.S. Geological Survey initiated a low-density (1 site per 1,600 square kilometers, 4,857 sites) geochemical and mineralogical survey of soils of the conterminous United States as part of the North American Soil Geochemical Landscapes Project. Sampling and analytical protocols were developed at a workshop in 2003, and pilot studies were conducted from 2004 to 2007 to test and refine these recommended protocols. The final sampling protocol for the national-scale survey included, at each site, a sample from a depth of 0 to 5 centimeters, a composite of the soil A horizon, and a deeper sample from the soil C horizon or, if the top of the C horizon was at a depth greater than 1 meter, from a depth of approximately 80–100 centimeters. The elements by methods that yield the total or near-total elemental content. The major mineralogical components in the samples from the soil A and C horizons were determined by a quantitative X-ray diffraction method using Rietveld refinement. Sampling in the conterminous United States was completed in 2010, with chemical and mineralogical analyses completed in May 2013. The resulting dataset provides an estimate of the abundance and spatial distribution of chemical elements and minerals in soils of the conterminous United States and represents a baseline for soil geochemistry and mineralogy against which future changes may be recognized and quantified. This report (1) describes the sampling, sample preparation, and analytical methods used; (2) gives details of the quality control protocols used to monitor the quality of chemical and mineralogical analyses over approximately six years; and (3) makes available the soil geochemical and mineralogical data in downloadable tables.

  3. IHY activities in Brazil

    Science.gov (United States)

    Dal Lago, Alisson

    The International Heliophysical Year is a program of international scientific colaboration planned to be held in the period from 2007-2009. Many brazilian institutions have shown interest in participating in the IHY activities. All of them provided information about their instrumental facilities and contact person. A list of institutions and their information is shown in the Latin-American IHY webpage (http://www.alage.org/IHYLA/ihyla.html), hosted by the Latin American Association on Space Geophysics - ALAGE. IHY Brazilian activities are being conducted in close colaboration with Latin-American Institutions. Five Coordinated Investigation programs (CIPs) have been proposed by scientists from brazilian institutions. Recentely, in February 2008, there has been the Latin American IHY School in Sao Paulo (Brazil), with the participation of 80 students from Brazil, Argentina, Peru, Mexico and Cuba. In this work, a report on the brazilian activities will be presented.

  4. Heliostat tailored to Brazil

    OpenAIRE

    Pfahl, Andreas; Bezerra, Pedro; Hölle, Erwin; Liedke, Phillip; Teramoto, Erico Tadao; Hertel,Johannes; Lampkowski, Marcelo; Oliveira, L

    2015-01-01

    For Brazil it is important to realize a high local production share because of high import tax rates. The rim drive concept offers an alternative for expensive heliostat drive solutions with slew and linear drives from abroad. By (locally produced) rims the demands on the drives regarding strength and precision are reduced to a very low value and low cost drives can be used. Sandwich facets (which are usually foreseen for rim drive heliostats) are not available from Brazilian manufacturers an...

  5. Innovation Policies of Brazil

    Science.gov (United States)

    2013-09-01

    by the other BRIC countries, particularly China. 18 Discussions with experts. See the appendix. 19 Brazil can have a low actual tariff rate of...Cassiolato, J. E., M. G Podcameni, M. C. Couto Soares, M. Szapiro, P. Koeller, F. Stalivieri, and F. Geremia. 2010. “ BRICS Description and Dynamics of...the Future of Internation Order. Center for a New American Security. Koeller, P, and J. L. Gordon. 2010. “ BRICS the Role of the State in National

  6. Práctica de la mineralogía óptica

    OpenAIRE

    Parra Sánchez, Luis Norberto

    1986-01-01

    Resumen: El presente documento contiene los procedimientos más comunes de la mineralogía óptica acompañados de las tablas de mayor utilidad y por lo tanto lo único que pretende es agrupar técnicas y aclarar posibles dudas sobre el uso de la terminología. El contenido hace parte del curso regular de mineralogía óptica dictado en la Universidad Nacional y ha sido el resultado de varios años en la práctica de esta materia

  7. Chemical and Mineralogical Characterization of a Hematite-bearing Ridge on Mauna Kea, Hawaii: A Potential Mineralogical Process Analog for the Mount Sharp Hematite Ridge

    Science.gov (United States)

    Graff, T. G.; Morris, R. V.; Ming, D. W.; Hamilton, J. C.; Adams, M.; Fraeman, A. A.; Arvidson, R. E.; Catalano, J. G.; Mertzman, S. A.

    2014-01-01

    The Mars Science Laboratory (MSL) rover Curiosity landed in Gale Crater in August 2012 and is currently roving towards the layered central mound known as Mount Sharp [1]. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) hyperspectral data indicate Mount Sharp contains an 5 km stratigraphic sequence including Fe-Mg smectites, hematite, and hydrated sulfates in the lower layers separated by an unconformity from the overlying anhydrous strata [1,2,3]. Hematite was initially detected in CRISM data to occur in the lower sulfate layers on the north side of the mound [2]. [3] further mapped a distinct hematite detection occurring as part of a 200 m wide ridge that extends 6.5 km NE-SW, approximately parallel with the base of Mount Sharp. It is likely a target for in-situ analyses by Curiosity. We document here the occurrence of a stratum of hematite-bearing breccia that is exposed on the Puu Poliahu cinder cone near the summit of Mauna Kea volcano (Hawaii) (Fig.1). The stratum is more resistant to weathering than surrounding material, giving it the appearance of a ridge. The Mauna Kea hematite ridge is thus arguably a potential terrestrial mineralogical and process analog for the Gale Crater hematite ridge. We are acquiring a variety of chemical and mineralogical data on the Mauna Kea samples, with a focus on the chemical and mineralogical information already available or planned for the Gale hematite ridge.

  8. Geochemical and mineralogical data for soils of the conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In 2007, the U.S. Geological Survey began a low-density (1 site per 1,600 sq. km., 4857 sites) geochemical and mineralogical survey of soils of the conterminous...

  9. Ashes from oily sewage sludge combustion: chemistry, mineralogy and leaching properties

    Directory of Open Access Journals (Sweden)

    Róbert Polc

    2016-07-01

    Full Text Available In the current paper the chemical and mineralogical properties of bottom ash and fly ash from oily sewage sludge combustion are investigated. The mineralogical composition and the morphology of ashes were determined by X-ray powder diffraction (XRD in combination with scanning electron microscopy with quantitative energy-dispersive X-ray microanalysis (SEM-EDX. In addition, a leaching test results are presented to shed light on the potential toxicity of studied materials and their impact on the environment is discussed. Both of the studied materials are final products of thermal oxidation at industrial sludge incinerator. This facility aims to sanitary disposal of mechanical and biological sludge from industrial wastewater treatment plant. Bottom ash and fly ash are relatively stable solid products with slightly different chemical and mineralogical composition that reflects their different origin – burning condition in furnace vs. flues gas cleaning technology. Leaching tests of both mentioned materials were implemented under laboratory conditions. The aim of the laboratory tests was to determine the possibility of the pollutants release into the environment. The data presented herein support the importance of detailed mineralogical and geochemical study for the better understanding of the leaching tests. The obtained results showed that both of the sewage sludge ash samples exceed the criteria for accepting waste in landfilles established for Slovakia.

  10. Mineralogy by X-ray Diffraction on Mars: The Chemin Instrument on Mars Science Laboratory

    Science.gov (United States)

    Vaniman, D. T.; Bristow, T. F.; Bish, D. L.; Ming, D. W.; Blake, D. F.; Morris, R. V.; Rampe, E. B.; Chipera, S. J.; Treiman, A. H.; Morrison, S. M.; Achilles, C. N.; Downs, R. T.; Farmer, J. D.; Crisp, J. A.; Morookian, J. M.; Des Marais, D. J.; Grotzinger, J. P.; Sarrazin, P.; Yen, A. S.

    2014-01-01

    To obtain detailed mineralogy information, the Mars Science Laboratory rover Curiosity carries CheMin, the first X-ray diffraction (XRD) instrument used on a planet other than Earth. CheMin has provided the first in situ XRD analyses of full phase assemblages on another planet.

  11. Sand and clay mineralogy of sal forest soils of the Doon Siwalik Himalayas

    Indian Academy of Sciences (India)

    Mukesh; R K Manhas; A K Tripathi; A K Raina; M K Gupta; S K Kamboj

    2011-02-01

    The peteromineralogical characterization of the soil was carried out for the 12 soil profiles exposed in the Shorea robusta dominated forests of the Siwalik forest division, Dehradun. The quartz was observed as the dominating light mineral fraction (64–80%) in all the profiles studied. Biotite, hornblende, zircon, tourmaline, rutile and opaques comprising of iron minerals constituted the heavy mineral fraction (20%). The mineralogy of both the sand and clay fractions revealed a mixed mineralogy. The clay minerals in the order of their dominance were vermiculite, illite, kaolinite and mixed layer minerals. The presence of vermiculite and illite in appreciable quantities indicates that these were synthesized from the K-rich soil solution, as orthoclase and micas were present in significant quantities in the sand minerals. The mineral suites identified in the study shows that the geological, climatological and topographical factors of the region collectively played a dominant role in their formation and transformation. After critical appraisal of the results, it may be deduced that the mineralogical composition, physicochemical properties and total elemental analysis of the soils do not show any deficiency of the bases and other plant nutrients in general. The inherent fertility of the soil is good as indicated by the sand and clay mineralogy of the soil and the biotite and feldspar together with the mica is an important source of nutrients for the vegetation in the soils of the Doon valley.

  12. Mineralogical analyses in various caves from the Băile Herculane area, the Cerna Passage

    Directory of Open Access Journals (Sweden)

    Ştefan Marincea

    2010-01-01

    Full Text Available In this paper we intend to show results from the mineralogical analyses performed on samples from three caves in the Baile Herculane area. All minerals presented here are described for the first time in the cave from which they were sampled.

  13. Mineralogical Composition of Urinary Stones and Their Frequency in Patients: Relationship to Gender and Age

    Directory of Open Access Journals (Sweden)

    Behnam Keshavarzi

    2016-12-01

    Full Text Available This investigation reports the mineralogy and possible pathological significance of urinary stones removed from patients in Fars province, Iran. X-ray diffraction (XRD, scanning electron microscopy (SEM and polarizing microscope (PM techniques were used to investigate the mineralogical compositions of urinary stones. The identified mineral components include whewellite, weddellite, hydroxyapatite, uricite and cystine. These techniques revealed that the whewellite and uricite were the most common mineral phases. Platy-like/monoclinic whewellite, prismatic/monoclinic uric acid and hexagonal cystine crystals were revealed by SEM. Biominerals (calcium carbonate and quartz were also identified in PM images. Of the variables determining the type of precipitated minerals, the effects of pH on depositional conditions proved to be the most apparent parameter, as shown by occurrences and relationships among the studied minerals. Our results revealed the importance of detailed knowledge of mineralogical composition in assessing the effects of age and sex. The highest incidence of urinary stones was observed in the 40–60 age group. Calcium oxalate and uric acid stones are more frequent in men than women. Finally, the study concluded that knowledge of the mineralogical composition of urinary stones is important as it helps the scientific community to explain the chemistry and the etiology of the calculi in the urinary system.

  14. Arsenic in New England: Mineralogical and geochemical studies of sources and enrichment pathways

    Science.gov (United States)

    Ayuso, Robert A.; Foley, Nora K.

    2003-01-01

    Detailed mineralogical, geochemical and radiogenic isotopic studies of iron-sulfide and secondary iron oxy-hydroxide minerals in natural bedrock in coastal Maine and New Hampshire test the link between arsenic-rich sulfide minerals in bedrock and secondary oxy-hydroxide minerals. Samples were selected from over 70 bedrock localities, including 22 within the regionally extensive and sulfide-mineral-rich Penobscot Formation and 10 associated with mineral deposits from coastal New Hampshire and Maine, and coupled with data from drill core collected at several sites including areas where well waters contain anomalous As abundances (e.g., Northport, ME). The data were used to establish a diversity of primary and secondary mineralogical hosts for arsenic in bedrock of this part of New England. The studies show that bedrock mineralogy is critical to contributing arsenic to groundwater and suggest a number of mineralogical pathways for arsenic that define weathering processes. The studies show that lead isotopic compositions of the sulfides and iron oxy-hydroxides overlap and establish a genetic link between the sulfides and secondary minerals. The data and interpretive results were presented at Arsenic in New England -- A multidisciplinary Scientific Conference, Manchester, New Hampshire, May 29-31, 2002, sponsored by the New Hampshire Consortium on Arsenic, are available in abstract and poster (full size = 84 by 36 inch sheet) formats.

  15. X-ray diffraction results from mars science laboratory: Mineralogy of rocknest at Gale crater

    NARCIS (Netherlands)

    Bish, D.L.; Blake, D.F.; Vaniman, D.T.; Chipera, S.J.; Morris, R.V.; Ming, D.W.; Treiman, A.H.; Sarrazin, P.; Morrison, S.M.; Downs, R.T.; Achilles, C.N.; Yen, A.S.; Bristow, T.F.; Crisp, J.A.; Morookian, J.M.; Farmer, J.D.; Rampe, E.B.; Stolper, E.M.; Spanovich, N.; MSL Science Team, the

    2013-01-01

    The Mars Science Laboratory rover Curiosity scooped samples of soil from the Rocknest aeolian bedform in Gale crater. Analysis of the soil with the Chemistry and Mineralogy (CheMin) x-ray diffraction (XRD) instrument revealed plagioclase (~An57), forsteritic olivine (~Fo62), augite, and pigeonite, w

  16. Mineralogy and pore water chemistry of a boiler ash from a MSW fluidized-bed incinerator.

    Science.gov (United States)

    Bodénan, F; Guyonnet, D; Piantone, P; Blanc, P

    2010-07-01

    This paper presents an investigation of the mineralogy and pore water chemistry of a boiler ash sampled from a municipal solid waste fluidized-bed incinerator, subject to 18 months of dynamic leaching in a large percolation column experiment. A particular focus is on the redox behaviour of Cr(VI) in relation to metal aluminium Al(0), as chromium may represent an environmental or health hazard. The leaching behaviour and interaction between Cr(VI) and Al(0) are interpreted on the basis of mineralogical evolutions observed over the 18-month period and of saturation indices calculated with the geochemical code PhreeqC and reviewed thermodynamic data. Results of mineralogical analyses show in particular the alteration of mineral phases during leaching (e.g. quartz and metal aluminium grains), while geochemical calculations suggest equilibria of percolating fluids with respect to specific mineral phases (e.g. monohydrocalcite and aluminium hydroxide). The combination of leaching data on a large scale and mineralogical analyses document the coupled leaching behaviour of aluminium and chromium, with chromium appearing in the pore fluids in its hexavalent and mobile state once metal aluminium is no longer available for chromium reduction.

  17. Prediction of potential compressive strength of Portland clinker from its mineralogy

    DEFF Research Database (Denmark)

    Svinning, K.; Høskuldsson, Agnar; Justnes, H.

    2010-01-01

    Based on a statistical model first applied for prediction of compressive strength up to 28 d from the microstructure of Portland cement, potential compressive strength of clinker has been predicted from its mineralogy. The prediction model was evaluated by partial least squares regression. The mi...

  18. Mineralogical, Spectral, and Compositional Changes During Heating of Hydrous Carbonaceous Chondrites

    Science.gov (United States)

    Nakamura, T.; Matsuoka, M.; Yamashita, S.; Sato, Y.; Mogi, K.; Enokido, Y.; Nakata, A.; Okumura, S.; Furukawa, Y.; Zolensky, M.

    2017-01-01

    Hydrous carbonaceous chondrites experienced hydration and subsequent dehydration by heating, which resulted in a variety of mineralogical and spectral features [e. g., 1-6]. The degree of heating is classified according to heating stage (HS) II to IV based on mineralogy of phyllosilicates [2], because they change, with elevating temperature, to poorly crystal-line phases and subsequently to aggregates of small secondary anhydrous silicates of mainly olivine. Heating of hydrous carbonaceous chondrites also causes spectral changes and volatile loss [3-6]. Experimental heating of Murchison CM chondrite showed flattening of whole visible-near infrared spectra, especially weakening of the 3µm band strength [1, 4, 7]. In order to understand mineralogical, spectral, and compositional changes during heating of hydrous carbonaceous chondrites, we have carried out systematic investigation of mineralogy, reflectance spectra, and volatile composition of hydrated and dehydrated carbonaceous chondrites as well as experimentally-heated hydrous carbonaceous chondrites. In addition, we investigated reflectance spectra of tochilinite that is a major phase of CM chondrites and has a low dehydration temperature (250degC).

  19. Christian Herrgen y la institucionalización de la mineralogía en Madrid

    Directory of Open Access Journals (Sweden)

    Parra, Dolores

    1996-06-01

    Full Text Available One of the goals of the scientific policy of the governments of the Borbones were that of favors the disciplines subject to be applied for the necessary stimulus of the Spanish economy. Such it was the case of the Mineralogy, science that was developed and imparted in several scientific cultured institutions. One of these centers were the Cabinet of Natural History from Madrid, in which the work of the German specialist Christian Herrgen contributed to the institutionalization of the Spanish Mineralogy.

    Uno de los objetivos de la política científica de los gobiernos borbones fue la de potenciar aquellas disciplinas susceptibles de ser aplicadas en el necesario fomento de la economía española. Tal fue el caso de la Mineralogía, ciencia que fue desarrollada e impartida en varias instituciones científicas ilustradas. Uno de estos centros fue el Gabinete de Historia Natural de Madrid, en el que la labor del especialista alemán Christian Herrgen contribuyó a la institucionalización de la mineralogía española.

  20. Detailed description of oil shale organic and mineralogical heterogeneity via fourier transform infrared mircoscopy

    Science.gov (United States)

    Washburn, Kathryn E.; Birdwell, Justin E.; Foster, Michael; Gutierrez, Fernando

    2015-01-01

    Mineralogical and geochemical information on reservoir and source rocks is necessary to assess and produce from petroleum systems. The standard methods in the petroleum industry for obtaining these properties are bulk measurements on homogenized, generally crushed, and pulverized rock samples and can take from hours to days to perform. New methods using Fourier transform infrared (FTIR) spectroscopy have been developed to more rapidly obtain information on mineralogy and geochemistry. However, these methods are also typically performed on bulk, homogenized samples. We present a new approach to rock sample characterization incorporating multivariate analysis and FTIR microscopy to provide non-destructive, spatially resolved mineralogy and geochemistry on whole rock samples. We are able to predict bulk mineralogy and organic carbon content within the same margin of error as standard characterization techniques, including X-ray diffraction (XRD) and total organic carbon (TOC) analysis. Validation of the method was performed using two oil shale samples from the Green River Formation in the Piceance Basin with differing sedimentary structures. One sample represents laminated Green River oil shales, and the other is representative of oil shale breccia. The FTIR microscopy results on the oil shales agree with XRD and LECO TOC data from the homogenized samples but also give additional detail regarding sample heterogeneity by providing information on the distribution of mineral phases and organic content. While measurements for this study were performed on oil shales, the method could also be applied to other geological samples, such as other mudrocks, complex carbonates, and soils.

  1. Mineralogical Characteristics of Specimens of a Meteorwrong Fall from NW Iran

    CERN Document Server

    Pourkhorsandi, Hamed

    2014-01-01

    In the early hours of October 22, 2011, people of a small town in NW Iran, called Khameneh (38{\\deg}11'47" N, 45{\\deg}38'14" E) noticed sounds of some colliding objects to home roofs and yard floors. Mineralogical investigations revealed the terrestrial and man-made origin of these stony samples.

  2. Brazil: Intercultural Experiential Learning Aid.

    Science.gov (United States)

    Brigham Young Univ., Provo, UT. Language Research Center.

    This booklet was designed to facilitate interactions and communication with the people of Brazil by providing information about their customs, attitudes and other cultural characteristics which influence their actions and values. A brief description of Brazil is given, covering the following: its size and geography, history, language, economy,…

  3. Petrography and U-Pb Zircon Geochronology of Geological Units of the Mesa de Cocodite, Península de Paraguaná, Venezuela

    Science.gov (United States)

    Mendi, D.; Baquero, M. L.; Oliveira, E. P.; Urbani, F.; Pinto, J.; Grande, S.; Valencia, V.

    2013-05-01

    Several continental crust units crop out in The Mesa de Cocodite, central Paraguaná Peninsula, Northwestern Venezuela, including a newly mapped quartz-feldspar gneiss that intruded the El Amparo Pluton, a major low-graded metamorphic unit of Permian age. It is unconformably overlying by Late Jurassic phyllites of the Pueblo Nuevo Formation. All these units are cross-cut by narrow dykes. This contribution focuses on the petrography and LA-ICP-MS U-Pb zircon dating of the igneous units, with the aim of constraining magmatism and its tectonic significance in the area. The quartz-feldspar gneiss consists of albite, bluish-smoked quartz, muscovite-chlorite, epidote and zircon. The enclosing El Amparo Pluton is typically a coarse-grained and thick-banded metagranodiorite, containing andesine, quartz, hornblende, epidote, K-feldspar, biotite, chlorite, titanite and zircon. The younger dykes consist of fine-grained, porphyritic hornblende diorites that contain numerous hornblende phenocrysts. The main minerals are andesine, hornblende, quartz, and chlorite. Accessory minerals include zircon, epidote and opaques. A felsic gneiss xenolith collected from the dykes contain quartz, K-feldspar, chlorite, epidote, albite and zircon. Zircon population in the quartz-feldspar gneiss displays a discordia trend, ranging in age from 1050-750 Ma but mostly around 950-900 Ma, which may represent a peak high-grade metamorphism in the area. The El Amparo Pluton provides a concordant Permian age (271.3±6.5 Ma), which is comparable with previous reported U-Pb ages in titanite. Because the porphyry dykes cross-cut all the units in the area, they should be post-Late Jurassic in Age; however, all dated zircons from the dykes are in the range of 1200-750 Ma. The absence of younger ages can be attributed to either formation during a relatively low temperature magmatic event, which generated very narrow younger zircon rims only and thus undetectable with the technique used, or a completely lack

  4. Mineral Supertrumps: A new card game to assist learning of mineralogy

    Science.gov (United States)

    Spandler, C.

    2015-12-01

    Mineralogy is considered one of the cornerstone subjects of geoscience curriculum. It provides the basic information from which we can understand the composition and behaviour of Earth and planetary materials, yet many students struggle to obtain adequate comprehension and knowledge of mineralogy during tertiary degree programs. Here, I introduce a new card game called "Mineral Supertrumps" that can be used to assist teaching of mineralogy at secondary and tertiary level. The card game is easy to learn and play, and is designed to promote active learning in a group environment. The game involves 3 to 6 people, and is similar to the "Top Trumps™" card games. The pack consists of 54 mineral cards, and 6 supertrump cards. Each mineral card includes information about the mineral such as the generic chemical formula, the classification, crystal system, the geological environment where the mineral is commonly found or formed, as well as information in the five playing categories (or trumps) of Hardness, Specific Gravity, Cleavage, Crustal Abundance, and Economic Value. The first three playing categories relate to distinct physical properties of the mineral, while last two categories rate the importance of the mineral in terms of abundance in the Earth's crust and value to modern societies. Results of a formal evaluation of the game by students in the second year of a tertiary geology program indicate that the game has clear benefits for learning about mineralogy. The majority of students enjoyed playing the game and considered it to be effective for enhancing learning about mineral properties and their application to other Earth Science disciplines. Therefore, inclusion of "Mineral Supertrumps" into Earth Science curriculum at secondary or tertiary level has the potential to redress the difficulties students face in learning of mineralogy, while requiring little to no adjustment to existing teaching programs.

  5. Skeletal mineralogy of coral recruits under high temperature and pCO2

    Directory of Open Access Journals (Sweden)

    T. Foster

    2015-08-01

    Full Text Available Aragonite, which is the polymorph of CaCO3 precipitated by modern corals during skeletal formation, has a higher solubility than the more stable polymorph calcite. This higher solubility leaves animals that produce aragonitic skeletons more vulnerable to anthropogenic ocean acidification. It is therefore, important to determine whether scleractinian corals have the plasticity to adapt and produce calcite in their skeletons in response to changing environmental conditions. Both high pCO2 and lower Mg / Ca ratios in seawater are thought to have driven changes in the skeletal mineralogy of major marine calcifiers in the past ∼540 myr. Experimentally reduced Mg / Ca ratios in ambient seawater have been shown to induce some calcite precipitation in both adult and newly settled modern corals, however, the impact of high pCO2 on the mineralogy of recruits is unknown. Here we determined the skeletal mineralogy of one-month old Acropora spicifera coral recruits grown under high temperature (+3 °C and pCO2 (∼900 μatm conditions, using X-ray diffraction and Raman spectroscopy. We found that newly settled coral recruits produced entirely aragonitic skeletons regardless of the treatment. Our results show that elevated pCO2 alone is unlikely to drive changes in the skeletal mineralogy of young corals. Not having an ability to switch from aragonite to calcite precipitation may leave corals and ultimately coral reef ecosystems more susceptible to predicted ocean acidification. An important area for prospective research would be to investigate the combined impact of high pCO2 and reduced Mg / Ca ratio on coral skeletal mineralogy.

  6. Phylomineralogy of the coralline red algae: correlation of skeletal mineralogy with molecular phylogeny.

    Science.gov (United States)

    Smith, A M; Sutherland, J E; Kregting, L; Farr, T J; Winter, D J

    2012-09-01

    The coralline algae in the orders Corallinales and Sporolithales (subclass Corallinophycidae), with their high degree of mineralogical variability, pose a challenge to projections regarding mineralogy and response to ocean acidification. Here we relate skeletal carbonate mineralogy to a well-established phylogenetic framework and draw inferences about the effects of future changes in sea-water chemistry on these calcified red algae. A collection of 191 coralline algal specimens from New Zealand, representing 13 genera and 28 species, included members of three families: Corallinaceae, Hapalidiaceae, and Sporolithaceae. While most skeletal specimens were entirely calcitic (range: 73-100 wt.% calcite, mean 97 wt.% calcite, std dev=5, n=172), a considerable number contained at least some aragonite. Mg in calcite ranged from 10.5 to 16.4 wt.% MgCO(3), with a mean of 13.1 wt.% MgCO(3) (std dev=1.1, n=172). The genera Mesophyllum and Lithophyllum were especially variable. Growth habit, too, was related to mineralogy: geniculate coralline algae do not generally contain any aragonite. Mg content varied among coralline families: the Corallinaceae had the highest Mg content, followed by the Sporolithaceae and the Hapalidiaceae. Despite the significant differences among families, variation and overlap prevent the use of carbonate mineralogy as a taxonomic character in the coralline algae. Latitude (as a proxy for water temperature) had only a slight relationship to Mg content in coralline algae, contrary to trends observed in other biomineralising taxa. Temperate magnesium calcites, like those produced by coralline algae, are particularly vulnerable to ocean acidification. Changes in biomineralisation or species distribution may occur over the next few decades, particularly to species producing high-Mg calcite, as pH and CO(2) dynamics change in coastal temperate oceans.

  7. Lithology, mineralogy and geochemical characterizations of sediment-hosted Sr-F deposits in the eastern Neo-Tethyan region - With special reference to evaporation and halokinesis in Tunisia

    Science.gov (United States)

    Dill, H. G.; Nolte, N.; Hansen, B. T.

    2014-04-01

    The Neo-Tethyan basin is known for its sediment-hosted Sr deposits in Spain, Turkey, Cyprus, and the Gulf Region. Sediment-hosted Sr-F deposits with base metals formed in the rim sinks and on top of salt domes resulting from halokinesis of Triassic evaporites near the southern edge of the Mediterranean Sea in Tunisia. These evaporites delivered part of the elements, created a basin-and-swell topography and provided the local and regional unconformities to which many of the mineral deposits are related. Five mineralizing processes, each with characteristic sedimentary ore textures, are related to this subsurface salt movement: (1 + 2) Early- and late-stage replacement ("zebra rocks"), (3) hydraulic fracturing ("fitting breccia" sensuDill and Weber, 2010b), (4) remobilization ("spinifex structures"), and (5) open-space filling ("caves and vein-like deposits"). Basinal brines from Mesozoic aquifers delivered Pb, Zn, Cd, REE, Y, Hg, and Se, while Sr, Cs, Be, Li, Cu and Co have been derived from Cenozoic salinas of the Neo-Tethyan basin. Mixing of Mesozoic and Cenozoic brines between 28 and 19 Ma provoked the emplacement of Sr-F mineralization at temperatures below 200 °C under strong alkaline conditions. Epigenetic polyphase Sr-F deposits bearing base-metals which are closely related to salt domes (Tunisian-Type) may be traced into epigenetic monophase Sr deposits within bioherms (Cyprus-Type) devoid of Pb, Zn and F. Moving eastward, syndiagenetic monophase Sr deposits in biostromes (Gulf-Type) herald the beginning of Sr concentration in Miocene sabkhas of the Neo-Tethys. The current results are based upon field-related sediment petrography and on mineralogical studies, which were supplemented by chemical studies. The present studies bridge the gap between epigenetic carbonate-hosted MVT and syndiagenetic evaporite deposits, both of which developed during the same time span (Neogene) and were hosted by the same environment (near-shore marine marginal facies of the Neo

  8. Geochemistry, petrography, and zircon U-Pb geochronology of Paleozoic metaigneous rocks in the Mount Veta area of east-central Alaska: implications for the evolution of the westernmost part of the Yukon-Tanana terrane

    Science.gov (United States)

    Dusel-Bacon, Cynthia; Day, Warren C.; Aleinikoff, John N.

    2013-01-01

    We report the results of new mapping, whole-rock major, minor, and trace-element geochemistry, and petrography for metaigneous rocks from the Mount Veta area in the westernmost part of the allochthonous Yukon–Tanana terrane (YTT) in east-central Alaska. These rocks include tonalitic mylonite gneiss and mafic metaigneous rocks from the Chicken metamorphic complex and the Nasina and Fortymile River assemblages. Whole-rock trace-element data from the tonalitic gneiss, whose igneous protolith was dated by SHRIMP U–Pb zircon geochronology at 332.6 ± 5.6 Ma, indicate derivation from tholeiitic arc basalt. Whole-rock analyses of the mafic rocks suggest that greenschist-facies rocks from the Chicken metamorphic complex, a mafic metavolcanic rock from the Nasina assemblage, and an amphibolite from the Fortymile River assemblage formed as island-arc tholeiite in a back-arc setting; another Nasina assemblage greenschist has MORB geochemical characteristics, and another mafic metaigneous rock from the Fortymile River assemblage has geochemical characteristics of calc-alkaline basalt. Our geochemical results imply derivation in an arc and back-arc spreading region within the allochthonous YTT crustal fragment, as previously proposed for correlative units in other parts of the terrane. We also describe the petrography and geochemistry of a newly discovered tectonic lens of Alpine-type metaharzburgite. The metaharzburgite is interpreted to be a sliver of lithospheric mantle from beneath the Seventymile ocean basin or from sub-continental mantle lithosphere of the allochthonous YTT or the western margin of Laurentia that was tectonically emplaced within crustal rocks during closure of the Seventymile ocean basin and subsequently displaced and fragmented by faults.

  9. Random and systematic spatial variability of 137Cs inventories at reference sites in South-Central Brazil

    Directory of Open Access Journals (Sweden)

    Correchel Vladia

    2005-01-01

    Full Text Available The precision of the 137Cs fallout redistribution technique for the evaluation of soil erosion rates is strongly dependent on the quality of an average inventory taken at a representative reference site. The knowledge of the sources and of the degree of variation of the 137Cs fallout spatial distribution plays an important role on its use. Four reference sites were selected in the South-Central region of Brazil which were characterized in terms of soil chemical, physical and mineralogical aspects as well as the spatial variability of 137Cs inventories. Some important differences in the patterns of 137Cs depth distribution in the soil profiles of the different sites were found. They are probably associated to chemical, physical, mineralogical and biological differences of the soils but many questions still remain open for future investigation, mainly those regarding the adsorption and dynamics of the 137Cs ions in soil profiles under tropical conditions. The random spatial variability (inside each reference site was higher than the systematic spatial variability (between reference sites but their causes were not clearly identified as possible consequences of chemical, physical, mineralogical variability, and/or precipitation.

  10. Mineralogy of S-complex Asteroids using Reflectance and Thermal Infrared Spectroscopy

    Science.gov (United States)

    Lindsay, S. S.; Emery, J. P.; Marchis, F.; Enriquez, E.; Assafin, M.

    2013-12-01

    The S-type asteroids display an astounding diversity in mineralogy. They range from monomineralic olivine to complex olivine/pyroxene assemblages to basaltic assemblages. These materials are thought to be representative of an entire range of bodies that span essentially unmelted to bodies that experienced complete melting and igneous differentiation. Hence, the diverse silicate mineralogy for the S-type asteroids traces the thermal history of the asteroids a few Myr after formation. As such, determining the composition of S-type asteroids is a powerful investigative tool for understanding the post-accretionary thermal evolution, partial melting, and differentiation of the asteroids in the early Solar System. Moreover, the Sq and S(IV) are thought to be the parent bodies of ordinary chondrites (OCs), and therefore represent essentially unmelted or un-thermally processed materials. The mineralogy of these relatively unprocessed asteroids thus provide a window into investigating primitive Solar System materials, which were the building blocks of the terrestrial planets. The mineralogy of S-complex asteroids is typically determined using the 1- and 2-μm absorption bands related to olivine and pyroxene. Comparing the band centers, depths, and areas of these two features (i.e., band analysis) to calibrated laboratory data yields the general silicate mineralogy. Based on the near-infrared (NIR) band analysis, the S-type asteroids can be divided into seven subtypes, S(I - VII), with S(I)s being monomineralic olivine (mantle matieral), S(IV)s being analogous to OCs (primitive silicate material), and S(VII)s being basaltic material (igneously processed crustal material). The mid-infrared (MIR) thermal emission from asteroid surfaces exhibits a suite of silicate features due to Si-O stretching and O-Si-O bending vibrations near 10 and 18 μm, respectively. Marchis et al. (2012) demonstrated that the S-type asteroids exhibit diversity in their MIR emission. We seek to examine

  11. Brazil-U.S. Relations

    Science.gov (United States)

    2010-03-05

    and expanding ties with nontraditional partners, including India and China. Brazil-U.S. cooperation has increased during President Lula’s second...August 21, 2009. 40 Fernanda Odilla, Simone Iglesias & Johanna Nublat, “Brasil vai dobrar efetivo militar no Haiti,” Folha de São Paulo, January 21...defenderá mais regulação no G-20,” O Globo (Brazil), August 6, 2009. 53 Gaurav Singh, “China, India , Brazil Commit to Meet Copenhagen Accord Deadline

  12. Tungsten resources of Brazil

    Science.gov (United States)

    White, Max Gregg

    1974-01-01

    Brazilian tungsten production, 85 percent of which is exported, comes almost entirely from scheelite-bearing tactites in northeast Brazil, and has reached an annual rate of about 2,000 metric tons (2,200 short tons) of scheelite concentrate with 70 percent WO3. Scheelite ore reserves, located principally in the State of Rio Grande do Norte, are estimated to be as high as 8,300,000 tons (9,100,000 short tons) containing 0.7 percent WO3. Minor deposits (or those about which only minimal information is available) of wolframite, with which some cassiterite is associated, are located in Sao Paulo, Santa Catarina, and Rio Grande do Sul. Both the scheelite and the wolframite deposits are considered . to be late Precambrian A (620 to 900 m.y.) or early Cambrian in age.

  13. Volcanic stratigraphy of intermediate to acidic rocks in southern Paraná Magmatic Province, Brazil

    Directory of Open Access Journals (Sweden)

    Liza Angélica Polo

    2014-06-01

    Full Text Available This article presents the first map in detail scale for an area covered by Palmas type volcanic rocks in the south border of the eocretaceous Paraná Magmatic Province, south Brazil. The study of the structural features coupled with petrography and geochemistry made it possible to separate these rocks into three main volcanic sequences and recognize their stratigraphy. The older Caxias do Sul sequence rests directly over the first low-Ti basalt flows (Gramado type, and corresponds to the stacking of lobated lava flows, laminar flows and lava domes, mostly emitted as continuous eruptions; only the latest eruptions are intercalated with thin sandstone deposits. These rocks have dacitic composition (~ 68 wt% SiO2 with microphenocrysts of plagioclase and subordinate pyroxenes and Ti-magnetite immersed in glassy or devitrified matrix. A second volcanic sequence, named Barros Cassal, is composed of several lava flows of basaltic andesite, andesitic and dacitic composition (~ 54; ~ 57 and ~ 63 wt% SiO2 , respectively, with microphenocrysts of plagioclase, pyroxenes and Ti-magnetite. The frequent intercalation of sandstone between the flows attests to the intermittent behaviour of this event. The upper sequence, Santa Maria, is made up of more silica-rich (~ 70 wt% SiO2 rocks occurring as laminar flows, lobated flows and lava-domes. These rocks have rhyolitic composition with microphenocrysts of plagioclase and Ti-magnetite set in a glassy or devitrified matrix with microlites. The structures and textures of all three silicic sequences favor the interpretation that they had a predominantly effusive character, which is thought to be a reflection of the remarkably high temperatures of the lavas (~ 1,000 ºC.

  14. Pediatric lymphomas in Brazil

    Directory of Open Access Journals (Sweden)

    Gabriela Gualco

    2010-01-01

    Full Text Available OBJECTIVE: This study provides the clinical pathological characteristics of 1301 cases of pediatric/adolescent lymphomas in patients from different geographic regions of Brazil. METHODS: A retrospective analyses of diagnosed pediatric lymphoma cases in a 10-year period was performed. We believe that it represents the largest series of pediatric lymphomas presented from Brazil. RESULTS: Non-Hodgkin lymphomas represented 68% of the cases, including those of precursor (36% and mature (64% cell origin. Mature cell lymphomas comprised 81% of the B-cell phenotype and 19% of the T-cell phenotype. Hodgkin lymphomas represented 32% of all cases, including 87% of the classical type and 13% of nodular lymphocyte predominant type. The geographic distribution showed 38.4% of the cases in the Southeast region, 28.7% in the Northeast, 16.1% in the South, 8.8% in the North, and 8% in the Central-west region. The distribution by age groups was 15-18 years old, 33%; 11-14 years old, 26%; 6-10 years old, 24%; and 6 years old or younger, 17%. Among mature B-cell lymphomas, most of the cases were Burkitt lymphomas (65%, followed by diffuse large B-cell lymphomas (24%. In the mature T-cell group, anaplastic large cell lymphoma, ALK-positive was the most prevalent (57%, followed by peripheral T-cell lymphoma, then not otherwise specified (25%. In the group of classic Hodgkin lymphomas, the main histological subtype was nodular sclerosis (76%. Nodular lymphocyte predominance occurred more frequently than in other series. CONCLUSION: Some of the results found in this study may reflect the heterogeneous socioeconomical status and environmental factors of the Brazilian population in different regions.

  15. Mineralogical Variation of Chelyabinsk with Depth from the Surface of the Parent Meteoroid

    Science.gov (United States)

    Yoshida, S.; Mikouchi, T.; Nagao, K.; Haba, M. K.; Hasegawa, H.; Komatsu, M.; Zolensky, M. E.

    2014-01-01

    The Chelyabinsk meteorite, which passed over the Chelyabinsk Oblast, Russia on Feb. 15th, 2013, brought serious damage by the shock wave and airburst. The diameter of the parent meteoroid is estimated to be approximately 20 m in diameter [1]. It was reported that the impact by this meteorite shower was 4,000 times as large as the TNT explosive and this was the largest airburst on Earth since the asteroid impact in Tunguska, Russia in 1908. The mineralogy and geochemical study of the recovered samples shows that Chelyabinsk is an LL5 chondrite [1]. In this study we analyzed several fragments of Chelyabinsk whose noble gas compositions have been measured and depths from the surface of the parent meteoroid were estimated [2]. We examined how mineralogical characteristics change with depth from the surface. This kind of study has never been performed and thus may be able to offer significant information about the evolution of meteorite parent bodies.

  16. Quantitative x-ray diffraction mineralogy of Los Angeles basin core samples

    Science.gov (United States)

    Hein, James R.; McIntyre, Brandie R.; Edwards, Brian D.; Lakota, Orion I.

    2006-01-01

    This report contains X-ray diffraction (XRD) analysis of mineralogy for 81 sediment samples from cores taken from three drill holes in the Los Angeles Basin in 2000-2001. We analyzed 26 samples from Pier F core, 29 from Pier C core, and 26 from the Webster core. These three sites provide an offshore-onshore record across the Southern California coastal zone. This report is designed to be a data repository; these data will be used in further studies, including geochemical modeling as part of the CABRILLO project. Summary tables quantify the major mineral groups, whereas detailed mineralogy is presented in three appendices. The rationale, methodology, and techniques are described in the following paper.

  17. Moessbauer study of the Fe mineralogy in two different Argentine soils

    Energy Technology Data Exchange (ETDEWEB)

    Mijovilovich, A. [Departamento de Fisica, Comision Nacional de Energia Atomica (Argentina); Morras, H. [Instituto de Suelos, INTA-CIRN (Argentina); Causevic, H. [Universidad de Buenos Aires, Ciudad Universitaria, Facultad de Ciencias Exactas y Naturales (Argentina); Saragovi, C. [Departamento de Fisica, Comision Nacional de Energia Atomica (Argentina)

    1999-11-15

    Two Argentine soils featuring different characteristics and compositions (mollisols and ultisols) have been studied by Moessbauer spectroscopy and X-ray diffraction. The first type has a weakly developed profile with a solum thickness of 40 cm; the Fe oxyhydroxides are present in low concentrations in mixtures with other slightly weathered minerals (e.g., quartz, feldspars, 2 : 1 phyllosilicates, etc.). The second one is a typic kandihumult, which is a highly weathered red coloured, deep soil. The Fe oxyhydroxides are abundant, mixed mainly with kaolinite clay minerals. Analyses of iron mineralogy show hematite and goethite in both soils. Their ratio is low in the first case and high in the last case. Magnetite-maghemite are also present in both situations, but in the mollisol their content is much lower than in the ultisol. The mineralogy found is related to the different lithological characteristics and processes of pedological evolution on both soils.

  18. Expected Geochemical and Mineralogical Properties of Meteorites from Mercury: Inferences from Messenger Data

    Science.gov (United States)

    McCubbin, F. M.; McCoy, T. J.

    2016-01-01

    Meteorites from the Moon, Mars, and many types of asteroid bodies have been identified among our global inventory of meteorites, however samples of Mercury and Venus have not been identified. The absence of mercurian and venusian meteorites could be attributed to an inability to recognize them in our collections due to a paucity of geochemical information for Venus and Mercury. In the case of mercurian meteorites, this possibility is further supported by dynamical calculations that suggest mercurian meteorites should be present on Earth at a factor of 2-3 less than meteorites from Mars [1]. In the present study, we focus on the putative mineralogy of mercurian meteorites using data obtained from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, which has provided us with our first quantitative constraints on the geochemistry of planet Mercury. We have used the MESSENGER data to compile a list of mineralogical and geochemical characteristics that a meteorite from Mercury is likely to exhibit.

  19. Metasomatic Mechanism of Weathering-Pedogenesis of Carbonate Rocks: I. Mineralogical and Micro-Textural Evidence

    Institute of Scientific and Technical Information of China (English)

    朱立军; 李景阳

    2002-01-01

    On the basis of mineralogical, geochemical and micro-textural studies of the typical sections of the red weathering crust of carbonate rocks in the subtropical karst areas of Guizhou Province and Guangxi Autonomous Region, we have found, either on a microscopic or on a macroscopical scale and in different positions of the sections, the most direct and most important mineralogical and micro-textural evidence for the development of metasomatism in the process of weathering-pedogenesis of numerous carbonate rocks. This paper also has expounded for the first time and systematically the mechanism of metasomatism involved in the process of weathering pedogenesis of carbonate rocks and proposed the sequence of mineral metasomatic evolution in the process of weathering-pedogenesis of carbonate rocks.

  20. XRF Analysis of mineralogical matrix effects and differences between pulverized and fused ferromanganese slag

    Directory of Open Access Journals (Sweden)

    VALENTINA ZIVANOVIC

    2011-06-01

    Full Text Available Determination and analysis is only as good as the sample preparation that preceded it. Even the most sophisticated analysis is worthless if it follows sloppy sampling and poor preparation. Whether one does plasma emission, infrared or X-ray fluorescence or another spectroscopic technique, it is essential to get reproducible and accurate analysis. This paper shows the effect of mineralogical matrix differences in quantitative measurements by XRF of the main elements (Al, Ca, Mg, Si, Mn and K as oxides of ferromanganese alloy slag. Fused and pulverized slag show a significant difference in XRF microstructure, micro heterogeneity and mineralogy although the results of measurements between pulverized and fused slag, expressed as a percentage of the main elements, is not different. Other analytical techniques such as ICP-OES and classical gravimetric and titrimetric were also used for checking the XRF calibration accuracy

  1. Characterisation of some Clays Used for Whiteware Ceramics I. Mineralogical composition

    Directory of Open Access Journals (Sweden)

    Marcel Benea

    2002-04-01

    Full Text Available In order to obtain a semiquantitative mineralogical composition of raw materials used for whiteware ceramics, four different clay types were analysed by X-ray diffraction. Studies were carried out by using a combination of analyses of the bulk sample, and of the fine fraction. Using a well-established pre-treatment methodology (use of chemicals, ultrasonic treatment, dispersion procedures, clay mineral concentration by centrifugation and sedimentation, oriented and random powder preparation, cation saturation, expansion/dehydration methods, 12 X-ray diffractometer traces were obtained from each sample. Based on these informations it was possible to establish the qualitative mineralogical composition, and also a semiquantitative one using peak intensities and peak area corrected by various factors. Scanning electron microscopy was also used in order to illustrate the identified mineral phases.

  2. Mineralogy, petrology and chemistry of ANT-suite rocks from the lunar highlands

    Science.gov (United States)

    Prinz, M.; Keil, K.

    1977-01-01

    Anorthositic-noritic-troctolitic (ANT) rocks are the oldest and most abundant rocks of the lunar surface, and comprise about 90% of the suite of the lunar highlands. Consideration is given to the mineralogy, petrology, bulk chemistry, and origin of ANT-suite rocks. Problems associated in classifying and labeling lunar highland rocks because of textural complexities occurring from impact modifications are discussed. The mineralogy of ANT-suite rocks, dominated by plagioclase, olivine and pyrozene, and containing various minor minerals, is outlined. The petrology of ANT-suite rocks is reviewed along with the major element bulk composition of these rocks, noting that they are extremely depleted in K2O and P2O5. Various models describing the origin of ANT-suite rocks are summarized, and it is suggested that this origin involves a parental liquid of high-alumina basalt with low Fe/Fe+Mg.

  3. Confidence Hills Mineralogy and Chemin Results from Base of Mt. Sharp, Pahrump Hills, Gale Crater, Mars

    Science.gov (United States)

    Cavanagh, P. D.; Bish, D. L.; Blake, D. F.; Vaniman, D. T.; Morris, R. V.; Ming, D. W.; Rampe, E. B.; Achilles, C. N.; Chipera, S. J.; Treiman, A. H.; Downs, R. T.; Morrison, S. M.; Fendrich, K. V.; Yen, A. S.; Grotzinger, J.; Crisp, J. A.; Bristow, T. F.; Sarrazin, P. C.; Farmer, J. D.; Des Marais, D. J.; Stolper, E. M.; Morookian, J. M.; Wilson, M. A.; Spanovich, N.; Anderson, R. C.

    2015-01-01

    The Mars Science Laboratory (MSL) rover Curiosity recently completed its fourth drill sampling of sediments on Mars. The Confidence Hills (CH) sample was drilled from a rock located in the Pahrump Hills region at the base of Mt. Sharp in Gale Crater. The CheMin X-ray diffractometer completed five nights of analysis on the sample, more than previously executed for a drill sample, and the data have been analyzed using Rietveld refinement and full-pattern fitting to determine quantitative mineralogy. Confidence Hills mineralogy has several important characteristics: 1) abundant hematite and lesser magnetite; 2) a 10 angstrom phyllosilicate; 3) multiple feldspars including plagioclase and alkali feldspar; 4) mafic silicates including forsterite, orthopyroxene, and two types of clinopyroxene (Ca-rich and Ca-poor), consistent with a basaltic source; and 5) minor contributions from sulfur-bearing species including jarosite.

  4. X-ray diffraction results from Mars Science Laboratory: mineralogy of Rocknest at Gale crater.

    Science.gov (United States)

    Bish, D L; Blake, D F; Vaniman, D T; Chipera, S J; Morris, R V; Ming, D W; Treiman, A H; Sarrazin, P; Morrison, S M; Downs, R T; Achilles, C N; Yen, A S; Bristow, T F; Crisp, J A; Morookian, J M; Farmer, J D; Rampe, E B; Stolper, E M; Spanovich, N

    2013-09-27

    The Mars Science Laboratory rover Curiosity scooped samples of soil from the Rocknest aeolian bedform in Gale crater. Analysis of the soil with the Chemistry and Mineralogy (CheMin) x-ray diffraction (XRD) instrument revealed plagioclase (~An57), forsteritic olivine (~Fo62), augite, and pigeonite, with minor K-feldspar, magnetite, quartz, anhydrite, hematite, and ilmenite. The minor phases are present at, or near, detection limits. The soil also contains 27 ± 14 weight percent x-ray amorphous material, likely containing multiple Fe(3+)- and volatile-bearing phases, including possibly a substance resembling hisingerite. The crystalline component is similar to the normative mineralogy of certain basaltic rocks from Gusev crater on Mars and of martian basaltic meteorites. The amorphous component is similar to that found on Earth in places such as soils on the Mauna Kea volcano, Hawaii.

  5. Thermal Emission Spectra of Silica-coated Basalt and Considerations for Martian Surface Mineralogy

    Science.gov (United States)

    Kraft, M. D.; Sharp, T. G.; Michalski, J. R.

    2003-01-01

    Among the most important discoveries made during the Mars Global Surveyor (MGS) mission was that the rocky materials of Mars are broadly divisible into two distinct rock types. The geological significance of this finding is dependent on the mineralogy of these rock types as well as their geographic and stratigraphic positions. Much work has yet to be done to understand these relationships and the small-scale variability of these units. For now, it is worth considering various scenarios that could have resulted in Mars global-scale mineralogical dichotomy. Such work will make clearer what must be looked for in Thermal Emission Spectrometer (TES) and Thermal Imaging Spectrometer (THEMIS) data, what to test with other data sets, and what geological processes can be considered or ruled out as we advance with interpreting Martian geologic history. Here, we suggest that exogenic coatings of secondary silica on basaltic rocks may provide a plausible explanation for the newly discovered distribution of rock types.

  6. On the Evolution of Dust Mineralogy, From Protoplanetary Disks to Planetary Systems

    CERN Document Server

    Oliveira, Isa; Pontoppidan, Klaus M; van Dishoeck, Ewine F; Augereau, Jean-Charles; Merin, Bruno

    2011-01-01

    Mineralogical studies of silicate features emitted by dust grains in protoplanetary disks and Solar System bodies can shed light on the progress of planet formation. The significant fraction of crystalline material in comets, chondritic meteorites and interplanetary dust particles indicates a modification of the almost completely amorphous ISM dust from which they formed. The production of crystalline silicates thus must happen in protoplanetary disks, where dust evolves to build planets and planetesimals. Different scenarios have been proposed, but it is still unclear how and when this happens. This paper presents dust grain mineralogy of a complete sample of protoplanetary disks in the young Serpens cluster. These results are compared to those in the young Taurus region and to sources that have retained their protoplanetary disks in the older Upper Scorpius and Eta Chamaeleontis stellar clusters, using the same analysis technique for all samples. This comparison allows an investigation of the grain mineralo...

  7. A Mexican kaolin deposit: XANES characterization, mineralogical phase analysis and applications

    OpenAIRE

    Martínez, A.; Garza, L. L.; L. M. Torres; Vázquez, F.; López, W.

    2009-01-01

    A kaolin obtained from Villa de Reyes, a region near to San Luis Potosí (México) was characterized by means of X-ray powder diffraction (XRD, optical microscopy (OM), scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-Ray Absorption Near Edge Spectroscopy (XANES), thermal analysis (DTA/TGA), dilatometry (DIL), and chemical analysis. Mineralogical and morphological characteristics of the mineral are presented. The kaolin sample was formed mainly by kaolinite, but other minor phase...

  8. The mineralogy and chemistry of cement and cement raw materials In the united arab emirates

    OpenAIRE

    Nasir, Sobhi J. [صبحي جابر نصر; El Etr, H.

    1996-01-01

    The raw materials, clinkers and cements from different cement factories in the United Arab Emirates have been investigated using polarizing microscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), and chemical analyses. The chemical and mineralogical analyses indicate that the local raw materials are suitable for cement industry. Geological review shows that there is a good potential for industrial-grade local occurrences of limestone, marl, gypsum and iron oxide, that may be ...

  9. Geological and Mineralogical-technological features chromite ore from nickel-weathering crusts Average Bug

    Directory of Open Access Journals (Sweden)

    Perkov E.S.

    2013-09-01

    Full Text Available Conditions of occurrence and distribution features of chromites ore bodies in the ultra-basic nickel bearing weathering crusts of Middle Bug Area are considered. Main types of exogenous chromites ores in weathering crusts and beyond of them are identified as well as mineralogical, chemical and grain features of mineralization are given. Obtained data are substantiated in order to apply them while developing the efficient schemes of mining and processing of exogenous chromites ores.

  10. Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy)

    Science.gov (United States)

    Dimuccio, Luca Antonio; Rodrigues, Nelson; Larocca, Felice; Pratas, João; Amado, Ana Margarida; de Carvalho, Luís A. E. Batista

    2017-02-01

    This study examines the geochemical and mineralogical variations in the ferruginous mineralisations that crop out within Grotta della Monaca, which is considered to be the most striking and best known example of a prehistoric iron mine-cave from the southern Apennines (Calabria, Italy). Previous archaeological research identified three local and distinct ancient exploitation phases of these ferruginous mineralisations: (1) an Upper Palaeolithic phase; (2) a Late Neolithic phase; and (3) a post-Medieval phase. These materials, which have various forms of complex mineralogical admixtures and range in colour from yellow-orange to red and darker brown shades, mainly consist of iron oxides/hydroxides (essentially goethite and lepidocrocite), which are often mixed with subordinate and variable amounts of other matrix components (carbonates, sulphates, arsenates, silicates and organic matter). Such ferruginous mineralisations generally correspond to geochemically heterogeneous massive dyke/vein/mammillary/stratiform facies that are exposed within the local caves along open fractures and inclined bedding planes and that partially cover cave wall niches/notches/pockets and ceiling cupolas/holes. Selected samples/sub-samples are analysed through a multi-technique approach with a handheld portable X-ray Fluorescence, X-ray Diffraction, micro-Raman and Fourier Transform Infrared spectroscope (both conventional and attenuated total reflection), which is combined with subsequent multivariate statistical analysis of the elemental concentration data. The geochemical and mineralogical results are used to individualise similar compositional clusters. As expected, the identified groups, each of which has very specific geochemical-mineralogical "fingerprints" and spatial distributions, enable us to identify the sampled ferruginous mineralisations. These specific mineral resources can be compared to similar raw materials that are found in other neighbouring archaeological sites, with

  11. Clay Mineralogy of AN Alluvial Aquifer in a Mountainous, Semiarid Terrain, AN Example from Rifle, Colorado

    Science.gov (United States)

    Elliott, W. C.; Lim, D.; Zaunbrecher, L. K.; Pickering, R. A.; Williams, K. H.; Navarre-Sitchler, A.; Long, P. E.; Noel, V.; Bargar, J.; Qafoku, N. P.

    2015-12-01

    Alluvial sediments deposited along the Colorado River corridor in the semi-arid regions of central to western Colorado can be important hosts for legacy contamination including U, V, As and Se. These alluvial sediments host aquifers which are thought to provide important "hot spots" and "hot moments" for microbiological activity controlling organic carbon processing and fluxes in the subsurface. Relatively little is known about the clay mineralogy of these alluvial aquifers and the parent alluvial sediments in spite of the fact that they commonly include lenses of silt-clay materials. These lenses are typically more reduced than coarser grained materials, but zones of reduced and more oxidized materials are present in these alluvial aquifer sediments. The clay mineralogy of the non-reduced parent alluvial sediments of the alluvial aquifer located in Rifle, CO (USA) is composed of chlorite, smectite, illite, kaolinite and quartz. The clay mineralogy of non-reduced fine-grained materials at Rifle are composed of the same suite of minerals found in the sediments plus a vermiculite-smectite intergrade that occurs near the bottom of the aquifer near the top of the Wasatch Formation. The clay mineral assemblages of the system reflect the mineralogically immature character of the source sediments. These assemblages are consistent with sediments and soils that formed in a moderately low rainfall climate and suggestive of minimal transport of the alluvial sediments from their source areas. Chlorite, smectite, smectite-vermiculite intergrade, and illite are the likely phases involved in the sorption of organic carbon and related microbial redox transformations of metals in these sediments. Both the occurrence and abundance of chlorite, smectite-vermiculite, illite and smectite can therefore exert an important control on the contaminant fluxes and are important determinants of biogeofacies in mountainous, semiarid terrains.

  12. Mineralogy, Petrology, Chronology, and Exposure History of the Chelyabinsk Meteorite and Parent Body

    Science.gov (United States)

    Righter, K.; Abell, P.; Agresti, D.; Berger, E. L.; Burton, A. S.; Delaney, J. S.; Fries, M. D.; Gibson, E. K.; Harrington, R.; Herzog, G. F.; Keller, L. P.; Locke, D.; Lindsay, F.; McCoy, T. J.; Morris, R. V.; Nagao, K.; Nakamura-Messenger, K.; Niles, P. B.; Nyquist, L.; Park, J.; Peng, Z. X.; Shih, C. Y.; Simon, J. I.; Swisher, C. C., III; Tappa, M.

    2015-01-01

    The Chelyabinsk meteorite fall on February 15, 2013 attracted much more attention worldwide than do most falls. A consortium led by JSC received 3 masses of Chelyabinsk (Chel-101, -102, -103) that were collected shortly after the fall and handled with care to minimize contamination. Initial studies were reported in 2013; we have studied these samples with a wide range of analytical techniques to better understand the mineralogy, petrology, chronology and exposure history of the Chelyabinsk parent body.

  13. The mineralogy and chemistry of fine-grained sediments, Morphou Bay, Cyprus

    Directory of Open Access Journals (Sweden)

    C. Neal

    2002-01-01

    Full Text Available The mineralogy and chemistry of the less than 20μm fraction of marine sediments at Morphou Bay, north-west Cyprus, are presented to characterise fine-grained sediment supplies from basic and ultrabasic rocks of the Troodos Massif within a typological setting. The sediments comprise a mixture of smectite, illite, kaolinite and iron rich chlorite. They also contain amorphous iron oxides/hydroxides, calcite (with some magnesium substitution for calcium and an amphibole. Spatial patterns in mineralogy occur: the near-shore sediments are rich in smectite, chlorite, amphibole and amorphous iron oxides/hydroxides, while the offshore sediments are rich in illite and calcite. The sediments are calcium, magnesium, iron, aluminium and potassium bearing, due to the presence of significant amounts of calcite (for Ca, clay minerals and aluminium and iron oxides/hydroxides. Potassium is present within the micaceous mineral illite, but it is also contained within other phases that are difficult to pinpoint. Statistical analysis reveals that the chemical composition of the sediments broadly follows the mineralogy with the dominant feature being related to spatial changes in the mineralogy. The patterns of change reflect a three component mix of clay-sized sediment types: (1 localised lithogenous sources rich in smectite with subsidiary amounts of amorphous iron oxides/hydroxides and amphibole, from Cyprus, the Troodos in particular, (2 illite rich and smectite chlorite and chlorite bearing material of lithogenous origin from other parts of the eastern Mediterranean and (3 calcite, mainly of marine origin. Keywords: smectite, illite, chlorite, kaolinite, calcite, sediments, Morphou Bay, Troodos, Cyprus, Mediterranean, calcium, potassium, magnesium, iron, silicon, phosphorus.

  14. Mineralogical, chemical and physical study of potential buffer and backfill materials from ABM. Test Package 1

    Energy Technology Data Exchange (ETDEWEB)

    Kumpulainen, S.; Kiviranta, L. (B and Tech Oy, Helsinki (Finland))

    2011-07-15

    In the ABM experiment, three test packages with centre steel heaters surrounded by stacks of compacted bentonite rings of various clay materials were placed in boreholes in Aespoe tunnel. The first parcel was saturated with Aespoe groundwater and the heater was turned on simultaneously with the start of saturation. This parcel was excavated 30 months after its installation. Chemical, mineralogical and physical properties of the MX-80, Dep-CaN, Asha and Friedland clay samples from the ABM parcel 1 were analysed and compared to reference samples. Chemical analyses (ICP-AES, C, CO{sub 3}, S, water soluble SO{sub 4}, Fe2+/Fe3+), exchangeable cation analyses, mineralogical analyses (XRD, FTIR) and selective extractions were used to determine changes in the chemistry and mineralogy of ABM materials. Swelling pressure and hydraulic conductivity measurements were performed both for extracted samples and for ground and recompacted samples. Major changes in exchangeable cation composition were observed in all samples originating from equilibration with Aespoe groundwater and interactions with equilibrated waters from neighbouring block materials. Some minor changes in chemical composition were observed as well. Increases in soluble sulphate content in the vicinity of the heater were thought to result from precipitation of sulphate salts. Decreases in sodium content and increases in calcium content were ascribed to changes in exchangeable cations. Interaction with iron was observed to occur only in the close vicinity (first few mm) of the heater. No significantly measureable change in mineralogical composition was seen in any of the studied materials. Extracted Dep-CaN samples showed a slight decrease in swelling pressure. However, when the material was ground, compacted and measured again the swelling pressure was fully recovered. No related change in hydraulic conductivities was observed. (orig.)

  15. Composition, mineralogy, and porosity of multiple asteroid systems from visible and near-infrared spectral data

    OpenAIRE

    Lindsay, S.S.; Marchis, F.; Emery, J.P.; Enriquez Rascon, J.E.; Assafin, M.

    2015-01-01

    We provide a taxonomic and compositional characterization of Multiple Asteroid Systems (MASs) located in the main belt (MB) using visible and near-infrared (0.45-2.5 um) spectral data of 42 MB MASs. The mineralogical analysis is applied to determine meteorite analogs for the MASs, which, in turn, are applied to the MAS density measurements of Marchis et al. (2012) to estimate the system porosity. The macroporosities are used to evaluate the primary MAS formation hypotheses. The visible observ...

  16. Clay Mineralogical Study of the Tertiary Malubog Formation, Cebu Province, Philippines

    OpenAIRE

    ALETA, Dennis Gerald A.; TOMITA, Katsutoshi; KAWANO, Motoharu; ALETA, Josephine T.; LUPO, Elena S.

    2003-01-01

    The Early Miocene Malubog Formation (MbF) is one of the most widespread Tertiary formations in Central Cebu, Philippines. The formation consists of mudstone, shale and occasional beds of conglomerate, limestone and coal. It exhibits poor bedding and shows rapid lithologic changes vertically and horizontally. The formation is subdivided into several members which are all essentially coal measures and limestones. Mineralogical study of the Malubog Formation focused on the gently dipping strata ...

  17. Mineralogy of Fluvio-Lacustrine Sediments Investigated by Curiosity During the Prime Mission: Implications for Diagenesis

    Science.gov (United States)

    Rampe, Elizabeth B.; Morris, R. V.; Bish, D. L.; Vaniman, D. T.; Bristow, T. F.; Chipera, S. J.; Blake, D. F.; Ming, D. W.; Farmer, J. D.; Morrison, S. M.; Treiman, A. H.; Archilles, C. N.; Crisp, J. A.; DesMarais, D. J.; Downs, R. T.; Morookian, J. M.; Sarrazin, P.; Spanovich, N.; Yen, A. S.

    2014-01-01

    The Mars Science Laboratory rover Curiosity investigated sedimentary rocks that were deposited in a diversity of fluvio-lacustrine settings. The entire science payload was employed to characterize the mineralogy and chemistry of the Sheepbed mudstone at Yellowknife Bay and the Windjana sandstone at the Kimberley. Data from the CheMin instrument, a transmission Xray diffractometer, were used to determine the quantitative mineralogy of both samples. The Sheepbed mudstone contains detrital basaltic minerals, calcium sulfates, iron oxides or hydroxides, iron sulfides, trioctahedral smectite, and amorphous material. The mineral assemblage and chemical data from APXS suggest that the trioctahedral smectite and magnetite formed authigenically as a result of alteration of olivine. The apparent lack of higher-grade phyllosilicates (e.g., illite and chlorite) and the presence of anhydrite indicate diagenesis at 50- 80 ºC. The mineralogy of the Windjana sandstone is different than the Sheepbed mudstone. Windjana contains significant abundances of K-feldspar, low- and high-Ca pyroxenes, magnetite, phyllosilicates, and amorphous material. At least two distinct phyllosilicate phases exist: a 10 Å phase and a component that is expanded with a peak at 11.8 Å. The identity of the expanded phase is currently unknown, but could be a smectite with interlayer H2O, and the 10 Å phase could be illite or collapsed smectite. Further work is necessary to characterize the phyllosilicates, but the presence of illite could suggest that Windjana experienced burial diagenesis. Candidates for the cementing agents include fine-grained phyllosilicates, Fe-oxides, and/or amorphous material. Interpretations of CheMin data from the Windjana sandstone are ongoing at the time of writing, but we will present an estimate of the composition of the amorphous material from mass balance calculations using the APXS bulk chemistry and quantitative mineralogy from CheMin.

  18. Carbonatitic lavas in Catanda (Kwanza Sul, Angola): Mineralogical and geochemical constraints on the parental melt

    Science.gov (United States)

    Campeny, Marc; Kamenetsky, Vadim S.; Melgarejo, Joan C.; Mangas, José; Manuel, José; Alfonso, Pura; Kamenetsky, Maya B.; Bambi, Aurora C. J. M.; Gonçalves, Antonio O.

    2015-09-01

    A set of small volcanic edifices with tuff ring and maar morphologies occur in the Catanda area, which is the only locality with extrusive carbonatites reported in Angola. Four outcrops of carbonatite lavas have been identified in this region and considering the mineralogical, textural and compositional features, we classify them as: silicocarbonatites (1), calciocarbonatites (2) and secondary calciocarbonatites produced by the alteration of primary natrocarbonatites (3). Even with their differences, we interpret these lava types as having been a single carbonatite suite related to the same parental magma. We have also estimated the composition of the parental magma from a study of melt inclusions hosted in magnetite microphenocrysts from all of these lavas. Melt inclusions revealed the presence of 13 different alkali-rich phases (e.g., nyerereite, shortite, halite and sylvite) that argues for an alkaline composition of the Catanda parental melts. Mineralogical, textural, compositional and isotopic features of some Catanda lavas are also similar to those described in altered natrocarbonatite localities worldwide such as Tinderet or Kerimasi, leading to our conclusion that the formation of some Catanda calciocarbonatite lavas was related to the occurrence of natrocarbonatite volcanism in this area. On the other hand, silicocarbonatite lavas, which are enriched in periclase, present very different mineralogical, compositional and isotopic features in comparison to the rest of Catanda lavas. We conclude that its formation was probably related to the decarbonation of primary dolomite bearing carbonatites.

  19. Role of ore mineralogy in optimizing conditions for bioleaching low-grade complex sulphide ores

    Institute of Scientific and Technical Information of China (English)

    P. A. OLUBAMBI; S. NDLOVU; J. H. POTGIETER; J. O. BORODE

    2008-01-01

    The role that ore mineralogy plays in understanding and optimizing the conditions favouring the bioleaching of complex sulphide ore containing high amounts of siderite was studied using mixed cultures of mesophilic bacteria, with emphasis on zinc,lead and copper recoveries. The influencing parameters investigated include particle size, stirring speed, volume of inoculum, pulp density, and pH. The results show that the mixed mesophilic cultures can extract about two and a half times the amount of zinc than copper over an equivalent period of time. The highest zinc and copper recoveries of 89.2% and 36.4% respectively are obtained at particle size of 75 μm, stirring speed of 150 r/min, pulp density of 10% (w/v), 12% (v/v) inoculum concentration, and a pH of 1.6. Variations in elemental composition within different particle sizes resulting from the mineralogy of the ore account for the bioleaching behaviour at varying particle sizes. The dissolution at varying pulp density, volume of inoculum, solution pH and the low solution potential observed are also influenced by ore mineralogy.

  20. Arsenic mineralogy and mobility in the arsenic-rich historical mine waste dump.

    Science.gov (United States)

    Filippi, Michal; Drahota, Petr; Machovič, Vladimír; Böhmová, Vlasta; Mihaljevič, Martin

    2015-12-01

    A more than 250 year-old mine dump was studied to document the products of long-term arsenopyrite oxidation under natural conditions in a coarse-grained mine waste dump and to evaluate the environmental hazards associated with this material. Using complementary mineralogical and chemical approaches (SEM/EDS/WDS, XRD, micro-Raman spectroscopy, pore water analysis, chemical extraction techniques and thermodynamic PHREEQC-2 modeling), we documented the mineralogical/geochemical characteristics of the dumped arsenopyrite-rich material and environmental stability of the newly formed secondary minerals. A distinct mineralogical zonation was found (listed based on the distance from the decomposed arsenopyrite): scorodite (locally associated with native sulfur pseudomorphs) plus amorphous ferric arsenate (AFA/pitticite), kaňkite, As-bearing ferric (hydr)oxides and jarosite. Ferric arsenates and ferric (hydr)oxides were found to dissolve and again precipitate from downward migrating As-rich solutions cementing rock fragments. Acidic pore water (pH3.8) has elevated concentrations of As with an average value of about 2.9 mg L(-1). Aqueous As is highly correlated with pH (R2=0.97, pdump and underlying soil has been found to be very effective, suggesting limited environmental impact of the mine waste dump on the surrounding soil ecosystems.

  1. Mineralogical and Geochemical Trends in a Fluviolacustrine Sequence in Gale Crater, Mars

    Science.gov (United States)

    Rampe, E.; Ming, D.; Morris, R.; Blake, D.; Vaniman, D.; Bristow, T.; Chipera, S.; Yen, A.; Grotzinger, J.; DesMarais, D.

    2016-01-01

    The Mars Science Laboratory rover, Curiosity, landed at Gale crater in August 2012 and has been investigating a sequence of dominantly fluviolacustrine sediments deposited 3.6-3.2 billion years ago. Curiosity collects quantitative mineralogical data with the CheMin XRD/XRF instrument and quantitative chemical data with the APXS and ChemCam instruments. These datasets show stratigraphic mineralogical and geochemical variability that suggest a complex aqueous history. The Murray Formation, primarily composed of fine-laminated mudstone, has been studied in detail since the arrival at the Pahrump Hills in September 2014. CheMin data from four samples show variable amounts of iron oxides, phyllosilicates, sulfates, amorphous and crystalline silica, and mafic silicate minerals. Geochemical data throughout the section show that there is significant variability in Zn, Ni, and Mn concentrations. Mineralogical and geochemical trends with stratigraphy suggest one of possibly several aqueous episodes involved alteration in an open system under acidic pH, though other working hypotheses may explain these and other trends. Data from the Murray Formation contrast with those collected from the Sheepbed mudstone located approximately 60 meters below the base of the Murray Formation, which showed evidence for diagenesis in a closed system at circumneutral pH. Ca-sulfates filled late-stage veins in both mudstones.

  2. Chemistry and Mineralogy of Antarctica Dry Valley Soils: Implications for Mars

    Science.gov (United States)

    Quinn, J. E.; Golden, D. C.; Graff, T. G.; Ming, D. W.; Morris, R. V.; Douglas, S.; Kounaves, S. P.; McKay, C. P.; Tamppari, L, K.; Smith, P. H.; Zent, A. P.; Archer, P. D., Jr.

    2011-01-01

    The Antarctic Dry Valleys (ADV) comprise the largest ice-free region of Antarctica. Precipitation almost always occurs as snow, relative humidity is frequently low, and mean annual temperatures are about -20 C. The ADV soils have previously been categorized into three soil moisture regimes: subxerous, xerous and ultraxerous, based on elevation and climate influences. The subxerous regime is predominately a coastal zone soil, and has the highest average temperature and precipitation, while the ultraxerous regime occurs at high elevation (>1000 m) and have very low temperature and precipitation. The amounts and types of salts present in the soils vary between regions. The nature, origin and significance of salts in the ADV have been previously investigated. Substantial work has focused on soil formation in the ADVs, however, little work has focused on the mineralogy of secondary alteration phases. The dominant weathering process in the ADV region is physical weathering, however, chemical weathering has been well documented. The objective of this study was to characterize the chemistry and mineralogy, including the alteration mineralogy, of soils from two sites, a subxerous soil in Taylor Valley, and an ultraxerous soil in University Valley. The style of aqueous alteration in the ADVs may have implications for pedogenic processes on Mars.

  3. Mineralogical Diversity in Lake Pavin: Connections with Water Column Chemistry and Biomineralization Processes

    Directory of Open Access Journals (Sweden)

    Jennyfer Miot

    2016-03-01

    Full Text Available As biominerals are good tracers of microbial interactions with the environment, they may provide signatures of microbial evolution and paleoenvironmental conditions. Since modern analogues of past environments help with defining proxies and biosignatures, we explored microbe mineral interactions in the water column of a maar lake, located in France: Lake Pavin. This lake is considered as a potential Precambrian ocean analogue, as it is ferruginous and meromictic, i.e., stratified with a superficial O2-rich layer (mixolimnion and a deeper permanently anoxic layer (monimolimnion. We combined bulk chemical analyses of dissolved and particulate matter in combination with electron microscopy analyses of the particulate matter at different depths along the water column. The mineralogy changed along with water chemistry, and most of the minerals were intimately associated with microorganisms. Evolution of the redox conditions with depth leads to the successive precipitation of silica and carbonates, Mn-bearing, Fe-bearing and S-containing phases, with a predominance of phosphates in the monimolimnion. This scheme parallels the currently-assessed changes of microbial diversity with depth. The present results corroborate previous studies that suggested a strong influence of microbial activity on mineralogical diversity through extracellular and intracellular biomineralization. This paper reports detailed data on mineralogical profiles of the water column and encourages extended investigation of these processes.

  4. Georgia marble at the Minnesota State Capitol The Effects of Mineralogy and Climate on Durability

    Science.gov (United States)

    Whitenack, Paul; Shotwell, L. Brad; Scheffler, Michael J.

    2016-11-01

    Based on visual observations and tests made of Georgia marble units that have been in service at the historic Minnesota State Capitol for 110 years, a fielddiscernible correlation exists between marble unit mineralogical composition and unit weathering performance. Field studies noted over the course of a five-year restoration project of the capitol exterior were used to categorize the original marble cladding into four perceptible types, which were evaluated by field testing that suggested a correlation between the textural and mineralogical differences within the marble and its long-term durability. To test this theory, field-issued repair assignments made during an exterior marble restoration project at the capitol were examined statistically. The nature and frequency of assigned repairs were compared to the type of marble from which they were originally fabricated to determine whether a correlation existed. The results of this comparison provided convincing statistical verification of the link between mineralogy and durability. This hypothesis was then verified through detailed petrographic analysis in a laboratory setting, which determined that marble consisting of a smaller, more interlocked grain configuration that was more dolomitic than calcitic in its basic chemistry consistently proved to be more durable in weathering performance over time. The paper describes the process followed by the authors to categorize and study the distinct varieties of Georgia marble present on the Minnesota State Capitol, and how this information was used to guide the restoration process with the intent of maximizing the anticipated service life of new marble replacements.

  5. Mineralogical Plasticity Acts as a Compensatory Mechanism to the Impacts of Ocean Acidification.

    Science.gov (United States)

    Leung, Jonathan Y S; Russell, Bayden D; Connell, Sean D

    2017-02-15

    Calcifying organisms are considered particularly susceptible to the future impacts of ocean acidification (OA), but recent evidence suggests that they may be able to maintain calcification and overall fitness. The underlying mechanism remains unclear but may be attributed to mineralogical plasticity, which modifies the energetic cost of calcification. To test the hypothesis that mineralogical plasticity enables the maintenance of shell growth and functionality under OA conditions, we assessed the biological performance of a gastropod (respiration rate, feeding rate, somatic growth, and shell growth of Austrocochlea constricta) and analyzed its shell mechanical and geochemical properties (shell hardness, elastic modulus, amorphous calcium carbonate, calcite to aragonite ratio, and magnesium to calcium ratio). Despite minor metabolic depression and no increase in feeding rate, shell growth was faster under OA conditions, probably due to increased precipitation of calcite and trade-offs against inner shell density. In addition, the resulting shell was functionally suitable for increasingly "corrosive" oceans, i.e., harder and less soluble shells. We conclude that mineralogical plasticity may act as a compensatory mechanism to maintain overall performance of calcifying organisms under OA conditions and could be a cornerstone of calcifying organisms to acclimate to and maintain their ecological functions in acidifying oceans.

  6. Chemical dispersants and pre-treatments to determine clay in soils with different mineralogy

    Directory of Open Access Journals (Sweden)

    Cristiane Rodrigues

    2011-10-01

    Full Text Available Knowledge of the soil physical properties, including the clay content, is of utmost importance for agriculture. The behavior of apparently similar soils can differ in intrinsic characteristics determined by different formation processes and nature of the parent material. The purpose of this study was to assess the efficacy of separate or combined pre-treatments, dispersion methods and chemical dispersant agents to determine clay in some soil classes, selected according to their mineralogy. Two Brazilian Oxisols, two Alfisols and one Mollisol with contrasting mineralogy were selected. Different treatments were applied: chemical substances as dispersants (lithium hydroxide, sodium hydroxide, and hexametaphosphate; pre-treatment with dithionite, ammonium oxalate, and hydrogen peroxide to eliminate organic matter; and coarse sand as abrasive and ultrasound, to test their mechanical action. The conclusion was drawn that different treatments must be applied to determine clay, in view of the soil mineralogy. Lithium hydroxide was not efficient to disperse low-CEC electropositive soils and very efficient in dispersing high-CEC electronegative soils. The use of coarse sand as an abrasive increased the clay content of all soils and in all treatments in which dispersion occurred, with or without the use of chemical dispersants. The efficiency of coarse sand is not the same for all soil classes.

  7. Characterization of raw and burnt oil shale from Dotternhausen: Petrographical and mineralogical evolution with temperature

    Energy Technology Data Exchange (ETDEWEB)

    Thiéry, Vincent, E-mail: vincent.thiery@mines-douai.fr [Mines Douai, LGCgE-GCE, F-59508 Douai (France); Université de Lille (France); Bourdot, Alexandra, E-mail: alexandra.bourdot@gmail.com [Mines Douai, LGCgE-GCE, F-59508 Douai (France); Bulteel, David, E-mail: david.bulteel@mines-douai.fr [Université de Lille (France)

    2015-08-15

    The Toarcian Posidonia shale from Dotternhausen, Germany, is quarried and burnt in a fluidized bed reactor to produce electricity. The combustion residue, namely burnt oil shale (BOS), is used in the adjacent cement work as an additive in blended cements. The starting material is a typical laminated oil shale with an organic matter content ranging from 6 to 18%. Mineral matter consists principally of quartz, feldspar, pyrite and clays. After calcination in the range, the resulting product, burnt oil shale, keeps the macroscopic layered texture however with different mineralogy (anhydrite, lime, iron oxides) and the formation of an amorphous phase. This one, studied under STEM, reveals a typical texture of incipient partial melting due to a long retention time (ca. 30 min) and quenching. An in-situ high temperature X-ray diffraction (HTXRD) allowed studying precisely the mineralogical changes associated with the temperature increase. - Highlights: • We present oil shale/burnt oil shale characterization. • The Posidonia Shale is burnt in a fluidized bed. • Mineralogical evolution with temperature is complex. • The burnt oil shale is used in composite cements.

  8. Mineralogía y termo-barometría de los Complejos máficos Sol de Mayo y Suya Taco, Norte de las Sierras de Comechingones, Córdoba Mineralogy and thermo-barometry of the Sol de Mayo and Suya Taco mafic complexes from northern Sierra de Comechingones, Córdoba

    Directory of Open Access Journals (Sweden)

    Alina M. Tibaldi

    2008-03-01

    Full Text Available Este trabajo presenta un estudio detallado de la petrografía, mineralogía química y termo-barometría de dos complejos máficos que afloran al norte de la sierra de Comechingones. Se aplicaron un conjunto de termómetros y barómetros empíricos con el propósito de determinar los rangos de P y T absolutas de cristalización de estas rocas. Las temperaturas de equilibrio en pares de piroxenos (cpx-opx se estimaron usando tres termómetros independientes. Dos calibraciones termométricas (Wells 1977, Kretz 1982 dan resultados consistentes y razonables indicando que los piroxenos registran condiciones de cristalización magmática (920-1150ºC, mientras que la tercera calibración (Lindsley 1983 estima temperaturas muy inferiores. Esta discrepancia puede estar relacionada con el hecho de que la última calibración no sería aplicable a rocas que cristalizaron a partir de magmas ricos en hierro. Por su parte, la termometría Amph-Pl sugiere temperaturas de equilibrio comprendidas entre 750-850ºC, para composiciones típicas de núcleos, mientras que para composiciones representativas de los bordes de grano las temperaturas estimadas son significativamente inferiores (This work presents a detailed study including petrography, mineral chemistry and thermo-barometry of igneous rock from two mafic complexes that outcrop in the north portion of the sierra de Comechingones. The range of absolute P and T under which these rocks crystallized is retrieved using a set of empiric barometers and thermometers. The estimations of equilibrium temperature determined in pairs of pyroxenes (cpx-opx were performed through three independent thermometers. Two of the thermometric formulations (Wells 1977, Kretz 1982 yield consistent and reasonable results indicating that these phases record magmatic crystallizations conditions (920-1150ºC, whereas the third calibration by Lindsley (1983 gives lower temperatures. This discrepancy is thought to reflect the fact that

  9. Contribution to the stratigraphy of the onshore Paraiba Basin, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rossetti, Dilce F.; Valeriano, Marcio M., E-mail: rossetti@dsr.inpe.br [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Divisao de Sensoriamento Remoto; Goes, Ana M.; Brito-Neves, Benjamim B. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Geociencias; Bezerra, Francisco H.R.; Ochoa, Felipe L. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Ciencias Exatas e da Terra. Departamento de Geologia

    2012-06-15

    Several publications have contributed to improve the stratigraphy of the Paraiba Basin in northeastern Brazil. However, the characterization and distribution of sedimentary units in onshore areas of this basin are still incomplete, despite their significance for reconstructing the tectono- sedimentary evolution of the South American passive margin. This work provides new information to differentiate among lithologically similar strata, otherwise entirely unrelated in time. This approach included morphological, sedimentological and stratigraphic descriptions based on surface and sub-surface data integrated with remote sensing, optically stimulated luminescence dating, U+Th/He dating of weathered goethite, and heavy mineral analysis. Based on this study, it was possible to show that Cretaceous units are constrained to the eastern part of the onshore Paraiba Basin. Except for a few outcrops of carbonatic-rocks nearby the modern coastline, deposits of this age are not exposed to the surface in the study area. Instead, the sedimentary cover throughout the basin is constituted by mineralogically and chronologically distinctive deposits, inserted in the Barreiras Formation and mostly in the Post-Barreiras Sediments, of early/middle Miocene and Late Pleistocene-Holocene ages, respectively. The data presented in this work support tectonic deformation as a factor of great relevance to the distribution of the sedimentary units of the Paraiba Basin. (author)

  10. Electrochemical studies on interplay of mineralogical variation and particle size on bioleaching low grade complex sulphide ores

    Institute of Scientific and Technical Information of China (English)

    P. A. OLUBAMBI; J. H. POTGIETER; S. NDLOVU; J. O. BORODE

    2009-01-01

    The interplay of mineralogical variation and mineral phase distribution within varying particle sizes on the dissolution behaviour of a low grade complex sulphide ore was investigated through bioleaching experiments and electrochemical technique. Investigations were carried out utilizing mineralogical data on the variations in mineral and phase distribution within particle sizes of<53 μm, 53-75 μm, 75-106 μm and 106-150 μm in mixed mesophilic cultures of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans. Electrochemical behaviour was studied using particulate electrodes from the four varying particle sizes and from massive electrodes prepared from the two major sulphide mineral rich phases (sphalerite-rich and galena-rich) and a complex mineralogical phase of the bulk ore. Bioleaching studies reveal the highest recoveries at a particle size of 75 μm, while electrochemical investigations reveal the highest dissolution at particle size of 106 μm. Electrochemical results show that sphalerite rich phase has the highest dissolution rate while galena-rich complex phase has the least. SEM studies confirm the highest bacterial attack at the sphalerite-rich phase. The discrepancies between the dissolutions within particle sizes obtained from bioleaching experiments and electrochemical studies are consistent with and attributed both to the physical and mineralogical influences. Electrochemical behaviour is influenced and controlled by galvanic interaction resulting from mineralogical variation, while bioleaching behaviour is influenced by mineralogical variation as well as physical effect of particle size.

  11. Quantification of aluminium in soil of the Solimões Formation, Acre State, Brazil

    Directory of Open Access Journals (Sweden)

    Thiago Andrade Bernini

    2013-12-01

    Full Text Available The variety of soils in the State of Acre is wide and their chemical profiles are still not fully understood. The nature of the material of origin of these soils is indicated by the high aluminium (Al content, commonly associated with high calcium (Ca and magnesium (Mg contents. The study objective was to use different methods to quantify Al in soils from toposequences formed from material of a sedimentary nature originating from the Solimões Formation, in Acre, Brazil. Trenches were opened at three distinct points in the landscape: shoulder, backslope and footslope positions. Soil samples were collected for physical, chemical, mineralogical analyses. The Al content was quantified using different methods. High Al contents were found in most of these horizons, associated with high Ca and Mg levels, representing the predominant cations in the sum of exchangeable bases. The mineralogy indicates that the soils are still in a low weathering phase, with the presence of significant quantities of 2:1 minerals. Similar Al contents were determined by the methods of NaOH titration, xylenol orange spectrometry and inductively coupled plasma optical emission spectrometry. However, no consistent data were obtained by the pyrocatechol violet method. Extraction with KCl overestimated the exchangeable Al content due to its ability to extract the non-exchangeable Al present in the smectite interlayers. It was observed that high Al contents are related to the instability of the hydroxyl-Al smectite interlayers.

  12. Characterization and classification of two soils derived from basic rocks in Pernambuco State Coast, Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Oliveira Lindomário Barros de

    2004-01-01

    Full Text Available Geomorphic surfaces that present soils derived from basic rocks under warm and humid climate are unique scenarios for studying tropical soils. This paper aimed to characterize and classify two pedons derived from basalt at the Atlantic Forest Zone, Pernambuco State, Northeastern coast of Brazil. Two representative pedons (P1 and P2 were selected on a hillslope at the Cabo de Santo Agostinho municipality. Field macromorphological descriptions were carried out and soil horizon were sampled for physical, chemical, mineralogical and micromorphological characterization. The soils were classified, according to the Brazilian System of Soil Classification (and US Soil Taxonomy as: "Latossolo Vermelho-Amarelo distroférrico argissólico" (Typic Hapludox (P1 and "Nitossolo Vermelho distroférrico típico" (Rhodic Paleudult (P2. Pedon 1 differs from Pedon 2 in some aspects. For instance, P1 presents more yellowish colors, absence of clay illuviation, more friable consistence and the prismatic structure undergoes transformation to angular and subangular blocks. Pedon 2 presents ferri-argilans and leptocutans which indicate that vertical and lateral illuviation of clay is an active process in their formation. These chemically poor and mineralogically uniform soils are a result of the high temperature and rainfall of the studied area.

  13. Neotectonics in northeastern Brazil

    Science.gov (United States)

    Bezerra, Francisco Hilario Rego

    The thesis describes neotectonic deformation in the continental intraplate region of northeastern Brazil and explores its links with modern seismicity. The region, which is under E-W-oriented compression and N-S-oriented extension, shows shallow earthquake swarms which last for several years and include 5.0-5.2 mb events. Remote sensing, borehole and geophysical data, in conjunction with field structural information, indicate a continuous faulting process since the Miocene which has reactivated Cretaceous faults and Precambrian shear zones or in places generated new faults which cut across existing structures. Three main sets of faults are recognised across the area: a NE-striking set, a NW-striking set and a N-striking set. The first and the second sets are pervasive and their cross-cutting relationships show that they locally form a conjugate set and display both a strike-slip and a dip-slip component of movement. They have generated troughs filled by as much as 260 m of Cainozoic sediments. Radiocarbon dating shows that some of the faults slipped as recently as 4,041-3,689 cal. yr BP. Although the elevation of coastal deposits is consistent with the predictions of glacioisostatic models for the area, tectonic influence can be detected notably near the Carnaubais fault, where rapid emergence by at least 5 m to the east of Sao Bento occurred 4,080-2,780 cal. yr BP. Secondary ground failure, which includes hydroplastic deformation, liquefaction and landslides, can be seen in Quaternary alluvial sediments and is reported in the historical record. The present data show that the potential for large earthquakes in northeastern Brazil has been underestimated. Empirical relationships using liquefaction and surface rupture point to events of at least Ms=6.8 compared to a maximum mb = 5.2 recorded instrumentally. The finding that NE- and NW-trending faults are favourably orientated for reactivation in relation to the current stress field is of potential value for seismic

  14. Iron oxides of Fazendao Deposit, East Border of Quadrilatero FerrIfero, Minas Gerais, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, A R P; Fabris, J D [Departamento de Quimica - Universidade Federal de Minas Gerais (Brazil); Rios, F J [Centro de Desenvolvimento da Tecnologia Nuclear - CDTN, Minas Gerais (Brazil); Rosiere, C A, E-mail: arpp@qui.dout.ufmg.b [Instituto de Geociencias - Universidade Federal de Minas Gerais (Brazil)

    2010-03-01

    The iron oxides highly influence the soil structure and aggregation of mineral particles in soil. They also play an important role in some economical variables, as those related to the use of land for agriculture practices or mineral exploitation, in ore mining activities. About 60 % of all industrial activities on iron processing in Brazil is based on ores mined in the geodomain of Quadrilatero FerrIfero, state of Minas Gerais, Brazil. Samples of a mining area for iron, the Fazendao Deposit in the east border of Quadrilatero FerrIfero have been studied in an attempt to contribute to a better understanding of the key chemical and mineralogical pathways related to the formation and transformation of iron oxides, involving hematite. From powder diffraction patterns, it is confirmed that hematite is the main mineralogical phase in all samples. The total iron contents were found to range between 65.15 and 70.00 mass%. The saturation magnetization values, {sigma} = 6.9 and 2.1 J T{sup -1} kg{sup -1} are significantly measurable only for the two samples showing some evidences of magnetite. 298 K-Moessbauer data confirmed the dominant occurrence of hematite in all samples, along with magnetite for the two samples showing non-zero magnetization. 110 K-Moessbauer data indicate that the hematite in all samples undergoes the Morin transition (T{sub M} {approx} 260 K), as expected for the relatively pure oxide. Maghemite could not be detected in any sample. New numerical analysis are now being performed, using Rietveld refinement of XRD data, in an attempt to obtain crystallographic results that could indicate more reliable evidences about the mechanisms of formation of hematite, particularly in the magnetic samples, for which the precursor is presumably magnetite.

  15. Policing violence in Brazil.

    Science.gov (United States)

    Sena, E

    1999-03-01

    This article is an excerpted summary of a speech on female police and domestic violence. The speech was given by a woman affiliated with the Association of Women Workers at an Oxfam workshop in northern Brazil. This organization successfully lobbied for female police, which resulted in more reports of domestic violence, especially rape. The organization is active in 13 counties. Female police are trained and usually given respect by police chiefs. In one city, in 1997, the appointment of female police resulted in registered reports of 387 cases of violence and hospital reports of 503 cases, of which 14% were child rape. During January-April 1998, there were 126 registered cases and 168 hospital cases. Policewomen formed a partnership over the past 2 years with the Human Rights Group and other popular political groups to train female police about laws. The compulsory course focused on four areas: legal concepts, penalties, and procedures on registration of complaints; the Brazilian Penal Code; civil law; and world judicial bureaucracies. Training includes a 1 month internship with the program's lawyer. Over 20 women have completed the course to date. Training in some cases resulted in greater expertise among the female police than their Police Chiefs. Female police have experienced harassment by local authorities.

  16. Hybrid genesis of Jurassic fayalite-bearing felsic subvolcanic rocks in South China: Inspired by petrography, geochronology, and Sr-Nd-O-Hf isotopes

    Science.gov (United States)

    Guo, Chunli; Zeng, Lingsen; Li, Qiuli; Fu, Jianming; Ding, Tiping

    2016-11-01

    Fayalite-bearing felsic (FBF) magmatic rocks are a special type of granitic rocks with controversial origins. A suite of fayalite- and ferrosilite-bearing subvolcanic rocks, namely, the Xishan FBF rocks in South China, is investigated in this study. The Xishan FBF rocks have high SiO2 contents of 69-70 wt.%, high K2O/Na2O ratios of 1.71-1.95, and high FeOt/(FeOt + MgO) ratios of 0.88-0.89. Fayalite (Fo = 7.3-9.6) and ferrosilite (Fs = 74.1-76.5) minerals are found in the Xishan FBF rocks. According to the Unmix function of Isoplot, the zircon U-Pb ages and initial Hf isotope compositions are categorized into two groups with ages of 156.6 Ma and 151.5 Ma and εHf(t) values of - 7.1 and - 5.2, respectively. The minerals show δ18O values of 8.8-9.8‰ for zircon, 6.0-8.1‰ for fayalite, and 7.0-8.2‰ for ferrosilite. The oxygen isotope fractionations between ferrosilite and fayalite (ΔOpx-Ol) vary from - 0.8‰ to + 1.5‰, which indicates disequilibrium crystallization. Whole-rock analyses show high initial 87Sr/86Sr ratios of 0.7169 to 0.7180 and negative εNd(t) values of - 7.3 to - 6.8; zircon analyses show εHf(t) values of - 9.1 to - 3.8 and δ18O values of 8.8-9.8‰. So whole rock and zircon isotopes indicate a crustal signature. Based on these mineralogical and geochemical data, the Xishan FBF rocks were attributed to A-type granites and derived from the mixing of two batches of crustal magmas, which were all derived from the partial melting of ancient igneous protolith under the conditions of high temperature (683-893 °C), moderate water (3-5 wt.%), and low oxygen fugacity (lg fO2 = - 1.21). Such rigorous physical conditions may be common for the FBF igneous rocks all over the world, which may be the primary factors controlling occurrence of the FBF rocks in limited volume and quantity.

  17. Brazil, China, US: a triangular relation?

    Directory of Open Access Journals (Sweden)

    José-Augusto Guilhon-Albuquerque

    2014-01-01

    Full Text Available This article is divided in three sections. The first one explores the so-called "strategic partnership" between Brazil and China. In the second section we shall examine how US-China relations in the global system could affect both Brazil-US, and Brazil-China bilateral relations. A final section presents some recommendations for Brazil strategic orientations regarding the current systemic transition in the allotment of global power.

  18. Brazil: Mitigation and Adaptation to Climate Change

    OpenAIRE

    Carlos E. Ludeña; Maria Netto

    2011-01-01

    In order to understand the implications of GHG emissions reduction targets in the Brazilian economy it is important to understand the sector composition of these emissions in Brazil. According to the 2010 Second National Communications of Brazil to the UNFCCC, in 2005, the majority of Brazil's emissions (87.2%) corresponded to carbon dioxide (CO2) emissions.

  19. Mineralogy of Soils from Different Agraecological Regions of Bangladesh : Region 25 - Level Barind Tract and Region 27 - Noth-eastern Barind Tract

    OpenAIRE

    Moslehuddin, Abu Zofar Md; Habibullah; Moniruzzaman, Md.; Egashira, Kazuhiko

    2008-01-01

    Bangladesh has been divided into 30 Agroecological Regions (AEZs) and the applied agricultural research has currently been conducted on this basis. In context of the lack of enough mineralogical information on the AEZ basis, an attempt has been taken to study mineralogy of important soils from all AEZs of Bangladesh in order to provide basic information for applied research. As a part of this attempt, the mineralogy of twelve soils from AEZ 25, Level Barind Tract, and that of ten soils from...

  20. Country watch: Brazil.

    Science.gov (United States)

    Szterenfeld, C

    1995-01-01

    The Health in Prostitution Project was launched in 1991 in Rio de Janeiro, Brazil. The project offers a multi-year training program of health education designed to both fight the stigmatization of and violence against commercial sex workers and enhance their self-esteem, self-determination, and access to civil rights. The project therefore promotes individual awareness while influencing public opinion and policies. At first, health agents were recruited among women and transvestites who work in street-based sex work. The program was then gradually expanded to include young male sex workers and other locations, such as private parlors, saunas, and escort services. People of all sexes and sexual orientation now comprise the health agent group. The program has a paid staff of five women, three young men, and three transvestites, and approximately 70 sex workers are trained annually. Basic training includes topics such as human sexuality, personal risk assessment, HIV/STD infection, negotiation of safer sex, and STD referral services. Year two training emphasizes reproductive and women's health issues, while year three courses prioritize street work methodologies. Theatrical performances, speaking English as a second language, and performing Bach flower therapy for clients take place during the fourth year. Program trainers include medical specialists, nurses, psychologists, health educators, lawyers, and university students. At least half of the 350 health agents trained thus far are estimated to be currently engaged in paid or voluntary prevention work. Two surveys with female sex workers in 1991 and 1993 found that reported regular condom use increased from 57% to 73%; the health agents are having an effect. The program is constantly evaluated and revised.

  1. Zika virus outbreak in Brazil.

    Science.gov (United States)

    Heukelbach, Jorg; Alencar, Carlos Henrique; Kelvin, Alyson Ann; de Oliveira, Wanderson Kleber; Pamplona de Góes Cavalcanti, Luciano

    2016-02-28

    Zika virus (ZIKV) infection is spreading rapidly within the Americas after originating from an outbreak in Brazil. We describe the current ZIKV infection epidemic in Brazil and the neurological symptoms arising. First cases of an acute exanthematic disease were reported in Brazil's Northeast region at the end of 2014. In March 2015, autochthonous ZIKV was determined to be the causative agent of the exanthematic disease. As cases of neurological syndromes in regions where ZIKV, dengue and/or Chikungunya viruses co-circulate were reported, ZIKV was also identified in the cerebrospinal fluid of patients with acute neurological syndromes and previous exanthematic disease. By the end of September 2015, an increasing number of infants with small head circumference or microcephaly were noted in Brazil's Northeast which was estimated to be 29 cases between August and October. ZIKV was identified in blood and tissue samples of a newborn and in mothers who had given birth to infants with microcephaly and ophthalmological anomalies. In 2015, there were an estimated 440,000 - 1,300,000 Zika cases in Brazil. There have been 4,783 suspected cases of microcephaly, most of them in the Northeast of Brazil associated with 76 deaths. The Ministry of Health is intensifying control measures against the mosquito Aedes aegypti and implemented intensive surveillance actions. Further studies are needed to confirm the suspected association between ZIKV infection and microcephaly; to identify antiviral, immunotherapy, or prophylactic vaccine; to introduce diagnostic ELISA testing. Clinical and epidemiological studies must be performed to describe viral dynamics and expansion of the outbreak.

  2. Fluid–rock interaction across the South Tibetan Detachment, Garhwal Himalaya (India): Mineralogical and geochemical evidences

    Indian Academy of Sciences (India)

    Anubhooti Saxena; Himanshu K Sachan; Pulok K Mukherjee; Dilip K Mukhopadhya

    2012-02-01

    The Malari Leucogranite in the Garhwal Himalaya is cut across by a continental-scale normal fault system called the South Tibetan Detachment (STD). A mineralogical, geochemical and fluid inclusion study of samples from the fault zone of the Malari Granite was performed to reveal the imprints of fluid–rock interaction. Fluid inclusion assemblages observed in the alteration zone indicate the presence of NaCl-dominated aqueous fluids with varied salinity of 6 –16 wt.% of NaCl equivalent. Mineralogical changes include the alteration of feldspar to muscovite and muscovite to chlorite. This alteration took place at temperatures of 275°–335°C and pressures between 1.9 and 4.2 kbars as revealed by the application of chlorite thermometry, fluid isochores, and presence of K-feldspar+muscovite+chlorite+quartz mineral assemblage. Geochemical mass-balance estimates predict 32% volume loss during alteration. An estimated fluid/rock ratio of 82 is based on loss of silica during alteration, and reveals presence of a moderately low amount of fluid at the time of faulting. Results of fluid inclusion and alteration mineralogy indicate that the Malari Leucogranites were exhumed due to normal faulting along the STD and erosion from mid-crustal levels. Most of the leucogranites in the Himalayas occur along the STD and possibly a regional-scale fluid flow all along the STD might have caused similar alteration of leucogranites along this tectonic break. Regional fluid flow was probably concentrated along the STD and channelized through mesoscopic fractures, microcracks and grain boundaries.

  3. Mineralogical discrimination of the pleistocene loess/paleosol sections in Srijem and Baranja, Croatia

    Science.gov (United States)

    Galović, Lidija; Peh, Zoran

    2016-06-01

    Previous investigations of the mineralogical composition of loess sections (loess, loess-like sediments, paleosols, alluvial intercalations) in the Carpathian Basin have concluded that the Danube River is the dominant control on the loessitic parent material. These investigations also identify a significant role for the Danube's tributaries in creating local variations. The north-south alignment of these sections forms a transect from the central part of the Carpathian Basin to its southern edge. In this work, the mineral origin of loess sediments was identified by using the multivariate statistical method of discriminant function analysis. Two models were constructed based on the modal composition as the suite of predictor (independent) variables: one is using geographic location as the a priori grouping criterion (SECTION); another employing the difference between the sampling media (LITHOLOGY). Both of the examined discriminant models demonstrate the existence of the mixing zones. The Erdut section is a clear mixture of the mineralogies at the other studied locations, while loesses appear generally intermediate in mineralogy between alluvium and paleosol. The main rationale for the observed difference in modal composition between the Šarengrad and other analyzed sections is the proximity of the Šarengrad section to the Sava River floodplain and Dinaric Ophiolite Zone (DOZ), both important source areas for aeolian sediments in the southern edge of the Carpathian Basin that transport material from the Central Bosnian Mountains unit of DOZ. Chemically, the most resistant heavy minerals together with opaque minerals are exclusively associated with paleosols, being typical products of geochemical pedogenic processes.

  4. Advances in EBSD and EBSD/EDS integration for the characterization of mineralogical samples

    Science.gov (United States)

    Palasse, L.; Goran, D.; Schwager, T.

    2013-12-01

    Electron BackScatter Diffraction (EBSD) is a well-known powerful technique for petrofabric studies using Scanning Electron Microscope. By assessing the quantitative microstructural information, i.e. crystallographic orientation data, it allows a large variety of applications: understanding the deformation mechanisms, seismic properties, metamorphic processes; and more recently, performing phase identification and discrimination when combined with Energy Dispersive X-Ray Spectroscopy (EDS). However, it is known that for multiphase mineralogical samples, the information delivered either by EBSD or by EDS alone is not enough to successfully distinguish the present phases. Typical examples for EBSD related indexing issues are phases creating similar patterns; and for EDS technique alone, phases with similar chemical composition like calcite and aragonite, quartz and cristobalite. Recent software and hardware developments have significantly improved the data quality as well as the efficiency/productivity. This presentation aims to reveal the latest development in data processing that has transformed the combination of the two complementary techniques into a powerful tool for characterizing multiphase materials. Through geosciences application examples, we will present the advantages brought by this new approach which uses the quantified EDS results and EBSP to identify the correct phase, reducing the need of data cleaning, and without spending extra time at the SEM. We will also demonstrate how powerful EBSD indexing algorithm can overcome the limitation from sample preparation, with some examples of high hit rate achieved on polyphase mineralogical specimen and even on shock-metamorphosed minerals. Last but not least, recent developments also enable the investigation of nanostructured materials in the scanning electron microscope (SEM) by Transmission Kikuchi Diffraction (TKD). Through some mineralogical applications, we will demonstrate the high spatial resolution

  5. Oral health policies in Brazil

    Directory of Open Access Journals (Sweden)

    Gilberto Alfredo Pucca Junior

    2009-06-01

    Full Text Available Since Oral Health policies in Brazil have been constructed according to circumstances and possibilities, they should be understood within a given context. The present analysis contextualizes several issues of the Brazilian Oral Health Policy, called "Smiling Brazil", and describes its present stage of development. Today it involves re-organizing basic oral health care by deploying Oral Health Teams within the Family Health strategy, setting up Centers of Dental Specialists within an Oral Health network as a secondary care measure, setting up Regional Laboratories of Dental Prosthesis and a more extensive fluoridation of the public water supply.

  6. Comparison of the Mineralogy of Comet Wild 2 Coma Grains to Other Astromaterials

    Science.gov (United States)

    Frank, David; Zolensky, Michael

    2010-01-01

    We propose that Kuiper Belt samples (in this case comet coma grains from the Jupiter family comet Wild 2) are recognizably different from the bulk of materials in outer belt asteroids, because of their different formation positions and times in the early solar system. We believe this despite similarities found between some Wild 2 grains and components of carbonaceous chondrites (i.e. some CAI and chondrules). Kuiper Belt samples must preserve measurable mineralogical and compositional evidence of formation at unique positions and times in the early solar nebula, and these formational differences must have imparted recognizable special characteristics. We hypothesize that these characteristics include: (1) Unique major element compositional ranges of common astromaterial minerals, especially olivine and pyroxene; (2) Unique minor element compositions of major silicate phases, especially olivine and low-Ca pyroxene; (3) Degree and effects of radiation processing -- including amorphous rims, metal coatings, and Glass with Embedded Metal and Sulfides (GEMS); (4) Presence of abundant presolar silicate grains as recognized by anomalous oxygen in silicates; (5) Oxidation state of the mineral assemblage. We are working our way through all available Wild 2 samples, selecting 1-2 non-consecutive viable TEM grids from each possible extracted Wild 2 grain. We especially prefer TEM grids from grains for which complete mineralogical details have not been published (which is to say the majority of the extracted grains). We are performing a basic mineralogic survey by E-beam techniques, to establish the essential features of the extracted Wild 2 grains. We are making a particular effort to carefully and accurately measure minor elements of olivine and pyroxene, as these minerals are widespread in astromaterials, and comparisons of their compositions will serve to place the Wild 2 silicates in contact with asteroids, meteorites and chondritic interplanetary dust particles

  7. Elemental composition and mineralogical characteristics of coastal marine sediments of Tutuila, American Samoa.

    Science.gov (United States)

    Morrison, R J; Peshut, P J; Lasorsa, Brenda K

    2010-06-01

    Surface sediment samples were collected from 5 pristine coastal areas and 1 potentially contaminated coastal site on Tutuila, the main island of American Samoa, an isolated island group in the South Pacific Ocean. Samples were analysed for total element analysis (15 elements) and mineralogy. The results indicated no evidence of trace element contamination at any site, including Pago Pago Harbour. Inter-site variations could be explained assuming the sediments consisted predominantly of coralline sand and rubble with varying quantities of basaltic materials derived from local catchments.

  8. The mineralogic evolution of the Martian surface through time: Implications from chemical reaction path modeling studies

    Science.gov (United States)

    Plumlee, G. S.; Ridley, W. I.; Debraal, J. D.; Reed, M. H.

    1993-01-01

    Chemical reaction path calculations were used to model the minerals that might have formed at or near the Martian surface as a result of volcano or meteorite impact driven hydrothermal systems; weathering at the Martian surface during an early warm, wet climate; and near-zero or sub-zero C brine-regolith reactions in the current cold climate. Although the chemical reaction path calculations carried out do not define the exact mineralogical evolution of the Martian surface over time, they do place valuable geochemical constraints on the types of minerals that formed from an aqueous phase under various surficial and geochemically complex conditions.

  9. Mineralogical and Biogeochemical Characteristics of Rhodolith from Wu Island, Jeju-do, Korea

    Science.gov (United States)

    Roh, Y.; Kang, S.; Roh, E. H.

    2012-12-01

    This study focused on investigation of mineralogical and biogeochemical characteristics of the rhodoliths and examination of the rhodolith origin whether they were formed by chemical or biological processes. Rhodoliths are free-living forms of calcareous, coralline red algae formed under specific environmental conditions, but their formation processes are still controversial. The rhodoliths and sea water were sampled at Seogwang-ri coast in the western part of Wu Island, Jeju-do, Korea. The chemical compositions and pHs of sea water were measured by ICP-AES and pH meter. Microorganisms enriched from rhodoliths were aerobically cultured at room temperature in D-1 media containing various concentrations (0, 30, 100 mM) of Ca and Mg-acetate, and the microorganisms were analyzed by 16S rRNA gene DGGE analysis to confirm microbial diversity. Mineralogical characteristics of the rhodoliths and precipitates formed by the enriched microorganisms were determined by XRF, XRD, and SEM-EDS analyses. The sea water had a range of pH 6 to 7, and consisted of approximately 400 mg/L of Ca and 1200 mg/L of Mg which are low to form carbonate minerals by chemical process in natural environments. XRF and XRD analyses showed the rhodoliths mainly consisted of 46% CaO and 5 % MgO and mineralogy is Mg-rich calcite. A 16S rRNA sequence analysis showed the enriched microorganisms contained a carbonate forming microorganism, Proteus mirabilis. The enriched microorganisms precipitated carbonate minerals using D-1 media containing Ca- and Mg-acetate (30, 100 mM) and mineralogy of the precipitated carbonate mineral was Mg-rich calcite, whereas the microorganisms did not form carbonate minerals without Ca- and Mg-acetate in D-1 media. SEM-EDS analyses showed that the Mg-rich calcite formed by the microorganisms had a rhombohedron shape. And the Mg-rich calcite consisted of Ca, Si and Mg with extracellular polymeric substance (EPS). These results indicate that the rhodoliths at Seogwang-ri coast

  10. Notas inéditas de Jovellanos sobre mineralogía

    OpenAIRE

    Ordaz Gargallo, Jorge; Gutiérrez Claverol, Manuel Alberto; Elena de LORENZO ÁLVAREZ

    2010-01-01

    Se presenta y analiza un manuscrito inédito de Gaspar Melchor de Jovellanos sobre la historia de la mineralogía, que redactó durante su cautiverio en el Castillo de Bellver (Palma de Mallorca). En el escrito considera de gran importancia los conocimientos químicos como fuente de otras ramas del saber científico y sus aplicaciones en distintos ámbitos de la agricultura, minería e industria. El autor hace una síntesis histórica repasando los hombres de ciencia que en mayor medida contribuyeron ...

  11. Mineralogical, geochemical and hydrocarbon potential of subsurface Cretaceous shales, Northern Western Desert, Egypt

    Directory of Open Access Journals (Sweden)

    D.A. Mousa

    2014-03-01

    Full Text Available Twenty four Cretaceous shale core samples of Gibb Afia-1, Betty-1, Salam-1X and Mersa Matruh-1 wells were mineralogically and geochemically studied using XRD, XRF and Rock Eval Pyrolysis. Kaolinite, smectite and illite are the main clay minerals in addition to rare chlorite, while the non-clay minerals include quartz, calcite, dolomite and rare siderite. The shales were derived through intensive chemical weathering of mafic basement and older sedimentary rocks. These sediments were deposited in a near-shore shallow marine environment with some terrestrial material input. The shales have poor to fair organic content. It is marginally to rarely mature.

  12. Accounting for mineralogical composition and origin of soils and sedimentary rocks in thermal property predictions

    Institute of Scientific and Technical Information of China (English)

    Rev I.Gavriliev

    2014-01-01

    A methodology for calculating the thermal conductivity of soils and rocks is developed which takes into account their origin and mineralogical composition. This method utilizes three approaches. One is founded on the structural modeling of contact heat interaction between particles and fills and estimates the statistical probability distribution of the particles in the volume of the medium. The second approach analyses perturbation to the temperature field of the matrix medium by ellipsoidal inclusions. The third approach is to find the mean thermal conductivity of the solid skeleton in the universal model at different composition of rock-forming minerals.

  13. Soil mineralogy and chemistry on Mars - Possible clues from salts and clays in SNC meteorites

    Science.gov (United States)

    Gooding, James L.

    1992-01-01

    If the shergottite, nakhlite, and chassignite (SNC) meteorites' parent planet is Mars, then the aqueous precipitates found in them imply that oxidizing, water-based solutions may have been chemically active on that planet over the past 200-1300 million yrs. It is suggested that the mixture of aqueous precipitates found in the SNCs furnish a self-consistent model for the bulk elemental composition of surface sediments at the Viking Lander sites. Further mineralogical and stable-isotope studies of the secondary minerals may establish the limits for biological activity over the last 1300 million years of Mars' water-based chemistry.

  14. Comment on “Stratigraphy, petrography and dispersion of the lower Permian syn-eruptive deposits in the Viar Basin, Spain” by S. Sierra, C. Moreno and E. Pascual [Sedimentary Geology 217 (2009) 1-29

    Science.gov (United States)

    Wagner, R. H.; Mayoral, E.

    2010-07-01

    Comments are provided on a published paper on "Lower Permian" strata in SW Spain [S. Sierra, C. Moreno and E. Pascual, Stratigraphy, petrography and dispersion of the lower Permian syn-eruptive deposits in the Viar Basin, Spain, Sedimentary Geology 217 (2009) 1-29], which failed to take into account up-to-date information on this most southerly occurrence in western Europe. This generally lacustrine basin commenced with valley fill deposits in a deeply incised palaeotopography and contains mainly red beds with two basaltic intervals and a major acidic volcanic episode linked to a nearby volcanic centre to the Northeast. The stratigraphic succession shows southeasterly onlap. Although a syn-sedimentary fault has been postulated on the NE basin margin, the field evidence disproves this notion as well as the assumption that this "Early Permian" basin would have been controlled by a rejuvenated Ossa-Morena/South Portuguese boundary fault. In fact, this basin lies within the (former) area of Ossa-Morena.

  15. The Byzantine ceramics from Pergamon excavations. Characterization of local and imported productions by elementary analysis using PIXE and INAA methods and by petrography; Les ceramiques byzantines des fouilles de Pergame. Caracterisation des productions locales et importees par analyse elementaire par les methodes PIXE et INAA et par petrographie

    Energy Technology Data Exchange (ETDEWEB)

    Waksman, S.Y.

    1995-01-12

    An important ceramics material dated back to the 12th-14th centuries has been excavated in Pergamon (Turkey). Among these findings, wasters, tripod stilts and unfinished ware attest to local production in the Byzantine period. Elemental analysis by the methods PIXE (Particle Induced X-ray Emission) and INAA (Instrumental Neutron Activation Analysis) has been performed on a representative sampling of 160 sherds, including attested local material. Multivariate statistical techniques were used to classify the sherds into groups of similar composition and thus to distinguish ceramics made in Pergamon from imported wares. Several groups of local production have been constituted, which correspond to wares differing in date and fabric. The geochemical characterization of the pastes, complemented with petrographical and mineralogical data, shows that specific raw materials have been used to manufacture each ware. The analytical data related to ceramics made in Pergamon will serve as reference data for future provenance studies. Such reference groups of Byzantine ceramics are very rare, and therefore the ceramics imported into Pergamon cannot be attributed as to their origin. Among the ceramics widely diffused in the Byzantine world, some importations belonging to the ``fine sgraffito`` and ``Zeuxippus ware`` types have been identified. The latter type has been a source of stylistic influence for the workshops of Pergamon, since the analyses show that imitated ``Zeuxippus ware`` has been produced there. These imitations were probably themselves diffused on a regional scale. (author). 238 refs., 48 figs., 53 tabs., 22 photos., 8 appends.

  16. Evaluating School Facilities in Brazil

    Science.gov (United States)

    Ornstein, Sheila Walbe; Moreira, Nanci Saraiva

    2008-01-01

    Brazil's Sao Paulo Metropolitan Region is conducting a performance evaluation pilot study at three schools serving disadvantaged populations. The objective is first to test methods which can facilitate Post Occupancy Evaluations (POEs) and then to carry out the evaluations. The preliminary results are provided below.

  17. [Nuptiality among Brazil's black population].

    Science.gov (United States)

    Berquo, E

    1987-08-01

    Data from a three percent sample of the 1980 census of Brazil are used to analyze nuptiality trends by ethnic group. The focus is on the homogamy of marriage by color and age and on the marriage patterns of the black population.

  18. Brazil and CERN get closer

    CERN Multimedia

    2002-01-01

    The map of countries affiliated to CERN may in future include Brazil. On a visit to CERN last week, the Brazilian Minister of State for Science and Technology, Ronaldo Mota Sardenberg, expressed his country's interest in closer links to the Laboratory.   Luciano Maiani and the Brazilian Minister of State for Science and Technology Ronaldo Mota Sardenberg shake hands on CERN-Brazil co-operation. During his visit, the Minister and CERN Director General Luciano Maiani issued a joint statement for the continuation of a Co-operation Agreement first established in 1990. They also agreed to study the possibility of Brazil joining CERN-led Grid computing infrastructure projects. Brazilian physicists are already involved in the LHCb, ATLAS and CMS experiments. At the conclusion of the Minister's visit, he and Director-General Maiani agreed to establish a Working Group to examine ways of strengthening Brazil's links with CERN, and to prepare the way for a Brazilian request to CERN Council to become an Observer at th...

  19. Brazils Rise to Global Power

    Science.gov (United States)

    2014-06-01

    Família, Real Plan, BRIC , Export Oriented Growth, Import Substitution Industrialization, South-South cooperation. 15. NUMBER OF PAGES 113 16...61 F. CAPABILITIES COMPARED TO BRIC ..................................................62 1. India...Desenvolvimento Econômico e Social BRIC Brazil, Russia, India, China EU European Union FTA Free Trade Agreement G8 Group of Eight G20 Group of Twenty GNP

  20. Mineralogical determination in situ of a highly heterogeneous material using a miniaturized laser ablation mass spectrometer with high spatial resolution

    Science.gov (United States)

    Neubeck, Anna; Tulej, Marek; Ivarsson, Magnus; Broman, Curt; Riedo, Andreas; McMahon, Sean; Wurz, Peter; Bengtson, Stefan

    2016-04-01

    Techniques enabling in situ elemental and mineralogical analysis on extraterrestrial planets are strongly required for upcoming missions and are being continuously developed. There is ample need for quantitative and high-sensitivity analysis of elemental as well as isotopic composition of heterogeneous materials. Here we present in situ spatial and depth elemental profiles of a heterogeneous rock sample on a depth-scale of nanometres using a miniaturized laser ablation mass spectrometer (LMS) designed for planetary space missions. We show that the LMS spectra alone could provide highly detailed compositional, three-dimensional information and oxidation properties of a natural, heterogeneous rock sample. We also show that a combination of the LMS and Raman spectroscopy provide comprehensive mineralogical details of the investigated sample. These findings are of great importance for future space missions where quick, in situ determination of the mineralogy could play a role in the process of selecting a suitable spot for drilling.

  1. Goldschmidt crater and the Moon's north polar region: Results from the Moon Mineralogy Mapper (M3)

    Science.gov (United States)

    Cheek, L.C.; Pieters, C.M.; Boardman, J.W.; Clark, R.N.; Combe, J.-P.; Head, J.W.; Isaacson, P.J.; McCord, T.B.; Moriarty, D.; Nettles, J.W.; Petro, N.E.; Sunshine, J.M.; Taylor, L.A.

    2011-01-01

    Soils within the impact crater Goldschmidt have been identified as spectrally distinct from the local highland material. High spatial and spectral resolution data from the Moon Mineralogy Mapper (M3) on the Chandrayaan-1 orbiter are used to examine the character of Goldschmidt crater in detail. Spectral parameters applied to a north polar mosaic of M3 data are used to discern large-scale compositional trends at the northern high latitudes, and spectra from three widely separated regions are compared to spectra from Goldschmidt. The results highlight the compositional diversity of the lunar nearside, in particular, where feldspathic soils with a low-Ca pyroxene component are pervasive, but exclusively feldspathic regions and small areas of basaltic composition are also observed. Additionally, we find that the relative strengths of the diagnostic OH/H2O absorption feature near 3000 nm are correlated with the mineralogy of the host material. On both global and local scales, the strongest hydrous absorptions occur on the more feldspathic surfaces. Thus, M3 data suggest that while the feldspathic soils within Goldschmidt crater are enhanced in OH/H2O compared to the relatively mafic nearside polar highlands, their hydration signatures are similar to those observed in the feldspathic highlands on the farside. Copyright 2011 by the American Geophysical Union.

  2. The geology, mineralogy and rare element geochemistry of the gem deposits of Sri Lanka

    Directory of Open Access Journals (Sweden)

    C. B. Dissanayake

    2000-01-01

    Full Text Available The gem deposits of Sri Lanka are studied from the point of view of their geology, mineralogy and geochemistry. Nearly all the gem formations are located in the central high-grade metamorphic terrain of the Highland Complex. The gem deposits are classified as sedimentary, metamorphic and magmatic; the sedimentary types being the most abundant. The mineralogy of the gem deposits varies widely with, among others, corundum, chrysoberyl, beryl, spinel, topaz,zircon, tourmaline, garnet and sphene being common.Rare element concentrations in sediments from the three main gem fields of Sri Lanka, namely Ratnapura, Elahera and Walawe, were studied. It was found that some sediments are considerably enriched in certain elements compared to their average continental crustal abundances. The Walawe Ganga sediments show anomalous enrichments of the high field strength and associated elements, particularly Zr, Hf, W and Ti. This is attributed to the presence of accessory mineralssuch as zircon, monazite and rutile. Some of these heavy minerals comprise as much as 50 wt% of sediment. The geochemical enrichment of some trace elements compared to their average crustal abundances indicates that highly differentiated granites and associated pegmatites have provided the source materials for enrichment.

  3. Mineralogy of Stardust Track 112 Particle: Relation to Amoeboid Olivine Aggregates

    Science.gov (United States)

    Komatsu, M.; Fagan, T.; Mikouchi, T.; Miyamoto, M.; Zolensky, M.; Ohsumi, K.

    2012-01-01

    The successful analysis of comet 81P/Wild 2 particles returned by the Stardust mission has revealed that the Wild 2 dust contains abundant silicate grains that are much larger than interstellar grains and appear to have formed in the inner regions of the solar nebula [1]. Wild 2 particles include minerals which are isotopically and mineralogically similar to CAIs [e.g., 2, 3] and chondrules [e.g., 4] in chondrites. In addition, particles similar to amoeboid olivine aggregates (AOAs) also have been discovered [5, 6,7]. C2067,2,112,1 is a terminal particle recovered from track #112 (T112). Nakamura-Messenger et al. [7] showed that the forsterite grain in T112 has O-16 enrichment of approximately 40 0/00 (vs. SMOW) and possibly formed together with AOAs. In this study, we have examined the mineralogy of the T112 particle and compared the possible relationships between T112 and AOAs in primitive meteorites.

  4. Iron mineralogy and uranium-binding environment in the rhizosphere of a wetland soil

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel I.; Kukkadapu, Ravi; Seaman, John C.; Arey, Bruce W.; Dohnalkova, Alice C.; Buettner, Shea; Li, Dien; Varga, Tamas; Scheckel, Kirk G.; Jaffé, Peter R.

    2016-11-01

    Wetlands mitigate the migration of groundwater contaminants through the creation of biogeochemical gradients that enhance multiple contaminant-binding processes. Our hypothesis was that wetland plants not only contribute organic carbon, produce strong redox gradients, and elevate microbial populations to soils, but together these conditions also promote the formation of Fe (oxyhydr)oxides within the plant rhizosphere that may also contribute to contaminant immobilization. Mineralogy and U binding environments of the rhizosphere (plant-impacted soil zone) were evaluated in samples collected from contaminated and non-contaminated areas of a wetland on the Savannah River Site in South Carolina. Based on Mossbauer spectroscopy, rhizosphere soil collected from the field study site was greatly enriched with poorly crystalline nanoparticulate Fe-oxide/ferrihydrite-like materials and nano-goethite (<15-nm). X-ray computed tomography or various microscopy techniques showed that root plaques, tens-of microns thick, were consisted of highly oriented nanoparticles in an orientation suggestive that the roots were involved in the Fe-nanoparticle formation. Because of detection limits, SEM/EDS could not confirm whether U was enriched in the rhizosphere but did demonstrate that U was enriched on root plaques. Uranium in the plaques was always found in association with P and frequently with Fe. Together these findings suggest that plants may not only alter soil microbial and chemical conditions, but also mineralogical conditions that may be conducive to aqueous contaminant immobilization in wetlands.

  5. Chemical and Mineralogical study of Nabataean painted pottery from Petra, Jordan.

    Science.gov (United States)

    Alawneh, Firas; Bala'awi, Fadi

    Nabataean pottery is distinguished by the thinness of its walls, which were sometimes only 1.5 mm thick. It was a pinkish/red color, often decorated by hand with dark brown flower and leaf designs. The typical (egg-shell) shallow open bowls productions were very difficult to make on the potter's wheel, demonstrating how skilled their craftsmen were Nabataean painted pottery from Petra Jordan were examined in order to determine the mineralogical characteristics of the raw pigment materials used for their production and to elucidate the ceramic manufacturing technologies employed. Optical microscopy, X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM-EDS) were the analytical techniques used. The initial examination of the ceramic shreds in optical microscopy showed all samples to be identical in their paint and paste textures. The mineralogical composition of the paste (unpainted outer surface) is typical of a clay poor in calcium and fired at moderate-high temperature in an oxidizing atmosphere. The paste is composed of quartz, plagioclase, potassium feldspar, hematite, dolomite, and calcite. The latter two phases might be attributed to post-depositional contamination, since examination with both optical and scanning electron microscopes show fine carbonate particles deposited in the pores and cracks of the shred. The paint on the inner surface of the vessel, on the other hand is composed of hematite as a major phase with only some quartz and plagioclase.

  6. Mineralogical evidence for lamproite magma mixing and storage at mantle depths: Socovos fault lamproites, SE Spain

    Science.gov (United States)

    Cambeses, A.; Garcia-Casco, A.; Scarrow, J. H.; Montero, P.; Pérez-Valera, L. A.; Bea, F.

    2016-12-01

    Detailed textural and mineral chemistry characterisation of lamproites from the Socovos fault zone, SE Spain Neogene Volcanic Province (NVP) combining X-ray element maps and LA-ICP-MS spot analyses has provided valuable information about mantle depth ultrapotassic magma mixing processes. Despite having similar whole-rock compositions, rocks emplaced in the Socovos fault are mineralogically varied: including type-A olivine-phlogopite lamproites; and type-B clinopyroxene-phlogopite lamproites. The Ol-lacking type-B predates Ol-bearing type-A by c. 2 million years. We propose that the mineralogical variations, which are representative of lamproites in the NVP as a whole, indicate mantle source heterogeneities. Major and trace element compositions of mineral phases suggest both metasomatised harzburgite and veined pyroxenite sources that were most likely closely spatially related. Thin section scale textural and compositional variations in mineral phases reveal heterogeneous mantle- and primitive magma-derived crystals. The variety of crystals points to interaction and mingling-mixing of ultrapotassic magma batches at mantle depths prior crustal emplacement. The mixing apparently occurred in a mantle melting zone with a channelised flow regime and localised magma chambers-reservoirs. Magma interaction was interrupted when the Socovos and other lithosphere-scale faults tore down to the mantle source region, triggering rapid ascent of the heterogeneous lamproite magma.

  7. Mineralogical, textural, structural and geochemical aspects of Nakhlak lead mine, Isfahan

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Jazi

    2010-11-01

    Full Text Available Nakhlak lead mine is located at the Nakhlak mountain 55 km NE of Anarak town in Isfahan province. The mineralogy is simple; galena and barite are the main primary minerals and cerussite is the main secondary mineral. Sphalerite, pyrite, chalcopyrite, tetrahedrite-tennantite and acanthite occur as minor and trace mineral inclusions in galena. Secondary minerals are anglesite, plattnerite, wulfenite and malachite. The host rock has undergone a pre-mineralization dolomitization process. Four types of dolomite have been identified which saddle dolomite is the most distinguished. Open space filling textures occur in the form of breccia, cockade, crustification and colloform. Analysis of the galena samples indicates presence of many trace elements in galena among which silver is the most important. Element pairs such as Ag-As, Zn-Cd, As-Cu and As-Sb are highly correlated. This correlation may be explained by the presence of inclusions. Ag-Sb-Bi ternary diagram indicates that galena samples from Nakhlak are rich in Ag and Sb and poor in Bi. Sb/Bi (3773 ratio in galena is suggestive of a low temperature of formation for the deposit. The Upper Cretaceous carbonate host rocks and their dolomitization, the stratabound and epigenetic mineralization, the absence of igneous activity, the open space filling texture, the simple mineralogy and geochemistry all point to a Mississippi valley type model for the Nakhlak Pb deposit.

  8. Relationship between water chemistry and sediment mineralogy in the Cerro Prieto geothermal field: a preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Valette-Silver, J.N. (Univ. de Perpignan, France); Thompson, J.M.; Ball, J.W.

    1981-01-01

    The chemical compositions of waters collected from the Cerro Prieto geothermal production wells and hydrothermal emanations are different. Compared to the Cerro Prieto well waters, the surficial waters generally contain significantly less potassium, slightly less calcium and chloride, and significantly more magnesium and sulfate. In comparison to the unaltered sediments, the changes in the mineralogy of the altered sediments appear to be controlled by the type of emanation (well, spring, mud pot, geyser, fumarole, or cold pool). However, an increase in quartz and potassium feldspar percentages seems to be characteristic of the majority of the sediments in contact with geothermal fluids. Preliminary attempts to model the chemical processes occurring in the Cerro Prieto geothermal field using chemical equilibrium calculations are reported. For this purpose the chemical compositions of thermal waters (well and surficial emanation) were used as input data to make calculations with SOLMNEQ and WATEQ2 computer programs. Then the theoretical mineral composition of altered sediments was predicted and compared to the mineralogy actually observed in the solid samples.

  9. Mineralogic variation in drill core UE-25 UZ{number_sign}16, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Chipera, S.J.; Vaniman, D.T.; Carlos, B.A.; Bish, D.L.

    1995-02-01

    Quantitative X-ray powder diffraction methods have been used to analyze 108 samples from drill core UE-25 UZ{number_sign}16 at Yucca Mountain, Nevada. This drill hole, located within the imbricate fault zone east of the potential Yucca Mountain repository site, confirms the authors` previous knowledge of gross-scale mineral distributions at Yucca Mountain and provides insight into possible shallow pathways for hydrologic recharge into the potential host rock. Analyses of samples from UE-25 UZ{number_sign}16 have shown that the distribution of major zeolitized horizons, of silica phases, and of glassy tuffs are similar to those noted in nearby drill cores. However, the continuous core and closer sample spacing in UE-25 UZ{number_sign}16 provide a more exact determination of mineral stratigraphy, particularly in hydrologically important units such as the Paintbrush bedded tuffs above the Topopah Spring Tuff and in the upper vitrophyre of the Topopah Spring Tuff. The discovery of matrix zeolitization in the devitrified Topopah Spring Tuff of UE25 UZ{number_sign}16 shows that some unexpected mineralogic features can still be encountered in the exploration of Yucca Mountain and emphasizes the importance of obtaining a more complete three-dimensional model of Yucca Mountain mineralogy.

  10. Mass Concentration and Mineralogical Characteristics Aerosol Particles Collected at Dunhuang During ACE-Asia

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Measurements were performed in spring 2001 and 2002 to determine the characteristics of soil dust in the Chinese desert region of Dunhuang, one of the ground sites of the Asia-Pacific Regional Aerosol Characterization Experiment (ACE-Asia). The mean mass concentrations of total suspended particle matter during the spring of 2001 and 2002 were 317 μg m-3 and 307 μg m-3, respectively. Eleven dust storm events were observed with a mean aerosol concentration of 1095 μg m-3, while the non-dusty days with calm or weak wind speed had a background aerosol loading of 196 μg m-3 on average in the springtime.The main minerals detected in the aerosol samples by X-ray diffraction were illite, kaolinite, chlorite, quartz,feldspar, calcite and dolomite. Gypsum, halite and amphibole were also detected in a few samples. The mineralogical data also show that Asian dust is characterized by a kaolinite to chlorite (K/C) ratio lower than 1 whereas Saharan dust exhibits a K/C ratio larger than 2. Air mass back-trajectory analysis show that three families of pathways are associated with the aerosol particle transport to Dunhuang, but these have similar K/C ratios, which further demonstrates that the mineralogical characteristics of Asian dust are different from African dust.

  11. Mineralogy of Cretaceous/Tertiary boundary clays in the Chicxulub structure in northern Yucatan

    Science.gov (United States)

    Ming, D. W.; Sharpton, Virgil L.; Schuraytz, B. C.

    1991-01-01

    The Cretaceous/Tertiary (K/T) boundary clay layer is thought to be derived from ejecta material from meteorite impact, based on the anomalous concentrations of noble metals in the layer. Because of recent findings of a half-meter thick ejecta deposit at the K/T boundary in Haiti, efforts have focused on locating a large impact feature in the Caribbean and the Gulf of Mexico. One of the leading candidates for the site of a large impact is the Chicxulub structure located on the northern Yucatan Peninsula in Mexico. The Chicxulub structure is a subsurface zone of upper Cretaceous igneous rocks, carbonates, and breccias. The structure has been interpreted to be a 200 km diameter; however, there is some question to the size of the structure or to the fact that it even is an impact feature. Little is known about the mineralogy of this structure; the objective of this study was to determine the clay mineralogy of core samples from within the Chicxulub structure.

  12. Mineralogical properties and internal structures of individual fine particles of Saharan dust

    Science.gov (United States)

    Jeong, Gi Young; Park, Mi Yeon; Kandler, Konrad; Nousiainen, Timo; Kemppinen, Osku

    2016-10-01

    Mineral dust interacts with incoming/outgoing radiation, gases, other aerosols, and clouds. The assessment of its optical and chemical impacts requires knowledge of the physical and chemical properties of bulk dust and single particles. Despite the existence of a large body of data from field measurements and laboratory analyses, the internal properties of single dust particles have not been defined precisely. Here, we report on the mineralogical organization and internal structures of individual fine ( common particle type was clay-rich agglomerate, dominated by illite-smectite series clay minerals with subordinate kaolinite. Submicron grains of iron (hydr)oxides (goethite and hematite) were commonly dispersed through the clay-rich particles. The median total volume of the iron (hydr)oxide grains included in the dust particles was estimated to be about 1.5 % vol. The average iron content of clay minerals, assuming 14 wt % H2O, was determined to be 5.0 wt %. Coarse mineral cores, several micrometers in size, were coated with thin layers of clay-rich agglomerate. Overall, the dust particles were roughly ellipsoidal, with an average axial ratio of 1.4 : 1.0 : 0.5. The mineralogical and structural properties of single Saharan dust particles provide a basis for the modeling of dust radiative properties. Major iron-bearing minerals, such as illite-smectite series clay minerals and iron (hydr)oxides, were commonly submicron- to nano-sized, possibly enhancing their biogeochemical availability to remote marine ecosystems lacking micronutrients.

  13. Characterization and pedogenesis of mangrove soils from Ilhéus-BA, Brazil

    Directory of Open Access Journals (Sweden)

    Felipe Haenel Gomes

    2016-12-01

    Full Text Available ABSTRACT Despite its importance, studies of mangrove soils are scarce, especially from a pedological perspective. The objective of this work was to study the genesis of soils in a mangrove environment in northeastern Brazil (Ilhéus, Bahia through a morphological, physical, chemical and mineralogical characterization. All soils presented a sandy texture, which is related to the parent material (Quaternary sand deposits. The tidal flooding and resulting hydromorphic conditions is responsible for dominance of dark grey colors, and high organic matter contents (paludization process. As well as the high values of electrical conductivity (EC and dominance of Na+ in the saturation extract (salinization and solodization processes, respectively. Contrastingly, the M3 profile, with aninga (Montrichardia linifera vegetation, a non-exclusive mangrove plant, showed colors with high chromas due to a lesser influence of tidal flooding. The pH values and the SO4=/Cl- ratios indicated the presence of sulfidic material and, thus, the occurrence of the sulfidization process. The soil organic matter fractionation evidenced the humin as the fraction with the highest content, probably because of removal of most soluble fractions due to tidal action. Similar to mangrove soils from southeast Brazil, the XRD analysis identified kaolinite, mica and expandable 2:1 minerals in the clay fraction.

  14. Cambro-Ordovician magmatism in the Araçuaí Belt (SE Brazil): Snapshots from a post-collisional event

    Science.gov (United States)

    De Campos, Cristina P.; de Medeiros, Silvia R.; Mendes, Julio C.; Pedrosa-Soares, Antonio C.; Dussin, Ivo; Ludka, Isabel P.; Dantas, Elton L.

    2016-07-01

    The focus of the present work is the rebound of the magmatism at the late stages of orogenic collapse in the Araçuaí Belt, in Brazil. At the end of the orogen bimodal inversely zoned plutons were emplaced along a tectonic corridor following the Atlantic coast of Brazil. This event culminates around 500 Ma. We review geology, petrography, geochemistry and geochronology of these plutonic structures in the region of Espírito Santo. New geochemical modeling of trace element data together with new whole rock Sm-Nd and Rb-Sr isotopic data depict a gradual process of mantle contamination during different stages of the orogen. In the post-orogenic stage contamination reaches extreme values. Basic rocks reach εNd(0.5Ga) values below -10. Gabbros to peridotites are more enriched in Ba, Zr, LREE and Sr than the surrounding metasediments. Four new U-Pb data sets from determinations in zircon and monazite crystals, (central northern part of the belt) confirm peak magma production around 500 ± 15 Ma, ranging up to 525 ± 3 Ma in one of the structures. Based on the pictured data, we discuss the significance of this magmatism and present a possible model: a process of gradational delamination of the subcontinental lithospheric mantle and adjacent deep continental crust through underplating. As a consequence, an already enriched mantle was dramatically further contaminated. At the end of this event the intrusion of alkaline melts, with less negative εNd (-5) and further enrichment in incompatible elements, point towards a new input of deeper juvenile mantle magma. Our data suggest the possible onset of a hotspot due to the destabilization of the asthenospheric mantle after orogenic collapse.

  15. Mineralogical correlation of surficial sediment from area drainages with selected sedimentary interbeds at the Idaho National Engineering Laboratory, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomay, R.C.

    1990-08-01

    Ongoing research by the US Geological Survey at the INEL involves investigation of the migration of radioactive elements contained in low-level radioactive waste, hydrologic and geologic factors affecting waste movement, and geochemical factors that influence the chemical composition of the waste. Identification of the mineralogy of the Snake River Plain is needed to aid in the study of the hydrology and geochemistry of subsurface waste disposal. The US Geological Surveys project office at the Idaho National Engineering Laboratory, in cooperation with the US Department of Energy, used mineralogical data to correlate surficial sediment samples from the Big Lost River, Little Lost River, and Birch Greek drainages with selected sedimentary interbed core samples taken from test holes at the RWMC (Radioactive Waste Management Complex), TRA (Test Reactors Area), ICPP (Idaho Chemical Processing Plant), and TAN (Test Area North). Correlating the mineralogy of a particular present-day drainage area with a particular sedimentary interbed provides information on historical source of sediment for interbeds in and near the INEL. Mineralogical data indicate that surficial sediment samples from the Big Lost River drainage contained a larger amount of feldspar and pyroxene and a smaller amount of calcite and dolomite than samples from the Little Lost River and Birch Creek drainages. Mineralogical data from sedimentary interbeds at the RWMC, TRA, and ICPP correlate with surficial sediment of the present-day big Lost River drainage. Mineralogical data from a sedimentary interbed at TAN correlate with surficial sediment of the present-day Birch Creek drainage. 13 refs., 5 figs., 3 tabs.

  16. Mineralogy of Rock Flour in Glaciated Volcanic Terrains: An Analog for a Cold and Icy Early Mars

    Science.gov (United States)

    Rampe, E. B.; Horgan, B.; Scudder, N.; Smith, R. J.; Rutledge, A. M.

    2017-01-01

    Geomorphological and mineralogical data from early Martian surfaces indicate liquid water was present on ancient Mars. The relative surface temperatures, however, remain a subject of debate. Was early Mars warm and wet or cold and icy with punctuated periods of warmth and ice melt? By characterizing the mineralogy and geochemistry of modern icy mafic terrains on Earth, we can search for these characteristics in early Martian terrains to better constrain the early Martian climate. Here, we describe the mineralogy of glacial flour in a modern glaciated volcanic terrain in Oregon, USA. We are particularly interested in secondary phases that form in these environments, and we hypothesize that poorly crystalline phases may preferentially form in these terrains because of the low temperatures and the seasonality of melt water production. A description of the mineralogy of the moraines, the composition of the amorphous materials, and the geochemistry of the glacial melt waters are presented elsewhere. Glacial flour is made up of silt- and clay-sized particles that form from the physical weathering of rock underlying a wet-based glacier as the glacier slides over it. Flour is usually transported from underneath a glacier by melt water streams. The geochemistry of glacial melt water streams has been studied extensively and has been used to infer weathering reactions within glacial systems. However, the mineralogy of these environments, especially on mafic volcanic terrains, is not well studied. Rock flour is a ubiquitous physical weathering product in glaciated terrains and, therefore, affects microbial habitats, stream and lake chemistry, and chemical weathering processes. and by studying the mineralogy of glacial flour, we can better understand geochemical and microbiological processes in subglacial and proglacial terrains.

  17. Visible and Near-IR Reflectance Spectra of Mars Analogue Materials Under Arid Conditions for Interpretation of Martian Surface Mineralogy

    Science.gov (United States)

    Morris, R. V.; Graff, T. G.; Achilles, C. N.; Agresti, D. G.; Ming, D. W.; Golden, D. C.

    2011-01-01

    Visible and near-IR (VNIR) spectra from the hyper-spectral imagers MRO-CRISM and Mars Express OMEGA in martian orbit have signatures from Fe-bearing phases (e.g., olivine, pyroxene, and jarosite), H2O/OH-bearing phases (e.g., smectites and other phyllosilicates, sulfates, and high-SiO2 phases), and carbonate [e.g., 1-5]. Mineralogical assignments of martian spectral features are made on the basis of VNIR spectra acquired in the laboratory under appropriate environmental conditions on samples whose mineralogical composition is known. We report here additional results for our ongoing project [6] to acquire VNIR spectra under arid conditions.

  18. A semiquantitative X-ray diffraction method to determine mineral composition in stream sediments with similar mineralogy

    Science.gov (United States)

    Webster, D.M.

    1989-01-01

    A semiquantitative X-ray diffraction procedure has been developed that can be used to acquire reproducible mineralogic data from geographically unrelated stream-sediment samples having similar mineralogy. Weight percentages for quartz, total-feldspar, and total-clay can be determined by direct comparison of intensities with standard-mineral mixtures of known weight percent. Matrix effects and mass-absorption differences are circumvented by taking the ratio of peak-intensity, in counts per second, for quartz relative to that of other minerals being quantified. Mineral percentages generally are reproducible to within 10 percent.

  19. Effect of compaction on microbial activity and carbon and nitrogen transformations in two oxisols with different mineralogy

    Directory of Open Access Journals (Sweden)

    Sérgio Ricardo Silva

    2011-08-01

    Full Text Available The use of machinery in agricultural and forest management activities frequently increases soil compaction, resulting in greater soil density and microporosity, which in turn reduces hydraulic conductivity and O2 and CO2 diffusion rates, among other negative effects. Thus, soil compaction has the potential to affect soil microbial activity and the processes involved in organic matter decomposition and nutrient cycling. This study was carried out under controlled conditions to evaluate the effect of soil compaction on microbial activity and carbon (C and nitrogen (N mineralization. Two Oxisols with different mineralogy were utilized: a clayey oxidic-gibbsitic Typic Acrustox and a clayey kaolinitic Xantic Haplustox (Latossolo Vermelho-Amarelo ácrico - LVA, and Latossolo Amarelo distrófico - LA, respectively, in the Brazil Soil Classification System. Eight treatments (compaction levels were assessed for each soil type in a complete block design, with six repetitions. The experimental unit consisted of PVC rings (height 6 cm, internal diameter 4.55 cm, volume 97.6 cm³. The PVC rings were filled with enough soil mass to reach a final density of 1.05 and 1.10 kg dm-3, respectively, in the LVA and LA. Then the soil samples were wetted (0.20 kg kg-1 = 80 % of field capacity and compacted by a hydraulic press at pressures of 0, 60, 120, 240, 360, 540, 720 and 900 kPa. After soil compression the new bulk density was calculated according to the new volume occupied by the soil. Subsequently each PVC ring was placed within a 1 L plastic pot which was then tightly closed. The soils were incubated under aerobic conditions for 35 days and the basal respiration rate (CO2-C production was estimated in the last two weeks. After the incubation period, the following soil chemical and microbiological properties were detremined: soil microbial biomass C (C MIC, total soil organic C (TOC, total N, and mineral N (NH4+-N and NO3--N. After that, mineral N, organic N

  20. Mineralogical analysis of attic dust samples for contamination source identification in an industrial area, Ajka, Hungary

    Science.gov (United States)

    Völgyesi, Péter; Jordan, Gyozo; Gosar, Mateja; Szabó, Csaba; Miler, Miloš; Kónya, Péter; Bartha, András

    2013-04-01

    The post-war centrally directed economy forced massive heavy industry in Hungary, producing huge amount of wastes and pollution. Long-term airborne emissions from mining, coal-fired power plants and alumina industry have left the legacy of widely distributed contamination around industrial areas and nearby settlements in the Ajka region. Recent research suggests that significant amount of airborne pollutants, deposited in the urban environment, can be efficiently studied by attic dust analysis. The sampling strategy followed a grid-based stratified random sampling design and 30 samples were collected in 27 houses (at least 30 years old) in a 8x8 grid of the 64 km2 project area. In order to determine the pollution potential of attic dust samples, geochemical and mineralogical analyses were performed. The main aim of the mineralogical analyses was to study the phase composition of the dust particles and to identify potential anthropogenic sources. The total concentrations of the toxic elements (As, Pb, Cd, Cu, Ni and Zn) were measured with ICP-OES and mercury content was analyzed with atomic absorption spectrometry. Phase analyses of the samples were carried out by the means of scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and X-Ray diffraction (XRD) methods. Laser particle size analyzer was used to measure the grain size of attic dust particles. Results showed that the studied attic dust in the Ajka urban area was contaminated mostly by Hg, Pb and Zn with contents ranging between 0.1-2 ppm, 42.5-881 ppm and 90.2-954 ppm, respectively. However, the study of extreme data values (statistical outliers) has shown that at certain points airborne dust can be extremely contaminated also with Cd (0.4-11.7 ppm). The size of the attic dust particles varied between 0.2 and 113 µm. Based on the SEM/EDS and XRD analysis, the most frequently identified mineralogical phases were quartz, calcite, gypsum and Fe- and Al-bearing phases. Fe

  1. Teaching Mineralogy, Petrology and Geochemistry in the 21st Century: Instructional Resources for Geoscience Faculty

    Science.gov (United States)

    Mogk, D. W.; Beane, R. J.; Whitney, D. L.; Nicolaysen, K. E.; Panero, W. R.; Peck, W. H.

    2011-12-01

    Mineralogy, petrology and geochemistry (MPG) are pillars of the geoscience curriculum because of their relevance in interpreting Earth history and processes, application to geo-hazards, resources, and environmental issues, and contributions to emerging fields such as geology and human health. To keep faculty current in scientific advances in these fields, and in modern instructional methods, the On the Cutting Edge program convened a workshop at the University of Minnesota in August, 2011. This workshop builds on the previous 15 year's work that has been focused on identifying, aggregating, and developing high-quality collections of teaching activities and related resources, and in building a community of scholars in support of excellence in instruction in MPG courses. The goals of the workshop were to: a) develop an integrated, comprehensive and reviewed curriculum for MPG courses, and to seek ways to make connections with the larger geoscience curriculum; b) to explore emerging topics in MPG such as geobiology and climate change; c) demonstrate effective methods in teaching MPG in the context of Earth system science; d) share effective teaching activities and strategies for the classroom, laboratory and field including advances in pedagogy, assessments and research on learning; e) keep faculty current on recent advances in mineralogy, petrology and geochemistry research and to apply these findings to our teaching; f) explore and utilize current societal and global issues that intersect mineralogy, petrology and geochemistry to heighten the relevancy of course content for students; and h) meet colleagues and foster future teaching and research collaborations. A significant outcome of this workshop is a peer reviewed of collection of 300+ existing teaching activities, and a gap analysis to identify teaching activities needed to make these collections comprehensive and coherent. In addition, a series of thematic collections were developed to assist high priority

  2. Arsenic mineralogy and mobility in the arsenic-rich historical mine waste dump

    Energy Technology Data Exchange (ETDEWEB)

    Filippi, Michal, E-mail: filippi@gli.cas.cz [Institute of Geology, The Czech Academy of Sciences, v.v.i., Rozvojová 269, 165 00 Prague 6 (Czech Republic); Drahota, Petr [Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2 (Czech Republic); Machovič, Vladimír [Institute of Chemical Technology Prague, Technická 5, 166 28 Prague 6 (Czech Republic); Böhmová, Vlasta [Institute of Geology, The Czech Academy of Sciences, v.v.i., Rozvojová 269, 165 00 Prague 6 (Czech Republic); Mihaljevič, Martin [Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2 (Czech Republic)

    2015-12-01

    A more than 250 year-old mine dump was studied to document the products of long-term arsenopyrite oxidation under natural conditions in a coarse-grained mine waste dump and to evaluate the environmental hazards associated with this material. Using complementary mineralogical and chemical approaches (SEM/EDS/WDS, XRD, micro-Raman spectroscopy, pore water analysis, chemical extraction techniques and thermodynamic PHREEQC-2 modeling), we documented the mineralogical/geochemical characteristics of the dumped arsenopyrite-rich material and environmental stability of the newly formed secondary minerals. A distinct mineralogical zonation was found (listed based on the distance from the decomposed arsenopyrite): scorodite (locally associated with native sulfur pseudomorphs) plus amorphous ferric arsenate (AFA/pitticite), kaňkite, As-bearing ferric (hydr)oxides and jarosite. Ferric arsenates and ferric (hydr)oxides were found to dissolve and again precipitate from downward migrating As-rich solutions cementing rock fragments. Acidic pore water (pH 3.8) has elevated concentrations of As with an average value of about 2.9 mg L{sup −1}. Aqueous As is highly correlated with pH (R{sup 2} = 0.97, p < 0.001) indicating that incongruent dissolution of ferric arsenates controls dissolved As well as the pH of the percolating waste solution. Arsenic released from the dissolution of ferric arsenates into the pore water is, however, trapped by latter and lower-down precipitating jarosite and especially ferric (hydr)oxides. The efficiency of As sequestration by ferric (hydr)oxides in the waste dump and underlying soil has been found to be very effective, suggesting limited environmental impact of the mine waste dump on the surrounding soil ecosystems. - Highlights: • More than 250 year-old arsenopyrite-rich mine waste dump was studied. • Mineral transformation and the environmental stability of different secondary arsenic mineral phases were assessed. • High efficiency of As

  3. An integrated geochemical and mineralogical approach for the evaluation of arsenic mobility in mining soils

    Energy Technology Data Exchange (ETDEWEB)

    Kreidie, Nadia; Mottana, Annibale [Rome Univ. (Italy). Dipt. Scienze Geologiche; Armiento, Giovanna; Crovato, Cinzia; Nardi, Elisa; Pacifico, Renata; Cremisini, Carlo [ENEA-Agenzia Nazionale per le Nuove Tecnologie, l' Energia e lo Sviluppo Economico Sostenibile-C.R. Casaccia, Rome (Italy); Cibin, Giannantonio; Cinque, Gianfelice [INFN-Laboratori Nazionali Frascati (Italy)

    2011-01-15

    Purpose: The assessment of risk related to the presence of potentially toxic elements in soils is strictly related to the knowledge of their form and mobility. These relevant properties depend on the complex interactions of the elements of concern with the soil particles that generally cannot be addressed by a single technique. This study presents an integrated approach implementing geochemical and mineralogical investigation techniques on samples from a former mining area (Tolfa Mountains district, northern Latium, Italy), where exploiting activities occurred until the recent past. In particular, the As total concentration and the As distribution in solid phases is studied with the aim to evaluate the possibility of environmental pollution and consequent risks for the health of people living in the area and possibly affected in case of significant mobilization of this toxic element. Materials and methods: Chemical (ICP-MS, ICP-OES) and mineralogical (X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray (SEM-EDX), X-ray absorption near-edge structure (XANES)) analyses and the evaluation of the heavy metal mobility (by means of a sequential extraction procedure) were performed. Results and discussion: Chemical analyses show a high As content in the soils collected immediately downstream the marcasite mine waste deposit, that is the starting point of As pollution over the whole area. XANES analyses show that As occurs in two oxidation states (As{sup III} and As{sup V}) simultaneously in the tailing samples and nearby, while it has been mainly or totally transformed into As{sup V} at increasing distance from the mine. XRD data show that sheet silicates don't affect As behavior, whereas sequential extractions and SEM-EDX analyses reveal the evident association of As and Fe oxyhydroxides content. Conclusions: The use of an integrated geochemical-mineralogical approach allows to single out the contaminant forms and the relative potential

  4. Fault imprint in clay units: magnetic fabric, structural and mineralogical signature

    Science.gov (United States)

    Moreno, Eva; Homberg, Catherine; Schnyder, Johann; Person, Alain; du Peloux1, Arthur; Dick, Pierre

    2014-05-01

    Fault-induced deformations in clay units can be difficult to decipher because strain markers are not always visible at outcrop scale or using geophysical methods. Previous studies have indicated that the anisotropy of magnetic susceptibility (ASM) provides a powerful and rapid technique to investigate tectonic deformation in clay units even when they appear quite homogenous and undeformed at the outcrop scale (Lee et al. 1990, Mattei et al. 1997). We report here a study based on ASM, structural analysis and magnetic and clay mineralogy from two boreholes (TF1 and ASM1)drilled horizontally in the Experimental Station of Tournemire of the Institute for Radiological Protection and Nuclear Safety (IRSN) in Aveyron (France). The boreholes intersect a N-S trending strike-slip fault from west to east. The ASM study indicates the evolution of the magnetic fabric from the undeformed host rock to the fault core. Also, all the fractures cutting the studied interval of the core have been measured as well as the slip vectors which are generally well preserved. In the two boreholes, the undeformed sediments outside the fault zone are characterized by an oblate fabric, a sub-vertical minimum susceptibility axis (k3) perpendicular to the bedding plane and without magnetic lineation. Within the fault zone, a tilt in the bedding plane has been observed in two boreholes TF1 and ASM1. In addition, in the TF1 core, the fault area presents a tectonic fabric characterized by a triaxial AMS ellipsoid. Moreover, the magnetic lineation increases and k3 switches from a vertical to a sub-horizontal plane. This kind of fabric has not been observed in borehole ASM1. The structural analysis of the individual fractures making the fault zone indicates a complex tectonic history with different imprint in the two fault segments cut by the two boreholes. The large majority of fractures correspond to dextral strike-slip faults but normal and reverse movements were observed and are more or less

  5. Luminescence properties of feldspars from the Northeast region of Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Santana, S T; Khoury, H J; Sullasi, H L; Guzzo, P L, E-mail: sergiotsantana@hotmail.co

    2010-11-01

    The aim of this study is to investigate the thermoluminescence (TL) and infrared-stimulated luminescence (IRSL) properties of three types of feldspars from the districts of Solonopole and Parelhas located in the Northeast region of Brazil in order to propose a preheat procedure to minimize the anomalous fading effect in these materials. The feldspar samples were characterized by X-ray diffraction (XRD) and X-ray fluorescence spectrometry (XRF). The XRD analysis showed that the feldspar from Solonopole and one of the samples from the Parelhas district were classified as microcline (K-feldspar). The other sample from Parelhas was classified as albite (Na-feldspar) mixed with low concentration of muscovite and quartz. Studies of the fading effects in TL and IRSL signals for 30 days and preheating effects from 50 to 250{sup 0}C for 10 minutes were carried out with these samples. The results show that preheating at 125{sup 0}C is sufficient to avoid the 30 days fading. The TL and IRSL dose responses for {sup 60}Co gamma radiation were studied in the range of 1 to 400 Gy. The results showed a linear response in the range of 1 to 100 Gy for the two types of Parelhas feldspars and from 50 to 400 Gy for the Solonopole feldspar. The low sensitivity showed by the feldspar from Solonopole is discussed in relation to its mineralogical composition. It is concluded that the TL and IRSL sensitivities are not associated with K- and Na- types of feldspar. The results of this paper will contribute to a standardized moderate annealing treatment for retrospective dosimetry and dating.

  6. Corruption - Can Brazil win this war?

    OpenAIRE

    Washington de Queiroz, Jorge

    2015-01-01

    Corruption in Brazil is endemic and has increased since the end of the military transition regime in 1985, a year marked by an indirect presidential election, which was followed by the 1988 Constitutional Reform. The present thesis answers the research question of how corruption affects well-being in Brazil" by investigating the existing cause-effect relationships and complex dynamics and logic between corruption and related variables in Brazil, with each of the twenty-s...

  7. Abortion in Brazil: A Search For Rights

    OpenAIRE

    Anjos, Karla Ferraz dos; Universidade Estadual do Sudoeste da Bahia; Santos, Vanessa Cruz; Universidade Estadual do Sudoeste da Bahia; Souzas, Raquel; Universidade Federal da Bahia; Eugênio, Benedito Gonçalves; Universidade Estadual do Sudoeste da Bahia

    2013-01-01

    Discussing the abortion theme in Brazil is highly problematic since it involves ethical, moral and legal precepts. The criminalization of abortion in Brazil favors a clandestine and unsafe practice and can lead to serious consequences to women´s health. In this perspective, this research deals with the legal context in which the abortion problem is inscribed in Brazil, coupled to the specific aims in pinpointing complications caused by the criminalization of clandestine abortion besides deali...

  8. Mineralogía de arenas y limos en suelos, sedimentos fluviales y eólicos actuales del sector austral de la cuenca Chacoparanense: Regionalización y áreas de aporte Sands and clay mineralogy in soils, fluvial and eolian Present sediments in the southern sector of the Chacoparanense basin: Different regions and source areas

    Directory of Open Access Journals (Sweden)

    M. C. Etchichury

    2004-06-01

    Corrientes provinces allowed to define two zones characterized by two genetically different mineralogical associations. Minerals of volcanic - pyroclastic origin (heavy: green, basaltic and brown hornblende, hypersthene, enstatite, augite, magnetite, hematite, ilmenite, leucoxene, epidote, zoicite, and light: plagioclase, volcanic fragments, pumice and glass shards, quartz, orthoclase are observed over a broad area including whole Buenos Aires and Cordoba provinces, northwestern regions of La Pampa, central and southern Santa Fe and southern Entre Ríos. The provenence of these minerals included the pampean and post-pampean sediments and scarce contribution from volcanic Mesozoic rocks of north Patagonia, Sierras Pampeanas and also Quaternary pyroclastic eruptions. Conversely, a heavy suite of metamorphic provenence (staurolite, kyanite, sillimanite, andalusite, hornblende, epidote, opaques and a light association composed of igneous and metamorphic clast (monocrystalline and polycrystalline quartz, orthoclase,microcline, schists and others of sedimentary origin (quartz arenites is recorded in Corrientes and northern Santa Fe and Entre Ríos provinces. These minerals are coming from older basement rocks outcropping in Brazil and Uruguay and the younger overlain sedimentary succession. The peculiar material distribution is related to the drainage systems and wind pattern. Quartz 30% frecuency isoplet points out the limit between both mineralogical associations.

  9. Spherical tokamak development in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, G.O.; Del Bosco, E.; Ferreira, J.G.; Berni, L.A.; Oliveira, R.M.; Andrade, M.C.R.; Shibata, C.S.; Ueda, M.; Barroso, J.J.; Castro, P.J. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma; Barbosa, L.F.W. [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo; Patire Junior, H. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Div. de Mecanica Espacial e Controle; The high-power microwave sources group

    2003-12-01

    This paper describes the general characteristics of spherical tokamaks, or spherical tori, with a brief overview of work in this area already performed or in progress at several institutions worldwide. The paper presents also the steps in the development of the ETE (Experimento Tokamak Esferico) project, its research program, technical characteristics and operating conditions as of December, 2002 at the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)

  10. Spherical tokamak development in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Gerson Otto; Bosco, Edson Del; Ferreira, Julio Guimaraes [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma] (and others)

    2003-07-01

    The general characteristics of spherical tokamaks, or spherical tori, with a brief view of work in this area already performed or in progress at several institutions worldwide are described. The paper presents also the steps in the development of the ETE (Experiment Tokamak spheric) project, its research program, technical characteristics and operating conditions as of December, 2002 a the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)

  11. National epilepsy movement in Brazil

    OpenAIRE

    P T Fernandes; Noronha, A. L. A.; Sander, J. W.; L. M. Li

    2007-01-01

    Purpose: To establish a social network of epilepsy lay organization in Brazil to provide advocacy for people with epilepsy and eventually forma powerful National Epilepsy movement. Method.-We actively searched for any associations, support groups or organizations related to epilepsy in the country by personal contacts, internet search and by telephone search. Contact was then established with any entity found. Results: The first meeting was held in Campinas in March 2003, and was attended by ...

  12. Brazil-U.S. Relations

    Science.gov (United States)

    2009-06-03

    Currently at least ten bilateral mechanisms are in place through which U.S. and Brazilian government and business leaders interface on issues of...base, 430 kilograms of crack cocaine, 182 metric tons of marijuana, 12 kilograms of heroin, 125,706 dosage units of ecstasy , and 95,653 dosage units of...States continue to work together to address intellectual property issues, primarily through the U.S.-Brazil Bilateral Consultative Mechanism and the

  13. Brazil, A Potential World Power?

    Science.gov (United States)

    1966-04-22

    inadequate transportation system. Much of the difficulty in exploiting the great natural wealth of the country has been the direct result of a poor ...exploding birth rate and high infant mortality; great wealth and degrading poverty . Much of the poverty and high mortality can be attributed to a vicious...circle of poverty creating ignorance and ignorance creating poverty . Brazil’s population is about 80 million and has been increas- ing at the rate of

  14. Brazil's Economy:Too Hot

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Brazil has a lot to be proud of.A decade of faster growth and progressive social policies has brought a prosperity that is ever more widely shared.The unemployment rate for April, at 6.4%, is the lowest on record.Credit is booming, particularly to the swelling numbers who have moved out of poverty and into the middle class.Income inequality, though still high, has fallen sharply.For most Brazilians life has never been so good.

  15. Decentralization and REDD+ in Brazil

    Directory of Open Access Journals (Sweden)

    Fabiano Toni

    2011-01-01

    Full Text Available Recent discussions on REDD+ (Reducing Emissions from Deforestation and Forest Degradation, plus conservation, sustainable management of forests and enhancement of forest carbon stocks have raised optimism about reducing carbon emissions and deforestation in tropical countries. If approved under the United Nations Framework Convention on Climate Change (UNFCCC, REDD+ mechanisms may generate a substantial influx of financial resources to developing countries. Some authors argue that this money could reverse the ongoing process of decentralization of forest policies that has spread through a large number of developing countries in the past two decades. Central states will be accountable for REDD+ money, and may be compelled to control and keep a significant share of REDD+ funds. Supporters of decentralization argue that centralized implementation of REDD+ will be ineffective and inefficient. In this paper, I examine the relation between subnational governments and REDD+ in Brazil. Data show that some state governments in the Brazilian Amazon have played a key role in creating protected areas (PAs after 2003, which helped decrease deforestation rates. Governors have different stimuli for creating PAs. Some respond to the needs of their political constituency; others have expectations to boost the forest sector so as to increase fiscal revenues. Governors also have led the discussion on REDD+ in Brazil since 2008. Considering their interests and political power, REDD+ is unlikely to curb decentralization in Brazil.

  16. Mineralogical Study of Hydrated IDPs: X-Ray Diffraction and Transmission Electron Microscopy

    Science.gov (United States)

    Nakamura, K.; Keller, L. P.; Nakamura, T.; Noguchi, T.; Zolensky, M. E.

    2004-01-01

    Chondritic hydrated interplanetary dust particles (IDPs) comprise up to 50% of all IDPs collected in the stratosphere [1]. Hydrated IDPs are generally believed to be derived from asteroidal sources that have undergone aqueous alteration. However, the high C contents of hydrated IDPs (by 2 to 6X CI levels [2,3]) indicate that they are probably not derived from the same parent bodies sampled by the known chondritic meteorites. Some hydrated IDPs exhibit large deuterium enrichments [4] similar to those observed in anhydrous IDPs. Both anhydrous and hydrated IDPs contain a variety of anhydrous minerals such as silicates, sulfides, oxides, and carbonates. Controversies on hydrated IDPs still exist regarding their formation, history, and relationship to other primitive solar system materials, because of the lack of a systematic series of analysis on individual hydrated IDPs. In this study, we combine our observations of the bulk mineralogy, mineral/ organic chemistry in order to derive a more complete picture of hydrated IDPs.

  17. Effect of grain-coating mineralogy on nitrate and sulfate storage in the unsaturated zone

    Science.gov (United States)

    Reilly, T.J.; Fishman, N.S.; Baehr, A.L.

    2009-01-01

    Unsaturated-zone sediments and the chemistry of shallow groundwater underlying a small (???8-km2) watershed were studied to identify the mechanisms responsible for anion storage within the Miocene Bridgeton Formation and weathered Coastal Plain deposits in southern New Jersey. Lower unsaturated-zone sediments and shallow groundwater samples were collected and concentrations of selected ions (including NO3- and SO42-) from 11 locations were determined. Grain size, sorting, and color of the lower unsaturated-zone sediments were determined and the mineralogy of these grains and the composition of coatings were analyzed by petrographic examination, scanning electron microscopy and energy dispersive analysis of x-rays, and quantitative whole-rock x-ray diffraction. The sediment grains, largely quartz and chert (80-94% w/w), are coated with a very fine-grained (Soil Science Society of America. All rights reserved.

  18. Mineralogical Transformation and Electrochemical Nature of Magnesium-Rich Primers during Natural Weathering

    Directory of Open Access Journals (Sweden)

    Shashi S. Pathak

    2014-07-01

    Full Text Available Magnesium-rich primers (MgRP have generated great interest as a promising alternative to chromium-based primers for the protection of aluminum substrates but their performance during exterior exposure has not been well documented. This paper focuses on the evaluation of MgRP during natural weathering to gain insight into its mineralogical phase transformation and electrochemical nature. Control studies were conducted on Mg and AA2024-T3 coupons. The results indicate that Mg particles in MgRP transform into a variety of hydroxide, carbonate, and hydroxy carbonates. During natural weathering, CO2 inhibited the dissolution of both Mg and AA2024-T3 as a result of protective carbonate layer formation in the coating.

  19. MSL Chemistry and Mineralogy X-Ray Diffraction X-Ray Fluorescence (CheMin) Instrument

    Science.gov (United States)

    Zimmerman, Wayne; Blake, Dave; Harris, William; Morookian, John Michael; Randall, Dave; Reder, Leonard J.; Sarrazin, Phillipe

    2013-01-01

    This paper provides an overview of the Mars Science Laboratory (MSL) Chemistry and Mineralogy Xray Diffraction (XRD), X-ray Fluorescence (XRF) (CheMin) Instrument, an element of the landed Curiosity rover payload, which landed on Mars in August of 2012. The scientific goal of the MSL mission is to explore and quantitatively assess regions in Gale Crater as a potential habitat for life - past or present. The CheMin instrument will receive Martian rock and soil samples from the MSL Sample Acquisition/Sample Processing and Handling (SA/SPaH) system, and process it utilizing X-Ray spectroscopy methods to determine mineral composition. The Chemin instrument will analyze Martian soil and rocks to enable scientists to investigate geophysical processes occurring on Mars. The CheMin science objectives and proposed surface operations are described along with the CheMin hardware with an emphasis on the system engineering challenges associated with developing such a complex instrument.

  20. Changes in porosity, permeability and surface area during rock dissolution: effects of mineralogical heterogeneity

    CERN Document Server

    Min, Ting; Chen, Li; Kang, Qinjun; Tao, Wen-Quan

    2015-01-01

    Effects of heterogeneity of mineral distribution and reaction rate on the rock dissolution process are investigated using a pore-scale reactive transport model based on the lattice Boltzmann method. Coupled fluid flow, species transport, chemical reaction and solid structure alternation due to dissolution are simulated. Effects of mineral distributions and chemical heterogeneity on the dissolution behaviors and evolutions of hydrologic properties are studied under different reactive transport conditions. Simulation results show that the coupling between advection, diffusion and reaction as well as the mineralogical heterogeneity leads to complex reactive transport behaviors and complicated temporal evolutions of hydrologic properties including porosity, permeability and reactive surface. Diverse relationships between surface area and volume are predicted, which cannot be described by simple models such as the spherical-grain model. Porosity-permeability relationships also differ under different mineral distri...

  1. Geochemical and mineralogical studies of dinosaur bone from the Morrison Formation at Dinosaur Ridge

    Science.gov (United States)

    Modreski, P.J.

    2001-01-01

    The dinosaur bones first discovered in 1877 in the Upper Jurassic Morrison Formation at Morrison, Colorado were the first major find of dinosaur skeletons in the western U.S. and led to the recognition of four new dinosaur genera (Apatosaurus, Allosaurus, Diplodocus, and Stegosaurus). Eight articles dealing with these bones which appeared as research reports in the annual reports of the Friends of Dinosaur Ridge from 1990-1999 are condensed and summarized with some additional comments. Two of the articles are about the mineralogy and preservation of the bones; two are about the physical description of the bone occurrence; two are about the history of the site, and two are about use of novel instrumental methods (ground-penetrating radar and a directional scintillometer) to search for new bones.

  2. Mineralogical Characterization of Baptistina Asteroid Family: Implications for K/T Impactor Source

    CERN Document Server

    Reddy, Vishnu; Lazzaro, Daniela; Michtchenko, Tatiana A; Gaffey, Michael J; Kelley, Michael S; Diniz, Thais Mothé; Candal, Alvaro Alvarez; Moskovitz, Nicholas A; Cloutis, Edward A; Ryan, Erin L; 10.1016/j.icarus.2011.08.027

    2011-01-01

    Bottke et al. (2007) linked the catastrophic formation of Baptistina Asteroid Family (BAF) to the K/T impact event. This linkage was based on dynamical and compositional evidence, which suggested the impactor had a composition similar to CM2 carbonaceous chondrites. However, our recent study (Reddy et al. 2009) suggests that the composition of (298) Baptistina is similar to LL-type ordinary chondrites rather than CM2 carbonaceous chondrites. This rules out any possibility of it being related to the source of the K/T impactor, if the impactor was of CM-type composition. Mineralogical study of asteroids in the vicinity of BAF has revealed a plethora of compositional types suggesting a complex formation and evolution environment. A detailed compositional analysis of 16 asteroids suggests several distinct surface assemblages including ordinary chondrites (Gaffey SIV subtype), primitive achondrites (Gaffey SIII subtype), basaltic achondrites (Gaffey SVII subtype and V-type), and a carbonaceous chondrite. Based on ...

  3. Mineralogy of Clay Raw Materials from Cote d'ivoire: Case of the Deposit from Katiola

    Science.gov (United States)

    Kpangni, E. B.; Andji, Y. Y. J.; Adouby, K.; Oyetola, S.; Kra, G.; Yvon, J.

    This study deals with two clays referenced K1 and K2, used in the local and traditional manufacture of pottery ware at Katiola. Those samples were analysed by X-rays diffraction, infrared spectroscopy and thermal differential and chemical techniques. The results show that the samples (K1 and K2) are mainly composed of montmorillonite, kaolinite and illite. Only K1 is inter-stratified. The mineralogical balance achieved from the reflection (001) of the oriented film, indicate for K1: 74.5% of montmorillonite; 13.5% of inter-stratified clay; 7% of kaolinite and 5.4% of illite and for K2: 73.4% of montmorillonite; 23.5% of kaolinite and 3.1% of illite. The results also indicate that the raw material may not be use only for pottery. It can be consider in the protection of the environment, cosmetic industry, vegetable oil treatment, medicine etc.

  4. Mineralogy. Discovery of bridgmanite, the most abundant mineral in Earth, in a shocked meteorite.

    Science.gov (United States)

    Tschauner, Oliver; Ma, Chi; Beckett, John R; Prescher, Clemens; Prakapenka, Vitali B; Rossman, George R

    2014-11-28

    Meteorites exposed to high pressures and temperatures during impact-induced shock often contain minerals whose occurrence and stability normally confine them to the deeper portions of Earth's mantle. One exception has been MgSiO3 in the perovskite structure, which is the most abundant solid phase in Earth. Here we report the discovery of this important phase as a mineral in the Tenham L6 chondrite and approved by the International Mineralogical Association (specimen IMA 2014-017). MgSiO3-perovskite is now called bridgmanite. The associated phase assemblage constrains peak shock conditions to ~ 24 gigapascals and 2300 kelvin. The discovery concludes a half century of efforts to find, identify, and characterize a natural specimen of this important mineral.

  5. Iron Mineralogy and Aqueous Alteration on Mars from the MER Moessbauer Spectrometers. Chapter 15

    Science.gov (United States)

    Morris, Richard V.; Klingelhoefer, Goestar

    2007-01-01

    The twin Mars Exploration Rovers Spirit (Gusev crater) and Opportunity (Meridiani Planum) used MIMOS II Moessbauer spectrometers to analyze martian surface materials in the first application of extraterrestrial Moessbauer spectroscopy. The instruments acquired spectra that identified the speciation of Fe according to oxidation state, coordination state, and mineralogical composition and provided quantitative information about the distribution of Fe among oxidation states, coordination states, and Fe-bearing phases. A total of 12 unique Fe-bearing phases were identified: Fe(2+) in olivine, pyroxene, and ilmenite; Fe(2+) and Fe(3+) in magnetite and chromite; Fe(3+) in nanophase ferric oxide (npOx), hematite, goethite, jarosite, an unassigned Fe3+ sulfate, and an unassigned Fe(3+) phase associated with jarosite; and Fe(0) in kamacite. Weakly altered basalts at Gusev crater (SO3 = 2.5 +/- 1.4 wt.% and Fe(3+)/Fe(sub T) = 0.24 +/- 0.11) are widespread on the Gusev plains and occur in less abundance on West Spur and Husband Hill in the Columbia Hills. Altered low-S rocks (SO3 = 5.2 +/- 2.0 wt.% and Fe(3+)/Fe(sub T) = 0.63 +/- 0.18) are the most common type of rock in the Columbia Hills. Ilm-bearing, weakly altered basalts were detected only in the Columbia Hills, as was the only occurrence of chromite in an altered low-S rock named Assemblee. Altered high-S rocks (SO3 > 14.2 wt.% and Fe(3+)/Fe(sub T) = 0.83 +/- 0.05) are the outcrop rocks of the ubiquitous Burns formation at Meridiani Planum. Two Fe(0)-bearing rocks at Meridiani Planum (Barberton and Heat Shield Rock) are meteorites. Laguna Class soil is weakly altered (SO3 = 6 +/- 2 wt.% and Fe(3+)/Fe(sub T) = 0.29 +/- 0.08) and widely distributed at both Gusev crater and Meridiani Planum, implying efficient global mixing processes or a global distribution of precursor rocks with comparable Fe mineralogical compositions. Paso Robles Class soil is heavily altered (SO3 approx. 31 wt.% and Fe(3+)/Fe(sub T) = 0.83 +/- 0

  6. A mineralogical study of Late Bronze Age ceramics from Palatca (Transylvania, Romania

    Directory of Open Access Journals (Sweden)

    Lucretia Ghergari

    2012-01-01

    Full Text Available Our paper studies the mineralogical and petrographical characteristics of 28 ceramic fragments that were excavated in the village of Palatca, Transylvania (Romania. Optical microscopy, X-Ray powder diffraction (XRD, scanning electron microscopy (SEM, grain size analyses, and porosity measurements were used to investigate the samples. Our objective was to describe or reconstruct the corresponding products and to elucidate the manufacturing process, the firing techniques, and the transformation pathways. Based on our results, we conclude that the Late Bronze Age ceramics (1600-1300 BC were produced from clay and temper material such as river sand and ceramoclasts. It has been modeled by hand and fired between 800 and 950°C. For most samples, we can narrow the temperature range to 850-900°C. We interpret the data further from a geoarchaeological point of view with respect to the historical evolution of the local culture.

  7. Mineralogical, optical, geochemical, and particle size properties of four sediment samples for optical physics research

    Science.gov (United States)

    Bice, K.; Clement, S. C.

    1981-01-01

    X-ray diffraction and spectroscopy were used to investigate the mineralogical and chemical properties of the Calvert, Ball Old Mine, Ball Martin, and Jordan Sediments. The particle size distribution and index of refraction of each sample were determined. The samples are composed primarily of quartz, kaolinite, and illite. The clay minerals are most abundant in the finer particle size fractions. The chemical properties of the four samples are similar. The Calvert sample is most notably different in that it contains a relatively high amount of iron. The dominant particle size fraction in each sample is silt, with lesser amounts of clay and sand. The indices of refraction of the sediments are the same with the exception of the Calvert sample which has a slightly higher value.

  8. Mineralogical, crystallographic and morphological characteristics of natural kaolins from the Ivory Coast (West Africa)

    Science.gov (United States)

    Sei, J.; Morato, F.; Kra, G.; Staunton, S.; Quiquampoix, H.; Jumas, J. C.; Olivier-Fourcade, J.

    2006-10-01

    Thirteen clay samples from four deposits in the Ivory Coast (West Africa) were studied using X-ray diffraction, thermogravimetric analysis and chemical analysis. Mineralogical, crystallographic and morphological characteristics of these samples are given. Kaolinite is the principal mineral but other minerals are present in small quantities: illite, quartz, anatase and iron oxides (oxides and oxyhydroxides). The crystallographic, morphological and surface characteristics are influenced by the presence of these impurities. In particular, the presence of iron oxides was associated with reduced structural ordering and thermal stability of kaolinite and increased specific surface area. These clays could be used in the ceramics industry to make tiles and bricks, and also in agronomy as supports for chemical fertilizers or for environmental protection by immobilising potentially toxic waste products.

  9. Mineralogy, paragenesis and genesis of the braunite deposits of the Mary Valley Manganese Belt, Queensland, Australia

    Science.gov (United States)

    Ostwald, J.

    1992-09-01

    The Mary Valley manganese deposits exhibit mineralogy and textures characteristic of at least four parageneses. The deposits consist mainly of isolated occurrences of braunite, together with a number of lower and higher valency manganese oxides, and manganese silicates, in bedded radiolarian cherts and jaspers of Permian age. The parageneses are: (a) Braunite — quartz (primary), (b) Braunite — hausmannite — spessartine — tephroite — quartz (metamorphic). (c) Hydrated manganese silicates — barite — braunite — hausmannite (hydrothermal veins), (d) Tetravalent manganese oxides (pyrolusite, cryptomelane, manjiroite, nsutite) (supergene). The primary mineralisation is interpreted as the result of the geochemical separation of Mn from Fe in a submarine exhalative system, and the precipitation of Mn as oxide within bedded radiolarian oozes and submarine lavas. During diagenesis this hydrothermal manganese oxide reacted with silica to produce primary braunite. The later geological of evolution of this volcanogenicsedimentary deposit involved metamorphism, hydrothermal veining by remobilised manganese, and supergene enrichment.

  10. An x-ray diffraction method for semiquantitative mineralogical analysis of chilean nitrate ore

    Science.gov (United States)

    John, C.; George, J.; Ericksen, E.

    1997-01-01

    Computer analysis of X-ray diffraction (XRD) data provides a simple method for determining the semiquantitative mineralogical composition of naturally occurring mixtures of saline minerals. The method herein described was adapted from a computer program for the study of mixtures of naturally occurring clay minerals. The program evaluates the relative intensities of selected diagnostic peaks for the minerals in a given mixture, and then calculates the relative concentrations of these minerals. The method requires precise calibration of XRD data for the minerals to be studied and selection of diffraction peaks that minimize inter-compound interferences. The calculated relative abundances are sufficiently accurate for direct comparison with bulk chemical analyses of naturally occurring saline mineral assemblages.

  11. Mineralogic and petrologic implications of viking geochemical results from Mars: interim report.

    Science.gov (United States)

    Baird, A K; Toulmin, P; Clark, B C; Rose, H J; Keil, K; Christian, R P; Gooding, J L

    1976-12-11

    Chemical results from four samples of martian fines delivered to Viking landers 1 and 2 are remarkably similar in that they all have high iron; moderate magnesium, calcium, and sulfur; low aluminum; and apparently very low alkalies and trace elements. This composition is best interpreted as representing the weathering products of mafic igneous rocks. A mineralogic model, derived from computer mixing studies and laboratory analog preparations, suggests that Mars fines could be an intimate mixture of about 80 percent iron-rich clay, about 10 percent magnesium sulfate (kieserite?), about 5 percent carbonate (calcite), and about 5 percent iron oxides (hematite, magnetite, maghemite, goethite?). The mafic nature of the present fines (distributed globally) and their probable source rocks seems to preclude large-scale planetary differentiation of a terrestrial nature.

  12. Psammoma bodies in two types of human ovarian tumours: a mineralogical study

    Science.gov (United States)

    Fanlu, Meng; Changqiu, Wang; Yan, Li; Anhuai, Lu; Fang, Mei; Jianying, Liu; Jingyun, Du; Yan, Zhang

    2015-06-01

    Psammoma body (PB) is a common form of calcification in pathological diagnosis and closely relevant to tumours. This paper focuses on the mineralogical characteristics of PBs in ovarian serous cancer and teratoma by using polarization microscope (POM), environmental scanning electron microscope (ESEM), micro-Fourier transform infrared spectroscopy (micro-FT-IR), transmission electron microscope (TEM), micro-area synchrotron radiation X-ray powder diffraction (μ-SRXRD) and fluorescence (μ-SRXRF). Both the PBs in tissues and separated from eight typical cases were investigated. POM and ESEM observation revealed the inside-out growth pattern of PBs. μ-SRXRD and micro-FT-IR results demonstrated the dominant mineral phase of PBs in ovarian serous cancer and teratoma was AB-type carbonate hydroxyapatite (Ca10[(PO4)6-x-y(CO3)x(HPO4 2-)y][(OH)2-u(CO3)u] with 0 ≤ x,y,u ≤ 2). As observed by ESEM and TEM, the layer-rich PBs in teratoma were up to 70 μm and mainly consisted of 5 nm-wide, 5-12 nm-long columnar crystals; the PBs in ovarian serous cancer with a maximum diameter of 35 μm were composed of slightly longer columnar crystals and granulates with 20-100 nm in diameter. The selected area electron diffraction patterns showed dispersed polycrystalline diffraction rings with arching behavior of (002) diffraction, indicating the aggregated nanocrystals grew in the preferred orientation of (002) face. The EDX and μ-SRXRF results together indicated the existence of Na, Mg, Zn and Sr in PBs. These detailed mineralogical characteristics may help uncover the nature of the pathological PBs in ovary.

  13. Erratum to: Psammoma bodies in two types of human ovarian tumours: a mineralogical study

    Science.gov (United States)

    Meng, Fanlu; Wang, Changqiu; Li, Yan; Lu, Anhuai; Mei, Fang; Liu, Jianying; Du, Jingyun; Zhang, Yan

    2015-06-01

    Psammoma body (PB) is a common form of calcification in pathological diagnosis and closely relevant to tumours. This paper focuses on the mineralogical characteristics of PBs in ovarian serous cancer and teratoma by using polarization microscope (POM), environmental scanning electron microscope (ESEM), micro-Fourier transform infrared spectroscopy (micro-FT-IR), transmission electron microscope (TEM), micro-area synchrotron radiation X-ray powder diffraction (μ-SRXRD) and fluorescence (μ-SRXRF). Both the PBs in tissues and separated from eight typical cases were investigated. POM and ESEM observation revealed the inside-out growth pattern of PBs. μ-SRXRD and micro-FT-IR results demonstrated the dominant mineral phase of PBs in ovarian serous cancer and teratoma was AB-type carbonate hydroxyapatite (Ca10[(PO4)6-x-y(CO3)x(HPO4)y][(OH)2-u(CO3)u] with 0 ≤ x,y,u ≤ 2). As observed by ESEM and TEM, the layer-rich PBs in teratoma were up to 70 μm and mainly consisted of 5 nm-wide, 5-12 nm-long columnar crystals; the PBs in ovarian serous cancer with a maximum diameter of 35 μm were composed of slightly longer columnar crystals and granulates with 20-100 nm in diameter. The selected area electron diffraction patterns showed dispersed polycrystalline diffraction rings with arching behavior of (002) diffraction, indicating the aggregated nanocrystals grew in the preferred orientation of (002) face. The EDX and μ-SRXRF results together indicated the existence of Na, Mg, Zn and Sr in PBs. These detailed mineralogical characteristics may help uncover the nature of the pathological PBs in ovary.

  14. Mineralogy of the clay fraction of Alfisols in two slope curvatures: III - spatial variability

    Directory of Open Access Journals (Sweden)

    Livia Arantes Camargo

    2013-04-01

    Full Text Available A good knowledge of the spatial distribution of clay minerals in the landscape facilitates the understanding of the influence of relief on the content and crystallographic attributes of soil minerals such as goethite, hematite, kaolinite and gibbsite. This study aimed at describing the relationships between the mineral properties of the clay fraction and landscape shapes by determining the mineral properties of goethite, hematite, kaolinite and gibbsite, and assessing their dependence and spatial variability, in two slope curvatures. To this end, two 100 × 100 m grids were used to establish a total of 121 regularly spaced georeferenced sampling nodes 10 m apart. Samples were collected from the layer 0.0-0.2 m and analysed for iron oxides, and kaolinite and gibbsite in the clay fraction. Minerals in the clay fraction were characterized from their X-ray diffraction (XRD patterns, which were interpreted and used to calculate the width at half height (WHH and mean crystallite dimension (MCD of iron oxides, kaolinite, and gibbsite, as well as aluminium substitution and specific surface area (SSA in hematite and goethite. Additional calculations included the goethite and hematite contents, and the goethite/(goethite+hematite [Gt/(Gt+Hm] and kaolinite/(kaolinite+gibbsite [Kt/(Kt+Gb] ratios. Mineral properties were established by statistical analysis of the XRD data, and spatial dependence was assessed geostatistically. Mineralogical properties differed significantly between the convex area and concave area. The geostatistical analysis showed a greater number of mineralogical properties with spatial dependence and a higher range in the convex than in the concave area.

  15. The Dlr Solar Furnace - A Facility For Astrophysical and Mineralogical Experiments

    Science.gov (United States)

    Sauerborn, M.; Neumann, A.; Seboldt, W.; Klerner, S.

    The energy of solar radiation can be used to cause thermal or photochemical effects in the irradiated materials. The DLR Solar Furnace in Cologne is a facility that concentrates the direct solar radiation (concentration factor up to 5200 suns) for research experiments. It offers many different possibilities of using concentrated solar radiation to scientists and industrial users. For astrophysical and mineralogical applications a vacuum chamber with a special design and different instruments for measurements were developed, installed in the solar furnace and tested in experiments with small solid samples. The goal of the first project was to simulate the formation of so-called `chondrules' - constituents of meteorites - by "flash- heating" appropriate mineral samples with the concentrated beam of the solar furnace. The samples were melted and solidified subsequently by controlled cooling. The experiments had to be carried out under vacuum or controlled oxygen fugacity. Some results are presented as part of the paper "DYNAMIC CRYSTALLIZATION EXPERIMENTS USING CONVENTIONAL and SOLAR FURNACE TECHNIQUES - IMPLICATIONS FOR THE FORMATION of REFRACTORY FORSTERITE IN CHONDRITES", submitted to this conference. In a second series of experiments a slightly varied design was used to cause thermal reduction of samples of metal oxide and of lunar regolith simulate. The goal of this ongoing activity is to produce oxygen by pyrolysis. The process is conducted under high vacuum. The paper describes the facility with its properties and presents first results of the mentioned experiments. The two projects are co-operations between the High Flux Solar Furnace of DLR in Cologne (a department of the Solar Technology Division) and the Mission Architecture and Advanced Technologies Section (a department of the Institute of Space Sensor Technology and Planetary Exploration of DLR). In the first experiments and in the sample analysis the Institute of Mineralogy and Geochemistry of the

  16. Mineralogical interpretation of Phobos OSIRIS reflectance spectrum: is Phobos a collisionally captured asteroid?

    Science.gov (United States)

    Pajola, M.; Lazzarin, M.; Dalle Ore, C. M.; Roush, T. L.; Magrin, S.; Bertini, I.; La Forgia, F.; Barbieri, C.

    2013-09-01

    We will present the reflectance spectrum of Phobos from Near Ultraviolet to Near Infrared (245.5-992.0 nm) acquired by the OSIRIS [1] instrument onboard the ESA Rosetta mission. The data have been acquired through the filters of the Wide and the Narrow Angle Camera of the OSIRIS instrument (see Tab. 1) during Rosetta Mars swing-by maneuver on February 24th and 25th , 2007 [2]. Since the time of the fly-by a wide Phobos paper [3] has been published, which focused on the NAC Phobos spectrophotometry and showed that the OSIRIS-NAC spectra are within the spectral dispersion of D-types asteroids. These results lead us to speculate on a possible asteroidal origin of Phobos and we decided to complement our work by performing an investigation of the conditions needed to collisionally capture Phobos in a way similar to that proposed for the irregular satellites of the giant planets [4, 5]. The observational and dynamical results we obtained strongly argued for an early capture of Phobos, likely immediately after the formation of Mars. With this work we are making a step forward from our Phobos paper [3] and we are showing the results we have accomplished in characterizing and interpreting the mineralogical possible origin of the Phobos OSIRIS data by analyzing the complete (NAC-WAC) reflectance spectrum. The observed area goes from 86.8°N to 90°S in latitude and from 126°W to 286°W in ongitude, belonging both to the leading and to the trailing hemisphere of the satellite. We have performed a mineralogical modeling of the surface composition of Phobos which plays in favor of the interpretation of Phobos as a possible collisionally captured asteroid

  17. Combined mineralogical and EXAFS characterization of polluted sediments for the definition of technological variables and constraints

    Science.gov (United States)

    Brigatti, M. F.; Elmi, C.; Laurora, A.; Malferrari, D.; Medici, L.

    2009-04-01

    An extremely severe aspect, both from environmental and economic viewpoint, is the management of polluted sediments removed from drainage and irrigation canals. Canals, in order to retain their functionality over the time, need to have their beds, periodically cleaned from sediments there accumulating. The management of removed sediments is extremely demanding, also from an economical perspective, if these latter needs to be treated as dangerous waste materials, as stated in numerous international standards. Furthermore the disposal of such a large amount of material may introduce a significant environmental impact as well. An appealing alternative is the recovery or reuse of these materials, for example in brick and tile industry, after obviously the application of appropriate techniques and protocols that could render these latter no longer a threat for human health. The assessment of the effective potential danger for human health and ecosystem of sediments before and after treatment obviously requires both a careful chemical and mineralogical characterization and, even if not always considered in the international standards, the definition of the coordination shell of heavy metals dangerous for human health, as a function of their oxidation state and coordination (e.g. Cr and Pb), and introducing technological constraints or affecting the features of the end products. Fe is a good representative for this second category, as the features of the end product, such as color, strongly depend not only from Fe concentration but also from its oxidation state, speciation and coordination. This work will first of all provide mineralogical characterization of sediments from various sampling points of irrigation and drainage canals of Po river region in the north-eastern of Italy. Samples were investigated with various approaches including X-ray powder diffraction under non-ambient conditions, thermal analysis and EXAFS spectroscopy. Obtained results, and in particular

  18. Coralline algae in a naturally acidified ecosystem persist by maintaining control of skeletal mineralogy and size

    Science.gov (United States)

    Perna, G.; Gambi, M. C.; Micheli, F.; Kroeker, K. J.

    2016-01-01

    To understand the effects of ocean acidification (OA) on marine calcifiers, the trade-offs among different sublethal responses within individual species and the emergent effects of these trade-offs must be determined in an ecosystem setting. Crustose coralline algae (CCA) provide a model to test the ecological consequences of such sublethal effects as they are important in ecosystem functioning, service provision, carbon cycling and use dissolved inorganic carbon to calcify and photosynthesize. Settlement tiles were placed in ambient pH, low pH and extremely low pH conditions for 14 months at a natural CO2 vent. The size, magnesium (Mg) content and molecular-scale skeletal disorder of CCA patches were assessed at 3.5, 6.5 and 14 months from tile deployment. Despite reductions in their abundance in low pH, the largest CCA from ambient and low pH zones were of similar sizes and had similar Mg content and skeletal disorder. This suggests that the most resilient CCA in low pH did not trade-off skeletal structure to maintain growth. CCA that settled in the extremely low pH, however, were significantly smaller and exhibited altered skeletal mineralogy (high Mg calcite to gypsum (hydrated calcium sulfate)), although at present it is unclear if these mineralogical changes offered any fitness benefits in extreme low pH. This field assessment of biological effects of OA provides endpoint information needed to generate an ecosystem relevant understanding of calcifying system persistence. PMID:27733544

  19. Physicochemistry and Mineralogy of Storm Dust and Dust Sediment in Northern China

    Institute of Scientific and Technical Information of China (English)

    刘蔚; 冯起; 王涛; 张艳武; 施建华

    2004-01-01

    Dust sediments collected from 1995 to 1998 in Beijing, Dunhuang, Inner Mongolia, Kashi, the Kunlun Mountains, Lanzhou, Ningxia, the Taklimakan Desert, and Xi'an, China, were characterized in terms of their physical, chemical, and mineralogical properties. Most aerosols and dust analysed ranged in texture from silty clay to clay loam. Their median particle diameters (Mds) generally ranged between 5 to 63μm,coinciding with those of loess from central China and the finest sand from northwestern China. The dust sediments were characterized by a predominance of SiO2 and Al2O3, followed by K2O. Their SiO2/Al2O3and K2O/SiO2 molar ratios ranged from 5.17 to 8.43 and from 0.009 to 0.0368, respectively. The mass concentration spectrum during a dust storm showed a single peak, rather than the triple peak generally observed under clear sky conditions. The dominant minerals were chlorite, illite, calcite, and dolomite.These physical, chemical, and mineralogical properties were consistent with those of aeolian soils and loess in western and central China. The results suggest that aerosols and fine-gained fractions of dust sediments collected in northern China are mainly composed of soil material transported from the arid and semiarid regions of China and Mongolia by prevailing winds. The rate of deposition and properties of dust falling on eastern China were strongly influenced by meteorological conditions, season, latitude, longitude, and altitude of the sampling sites.

  20. The mineralogical responses of marine calcifiers to CO2-induced ocean acidification

    Science.gov (United States)

    Ries, J. B.; Cohen, A. L.; McCorkle, D. C.

    2008-12-01

    We have conducted 6-month laboratory experiments to investigate the effect of pCO2-induced reductions in seawater CaCO3 saturation state on biocalcification by 18 aragonitic and calcitic (low-high Mg) taxa representing eight of the major marine calcifying groups: Chlorophyta; Rhodophyta; Crustacea; Bivalvia; Gastropoda; Annelida; Cnidaria; and Echinodermata. The CaCO3 saturation states of the experimental seawaters, constrained by intercalibrated determinations of pH, alkalinity, and DIC, were attained with bubbled air-CO2 mixtures of 400 (ambient), 600, 900, and 2850 ppm pCO2, yielding Ωarag of 2.5 (ambient), 2.0, 1.5, 0.7, respectively. We previously showed that while rates of net calcification obtained from buoyant weighing declined with increasing pCO2 for nearly half of the species investigated, a nearly equal number exhibited constant or, in some cases, increased calcification under moderately (600 ppm) or extremely (900 or 2850 ppm) elevated pCO2. The organisms' investigated in this study secrete various forms of CaCO3, which differ in crystallographic structure and therefore solubility: aragonite and high-Mg are generally more soluble than low-Mg calcite. We have employed powder x-ray diffraction, Raman spectroscopy, inductively-coupled-plasma mass-spectrometry, and scanning electron microscopy to quantify changes in the organisms' skeletal mineralogy (aragonite:calcite ratio) and Mg-content (MgCO3:CaCO3 ratio) that occurred in response to the prescribed reductions in seawater CaCO3 saturation state. We will compare calcification and mineralogical response patterns amongst the organisms to elucidate the role of mineral lability in driving species-specific responses to CO2-induced ocean acidification.

  1. Selected Soil Morphological, Mineralogical and Sesquioxide Properties of Rehabilitated and Secondary Forests

    Directory of Open Access Journals (Sweden)

    B. T. Saga

    2010-01-01

    Full Text Available Problem statement: The tropical rain forests in Southeast Asia have been characterized by several researchers. However empirical data on soil characteristics under degraded forest land in tropical rain forest and rehabilitated program are limited. A study was conducted to evaluate the soil morphology, mineralogical and sesquioxide properties of a rehabilitated degraded forest land (19 years after it was planted with various indigenous species in comparison with an adjacent secondary forest. Approach: Soil samples were air-dried and pass through a 2 mm sieve. Soil morphology was determined based on field observation. The non-crystalline (amorphous of Al, Fe and Si oxides and hydroxides (Alo, Feo and Sio were extracted with ammonium oxalate while the dithionate-citrate-bicarbonate (DCB method was used for extracting (crystalline the Al, Fe and Si oxides and hydroxides (Ald, Fed and Sid. The concentrations of extracted Al, Fe and Si were determined by atomic absorption spectroscopy. Mineralogical compositions were identified by X-ray diffraction method. Results: The A-horizon of secondary forest was darker and thicker than that of the rehabilitated forest. Root mat at the secondary forest was well-developed compared to the rehabilitated forest. The clay minerals were dominated with kaolinite and illite to a lesser extent of goethite and hematite accompanied with low values of activity ratio of Al and Fe oxides and hydroxides, indicating that the soils were highly weathered. Conclusion/Recommendations: The difference between rehabilitated and secondary forests was root abundance where secondary forest had most. Good root penetration in the secondary forest indicates that the soil texture there was not heavy. Soils in the rehabilitated and secondary forests were strongly weathered (high presence of kaolin minerals, but the low presence of sesquioxides suggests that they are yet to reached the ultimately weathered phase. The soil properties in terms

  2. Mineralogy, 57Fe Mössbauer spectra and magnetization of chalcolithic pottery

    Science.gov (United States)

    Keller, R.; Masch, L.; Pohl, J.; Schmidbauer, E.

    2005-06-01

    Three chalcolithic pottery sherds, paint removed from the surface of each sherd, and an unheated red pigment (Tell-Halaf culture, Turkey) were analysed within the frame of archaeometric studies using mineralogical methods, 57Fe Mössbauer spectroscopy, magnetization and rotational hysteresis data. From mineralogical results, the individual minerals forming the cores of the sherds were determined. It was found that the sherds are lime-rich. High temperature X-ray analysis on comparable Ca-rich material showed that the established composition is consistent with a firing temperature of 750-950°C. Apart from the pigment, each Mössbauer spectrum of Fe-bearing components consists of dominating paramagnetic doublets, arising mostly from silicate phases, and of a six-line pattern with reduced intensity, due to ferri- and/or antiferromagnetic Fe-oxide phases. For three samples, an Fe3+ silicate component of the spectra is clearly dominating, which points to oxidizing conditions during firing. For the others Fe2+ and Fe3+ components occur in about equal intensities. For the pigment, the magnetic sextet is of similar intensity to the Fe3+ silicate component. From magnetic analysis of ferrimagnetic phases it follows that a low percentage of particles of solid solutions γ-Fe2O3 Fe3O4 exist, probably in part ≤0.1 μm in diameter. The ferrimagnetic particles of at least one paint are probably covered by a thin layer of hematite as found from rotational hysteresis data. An attempt is made to draw conclusions from the experimental results, regarding the firing conditions of the sherds and paints.

  3. Genesis, maturity and weathering of some Upper Cretaceous Egyptian glauconites: Mineralogical and geochemical implications

    Science.gov (United States)

    Essa, Mahmoud A.; Ahmed, Ezzat A.; Kurzweil, Hans

    2016-12-01

    Mineralogical and geochemical studies were carried out on Upper Cretaceous (Cenomanian - Maastrichtian) glauconites from Egypt by means of polarizing microscope, XRD, SEM, microprobe and XRF techniques. Most of the investigated glauconite grains display zoning-like appearance. X-ray diffraction analyses reveal the presence of glauconite, quartz, dolomite, jarosite, goethite and glauconite (illite)-smectite mixed layer minerals. SEM and microprobe investigations revealed that jarosite is present as a weathering product of pyrite especially in Abu Tartur and Wadi Feiran areas. However, goethite was encountered as oxidation product of both pyrite and glauconite. The microprobe analyses of the glauconite grains reflect clearly their low Alumina (TiO2, Al2O3, MgO, Zr, Ce and La, whereas those of Saint Paul exhibit richness in Y and Rb. Gabal Dist samples display appreciable content of Fe2O3(t), K2O, Pb, Zn, Ni, Co, Sc and V whereas the P2O5 and SO3 show their abundance patterns at Abu Tartur locality. These fluctuations could be attributed to their differences in the mineralogical content (pyrite, goethite, and jarosite). The strong correlation between TiO2/Al2O3 and Zr/Al2O3 ratios may reflects mixed origin or reworking of sedimentary rocks from the continental hinterland in all the studied areas. The values of trace elements indices, such as Ni/Co, V/Cr and V/(V + Ni), suggest oxic to suboxic environments. However, some of the chalcophile elements (Pb, Zn, Ni, Co, Cu, Fe and Ga), which are correlated with pyrite and its alteration product (goethite), occur with relatively high concentrations in some studied glauconite beds reflecting reducing and/or suboxic conditions during the precipitation of these beds.

  4. CHEMICAL AND MINERALOGICAL CHARACTERISTICS OF FRENCH GREEN CLAYS USED FOR HEALING.

    Science.gov (United States)

    Williams, Lynda B; Haydel, Shelley E; Giese, Rossman F; Eberl, Dennis D

    2008-08-01

    The worldwide emergence of infectious diseases, together with the increasing incidence of antibiotic-resistant bacteria, elevate the need to properly detect, prevent, and effectively treat these infections. The overuse and misuse of common antibiotics in recent decades stimulates the need to identify new inhibitory agents. Therefore, natural products like clays, that display antibacterial properties, are of particular interest.The absorptive properties of clay minerals are well documented for healing skin and gastrointestinal ailments. However, the antibacterial properties of clays have received less scientific attention. French green clays have recently been shown to heal Buruli ulcer, a necrotic or 'flesh-eating' infection caused by Mycobacterium ulcerans. Assessing the antibacterial properties of these clays could provide an inexpensive treatment for Buruli ulcer and other skin infections.Antimicrobial testing of the two clays on a broad-spectrum of bacterial pathogens showed that one clay promotes bacterial growth (possibly provoking a response from the natural immune system), while another kills bacteria or significantly inhibits bacterial growth. This paper compares the mineralogy and chemical composition of the two French green clays used in the treatment of Buruli ulcer.Mineralogically, the two clays are dominated by 1Md illite and Fe-smectite. Comparing the chemistry of the clay minerals and exchangeable ions, we conclude that the chemistry of the clay, and the surface properties that affect pH and oxidation state, control the chemistry of the water used to moisten the clay poultices and contribute the critical antibacterial agent(s) that ultimately debilitate the bacteria.

  5. Chemical and mineralogical characteristics of French green clays used for healing

    Science.gov (United States)

    Williams, L.B.; Haydel, S.E.; Giese, R.F.; Eberl, D.D.

    2008-01-01

    The worldwide emergence of infectious diseases, together with the increasing incidence of antibiotic-resistant bacteria, elevate the need to properly detect, prevent, and effectively treat these infections. The overuse and misuse of common antibiotics in recent decades stimulates the need to identify new inhibitory agents. Therefore, natural products like clays, that display antibacterial properties, are of particular interest. The absorptive properties of clay minerals are well documented for healing skin and gastrointestinal ailments. However, the antibacterial properties of clays have received less scientific attention. French green clays have recently been shown to heal Buruli ulcer, a necrotic or 'flesh-eating' infection caused by Mycobacterium ulcerans. Assessing the antibacterial properties of these clays could provide an inexpensive treatment for Buruli ulcer and other skin infections. Antimicrobial testing of the two clays on a broad-spectrum of bacterial pathogens showed that one clay promotes bacterial growth (possibly provoking a response from the natural immune system), while another kills bacteria or significantly inhibits bacterial growth. This paper compares the mineralogy and chemical composition of the two French green clays used in the treatment of Buruli ulcer. Mineralogically, the two clays are dominated by 1Md illite and Fe-smectite. Comparing the chemistry of the clay minerals and exchangeable ions, we conclude that the chemistry of the clay, and the surface properties that affect pH and oxidation state, control the chemistry of the water used to moisten the clay poultices and contribute the critical antibacterial agent(s) that ultimately debilitate the bacteria. Copyright ?? 2008, The Clay Minerals Society.

  6. Mineralogical and Organo-Geochemical Properties of the Denizli (sw Turkey) Coals

    Science.gov (United States)

    Banu Koralay, Demet; Koralay, Tamer

    2016-04-01

    Coal samples for this study were systematically collected from the Yeşilyuva town of Denizli (SW Turkey) province. In order to be evaluated in terms of their mineralogic composition, source rock potential, total organic carbon (TOC, %), and thermal maturity. To find out the mineralogical composition of the Yeşilyuva coals, X-Ray Diffractometer (XRD) analysis was performed. Quartz, feldspar, calcite, pyrite, gypsum and clay minerals are determined in XRD analysis as the mineral matter in Yeşilyuva coals. The organo-geochemical results of samples suggest that the Yeşilyuva coals have excellent source rock quantity according to total organic carbon (TOC, %) contents (ranging from 8.82 to 43.80 wt. %), indicating that their present circumstances in the basin that preferred production and preservation of organic matter. According to genetic potential (GP, averaging 37.42 mg hydrocarbon/g rock), S1 (averaging 2.11 mg hydrocarbon/g rock) and S2 (averaging 35.31 mg hydrocarbon/g rock) values, all the coal samples show good to excellent source rock potential. The hydrogen index (HI) and S2/S3 values of Yeşilyuva coals range from 43 to 171 mg HC/g TOC and 0.64 to 2.83, respectively. These values indicate that all the coal samples have gas potential. Determination of the thermal maturity is based on production index (PI) and Tmax values, and the potential source rock is considered immature for PI values Mineral composition, Organo-Geochemical properties. Total Organic Carbon (TOC), Hydrocarbon Potential Acknowledgement: This study was financially supported by The Scientific and Technological Research Council of Turkey (TUBITAK, project number 114Y668)

  7. Mineralogy and sealing properties of various bentonites and smectite-rich clay materials

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Olsson, Siv; Nilsson, Ulf (Clay Technology AB (SE))

    2006-12-15

    The present work includes a coherent study of Wyoming bentonite with respect to the most relevant properties for use in a repository, and a parallel study of other potential buffer and tunnel backfilling materials. The reason for this is twofold; to quantify the effect of mineralogical variations on the various important sealing properties of bentonite, and to verify that there are alternative potential sources of bentonite. The latter is motivated by the fact that Sweden alone plans to deposit at least 6,000 copper canisters which include approximately 130,000 metric tones bentonite buffer material and several times more as tunnel backfill material. Different types of sealing clay materials may also be relevant to use, since the demands on the clay will be different at the various locations in a repository. Alternative sources of bentonite would consequently be valuable in order to secure quality, supply, and price. Important aspects on buffer and tunnel backfilling materials may be summarized as: Original sealing properties. Hazardous substances in any respect. Short-term effects of ground-water chemistry. Long-term stability, i.e. effects of temperature and ground-water chemistry. Availability. Costs. The focus in this study is on the first three items. The long-term stability is indirectly considered in that mineralogical composition is determined. The availability is only considered in such a way that most of the analyzed materials represent huge clay formations, which contain much more material than needed for a repository. The cost aspects have not been included, mainly because the present day price is not relevant due to the time frame of the construction of a repository

  8. Olivine melilitites of the SW German tertiary volcanic province: mineralogy and petrogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Dunworth, E.A.; Wilson, M. [Leeds University (United Kingdom). Dept. of Earth Sciences

    1998-12-31

    The mineralogy and mineral chemistry of olivine melilitites from the Late Tertiary Urach and Hegau volcanic provinces of SW Germany, and from Mahlberg Castle, north of the Kaisertuhl carbonatite complex within the Upper Rhinegraben, provide important constraints on the petrogenesis of these rather rare magma types. The principal features of the mineralogy are controlled by the high degree of silica undersaturation, relatively low total alkalis (<5 wt%, Na{sub 2}O > K{sub 2}O), and the high Ca and Mg contents of the magmas. Olivine (Fo{sub 79-89}), frequently reverse-zoned, Ca-saturated clinopyroxene exhibiting strong disequilibrium zonation, and akermanite-rich melilite are the dominant crystallizing phases, along with Cr-spinel and magnetite. Rare Ba-Ti phlogopite, containing up to 18 wt% BaO and 9 wt% TiO{sub 2}, occurs in the groundmass of most samples, along with Nb-rich perovskite, fluoraphatite, nepheline and devitrified glass. The combination of previously published geochemical data with the results of this petrographic study suggest that initial melt generation occurred within the dolomite-garnet stability field in the asthenosphere, the main episode of magma generation occurred at the base of the lithosphere, and additional wall-rock assimilation occurred as the magmas rose through the lithosphere, including the incorporation of spinel peridotite xenoliths and sheared olivine xenocrysts which last equilibriated close to the base of the crust. Thus, the bulk-rock composition of the magmas records a composite product of a complex multi-stage and multi-source history. (author)

  9. Paleoproterozoic andesitic volcanism in the southern Amazonian craton (northern Brazil); lithofacies analysis and geodynamic setting

    Science.gov (United States)

    Roverato, Matteo; Juliani, Caetano; Capra, Lucia; Dias Fernandes, Carlos Marcelo

    2016-04-01

    Precambrian volcanism played an important role in geological evolution and formation of new crust. Most of the literature on Precambrian volcanic rocks describes settings belonging to subaqueous volcanic systems. This is likely because subaerial volcanic rocks in Proterozoic and Archean volcano-sedimentary succession are poorly preserved due to erosive/weathering processes. The late Paleoproterozoic Sobreiro Formation (SF) here described, seems to be one of the rare exceptions to the rule and deserves particular attention. SF represents the subaerial expression of an andesitic magmatism that, linked with the upper felsic Santa Rosa F., composes the Uatumã Group. Uatumã Group is an extensive magmatic event located in the Xingú region, southwestern of Pará state, Amazonian Craton (northern Brazil). The Sobreiro volcanism is thought to be related to an ocean-continent convergent margin. It is characterized by ~1880 Ma well-preserved calc-alkaline basaltic/andesitic to andesitic lava flows, pyroclastic rocks and associated reworked successions. The superb preservation of its rock-textures allowed us to describe in detail a large variety of volcaniclastic deposits. We divided them into primary and secondary, depending if they result from a direct volcanic activity (pyroclastic) or reworked processes. Our study reinforces the importance of ancient volcanic arcs and rocks contribution to the terrestrial volcaniclastic sedimentation and evolution of plate tectonics. The volcanic activity that produced pyroclastic rocks influenced the amount of detritus shed into sedimentary basins and played a major role in the control of sedimentary dispersal patterns. This study aims to provide, for the first time, an analysis of the physical volcanic processes for the subaerial SF, based in field observation, lithofacies analysis, thin section petrography and less geochemical data. The modern volcanological approach here used can serve as a model about the evolution of Precambrian

  10. Counseling in Brazil: Past, Present, and Future

    Science.gov (United States)

    Hutz-Midgett, Aida; Hutz, Claudio Simon

    2012-01-01

    This article describes counseling in Brazil, which is rooted in career and vocational guidance. Although considered a distinct discipline, counseling falls under the umbrella of psychology. The multicultural movement is gaining momentum in Brazil, and counselors are pioneers working with socioracial minority college students. This is an emerging…

  11. Higher Education Reform in Brazil: Reinforcing Marketization

    Science.gov (United States)

    de Siqueira, Angela C.

    2009-01-01

    Higher education in Brazil began based on institutions organized as isolated establishments, and mostly privately owned. Nonetheless, public institutions created as universities and developing research activities and other services became the desired ideal for higher education. The first educational institutions in Brazil were created in the…

  12. Rising Expectations in Brazil and Chile

    Science.gov (United States)

    Elacqua, Gregory; Alves, Fatima

    2014-01-01

    Two themes connect Brazil and Chile: one is economic success; the other is social unrest. Protests rocked cities across Brazil in June 2013, and in Chile, recent student protests turned violent. Yet living conditions in both nations are better now than they've ever been. Successful economic and social reforms over the last two decades have led to…

  13. Inequality and School Reform in Bahia, Brazil

    Science.gov (United States)

    Reiter, Bernd

    2009-01-01

    This article compares public and community schools in Salvador, the state capital of Bahia, Brazil. Based on quantitative data analysis and qualitative research conducted on-site during three research trips in 2001, 2003 and 2005, the author finds that Brazil's extreme inequality and the associated concentration of state power in a few hands stand…

  14. Rainfall erosivity in Brazil: A Review

    Science.gov (United States)

    In this paper, we review the erosivity studies conducted in Brazil to verify the quality and representativeness of the results generated and to provide a greater understanding of the rainfall erosivity (R-factor) in Brazil. We searched the ISI Web of Science, Scopus, SciELO, and Google Scholar datab...

  15. History of nuclear power in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, L.P.

    2006-07-15

    The 1973 energy crisis prompted the United States to suspend supplies of enriched uranium to the reactor being built in Brazil, Angra I. In 1975, the Brazil-Germany Nuclear Agreement was announced. The Programme was a failure. Today the Angra II nuclear reactor has been completed, the only reactor completed under the agreement with Germany. Brazil's last military President implemented the Parallel Nuclear Programme, which included uranium enrichment with the justification of developing the technology that had not been transferred through the Nuclear Agreement with Germany. In 1986, the existence of a deep shaft drilled by the Air Force was revealed. A Technical Report concluded that it had all the characteristics and dimensions required to test a nuclear bomb. Some years later, the Civilian Government acknowledged the existence of an underground nuclear explosion facility and symbolically sealed this shaft. The situation in Brazil has improved recently. Brazil ratified the Treaty of Tlatelolco on the denuclearisation of Latin America and established ABACC, an agency handling mutual inspections of nuclear facilities in Brazil and Argentina. Brazil also signed the Nuclear Weapons Non-Proliferation Treaty. The uranium enrichment activities are being transferred to a civilian industry. More importantly, I do not believe that the uranium enrichment project is intended to endow Brazil with the capacity to produce nuclear weapons. (author)

  16. Brazil = Brasil. America = Las Americas [Series].

    Science.gov (United States)

    Toro, Leonor; And Others

    Written for teachers to use with migrant children in elementary grades, this bilingual English/Spanish social studies resource booklet provides an encyclopedia-style overview of Brazil's history, geography, economy, and culture. Topics include Brazil's form of government; geographic regions; holidays; climate; people; music; carnaval celebration;…

  17. Popular Documentation and Communication Centres in Brazil.

    Science.gov (United States)

    Cardoso, Ana Maria P.

    1993-01-01

    Presents a study of the popular documentation and communication centers in Brazil which have developed to preserve the history of the struggles of the lower classes and to act as popular information services that fill information needs not met by traditional libraries. Social, economic, and political issues in Brazil are outlined. (Contains 10…

  18. US and Brazil: Prospective National Security Partners

    Science.gov (United States)

    2001-01-01

    Chapter 5, “National Security,” data as of April 1997. Maxwell, Kenneth. “George W., King Canute , and Brazil,” Article published by Council on Foreign...22. [22] Kenneth Maxwell, “George W., King Canute , and Brazil,” article published by Council on Foreign Relations, 15 Dec 2000. (Hereafter referred

  19. Rising Expectations in Brazil and Chile

    Science.gov (United States)

    Elacqua, Gregory; Alves, Fatima

    2014-01-01

    Two themes connect Brazil and Chile: one is economic success; the other is social unrest. Protests rocked cities across Brazil in June 2013, and in Chile, recent student protests turned violent. Yet living conditions in both nations are better now than they've ever been. Successful economic and social reforms over the last two decades have…

  20. Reflectância espectral e mineralogia de materiais formados sobre diabásio Spectral reflectance and mineralogy of soil materials developed from diabase

    Directory of Open Access Journals (Sweden)

    Celso Augusto Clemente

    2000-03-01

    Full Text Available O presente estudo teve por objetivo caracterizar diferentes fases de intemperismo de um solo e relacioná-las com seu comportamento espectral. Um perfil pedológico desenvolvido sobre diabásio da região de Capivari-SP, foi descrito morfologicamente, identificando-se seis fases de alteração. Os atributos analisados foram granulometria, composição química e mineralógica. A reflectância espectral do solo foi avaliada em laboratório através de espectrorradiômetro na faixa de 300 a 2500 nm. O perfil apresentou grau de intemperismo moderado, o que foi evidenciado pela alta relação silte/argila observada abaixo do horizonte Bi. Os horizontes subsuperficiais também apresentaram alto teor de nutrientes, especialmente P, Ca e Mg, que estavam relacionados com a presença em subsuperfície de saprolito com razoável reserva de minerais intemperizáveis. A evolução dos minerais primários iniciou pela formação de óxidos de ferro e de argilas 2:1, como vermiculita ou vermiculita-esmectita, que foram transformadas em caulinita e gibbsita em direção ao topo do perfil. Na medida em que ocorreram alterações na composição mineralógica no perfil, foram verificadas variações nos dados espectrais. Basicamente a reflectância foi influenciada diferenciadamente pela ocorrência de óxidos de ferro, diferentes tipos de argilas e minerais primários como piroxênios e magnetita.The aim of this study was to characterize soil materials with different degrees of weathering and then associate their composition with their spectral behavior. One pedological profile developed from diabase was studied in Capivari-SP, Brazil. The morphological description allowed to separate six phases of rock-soil alteration. Afterwards, granulometry, chemical and mineralogical analysis were carried out. The soil spectral reflectance was evaluated with a laboratory spectroradiometer using the wavelength range of 300 to 2500 nm. The profile was moderately weathered as

  1. Mineralogical composition and geographical distribution of African and Brazilian periatlantic laterites. The influence of continental drift and tropical paleoclimates during the past 150 million years and implications for India and Australia

    Science.gov (United States)

    Tardy, Y.; Kobilsek, B.; Paquet, H.

    Following the break-up of Pangea at the end of the Jurassic time, the African and South American continents and then India and Australia drifted into the fringes of the equatorial or tropical climatic zone with the humidity varying according to the epochs. India, Brazil and the southern part of East Africa which were previously more arid and probably hotter during the Jurassic, became progressively more humid and cooler. By contrast, West Africa, Central Africa and Australia, formerly subject to very humid climates became subject to warmer and drier climatic conditions. In the first case, the ferricretes were rarely preserved intact but bauxites, generally massive and non pisolitic and essentially formed of gibbsite (Al(OH) 3) are abundant. In the second case, hematite (Fe 2O 3) occurring as nodular ferricretes are extensively developed together with gibbsite-bearing pisolitic bauxites and boehmite (AlOOH). Gibbsite and goethite are hydrated minerals related to humid and rather cool climates, whereas hematite and boehmite are dehydrated minerals related to less humid and warmer climatic conditions. Thus temperature, relative humidity of the atmosphere and the activity of water are the major climatic and thermodynamic parameters controlling the mechanisms of formation, the processes of evolution and the geographical distribution of bauxites and ferricretes. Furthermore, the geographical distribution and the mineralogical composition of ferricretes and bauxites are considered to be controlled not only by the different present-day climates but also and perhaps above all by the succession of paleoclimates during the past 150 million years.

  2. Geology, mineralogy and geochemistry of Ferezneh ferromanganese anomaly, east of Sangan mines complex, NE Iran

    Directory of Open Access Journals (Sweden)

    Nazi Mazhari

    2015-04-01

    Full Text Available Introduction The Ferezneh prospect area is one of the eastern anomalies of Khaf’s Sangan iron mine. The Sangan mines complex is located within the Khaf-Kashmar-Bardeskan volcano-plutonic and metallogenic belt in northeastern Iran. The Sangan mine is the largest Fe skarn in western Asia, having a proven reserve of over 1000 Mt iron ore @ 53% Fe (Golmohammadi et al., 2015 and consisting of three parts; western, central and eastern Sangan, each part including several anomalies. In this study, Ferezneh (North and West prospect area which is an eastern anomaly of the Sangan iron ore is discussed. Ferezneh anomaly is located in 60°36'7" - 60°34'27"E and 34°30'47" - 34°29'46"N, 35 km south of the city of Taybad, 10 km southeast of Karat and 1.5 km southwest of Ferezneh village. The purpose of this study was to prepare a geologic map for separation and identification of the intrusions, determining their relationships with mineralization, distinguishing the type of mineralization, mineralogy, petrology and geochemistry of the mineral deposits, and finally their relationship with other major Sangan’s deposits. Materials and methods In order to achieve the objectives of the study: 1- 140 thin sections of the intrusive rocks, marble limestone and dolomite, as well as 40 polished sections of ore were taken in an area of 9.5 km2. Mineralogy and mineralization studies were performed in the Economic Geology Laboratory of Ferdowsi University of Mashhad. 2- A few samples were selected for X-ray diffraction analysis in order to ensure accuracy of mineralogical studies and were sent to Binalood Laboratory in Tehran. 3- In addition to major and minor elements geochemistry study of the ores, 10 samples were sent to East Amitis Laboratory in Mashhad for XRF analysis and also to Canada S.G.S Laboratory for ICP-MS analysis. Discussion and results Mineralization in the Ferezneh prospect area was limited to iron and manganese oxides in the form of massive and

  3. Detection and context of hydrated mineralogy in the Tyrrhena Terra region, Mars

    Science.gov (United States)

    den Haan, J.; Zegers, T. E.; van Ruitenbeek, F. J. A.; van der Werff, H. M. A.; Rossi, A.

    2008-09-01

    Introduction The discovery of phyllosilicates on Mars [1] has had major implications on the perceived geologic and climatologic evolution of Mars [2]. Not only do phyllosilicates represent a `wet' period on Mars, they might also represent a potentially favorable environment for life. The phyllosilicates have so far exclusively been found in or close to ancient Noachian highland terrain. Those phyllosilicate deposits studied (e.g. [3]) show a clear association between hydrated mineralogy and heavily eroded and crater-saturated outcrops. Phyllosilicates on Earth are associated with a wide variety of geological processes (volcanism, metamorphism, hydrothermal alteration, sedimentation). The occurrence of phyllosilicates on Mars may be equally diverse in nature. To be able to place constraints on the early Martian environment, the processes by which these phyllosilicates formed need to be reconstructed. To derive this information from individual phyllosilicate deposits, it is necessary to interpret their composition in relation to their geological context and relative time relationships. We conducted such an integrated hyperspectral and geological study of the Tyrrhena Terra region. Data products ad methods HRSC data products (both image at 12 m/pixel and stereo-derived DTMs) are used for examining geologic cross-cutting relationships, geomorphologic landforms and visual determination of unit boundaries. Odyssey THEMIS nighttime TIR images are analyzed for spatial variations in thermal inertia. Where available, HRSC is supplemented by higher-resolution visible observations of CTX or MOC. Hyperspectral analysis is conducted using data from the OMEGA hyperspectral instrument. In order to batch-process large amounts of OMEGA data, an IDL/ENVI tool was developed on top of the existing SOFT04, distributed by PSA. The applied atmospheric correction assumes that atmospheric contributions are multiplicative, and follow a power-law distribution with altitude [4]. The ratio of

  4. Mineralogical characterization of a highly-weathered soil by the Rietveld Method Caracterização mineralógica de um solo altamente intemperizado pelo Método de Rietveld

    Directory of Open Access Journals (Sweden)

    André Maurício Brinatti

    2010-08-01

    Full Text Available The mineralogical characterization through mineral quantification of Brazilian soils by X-ray diffraction data using the Rietveld Method is not common. A mineralogical quantification of an Acric Ferralsol from the Ponta Grossa region, state of Paraná, Brazil, was carried out using this Method with X-Ray Diffraction data to verify if this method was suitable for mineral quantification of a highly-weathered soil. The A, AB and B3 horizons were fractioned to separate the different particle sizes: clay, silt, fine sand (by Stokes Law and coarse sand fractions (by sieving, with the procedure free of chemical treatments. X-ray Fluorescence, Inductively Coupled Plasma Atomic Emission Spectrometry, Infrared Spectroscopy and Mössbauer Spectroscopy were used in order to assist the mineral identification and quantification. The Rietveld Method enabled the quantification of the present minerals. In a general way, the quantitative mineralogical characterization by the Rietveld Method revealed that quartz, gibbsite, rutile, hematite, goethite, kaolinite and halloysite were present in the clay and silt fractions of all horizons. The silt fractions of the deeper horizons were different from the more superficial ones due to the presence of large amounts of quartz. The fine and the coarse sand fractions are constituted mainly by quartz. Therefore, a mineralogical quantification of the finer fraction (clay and silt by the Rietveld Method was successful.A caracterização mineralógica por meio da quantificação dos minerais presentes em solos brasileiros por difração de raios X usando o Método de Rietveld é, ainda, pouco comum. Neste trabalho foi realizada a quantificação mineralógica de um Latossolo Vermelho ácrico da região de Ponta Grossa, Paraná, Brasil, utilizando o Método de Rietveld com dados de Difração de Raios X e também verificado se o método foi adequado na quantificação mineral de um solo altamente intemperizado. Os horizontes A

  5. Paleoproterozoic high-sulfidation mineralization in the Tapajós gold province, Amazonian Craton, Brazil: geology, mineralogy, alunite argon age, and stable-isotope constraints

    Science.gov (United States)

    Juliani, Caetano; Rye, Robert O.; Nunes, Carmen M.D.; Snee, Lawrence W.; Correa, Rafael H.; Monteiro, Lena V.S.; Bettencourt, Jorge S.; Neumann, Rainer; Neto, Arnaldo A.

    2005-01-01

    The Brazilian Tapajós gold province contains the first evidence of high-sulfidation gold mineralization in the Amazonian Craton. The mineralization appears to be in large nested calderas. The Tapajós–Parima (or Ventuari–Tapajós) geological province consists of a metamorphic, igneous, and sedimentary sequence formed during a 2.10 to 1.87 Ga ocean−continent orogeny. The high-sulfidation mineralization with magmatic-hydrothermal alunite is related to hydrothermal breccias hosted in a rhyolitic volcanic ring complex that contains granitic stocks ranging in age from 1.89 to 1.87 Ga. Cone-shaped hydrothermal breccias, which flare upward, contain vuggy silica and have an overlying brecciated cap of massive silica; the deposits are located in the uppermost part of a ring-structure volcanic cone. Drill cores of one of the hydrothermal breccias contain alunite, natroalunite, pyrophyllite, andalusite, quartz, rutile, diaspore, woodhouseite–svanbergite, kaolinite, and pyrite along with inclusions of enargite–luzonite, chalcopyrite, bornite, and covellite. The siliceous core of this alteration center is surrounded by advanced argillic and argillic alteration zones that grade outward into large areas of propylitically altered rocks with sericitic alteration assemblages at depth. Several occurrences and generations of alunite are observed. Alunite is disseminated in the advanced argillic haloes that envelop massive and vuggy silica or that underlie the brecciated silica cap. Coarse-grained alunite also occurs in branching veins and locally is partly replaced by a later generation of fine-grained alunite. Silicified hydrothermal breccias associated with the alunite contain an estimated reserve of 30 tonnes of gold in rock that grades up to 4.5 g t−1 Au. Seven alunite samples gave 40Ar/39Ar ages of 1.869 to 1.846 Ga, with various degrees of apparent minor Ar loss. Stable isotopic data require a magmatic-hydrothermal origin for the alunite, typical for high-sulfidation mineralization. The δ34S values of most samples of alunite range from 14.0‰ to 36.9‰. Sulfur isotopic alunite–pyrite and oxygen isotopic alunite SO4−OH temperatures range from 130 to 420 °C. The δDH2O and δ18OH2O values for alunite-forming hydrothermal fluids suggest a predominance of magmatic water, with a small meteoric contribution. A rare sample of supergene alunite has a δ34S value of 4.1‰ and an 40Ar/39Ar age of 51.3±0.1 Ma. Other than local foliation in the volcanic rocks and recrystallization of alunite near faults, the mineralization and associated alteration appears to have been remarkably undisturbed by later metamorphism and by supergene alteration. The Au mineralization was preserved because of burial by sediments and tuffs in taphrogenic basins that probably developed shortly after mineralization and were probably first exhumed at about 60 Ma. Because high-sulfidation mineralization forms at relatively shallow crustal levels, the discoveries in Tapajós province provide new perspectives for mineral exploration for the Amazonian and perhaps for other Precambrian cratons.

  6. Geodiversity and geoconservation in Brazil

    Science.gov (United States)

    Cardozo Moreira, Jasmine; Muggler, Cristine Carole

    2014-05-01

    Brazil is a large country with a wide diversity of landscapes and geological features and has been an important world producer of mineral resources. Despite this, until the 90's of last century, there has not been much concern and policies about geological heritage and geoconservation. Only at the end of the century the National Geological Service (CPRM) included the physical characterization of areas with geotouristic interest in its mission of generation and diffusion of geological information. In 1997, was created the Brazilian Commission of Geological and Paleobiological Sites (SIGEP, http://sigep.cprm.gov.br), responsible for the assessment, description and publicizing the sites of geological heritage. This is by now the most comprehensive and relevant initiative to protect the national heritage. It is composed by a fully accessible national database composed by 167 certified sites presented as scientific papers. Furthermore, a web-based applicative for the inventory and protection of geological heritage sites is being developed by the National Geological Service. The wider knowledge about geological heritage can be a useful tool for its conservation and this has been an important goal in the creation of protected areas, by means of environmental education and tourism. In Brazil, actions, research and publications about the subject have increased in the last five years, as well as the outreach and responsible use of the geological heritage. Scientific meetings, conferences and courses are growing and spreading around the country. The main scientific meeting has been the Brazilian Symposium of Geological Heritage that in its second edition (2013) had more than 200 papers presented. At that meeting it was also created the Association in Defence of the Geomining Heritage and the Association of Aspiring Geoparks. Brazil has only one geopark in the Unesco's Global Geopark Network, that is the Araripe Geopark, created in 2006. By the moment, propositions are being

  7. H3 internationalization to Brazil

    OpenAIRE

    2012-01-01

    A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics h3 is a Portuguese firm competing in the fast food market with a hamburger gourmet concept. The firm is now a strong player in Portugal (39 stores); Poland, Warsaw (1 store); Spain, Madrid (1 store) and Brazil, São Paulo (2 stores). As a result of their successes in the domestic market, internationalization was a natural step. One o...

  8. Brazil ALDF System Error Analysis

    Science.gov (United States)

    Rompala, John T.

    1999-01-01

    In a cooperative effort among: the Global Hydrology Climate Center (GHCC) of NASA's Marshal Space Flight Center (MSFC), the Atmospheric Electric Group of the Brazilian National Institute of Space Research, the University of San Paulo (USP), and the Brazilian National Institute of Meteorology (INME), a network of four lightning detectors has been established in Brazil's Rhondonian region. This paper surveys the efforts of GHCC researchers to develop algorithms and field procedures which reliable determine lightning strike locations based on site data comprised of the signal time of arrival, and radiated electromagnetic field.

  9. Mineralogical composition of Oravita calcic skarns as a function of the high-temperature contact

    Science.gov (United States)

    Ghinet, Cristina; Marincea, Stefan; Dumitras, Delia

    2014-05-01

    Insignificant in terms of mineralization, the skarns of Oravita are scientifically interested because of their mineralogical associations. The higher crystallinity and good natural conditions (they are generally barren) are two characteristics of this rocks that can provide the ideally system to understand the behavior of the mineralogical components in certain conditions of temperature and pressure, but also for the hydrated carbonate phases whose forming understanding may be useful in the applied mineralogy. The occurrence of skarns from Oraviţa includes, as representative species, gehlenite, calcic garnet, monticellite, ellestadite-(OH), vesuvianite, that means in the geochemically terms CaO - SiO2 - H2O - Al2O3 system, usually described as C-S-H-A phases by the cement researches, difficult to study because of the small dimensions of the compounds crystals. The inner skarn zone is dominated by the presence of the gehlenite, an aluminum calcium silicate whose formation involves, as conditions, high temperature (~ 750oC) and low pressure (up to 1kbar). Typically, it is associated with monticellite, ellestadite-(OH), wollastonite 2M, diopside and calcic garnets. As it is expected, the intensity of the contact metamorphism decreases from the innermost to the outermost parts of the aureole, reflected in the chemical activity of the cations that participated at the chemical reactions. In this respect, the observed garnets are zoned, being characterized by a peripheral rich in Al, while the centers of the crystals are characterized by a high content of Fe and Ti. The replacement of gehlenite with vesuvianite along the metasomtatic front, a process that was observed at the optical microscope, indicates the existence of late stage metasomatic mineral phases. The presence of the vesuvianite, frequently including partially chloritized clintonite slides, and its main associated minerals as wollastonite 2M and calcium garnet with an andradite composition, points out the

  10. "Let's take back our roots through Science". The Sicilian Sulfur: a mineralogical treasure to rediscover.

    Science.gov (United States)

    Parisi, Bianca

    2015-04-01

    The name of sulfur is synonymous of Sicily! Sicilian Sulfur minerals and evaporitic deposits are well-known because they are connected with an important evolution stage of the old mediterranean area. In this Island, in the southern part of Italy, a geological formation of Messinian age, called "gessoso solfifera", outcrops. These rocks are widespread in the south and south-west Sicily, and, there, salt mines and "zolfare", sulfur mines, were located. The formation is characterized by large amounts of gypsum, potassium salts, sodium chlorates and other deposits. Most of the main mineralogical museum collections all over the world have at least a sample of one of these minerals that are usually characterized by a high aesthetic quality. When I proposed a lesson on the origin of sulfur in evaporitic rocks, I realized that an important part of the hystory of our region was in danger to be forgotten by younger generation. The exploitation of this mineral resource in the past is strictly linked to the troubled social and cultural transformation of Sicily during the last century. Thus, this is a particularly suitable topic for a multidisciplinary approach. In cooperation with the Mineralogical Museum (SteBiCeF Department, University of Palermo), a learning project was proposed to a group of 4th year high school students. It has been carrying on in order to develop the knowledge of the geological and chemical features of evaporitic deposits and to promote scientific abilities together with a better understanding of social-environmental issues. Project aims and activities include: ➢ Solubility and saturation experiments to reconstruct a simplified model of minerals deposition ➢ Working in groups: collection of data about old geological outcrops and current evaporating basins where rocks are forming in the world as well as information on sicilian mines from literature and historical documents (video, interviews, pictures, newspapers and others) ➢ a guided tour of the

  11. To what extent clay mineralogy affects soil aggregation? Consequences for soil organic matter stabilization

    Science.gov (United States)

    Fernandez-Ugalde, O.; Barré, P.; Hubert, F.; Virto, I.; Chenu, C.; Ferrage, E.; Caner, L.

    2012-12-01

    Aggregation is a key process for soil functioning as it influences C storage, vulnerability to erosion and water holding capacity. While the influence of soil organic C on aggregation has been documented, much less is known about the role of soil mineralogy. Soils usually contain a mixture of clay minerals with contrasted surface properties, which should result on different abilities of clay minerals to aggregation. We took advantage of the intrinsic mineral heterogeneity of a temperate Luvisol to compare the role of clay minerals (illite, smectite, kaolinite, and mixed-layer illite-smectite) in aggregation. In a first step, grassland and tilled soil samples were fractionated in water in aggregate-size classes according to the hierarchical model of aggregation (Tisdall and Oades, 1982). Clay mineralogy and organic C in the aggregate-size classes were analyzed. The results showed that interstratified minerals containing swelling phases accumulated in aggregated fractions (>2 μm) compared to free clay fractions (500 μm) to micro-aggregates (50-250 μm). C concentration and C/N ratio followed the opposite trend. These results constitute a clay mineral-based evidence for the hierarchical model of aggregation, which postulates an increasing importance of the reactivity of clay minerals in the formation of micro-aggregates compared to larger aggregates. In the latter aggregates, formation relies on the physical enmeshment of particles by fungal hyphae, and root and microbial exudates. In a second step, micro-aggregates from the tilled soil samples were submitted to increasingly disaggregating treatments by sonication to evaluate the link between their water stability and clay mineralogy. Micro-aggregates with increasing stability showed an increase of interstratified minerals containing swelling phases and C concentration for low intensities of disaggregation (from 0 to 5 J mL-1). This suggests that swelling phases promote their stability. Swelling phases and organic C

  12. RESIDUES FROM COAL CONVERSION AND UTILIZATION: ADVANCED MINERALOGICAL CHARACTERIZATION AND DISPOSED BYPRODUCT DIAGENESIS

    Energy Technology Data Exchange (ETDEWEB)

    Gregory J. McCarthy; Dean G. Grier

    2001-01-01

    Prior to the initiation of this study, understanding of the long-term behavior of environmentally-exposed Coal Combustion By-Products (CCBs) was lacking in (among others) two primary areas addressed in this work. First, no method had been successfully applied to achieve full quantitative analysis of the partitioning of chemical constituents into reactive or passive crystalline or noncrystalline compounds. Rather, only semi-quantitative methods were available, with large associated errors. Second, our understanding of the long-term behavior of various CCBs in contact with the natural environment was based on a relatively limited set of study materials. This study addressed these areas with two objectives, producing (1) a set of protocols for fully quantitative phase analysis using the Rietveld Quantitative X-ray Diffraction (RQXRD) method and (2) greater understanding of the hydrologic and geochemical nature of the long-term behavior of disposed and utilized CCBs. The RQXRD technique was initially tested using (1) mixtures of National Institute of Standards and Technology (NIST) crystalline standards, and (2) mixtures of synthetic reagents simulating various CCBs, to determine accuracy and precision of the method, and to determine the most favorable protocols to follow in order to efficiently quantify multi-phase mixtures. Four sets of borehole samples of disposed or utilized CCBs were retrieved and analyzed by RQXRD according to the protocols developed under the first objective. The first set of samples, from a Class F ash settling pond in Kentucky disposed for up to 20 years, showed little mineralogical alteration, as expected. The second set of samples, from an embankment in Indiana containing a mixture of chain-grate (stoker) furnace ash and fluidized bed combustion (FBC) residues, showed formation of the mineral thaumasite, as observed in previously studied exposed FBC materials. Two high-calcium CCBs studied, including a dry-process flue gas desulfurization

  13. Physical and mineralogical properties and shear strength of landslide soils in Amami-Oshima Island

    Science.gov (United States)

    Ose, Anna; Nakamura, Shinya

    2013-04-01

    Many landslides were triggered by the three heavy rainfalls in the Amami-Oshima Island, Kagoshima Prefecture, Japan in October, 2010, September, 2011 and November, 2011. Especially, the 2010 heavy rainfall from October 18th to 21st was the highest recorded torrential downpour in a century and resulted in triggering 57 landslides that destroyed property and killed three peoples. During recent years, climatic aberrations that result in this type of heavy rainfall have been common and could expect to increase the risk of landslide disasters in the Amami-Oshima Island in the future. The fully-softened, residual and peak strength are important at the time of the occurrence and the re-sliding of landslides. In this study, we examined the physical and mineralogical properties and shear strength characteristics of landslides in Amami-Oshima Island in order to understand the characteristics of landslides clear and the occurrence. Soil samples were collected from the scarp at the four sites of Ura, Ashikebu, Akinagawa and Sokaru. The Ashikebu sample has high Liquid and Plastic limits and high Specific Surface Area (SSA). All samples were dominated by quartz, and contents mica, feldspar and so on. The Ashikebu sample contained more halloysite and a high percentage of clay. These reasons cause the SSA to be high. There is an inversely proportionate relation between ?r and SSA. It is considered that Ashikebu indicating high SSA showed the low ?r, and Akinagawa of low SSA showed the high ?r. The torsional ring shear test was conducted for these two samples. For the Ashikebu sample, the peak strength parameter was obtained to be ?sf=38.2° , residual strength parameter was estimated ?r=17.7° . For the Akinagawa sample, those were obtained ?sf=38.0° and ?r=28.1° . In the stress-displacement relations of Ashikebu sample, the shear stress decreased sharply after reaching the peak value, namely fully-softened strength, the attained the residual state at displacement of around 746

  14. Chemical and mineralogical characterization of blast-furnace sludge from an abandoned landfill.

    Science.gov (United States)

    Mansfeldt, Tim; Dohrmann, Reiner

    2004-11-15

    Blast-furnace sludge is generated during the production of pig iron and is disposed of in the environment in large surface landfills. We investigated blast-furnace sludge samples of an abandoned landfill in order to determine its chemical and mineralogical nature and to evaluate some environmental hazards that may arise from this industrial waste. The mineralogical inventory, which was quantified by Rietveld refinement of XRD analyses using the fundamental-parameter approach, revealed that blast-furnace sludge is dominated by X-ray amorphous substances (with a mean of 590 g kg(-1)) including coke and (hydr)oxides of Fe, Si, Al, Zn, and Pb. Calcite (CaCO3) (136 g kg(-1)), dolomite (Ca,Mg[CO3]2) (14 g kg(-1)), quartz (SiO2) (55 g kg(-1)), kaolinite (Al2[OH]4Si2O5) (40 g kg(-1)), graphite (C) (27 g kg(-1)), and chemically not specified layered double hydroxides (28 g kg(-1)) were identified in almost all samples. Iron is present as magnetite (Fe3O4) (34 g kg(-1)), hematite (Fe2O3) (38 g kg(-1)), wuestite (FeO) (20 g kg(-1)) and alpha-iron (Fe0) (6 g kg(-1)). Chemically, blast-furnace sludge is dominated by C (190 g kg(-1)) and Fe (158 g kg(-1)) reflecting the process of pig-iron production. On the basis of total contents, environmentally problematic metals (including As) are Zn (32.6 g kg(-1)), Pb (10.3 g kg(-1)), Cd (81 mg kg(-1)), and As (129 mg kg(-1)). As the forested landfill is used by residents for leisure activities, the exposure assessment by pathway oral uptake of blast-furnace sludge particles by humans has to be critically evaluated, particularly as significant proportions of metals are acid-soluble. However, under the prevailing slightly alkaline pH values of the sludge (pH 7.6-9.2), the solubility of the metals is very low as indicated by low pore water concentrations. Currently, groundwater monitoring should be focused mainly on F- since the F- concentrations in the pore water of blast-furnace sludge are at high level (2.65-24.1 mg of F- L(-1)).

  15. Radiocesium sorption in relation to clay mineralogy of paddy soils in Fukushima, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, Atsushi, E-mail: na_4_ka_triplochiton@kpu.ac.jp [Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Hangi-cho 1-5, Shimogamo, Sakyo-ku, Kyoto 606-8522 (Japan); Ogasawara, Sho [Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Hangi-cho 1-5, Shimogamo, Sakyo-ku, Kyoto 606-8522 (Japan); Sano, Oki; Ito, Toyoaki [Field Science Center, Graduate School of Agricultural Science, Tohoku University, Naruko-Onsen 232-3, Osaki, Miyagi 989-6711 (Japan); Yanai, Junta [Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Hangi-cho 1-5, Shimogamo, Sakyo-ku, Kyoto 606-8522 (Japan)

    2014-01-01

    Relationships between Radiocesium Interception Potential (RIP) and mineralogical characteristics of the clay fraction isolated from 97 paddy soils (Hama-dori, n = 25; Naka-dori, n = 36; Aizu, n = 36) in Fukushima Prefecture, Japan were investigated to clarify the mineralogical factors controlling the {sup 137}Cs retention ability of soils (half-life 30.1 y). Of all the fission products released by the Fukushima accident, {sup 137}Cs is the most important long-term contributor to the environmental contamination. The RIP, a quantitative index of the {sup 137}Cs retention ability, was determined for the soil clays. The composition of clay minerals in the soil clays was estimated from peak areas obtained using X-ray diffraction (XRD) analyses. The predominant clay mineral was smectite in soils from Hama-dori and Aizu, while this was variable for those from Naka-dori. Native K content of the soil clays was found to be an indicator of the amount of micaceous minerals. The average RIP for the 97 soil clays was 7.8 mol kg{sup −1}, and ranged from 2.4 mol kg{sup −1} to 19.4 mol kg{sup −1}. The RIP was significantly and positively correlated with native K content for each of the geographical regions, Hama-dori (r = 0.76, p < 0.001), Naka-dori (r = 0.43, p < 0.05), and Aizu (r = 0.76, P < 0.001), while it was not related to the relative abundance of smectite. The linear relationship between RIP and native K content not only indicate a large contribution of micaceous minerals to the {sup 137}Cs retention ability of the soil clays, but also could be used to predict the {sup 137}Cs retention ability of soil clays for other paddy fields in Fukushima and other areas. - Highlights: • RIP was measured for 97 paddy soils from Fukushima to assess {sup 137}Cs retention ability. • The dominant clay mineral was smectite, but this did not control RIP. • RIP was positively correlated with native K content. • Micaceous minerals were found to control the {sup 137}Cs retention

  16. Internal Structure and Mineralogy of Differentiated Asteroids Assuming Chondritic Bulk Composition: The Case of Vesta

    Science.gov (United States)

    Toplis, M. J.; Mizzon, H.; Forni, O.; Monnereau, M.; Prettyman, T. H.; McSween, H. Y.; McCoy, T. J.; Mittlefehldt, D. W.; DeSanctis, M. C.; Raymond, C. A.; Russell, C. T.

    2012-01-01

    Bulk composition (including oxygen content) is a primary control on the internal structure and mineralogy of differentiated asteroids. For example, oxidation state will affect core size, as well as Mg# and pyroxene content of the silicate mantle. The Howardite-Eucrite-Diogenite class of meteorites (HED) provide an interesting test-case of this idea, in particular in light of results of the Dawn mission which provide information on the size, density and differentiation state of Vesta, the parent body of the HED's. In this work we explore plausible bulk compositions of Vesta and use mass-balance and geochemical modelling to predict possible internal structures and crust/mantle compositions and mineralogies. Models are constrained to be consistent with known HED samples, but the approach has the potential to extend predictions to thermodynamically plausible rock types that are not necessarily present in the HED collection. Nine chondritic bulk compositions are considered (CI, CV, CO, CM, H, L, LL, EH, EL). For each, relative proportions and densities of the core, mantle, and crust are quantified. Considering that the basaltic crust has the composition of the primitive eucrite Juvinas and assuming that this crust is in thermodynamic equilibrium with the residual mantle, it is possible to calculate how much iron is in metallic form (in the core) and how much in oxidized form (in the mantle and crust) for a given bulk composition. Of the nine bulk compositions tested, solutions corresponding to CI and LL groups predicted a negative metal fraction and were not considered further. Solutions for enstatite chondrites imply significant oxidation relative to the starting materials and these solutions too are considered unlikely. For the remaining bulk compositions, the relative proportion of crust to bulk silicate is typically in the range 15 to 20% corresponding to crustal thicknesses of 15 to 20 km for a porosity-free Vesta-sized body. The mantle is predicted to be largely

  17. Sedimentological, Mineralogical and Geochemical Characterization of Sand Dunes in Saudi Arabia

    Science.gov (United States)

    Benaafi, Mohammed; Abdullatif, Osman

    2014-05-01

    Sedimentological, mineralogical, morphological and geochemical studies of sand dunes from ten locations in Saudi Arabia were conducted in order to determine the differences between them and to find out the provenance and tectonic setting of these sand dunes. Sixty seven samples were collected from different sand dunes types ranging in morphology from linear, barchans, parabolic to stars dunes. In overall, the sand dunes are fine to coarse grained mean grain size, moderately sorted, near symmetrical skewness with mesokurtic distribution characterized sand dunes in most locations. The sand dunes grains are subrounded in all locations except in the Red sea, Qassim, central Arabia and the eastern province which showed sub-angular grains. The main mineral compositions of studied aeolian sand dunes are quartz, feldspar, calcite, and mica. Quartz is the dominant mineral in locations with significant amount of feldspars and mica in Najran, Red sea and Central Arabia locations. Moreover, calcite is present in Sakaka and NW Empty Quarter (Jafurah). Basement related sand dunes in Najran, Central Arabia and Red sea locations are sub-mature in terms of their mineralogical maturity. Whereas, sand dunes in other locations are texturally mature except those from the Red sea which showed sub-mature sand. The sands are classified as quartz arenite, except in the basement related sand dunes in Najran, central Arabia and the Red sea are ranging from sub-arkose, sub-litharenite and lithraenite. Morphologically, parallel to sub-parallel sand ridges with NE-SW orientation occurred in east and north parts of Empty Quarter (Najran and Jafurah) and NW-SE orientation in Dahna and Nafud deserts in central and north regions of Saudi Arabia. Parabolic sand dunes characterized the Nafud desert (Hail, Sakaka, Tayma locations). Barchans and star sand dunes characterize the Empty Quarter (Jafurah). Major, trace, and rare earth elements studies were carried out to determine the composition

  18. Stabilization of labile organic C along a chronosequence of soil development: mineralogical vs. biological controls

    Science.gov (United States)

    McFarland, J. W.; Waldrop, M. P.; Strawn, D.; Harden, J. W.

    2010-12-01

    Soil organic matter (SOM) represents an important reservoir for carbon (C), nitrogen (N), and other essential nutrients. Consequently, variation in SOM turnover rates regulates resource availability for soil microbial activity and plant growth. Long-term SOM stabilization generally involves restricted microbial access to SOM through a variety of processes including complexation with soil minerals. These organo-mineral interactions are influenced by mineral composition and texture, often related to soil age. Soil microorganisms also influence the stabilization of C inputs to the pedosphere through the production of refractory residues controlled in part by C allocation patterns during metabolism. In this study we examined, simultaneously, the contribution of these two C stabilizing mechanisms by ‘tracing’ the fate of two 13C-labeled substrates (glucose and p-hydroxybenzoic acid) along a 1600Kya chronosequence of soil development along the Cowlitz River in southwest Washington. Our objective was to evaluate the relationship between mineralogical and biological controls over C sequestration in soils. Mineralogical analyses were done using the selective dissolutions ammonium oxalate (AOD), and dithionite-citrate extraction (CBD). In this cool, humid environment, intermediate aged soils derived from the late Wisconsin Evans Creek drift (24ka) had the highest AOD extractable Al, Fe, and Si, indicating a higher concentration of poorly crystalline minerals relative to other terraces. Correspondingly, CBD extractable Fe increases with soil age, further supporting the idea that crystalline iron oxides are also more prevalent with weathering. Turnover of both 13C-labeled substrates was rapid (< 12.5 hrs) However, the proportion of substrate mineralized to CO2 varied among terraces. Mineralization to CO2 was significantly lower at 24ka than that for the other three age classes (0.25k, 220k, and 1,600k years bp), corresponding to higher recovery of 13C in bulk soil for this

  19. The influence of natural pozzolana mineralogical composition in the properties of blended cement

    Directory of Open Access Journals (Sweden)

    Gener Rizo, M.

    2002-09-01

    Full Text Available The pozzolana activity is the main property of the active additions but, in order to select them, we have to consider - between other factors- its mineralogical composition with a great influence, not only in the active component, but also in other cement properties. In the present work we have studied 4 different Cuban natural pozzolanes, characterized with the help of X ray diffraction and with thermic and chemical analysis. The pozzolanic activity was also evaluated through a chemical and physicomechanic method. Some cements were prepared with different contents of each one of the pozzolanics, and analysed their physicomechanic and chemical properties. Finally, we found that the pozzolanics mineralogical composition has a great influence in the pozzolanic activity and in the properties of mixed cements. Also we found that it 5 possible to obtain the best resistances in the time and the smaller needs of water when the vitreous phase prevail in the additions.

    La actividad puzolánica es la propiedad fundamental de las adiciones activas, pero para la selección de la misma se debe considerar, entre otros factores, su composición mineralógica, que influye no sólo en los constituyentes activos, sino también en muchas propiedades de los cementos. En el presente trabajo, como material puzolánico se estudiaron 4 puzolanas naturales cubanas, las cuales fueron caracterizadas mediante difracción de Rayos X, análisis térmico y análisis químico; se evaluó, además, la actividad puzolánica mediante un método químico y otro físico-mecánico. Se prepararon cementos con diferentes contenidos de cada una de las puzolanas y se analizaron sus propiedades químicas y físico-mecánicas. Se concluye que la composición mineralógica de las puzolanas influye de forma determinante en la actividad puzolánica y en las propiedades de los cementos mezclados; que los mejores desarrollos de resistencias en el tiempo y los menores requerimientos

  20. The Latitudinal Gradient of Rainfall, Mineralogy, Albedo and Magnetic Susceptibility in West Africa

    Science.gov (United States)

    Williams, E. R.; Balsam, W.; Schaaf, C.; Yang, X.; Zhang, Q.; Ji, J.; Rossman, G.; Garimella, S.; Oldfield, F.; Lyons, J. R.; Ellwood, B.; Hartman, H.; Hicks, E.; Mansot, J. L.; Cesaire, T.; Thomas, P.

    2008-12-01

    In order to investigate the effect of climate on soil and surface sediment properties we examined four transects around the Sahara Desert. The transects were located in Mali, Niger, Benin, Togo, Egypt and Morocco and, with the exception of Egypt, each crossed a significant climatological rainfall gradient. The Egyptian transect was designed to characterize one of the driest portions of the Sahara Desert. Our study included laboratory measurements of mineralogy (XRD), elemental composition (XRF), grain size, optical reflectance (lab), magnetic susceptibility (MS)and remanences. In addition, albedo was determined from the MODIS satellite imagery from space. Many of our laboratory measurements exhibited variations with the rainfall gradient. Iron oxides (hematite and goethite), kaolinite, Al2O3, and TiO2 increased with increasing rainfall whereas SiO2, illite, and grain size decreased with increasing rainfall. Both laboratory-determined reflectivity and satellite-determine albedo decreased as rainfall increased. In part, this decrease in reflectivity/albedo with increasing rainfall appears to be the result of hematite, the dominant coloring agent for the soil in this region and the origin of the 'red' Sahel. The physical interpretation of these results centers on rainfall as a long-term leaching agent of surface material, and the control of physical properties by specific mineralogy. SiO2 is highly reflective and iron oxides are strongly absorptive in the visible range. The solubility of SiO2 in rainwater is orders of magnitude larger than all the iron oxides, with hematite the least soluble. It has long been recognized that leaching by rainfall produces dark red laterite in the near-surface oxidizing environment, a prominent geological feature throughout the high rainfall belt of West Africa. Laterite beds represent simultaneous enrichments of all iron oxides and a reduction in SiO2 by leaching. In the Sahara desert where rainfall is minimal (<10 mm/yr), SiO2 is

  1. Stratigraphy, mineralogy, and origin of layered deposits inside Terby crater, Mars

    Science.gov (United States)

    Ansan, V.; Loizeau, D.; Mangold, N.; Le Mouélic, S.; Carter, J.; Poulet, F.; Dromart, G.; Lucas, A.; Bibring, J.-P.; Gendrin, A.; Gondet, B.; Langevin, Y.; Masson, Ph.; Murchie, S.; Mustard, J. F.; Neukum, G.

    2011-01-01

    The 174 km diameter Terby impact crater (28.0°S-74.1°E) located on the northern rim of the Hellas basin displays anomalous inner morphology, including a flat floor and light-toned layered deposits. An analysis of these deposits was performed using multiple datasets from Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter missions, with visible images for interpretation, near-infrared data for mineralogical mapping, and topography for geometry. The geometry of layered deposits was consistent with that of sediments that settled mainly in a sub-aqueous environment, during the Noachian period as determined by crater counts. To the north, the thickest sediments displayed sequences for fan deltas, as identified by 100 m to 1 km long clinoforms, as defined by horizontal beds passing to foreset beds dipping by 6-10° toward the center of the Terby crater. The identification of distinct sub-aqueous fan sequences, separated by unconformities and local wedges, showed the accumulation of sediments from prograding/onlapping depositional sequences, due to lake level and sediment supply variations. The mineralogy of several layers with hydrated minerals, including Fe/Mg phyllosilicates, supports this type of sedimentary environment. The volume of fan sediments was estimated as >5000 km 3 (a large amount considering classical martian fan deltas such as Eberswalde (6 km 3)) and requires sustained liquid water activity. Such a large sedimentary deposition in Terby crater is characteristic of the Noachian/Phyllosian period during which the environment favored the formation of phyllosilicates. The latter were detected by spectral data in the layered deposits of Terby crater in three distinct layer sequences. During the Hesperian period, the sediments experienced strong erosion, possibly enhanced by more acidic conditions, forming the current morphology with three mesas and closed depressions. Small fluvial valleys and alluvial fans formed subsequently

  2. Detection Capability Evaluation on Chang'e-5 Lunar Mineralogical Spectrometer (LMS)

    Science.gov (United States)

    Liu, Bin; Ren, Xin; Yan, Wei; Xu, Xuesen; Cai, Tingni; Liu, Dawei; Liu, Jianjun; Li, Chunlai

    2016-04-01

    The Chang'e-5 (CE-5) lunar sample return mission is scheduled to launch in 2017 to bring back lunar regolith and drill samples. The Chang'e-5 Lunar Mineralogical Spectrometer (LMS), as one of the three sets of scientific payload installed on the lander, is used to collect in-situ spectrum and analyze the mineralogical composition of the sampling site. It can also help to select the sampling site , and to compare the measured laboratory spectrum of returned sample with in-situ data. LMS employs acousto-optic tunable filters (AOTFs) and is composed of a VIS/NIR module (0.48μm-1.45μm) and an IR module (1.4μm -3.2μm). It has spectral resolution ranging from 3 to 25 nm, with a field of view (FOV) of 4.24°×4.24°. Unlike Chang'e-3 VIS/NIR Imaging Spectrometer (VNIS), the spectral coverage of LMS is extended from 2.4μm to 3.2μm, which has capability to identify H2O/OH absorption features around 2.7μm. An aluminum plate and an Infragold plate are fixed in the dust cover, being used as calibration targets in the VIS/NIR and IR spectral range respectively when the dust cover is open. Before launch, a ground verification test of LMS needs to be conducted in order to: 1) test and verify the detection capability of LMS through evaluation on the quality of image and spectral data collected for the simulated lunar samples; and 2) evaluate the accuracy of data processing methods by the simulation of instrument working on the moon. The ground verification test will be conducted both in the lab and field. The spectra of simulated lunar regolith/mineral samples will be collected simultaneously by the LMS and two calibrated spectrometers: a FTIR spectrometer (Model 102F) and an ASD FieldSpec 4 Hi-Res spectrometer. In this study, the results of the LMS ground verification test will be reported including the evaluation on the LMS spectral and image data quality, mineral identification and inversion ability, accuracy of calibration and geometric positioning .

  3. Nuclear research reactors in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Cota, Anna Paula Leite; Mesquita, Amir Zacarias, E-mail: aplc@cdtn.b, E-mail: amir@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The rising concerns about global warming and energy security have spurred a revival of interest in nuclear energy, giving birth to a 'nuclear power renaissance' in several countries in the world. Particularly in Brazil, in the recent years, the nuclear power renaissance can be seen in the actions that comprise its nuclear program, summarily the increase of the investments in nuclear research institutes and the government target to design and build the Brazilian Multipurpose research Reactor (BMR). In the last 50 years, Brazilian research reactors have been used for training, for producing radioisotopes to meet demands in industry and nuclear medicine, for miscellaneous irradiation services and for academic research. Moreover, the research reactors are used as laboratories to develop technologies in power reactors, which are evaluated today at around 450 worldwide. In this application, those reactors become more viable in relation to power reactors by the lowest cost, by the operation at low temperatures and, furthermore, by lower demand for nuclear fuel. In Brazil, four research reactors were installed: the IEA-R1 and the MB-01 reactors, both at the Instituto de Pesquisas Energeticas Nucleares (IPEN, Sao Paulo); the Argonauta, at the Instituto de Engenharia Nuclear (IEN, Rio de Janeiro) and the IPR-R1 TRIGA reactor, at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN, Belo Horizonte). The present paper intends to enumerate the characteristics of these reactors, their utilization and current academic research. Therefore, through this paper, we intend to collaborate on the BMR project. (author)

  4. [Women and development in Brazil].

    Science.gov (United States)

    Cunha Neves, A

    1980-01-01

    This paper discusses the social, political and cultural status of women in Brazil. In 1976 only 29.6% of Brazilian women participated in economic activities; 54.3% of these were still employed as laborers in the countryside, while only 6% were employed in urban and industrial jobs. The greatest concentration of female labor is in the category of the very badly paid domestic employment. Man is traditionally the head of the family, even when he is not the breadwinner. Illiteracy has decreased in Brazil to 24.3%, but female analphabetism is 26.5% versus 21.9% male analphabetism. Schools are open to males and females at all levels, but the traditional and cultural structure of Brazilian society considers the home, not the school, as the only proper place for young girls, and maternity is still the primary social function of women. Politically Brazilian women have very little power, even if they make up 44% of the electoral body. Sex education does not exist in the school or in the home, and any sexuality exercised outside the bonds of marriage is considered as deviant.

  5. Homosexuality and adoption in Brazil.

    Science.gov (United States)

    Uziel, A P

    2001-11-01

    Western societies are undergoing legal and policy changes in relation to laws governing the family, marital status, sexual orientation and the welfare of children, including in Brazil where, in the 1990s, the rights of homosexuals were incorporated into ongoing debates about what constitutes a family. This paper discusses the issue of adoption of children by homosexual men in Brazil, using information from court records from 1995-2000 in Rio de Janeiro, and from interviews with two judges, five psychologists and four social workers who evaluate those wishing to adopt. It uses the case records of one man's application to adopt, in which homosexuality became a central issue. Both the construction of masculinity in relation to parenting and concepts of the family were the parameters upon which the decision to allow him to adopt or not depended. Because the legislation does not specify what the sexual orientation of would-be adoptive parents should be, it is possible for single persons to adopt if they show they can be good parents. As more single people, alone or in couples, seek to adopt, it is important to clarify the criteria for judicial decisions on adoption applications. A dialogue is therefore needed on the meaning of family and whether and how it relates to sexual orientation. It is only on this basis that the courts can take a clear decision as to whether being homosexual is a relevant issue in regard to applications to adopt or not.

  6. Lymnaea columella in northern Brazil

    Directory of Open Access Journals (Sweden)

    W. Lobato Paraense

    1983-12-01

    Full Text Available The occurrence of a mollusc of the family Lymnaeidae is recorded for the first time in Brazil north of parallel 15ºS, as a result of the finding of Lymnaea columella in Manus and Benjamin Constant, state of Amazonas. A description is given of its shell, renal organ, genital system and radula, pointing to the morphological characteristics of diagnostic value to separate it from two other species previously studied by the author, Lymnaea viatrix and L. rupestris, which also occur in Brazil.Pela primeira vez é verificada a ocorrência de um molusco da família Lymnaeidae ao norte do paralelo 15ºS no Brasil, como resultado do encontro da lYmnaea columella em Manus e Benjamin Constant, Estado do Amazonas. É apresentada uma descrição da concha, do órgão renal, do sistema genital e da rádula, sendo indicados os caracteres morfológicos que permitem distinguir a Lymnaea columella de outras espécies que também ocorrem no Brasil, previamente estudadas pelo autor, L. viatrix e L. rupestris.

  7. Determination of sediment provenance by unmixing the mineralogy of source-area sediments: The "SedUnMix" program

    Science.gov (United States)

    Andrews, John T.; Eberl, D.D.

    2012-01-01

    Along the margins of areas such as Greenland and Baffin Bay, sediment composition reflects a complex mixture of sources associated with the transport of sediment in sea ice, icebergs, melt-water and turbidite plumes. Similar situations arise in many contexts associated with sediment transport and with the mixing of sediments from different source areas. The question is: can contributions from discrete sediment (bedrock) sources be distinguished in a mixed sediment by using mineralogy, and, if so, how accurately? To solve this problem, four end-member source sediments were mixed in various proportions to form eleven artificial mixtures. Two of the end-member sediments are felsic, and the other two have more mafic compositions. End member and mixed sediment mineralogies were measured for the Elsevier B.V..

  8. Density, porosity, mineralogy, and internal structure of cosmic dust and alteration of its properties during high velocity atmospheric entry

    CERN Document Server

    Kohout, T; Suuronen, J -P; Rochette, P; Hutzler, A; Gattacceca, J; Skála, D D Badjukov R; Böhmová, V; Čuda, J

    2014-01-01

    X-ray microtomography (XMT), X-ray diffraction (XRD) and magnetic hysteresis measurements were used to determine micrometeorite internal structure, mineralogy, crystallography, and physical properties at ~{\\mu}m resolution. The study samples include unmelted, partially melted (scoriaceous) and completely melted (cosmic spherules) micrometeorites. This variety not only allows comparison of the mineralogy and porosity of these three micrometeorite types, but also reveals changes in meteoroid properties during atmospheric entry at various velocities. At low entry velocities, meteoroids do not melt, and their physical properties do not change. The porosity of unmelted micrometeorites varies considerably (0-12%) with one friable example having porosity around 50%. At higher velocities, the range of meteoroid porosity narrows, but average porosity increases (to 16-27%) due to volatile evaporation and partial melting (scoriaceous phase). Metal distribution seems to be mostly unaffected at this stage. At even higher ...

  9. Comparative Mineralogy, Microstructure and Compositional Trends in the Sub-Micron Size Fractions of Mare and Highland Lunar Soils

    Science.gov (United States)

    Thompson, M. S.; Christoffersen, R.; Noble, S. K.; Keller, L. P.

    2012-01-01

    The morphology, mineralogy, chemical composition and optical properties of lunar soils show distinct correlations as a function of grain size and origin [1,2,3]. In the fraction, there is an increased correlation between lunar surface properties observed through remote sensing techniques and those attributed to space weathering phenomenae [1,2]. Despite the establishment of recognizable trends in lunar grains fraction fraction for both highland and mare derived soils. The properties of these materials provide the focus for many aspects of lunar research including the nature of space weathering on surface properties, electrostatic grain transport [4,5] and dusty plasmas [5]. In this study, we have used analytical transmission and scanning transmission electron microscopy (S/TEM) to characterize the mineralogy type, microstructure and major element compositions of grains in this important size range in lunar soils.

  10. The effect of mineralogy, texture and mechanical properties of anti-skid and asphalt aggregates on urban dust

    OpenAIRE

    RÀisÀnen, M.; Kupiainen, K.; Tervahattu, H.

    2003-01-01

    In northern latitudes mineral dust is formed when cars use studded tyres and roads are sanded to obtain more traction on the icy surfaces. Anti-skid and asphalt aggregates with different textural, mineralogical and mechanical properties were tested with an indoor road simulator fitted with studded and friction tyres. The particle size distribution and proportions of dust from pavement and anti-skid aggregate were analyzed using SEM-EDX. The wear on the road pavement...

  11. Sorption and distribution of Zn in a sludge-amended soil: influence of the soil clay mineralogy

    OpenAIRE

    Proust, D.

    2015-01-01

    International audience; Purpose Conventional pedological survey generally assesses soil metal pollution by comparing total metal concentrations in soil to geochemical baselines in parent rock. This global approach overlooks the sorption capacities of the clay minerals which form at micrometric scale in weathering microsystems and are essential for the behaviour of metals in soil. Therefore, our aim was to investigate the impact of these weathering microsystems and their clay mineralogy upon Z...

  12. Advances in characterization of the soil clay mineralogy using X-ray diffraction: from decomposition to profile fitting

    OpenAIRE

    2009-01-01

    International audience; Structural characterization of soil clay minerals often remains limited despite their key influence on soil properties. In soils, complex clay parageneses result from the coexistence of clay species with contrasting particle sizes and crystal-chemistry and from the profusion of mixed layers with variable compositions. The present study aimed at characterizing the mineralogy and crystal chemistry of the < 2 μm fraction along a profile typical of soils from Western Europ...

  13. Ferricretes of the Early Tertiary Dammam Formation in the Dukhan Area, Western Qatar: mineralogy, geochemistry, and environment of deposition

    OpenAIRE

    Nasir, Sobhi J. [صبحي جابر نصر; Al-Saad, Hamad; Al-Sayigh, Abdul Razak; Al-Harthy, Abdul Rahman; Almishwat, Ali; Dill, Harald

    2003-01-01

    Ferricretes of the Middle Eocene Dammam Formation, Western Qatar, were investigated using petrographic and ore microscopy, IR TGA, XRD, and geochemical analyses. The ferricretes mainly consist of goethite, which is very varigated in habit and texture. Geochemical analyses show that the ferricretes consist of impure chemical sediments, iron hydroxides plus variable amounts of carbonate and siliciclastic materials. The ferricretes resemble with respect to texture, mineralogy and chemistry mo...

  14. Mineralogy of metamorphosed carbonatite of the Vesely occurrence, Northern Transbaikal region, Russia

    Science.gov (United States)

    Lastochkin, E. I.; Ripp, G. S.; Doroshkevich, A. G.

    2011-06-01

    Metamorphism of carbonatite is exemplified in the Vesely occurrence. According to available data, the age of the carbonatite is 596 ± 3.5Ma, whereas metamorphism is dated at 550 ± 14 Ma. The rocks at the Vesely occurrence were metamorphosed under conditions of greenschist facies (epidote-muscovite-chlorite subfacies) under elevated pressure. Microthermometry of fluid inclusions in minerals indicates that the temperature of metamorphism is 377-450°C and the pressure estimated from phengite geobarometer is 6-8 kbar. The low-grade metamorphism led to the partial recrystallization of carbonates and apatite with removal of trace elements. This process resulted in a change of the oxygen isotopic composition of the studied minerals. Metamorphism was accompanied by formation of talc, phengite, chlorite, quartz, tremolite-actinolite, and anthophyllite, which are not typical of carbonatite. The data obtained show that the metamorphism exerted an effect on the mineralogical, isotopic, geochemical, and technological properties of the carbonatite. The effect of metamorphism should be taken into account in determination of the nature of ore mineralization and estimation of ore quality and perspective of the occurrence.

  15. Thermal conductivity of sedimentary rocks - selected methodological, mineralogical and textural studies

    Energy Technology Data Exchange (ETDEWEB)

    Midttoemme, Kirsti

    1997-12-31

    The thermal conductivity of sedimentary rocks is an important parameter in basin modelling as the main parameter controlling the temperature within a sedimentary basin. This thesis presents measured thermal conductivities, mainly on clay- and mudstone. The measured values are compared with values obtained by using thermal conductivity models. Some new thermal conductivity models are developed based on the measured values. The values obtained are less than most previously published values. In a study of unconsolidated sediments a constant deviation was found between thermal conductivities measured with a needle probe and a divided bas apparatus. Accepted thermal conductivity models based on the geometric mean model fail to predict the thermal conductivity of clay- and mudstone. Despite this, models based on the geometric mean model, where the effect of porosity is taken account of by the geometric mean equation, seem to be the best. Existing models underestimate the textural influence on the thermal conductivity of clay- and mudstone. The grain size was found to influence the thermal conductivity of artificial quartz samples. The clay mineral content seems to be a point of uncertainty in both measuring and modelling thermal conductivity. A good universal thermal conductivity model must include many mineralogical and textural factors. Since this is difficult, different models restricted to specific sediment types and textures are suggested to be the best solution to obtain realistic estimates applicable in basin modelling. 243 refs., 64 figs., 31 tabs.

  16. Magnetic and mineralogical properties of salt rocks from the Zechstein of the Northern German Basin

    Science.gov (United States)

    Heinrich, Frances C.; Schmidt, Volkmar; Schramm, Michael; Mertineit, Michael

    2017-01-01

    Magnetic properties of rocks are often studied to characterize composition and fabric of rocks. For salt rocks, the basic relationships between their magnetic properties and composition, which are necessary to interpret rock magnetic data, are not yet established. Therefore, we studied different types of natural salt rock and pure salt minerals. We measured their magnetic properties (magnetic susceptibility, IRM acquisition curves, FORC diagrams, temperature-dependent magnetic susceptibility) and used analytical methods such as microscopy, XRD and ICP-OES to understand the relationship between magnetic properties and mineralogy. Salt rocks mainly consist of the diamagnetic minerals halite, carnallite, sylvine and anhydrite with negative magnetic susceptibilities. The magnetic susceptibilities of pure synthetic NaCl and KCl single crystals, show values of -14.5 × 10-6 SI and -13.5 × 10-6 SI, respectively. In contrast, in natural salt rocks higher magnetic susceptibility values were measured. The magnetic susceptibility of the samples investigated in this study shows a general increase from light rock salt (max. -10 × 10-6 SI) over carnallitite (max. 134 × 10-6 SI) to red sylvinite (max. 270 × 10-6 SI). Whole rock analyses suggests that increased magnetic susceptibility can be attributed to paramagnetic and ferromagnetic minerals that are contained within the insoluble residue. The magnetic susceptibility is mainly controlled by magnetite and phyllosilicates. Its measurement can therefore be used to detect subtle changes in the content of these minerals.

  17. EH3 matrix mineralogy with major and trace element composition compared to chondrules

    Science.gov (United States)

    Lehner, S. W.; McDonough, W. F.; NéMeth, P.

    2014-12-01

    We investigated the matrix mineralogy in primitive EH3 chondrites Sahara 97072, ALH 84170, and LAR 06252 with transmission electron microscopy; measured the trace and major element compositions of Sahara 97072 matrix and ferromagnesian chondrules with laser-ablation, inductively coupled, plasma mass spectrometry (LA-ICPMS); and analyzed the bulk composition of Sahara 97072 with LA-ICPMS, solution ICPMS, and inductively coupled plasma atomic emission spectroscopy. The fine-grained matrix of EH3 chondrites is unlike that in other chondrite groups, consisting primarily of enstatite, cristobalite, troilite, and kamacite with a notable absence of olivine. Matrix and pyroxene-rich chondrule compositions differ from one another and are distinct from the bulk meteorite. Refractory lithophile elements are enriched by a factor of 1.5-3 in chondrules relative to matrix, whereas the matrix is enriched in moderately volatile elements. The compositional relation between the chondrules and matrix is reminiscent of the difference between EH3 pyroxene-rich chondrules and EH3 Si-rich, highly sulfidized chondrules. Similar refractory element ratios between the matrix and the pyroxene-rich chondrules suggest the fine-grained material primarily consists of the shattered, sulfidized remains of the formerly pyroxene-rich chondrules with the minor addition of metal clasts. The matrix, chondrule, and metal-sulfide nodule compositions are probably complementary, suggesting all the components of the EH3 chondrites came from the same nebular reservoir.

  18. Mineralogy, size, morphology and porosity of aggregates and their relationship with soil susceptibility to water erosion

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, M. do A, E-mail: mucfig@hotmail.com; Augustin, C.H.R.R. [Instituto de Geociencias, Universidade Federal de Minas Gerais, Departamento de Geografia (Brazil)], E-mail: mucfig@hotmail.com; Fabris, J.D. [Universidade Federal de Minas Gerais, Departamento de Quimica, Instituto de Ciencias Exatas (Brazil)], E-mail: fabris@dedalus.lcc.ufmg.br

    1999-11-15

    Soil erosion has been considered as the main process related to losses of soil mass and decrease of productivity in cultivated lands as well as on e of the most important processes in landscape evolution. Attention has been paid to many pedological variables affecting intensity of erosion, but little to the influence of iron compounds on the type, size, shape and porosity of soil aggregates. In the present study, three lithopedodomains which were assumed to be closely related to the dominant lithology of the soil parent material, varying in the degree of water erosion intensity, were selected for further analysis which focused mainly on the influence of iron oxide mineralogy on the soil aggregation. Powder X-ray diffractometry, 80 K Moessbauer data and SEM images are used to correlate all these variables with observed erosion activity in the field. The present data indicate that the more the soil is rich in iron (hematite and/or goethite) or aluminium (gibbsite) (hydr)oxide, the smaller are its aggregates and is porous. Soils derived from metabasic rocks are much more susceptible to collapse under wetting than those from other lithologies. They have the highest iron and clay content. Schist-derived soil is richer in muscovite, has bigger aggregates and porous and are less prone to collapse, while the granite-derived soil presents relatively intermediate resistance, when humid.

  19. Geochemistry and mineralogy of vanadium in mine tailings at Berg Aukas, northeastern Namibia

    Science.gov (United States)

    Sracek, O.; Mihaljevič, M.; Kříbek, B.; Majer, V.; Filip, J.; Vaněk, A.; Penížek, V.; Ettler, V.; Mapani, B.

    2014-08-01

    Vanadium-rich mine tailings at Berg Aukas, site with a world-known vanadium mineralization in northeastern Namibia, were investigated using a combination of solid phase and mineralogical analyses, leaching tests and speciation modeling. Principal objective of the study was to determine, if vanadium can be released into the environment. In spite of >30 y of weathering and oxidation of tailings material to a maximum sampling depth of 2.4 m, a large portion of V still remains in the primary mineral descloizite, (Pb, Zn)2(OH)VO4. A part of V was mobilized and adsorbed/co-precipitated with ferric oxyhydroxides. Based on sequential extraction and 57Fe Mössbauer spectroscopy, a large amount of ferric iron is present in insoluble hematite and goethite, where V is effectively bound. Other potential contaminants are Zn, present mostly in the primary mineral willemite, Zn2SiO4, descloizite and also in secondary smithsonite, ZnCO3; and Pb, which was transferred from completely dissolved galena to cerussite, PbCO3 and is also partly present in primary descloizite. Conditions in the mine tailings are alkaline (pH generally >8.2) and oxidizing during dry period, but mobility of V is low due to low solubility of descloizite and secondary crystalline ferric phases such as hematite. In contrast, Zn and especially Pb in secondary carbonates, probably represent more serious environmental and health risks.

  20. Mineralogical Zonation of Wall-Rock Alteration in Jiaodong Gold Province, North China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Mineralogical zonation of wall-rock alterations in Mesozoic granitoids is summarized from 18 gold deposits in Jiaodong gold province on the Asian mobile continental margin of the west circum-Pacific rim. This paper deals with wall-rock alterations developed around gold mineralizations of the quartz-vein type in granitoids and the wall-rock alteration type in granitoid-basement contacts alongMesozoic fault zones trending mostly NNE-SSW and NE-SW. Five alteration zones are distinguished from host rock to ore zone, namely the chloritization and sericitization zone, the hematitization-rutilization and microclinization zone, the quartz-sericitization zone, the pyrite-quartz-sericitization zone and the pyrite-silicification zone. The former two are outer zones marked by incomplete alteration of first mafic and then felsic minerals of the granitoids, while the later three are inner zones marked by complete alteration of both mafic and felsic minerals of the granitoids leading to retrogressive sericitization and progressive silicification with participation of ore elements. The whole process proceeds under dynamometamorphism with high fugacity of volatiles. Wall-rock alteration is the intermediate link between unaltered host rock and ore mineralization both in time and space. Development of the alteration zonation and its mineral composition controls genetic type of mineralization, size and grade of the deposit and location of the ore zones.

  1. Mineralogy and Microbial Diversity of the Microbialites in the Hypersaline Storr's Lake, the Bahamas

    Science.gov (United States)

    Paul, Varun G.; Wronkiewicz, David J.; Mormile, Melanie R.; Foster, Jamie S.

    2016-04-01

    Microbialites found in the low-light-intensity, hypersaline waters of Storr's Lake (SL), San Salvador Island, the Bahamas, were investigated with respect to their morphology, mineralogy, and microbial diversity. Previously described microbialite morphologies, as well as a newly identified "multi-cuspate" morphology, were observed at various depths. Electron microscopy analysis revealed the presence of angular, blocky, and needle-shaped crystals with mineralized cyanobacterial filaments and remains of exopolymeric substances. X-ray diffraction studies confirmed the presence of both Mg-calcite and aragonite in the plateau-mushroom and pinnacle mound microbialites, whereas only Mg-calcite was identified in the other microbialite morphotypes. A comprehensive molecular analysis using barcoded pyrosequencing of five different microbial mat communities identified at least 12 dominant bacterial phyla. Cyanobacteria were generally low in abundance and ranged from ˜0.01% in the deeper pinnacle mounds to ˜3.2% in the shallow calcareous knobs. Other photosynthetic members included green nonsulfur bacteria of the phylum Chloroflexi and purple sulfur bacteria of the class Gammaproteobacteria. All mat types contained significant amounts of sulfate-reducing and dehalogenating bacteria. The low light intensity reaching the deeper microbialites, the lack of dominant cyanobacteria, and the abundance of sulfate reducers and Chloroflexi collectively suggest that sulfate reduction and anoxygenic photosynthetic processes influence the carbonate biomineralization process in these systems.

  2. Mineralogical residence of alpha-emitting contamination and implications for mobilization from uranium mill tailings

    Science.gov (United States)

    Morrison, Stan J.; Cahn, Lorie S.

    1991-09-01

    The rate and magnitude of contaminant release from mill tailings to groundwater are known to depend on the form and mineralogy of the host grains. Using samples from three uranium mill sites in the western United States, we identified four types of α-emitting host grains — those containing bariumstrontium sulfates, authigenic siliceous material, uranium minerals, and irontitaniumvanadium oxides. These four grain types constitute scheme for the tailings. Each milling process (acid or alkaline) produces distinct types of grains. In acid-milled tailings, such as those at Slick Rock, Colorado, the dominant source of α emissions is from bariumstrontium sulfate. The barium-to-strontium ratio covers the entire solid-solution range between barite and celestine. In alkaline-milled tailings, α emissions come predominantly from siliceous composite grains, which are interpreted as grains from the mill feed that have been altered during milling. In the siliceous composite grains, radionuclides are encased by siliceous material resembling chalcedony. Other α-emitting grains appear to be unrelated to milling; some uranium minerals and irontitaniumvanadium oxides appear to have passed through the milling process relatively unaltered. The classification scheme identified in this study reflects the geochemical reactivity of the tailings with groundwater. Our findings can be used to improve confidence levels when predicting; (1) source loading to a groundwater system; (2) health effects from inhaled radioactive dust; and (3) long-term performance of uranium tailings containment cells.

  3. Maximum availability and mineralogical control of chromium released from AOD slag.

    Science.gov (United States)

    Li, Junguo; Liu, Bao; Zeng, Yanan; Wang, Ziming; Gao, Zhiyuan

    2017-03-01

    AOD (argon oxygen decarburization) slag is the by-product in the stainless steel refining process. Chromium existing in AOD slag can leach out and probably poses a serious threat to the environment. To assess the leaching toxicity of chromium released from AOD slag, the temperature-dependent maximum availability leaching test was performed. To determine the controlling mineralogical phases of chromium released from AOD slag, a Visual MINTEQ simulation was established based on Vminteq30 and the FactSage 7.0 database. The leaching tests indicated that the leaching availability of chromium was slight and mainly consisted of trivalent chromium. Aging of AOD slag under the atmosphere can oxidize trivalent chromium to hexavalent chromium, which could be leached out by rainwater. According to the simulation, the chromium concentration in leachates was controlled by the freely soluble pseudo-binary phases in the pH = 7.0 leaching process and controlled by the Cr2O3 phase in the pH = 4.0 leaching process. Chromium concentrations were underestimated when the controlling phases were determined to be FeCr2O4 and MgCr2O4. Facilitating the generation of the insoluble spinel-like phases during the cooling and disposal process of the molten slag could be an effective approach to decreasing the leaching concentration of chromium and its environmental risk.

  4. Newer views of the Moon: Comparing spectra from Clementine and the Moon Mineralogy Mapper

    Science.gov (United States)

    Kramer, G.Y.; Besse, S.; Nettles, J.; Combe, J.-P.; Clark, R.N.; Pieters, C.M.; Staid, M.; Malaret, E.; Boardman, J.; Green, R.O.; Head, J.W.; McCord, T.B.

    2011-01-01

    The Moon Mineralogy Mapper (M3) provided the first global hyperspectral data of the lunar surface in 85 bands from 460 to 2980 nm. The Clementine mission provided the first global multispectral maps the lunar surface in 11 spectral bands across the ultraviolet-visible (UV-VIS) and near-infrared (NIR). In an effort to understand how M3 improves our ability to analyze and interpret lunar data, we compare M3 spectra with those from Clementine's UV-VIS and NIR cameras. The Clementine mission provided the first global multispectral maps the lunar surface in 11 spectral bands across the UV-VIS and NIR. We have found that M3 reflectance values are lower across all wavelengths compared with albedos from both of Clementine's UV-VIS and NIR cameras. M3 spectra show the Moon to be redder, that is, have a steeper continuum slope, than indicated by Clementine. The 1 m absorption band depths may be comparable between the instruments, but Clementine data consistently exhibit shallower 2 m band depths than M 3. Absorption band minimums are difficult to compare due to the significantly different spectral resolutions. Copyright 2011 by the American Geophysical Union.

  5. Compositional diversity and geologic insights of the Aristarchus crater from Moon Mineralogy Mapper data

    Science.gov (United States)

    Mustard, J.F.; Pieters, C.M.; Isaacson, P.J.; Head, J.W.; Besse, S.; Clark, R.N.; Klima, R.L.; Petro, N.E.; Staid, M.I.; Sunshine, J.M.; Runyon, C.J.; Tompkins, S.

    2011-01-01

    The Moon Mineralogy Mapper (M3) acquired high spatial and spectral resolution data of the Aristarchus Plateau with 140 m/pixel in 85 spectral bands from 0.43 to 3.0 m. The data were collected as radiance and converted to reflectance using the observational constraints and a solar spectrum scaled to the Moon-Sun distance. Summary spectral parameters for the area of mafic silicate 1 and 2 m bands were calculated from the M3 data and used to map the distribution of key units that were then analyzed in detail with the spectral data. This analysis focuses on five key compositional units in the region. (1) The central peaks are shown to be strongly enriched in feldspar and are likely from the upper plagioclase-rich crust of the Moon. (2) The impact melt is compositionally diverse with clear signatures of feldspathic crust, olivine, and glass. (3) The crater walls and ejecta show a high degree of spatial heterogeneity and evidence for massive breccia blocks. (4) Olivine, strongly concentrated on the rim, wall, and exterior of the southeastern quadrant of the crater, is commonly associated the impact melt. (5) There are at least two types of glass deposits observed: pyroclastic glass and impact glass. Copyright 2011 by the American Geophysical Union.

  6. Geochemical and mineralogical studies of a South Texas roll-front uranium deposit

    Science.gov (United States)

    Goldhaber, Martin B.; Reynolds, Richard L.

    1977-01-01

    Core samples from a roll-front uranium deposit in south Texas have been analyzed for iron sulfide content and mineralogy, organic carbon content and the abundance of carbonate, iron, manganese and titanium. Sulfide occurs almost exclusively as the iron disulfides pyrite and marcasite, in concentrations as high as 2 percent of the coarse (>62 ?m) fraction. Marcasite is particularly abundant relative to pyrite in the vicinity of the roll front. Because marcasite precipitation requires acidic pH's and the most likely mechanism for generating a low pH is oxidation of preore sulfide, it is argued that marcasite formation is, at least in part, related to roll-front development. Organic carbon analyses from various representative parts of the deposit are uniformly low (bacteria were not involved in either initial sulfidation of the host rock or during later sulfidization that was related to the ore-forming episode. carbonate minerals, such as calcite, are quite abundant, but appear to have formed after the ore. The overall abundance of iron apparently is not systematically related to position with respect to the roll front, whereas manganese probably is concentrated near the redox interface. Titanium like iron does not show a systematic relationship to position about the roll. However, titanium is systematically more abundant in the fine fraction (462 ?m) relative to the coarse fraction with distance downdip. This reflects a progressively more intense alteration of precursor iron titanium oxide minerals to fine-grained TiO2.

  7. Clay mineralogy of the Greenvale Ore Body, Queensland, Australia: Implications for the interpretation of paleoclimate

    Energy Technology Data Exchange (ETDEWEB)

    Lev, S.; Anderson, K.; Ramirez, B.; Sun, H.; Swank, R.; Yost, D.; Huff, W.; Maynard, J.B. (Univ. of Cincinnati, OH (United States). Dept. of Geology)

    1994-03-01

    A 3--5% nickel enriched laterite in the Greenvale Ore Body of Queensland, Australia, is the result of weathering a serpentinized ultramafic intrusion. Variations in solubilities and drainage, typical of laterite deposits, resulted in the formation of three primary zones: (1) the Saprolite zone, (2) the Intermediate zone, and (3) the Limonite zone. Within these zones, clay mineral species with distinct chemistries and/or mineralogies have been identified, including: Ni-rich Smectite, Halloysite, and Palygorskite. Clay minerals were analyzed using powder X-ray diffraction and SEM. Bulk chemistry was determined by X-ray fluorescence in an attempt to better constrain the chemical conditions at the time of formation of the clay minerals. Results indicate a complex drainage system and history for the Greenvale Ore Body. Based on the distribution of ore grade material, it is apparent that the deposit was initially characterized by fracture controlled drainage. Owing to precipitation of Ni-rich smectite, halloysite, and palygorskite, subsequent alteration of the ore body drainage network and/or local climate can be inferred.

  8. Geology and Mineralogy of Uranium Deposits from Mount Isa, Australia: Implications for Albitite Uranium Deposit Models

    Directory of Open Access Journals (Sweden)

    Nick Wilson

    2013-06-01

    Full Text Available New geological, bulk chemical and mineralogical (QEMSCAN and FEG-EPMA data are presented for albitite-type uranium deposits of the Mount Isa region of Queensland, Australia. Early albitisation of interbedded metabasalt and metasiltstone predated intense deformation along D2 high strain (mylonite zones. The early sodic alteration paragenetic stage includes albite, riebeckite, aegirine, apatite, zircon and magnetite. This paragenetic stage was overprinted by potassic microveins, containing K-feldspar, biotite, coffinite, brannerite, rare uraninite, ilmenite and rutile. An unusual U-Zr phase has also been identified which exhibits continuous solid solution with a uranium silicate possibly coffinite or nenadkevite. Calcite, epidote and sulphide veinlets represent the latest stage of mineralisation. This transition from ductile deformation and sodic alteration to vein-controlled uranium is mirrored in other examples of the deposit type. The association of uranium with F-rich minerals and a suite of high field strength elements; phosphorous and zirconium is interpreted to be indicative of a magmatic rather than metamorphic or basinal fluid source. No large intrusions of appropriate age outcrop near the deposits; but we suggest a relationship with B- and Be-rich pegmatites and quartz-tourmaline veins.

  9. Geochemistry and Mineralogy of Tuff in Zhongliangshan Mine, Chongqing, Southwestern China

    Directory of Open Access Journals (Sweden)

    Jianhua Zou

    2016-05-01

    Full Text Available Coal-bearing strata that host rare metal deposits are currently a hot issue in the field of coal geology. The purpose of this paper is to illustrate the mineralogy, geochemistry, and potential economic significance of rare metals in the late Permian tuff in Zhongliangshan mine, Chongqing, southwestern China. The methods applied in this study are X-ray fluorescence spectrometry (XRF, inductively coupled mass spectrometry (ICP-MS, X-ray diffraction analysis (XRD plus Siroquant, and scanning electron microscopy in conjunction with an energy-dispersive X-ray spectrometry (SEM-EDX. The results indicate that some trace elements including Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Zr, Nb, Cd, Sb, REE, Hf, Ta, Re, Th, and U are enriched in the tuff from Zhongliangshan mine. The minerals in the tuff mainly include kaolinite, illite, pyrite, anatase, calcite, gypsum, quartz, and traces of minerals such as zircon, florencite, jarosite, and barite. The tuff is of mafic volcanic origin with features of alkali basalt. Some minerals including florencite, gypsum, barite and a portion of anatase and zircon have been derived from hydrothermal solutions. It is suggested that Zhongliangshan tuff is a potential polymetallic ore and the recovery of these valuable elements needs to be further investigated.

  10. Ore mineralogy and textural zonation in the world-class epithermal Waihi Vein System, Hauraki Goldfield

    Science.gov (United States)

    Mauk, Jeffrey L.; Skinner, Erin G; Fyfe, Sarah J; Menzies, Andrew H; Lowers, Heather A.; Koenig, Alan E.

    2016-01-01

    The Waihi district in the Hauraki Goldfield of New Zealand contains adularia-sericite epithermal gold-silver veins that have produced more than 7.7 Moz gold. The outermost veins of the district (Martha, Favona, Moonlight, and Cowshed) contain abundant colloform, cherty, and black quartz fill textures, with minor crustiform and massive quartz. The central veins (Amaranth, Trio, and Union) contain predominantly massive and crustiform textures, and these veins are also commonly coarser grained than outermost veins. Pyrite, sphalerite, galena, chalcopyrite, electrum, and acanthite occur in both outermost and central veins; base metal sulfide minerals typically increase in abundance in deeper samples. Antimony-, arsenic-, and selenium-bearing minerals are most abundant in the Favona and Moonlight veins, whereas base metal sulfide minerals are more abundant in the central veins at Correnso. Throughout the Waihi vein system, electrum is by far the most widespread, abundant, and significant gold-bearing mineral, but LA-ICP-MS analyses show that arsenian pyrite also contains some gold. Mineralogical and textural data are consistent with the central veins forming at a deeper structural level, or from hydrothermal fluids with different chemistry, or both.

  11. MINERALOGY OF PRESOLAR SILICATE AND OXIDE GRAINS OF DIVERSE STELLAR ORIGINS

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ann N.; Keller, Lindsay P.; Messenger, Scott, E-mail: lan-anh.n.nguyen@nasa.gov [Robert M. Walker Laboratory for Space Science, EISD Directorate, Astromaterials Research and Exploration Science, NASA Johnson Space Center, Houston, TX 77058 (United States)

    2016-02-10

    We report the chemical and structural analysis of nine presolar silicate grains and one presolar oxide grain from the ungrouped chondrite Acfer 094 and the CR chondrite Queen Alexandra Range 99177. Oxygen isotopic analyses indicate that five of these grains condensed in the outflows of asymptotic giant branch (AGB) stars, four have supernova (SN) origins, and one grain likely has a nova origin. Transmission electron microscopy studies show that most of the grains are amorphous with widely varying non-stoichiometric chemical compositions. Three crystalline AGB grains were identified: a clinoenstatite-containing grain assemblage, a Fe-rich olivine grain, and a nanocrystalline enstatite grain encased in an amorphous silicate shell. An amorphous stoichiometric enstatite (MgSiO{sub 3}) SN grain likely condensed as a crystal and was later rendered amorphous. We do not observe a systematic difference in the chemistries and mineralogies of presolar silicates from different stellar sources, suggesting that the grains formed under a similar range of conditions.

  12. Mineralogical characterization of Greda clays and monitoring of their phase transformations on thermal treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chavez Panduro, E., E-mail: 04130127@unmsm.edu.pe; Bravo Cabrejos, J., E-mail: jbravoc@unmsm.edu.pe [Universidad Nacional Mayor de San Marcos, Facultad de Ciencias Fisicas (Peru)

    2010-01-15

    The mineralogical characterization of two clay samples from the Central Andean Region of Peru, denominated White Greda and Red Greda, is reported. These clays contain the clay minerals mica and illite respectively. Both clays were treated thermally in an oxidising atmosphere under controlled conditions up to 1,100 deg. C with the purpose of obtaining information about structural changes that may be useful for pottery manufacture. X-ray fluorescence was used for the elemental characterization of the samples and X-ray diffractometry was used to determine the collapse and formation of the mineral phases present in the samples caused by thermal treatment. At temperatures above 1,000 deg. C it is observed the formation of spinel in the case of White Greda and of hematite, corundum and cristobalite in the case of Red Greda. Room temperature transmission Moessbauer spectroscopy allowed the monitoring of the variation of the hyperfine parameters with the thermal treatment temperature; In the case of the evolution of the quadruple splitting of the paramagnetic Fe{sup 3+} sites with temperature, in both clays, the analyses reproduced results such as the 'camel back' curve shape, found by other workers (Wagner and Wagner, Hyperfine Interact 154:35-82, 2004; Wagner and Kyek, Hyperfine Interact 154:5-33, 2004).

  13. Mineralogical characterization of Greda clays and monitoring of their phase transformations on thermal treatment

    Science.gov (United States)

    Panduro, E. Chavez; Cabrejos, J. Bravo

    2010-01-01

    The mineralogical characterization of two clay samples from the Central Andean Region of Peru, denominated White Greda and Red Greda, is reported. These clays contain the clay minerals mica and illite respectively. Both clays were treated thermally in an oxidising atmosphere under controlled conditions up to 1,100°C with the purpose of obtaining information about structural changes that may be useful for pottery manufacture. X-ray fluorescence was used for the elemental characterization of the samples and X-ray diffractometry was used to determine the collapse and formation of the mineral phases present in the samples caused by thermal treatment. At temperatures above 1,000°C it is observed the formation of spinel in the case of White Greda and of hematite, corundum and cristobalite in the case of Red Greda. Room temperature transmission Mössbauer spectroscopy allowed the monitoring of the variation of the hyperfine parameters with the thermal treatment temperature; In the case of the evolution of the quadruple splitting of the paramagnetic Fe3 + sites with temperature, in both clays, the analyses reproduced results such as the “camel back” curve shape, found by other workers (Wagner and Wagner, Hyperfine Interact 154:35-82, 2004; Wagner and Kyek, Hyperfine Interact 154:5-33, 2004).

  14. Composition, Mineralogy, and Porosity of Multiple Asteroid Systems from Visible and Near-infrared Spectral Data

    CERN Document Server

    Lindsay, Sean S; Emery, Joshua P; Enriquez, J Emilio; Assafin, Marcelo

    2014-01-01

    We provide a taxonomic and compositional characterization of Multiple Asteroid Systems (MASs) located in the main belt (MB) using visible and near-infrared (0.45-2.5 um) spectral data of 42 MB MASs. The mineralogical analysis is applied to determine meteorite analogs for the MASs, which, in turn, are applied to the MAS density measurements of Marchis et al. (2012) to estimate the system porosity. The macroporosities are used to evaluate the primary MAS formation hypotheses. The visible observing campaign includes 25 MASs obtained using the SOAR telescope with the Goodman High Throughput Spectrometer. The infrared observing campaign includes 34 MASs obtained using the NASA IRTF with the SpeX spectragraph. The MASs are classified using the Bus-DeMeo taxonomic system. We perform a NIR spectral band parameter analysis using a new analysis routine, the Spectral Analysis Routine for Asteroids (SARA). The SARA routine determines band centers, areas, and depths by utilizing the diagnostic absorption features near 1- ...

  15. Mineralogical composition of the meteorite El Pozo (Mexico): a Raman, infrared and XRD study.

    Science.gov (United States)

    Ostrooumov, Mikhail; Hernández-Bernal, Maria del Sol

    2011-12-01

    The Raman (RMP), infrared (IR) and XRD analysis have been applied to the examination of mineralogical composition of El Pozo meteorite (an ordinary chondrite L5 type; village Valle of Allende, founded in State of Chihuahua, Mexico: 26°56'N and 105°24'W, 1998). RMP measurements in the range of 100-3500 cm(-1) revealed principal characteristic bands of the major minerals: olivine, two polymorph modifications of pyroxene (OPx and CPx) and plagioclase. Some bands of the minor minerals (hematite and goethite) were also identified. All these minerals were clearly distinguished using IR and XRD techniques. XRD technique has shown the presence of some metallic phases such as kamacite and taenite as well as troilite and chromite. These minerals do not have characteristic Raman spectra because Fe-Ni metals have no active modes for Raman spectroscopy and troilite is a weak Raman scatterer. Raman mapping microspectroscopy was a key part in the investigation of El Pozo meteorite's spatial distribution of the main minerals because these samples are structurally and chemically complex and heterogeneous. The mineral mapping by Raman spectroscopy has provided information for a certain spatial region on which a spatial distribution coexists of the three typical mineral assemblages: olivine; olivine+orthopyroxene; and orthopyroxene.

  16. Mineralogy, Geochemistry and Stable Isotope Studies of the Dopolan Bauxite Deposit, Zagros Mountain, Iran

    Directory of Open Access Journals (Sweden)

    Somayeh Salamab Ellahi

    2016-02-01

    Full Text Available The Dopolan deposit is a Mediterranean-type bauxite located in the Zagros Fold-Thrust Zone, Iran. This deposit consists of five lithological members including iron-rich, clay-rich, oolitic, pisolitic and organic matter-containing bauxites. The mineralogy of the deposit includes diaspore, boehmite, and kaolinite, nacrite, with minor pyrite, anatase and rutile. Geochemical studies show that light rare earth elements (LREEs are enriched relative to heavy rare earth elements (HREEs in all members, supporting an authigenic origin. Mass changes based on Ti as an immobile element indicate that conventionally-immobile elements (Al, Nb, Ta, Zr, Hf are enriched in situ in the residual units, whereas mobile elements (K, Ca, Si were depleted during bauxitization. This study shows that the Khaneh–Kat argillitic dolomite is the likely parent rock. The δ18O (7.63‰to 9.35‰ and D values (49.91‰to 66.49‰ for kaolinite in the bauxite samples suggest equilibration with meteoric waters which supports a supergene origin. Bauxitization occurred in a warm climate with relatively constant isotopic composition suggesting climate stability during the development of bauxite horizons and remobilization of Al (with formation of secondary boehmite. The δ13C values of calcite (7.3‰ in the bauxite support the idea that the Khaneh–Kat Formation has experienced post-depositional isotope exchange with meteoric waters during the karstification process.

  17. Low Hesperian PCO2 constrained from in situ mineralogical analysis at Gale Crater, Mars

    Science.gov (United States)

    Bristow, Thomas F.; Haberle, Robert M.; Blake, David F.; Des Marais, David J.; Eigenbrode, Jennifer L.; Fairén, Alberto G.; Grotzinger, John P.; Stack, Kathryn M.; Mischna, Michael A.; Rampe, Elizabeth B.; Siebach, Kirsten L.; Sutter, Brad; Vaniman, David T.; Vasavada, Ashwin R.

    2017-01-01

    Carbon dioxide is an essential atmospheric component in martian climate models that attempt to reconcile a faint young sun with planetwide evidence of liquid water in the Noachian and Early Hesperian. In this study, we use mineral and contextual sedimentary environmental data measured by the Mars Science Laboratory (MSL) Rover Curiosity to estimate the atmospheric partial pressure of CO2 (PCO2) coinciding with a long-lived lake system in Gale Crater at ∼3.5 Ga. A reaction–transport model that simulates mineralogy observed within the Sheepbed member at Yellowknife Bay (YKB), by coupling mineral equilibria with carbonate precipitation kinetics and rates of sedimentation, indicates atmospheric PCO2 levels in the 10s mbar range. At such low PCO2 levels, existing climate models are unable to warm Hesperian Mars anywhere near the freezing point of water, and other gases are required to raise atmospheric pressure to prevent lake waters from being lost to the atmosphere. Thus, either lacustrine features of Gale formed in a cold environment by a mechanism yet to be determined, or the climate models still lack an essential component that would serve to elevate surface temperatures, at least locally, on Hesperian Mars. Our results also impose restrictions on the potential role of atmospheric CO2 in inferred warmer conditions and valley network formation of the late Noachian. PMID:28167765

  18. Mineralogy, geochemistry and pyrite content of Bulgarian subbituminous coals, Pernik Basin

    Energy Technology Data Exchange (ETDEWEB)

    Kostova, I.; Petrov, O.; Kortenski, J. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. of Applied Mineralogy

    1996-08-01

    The mineralogy and geochemistry of Pernik subbituminous coals (coal bed A) and some genetic peculiarities related to the mineral formation were studied. The mineral matter of the coal consists chiefly of pyrite, kaolinite, siderite, quartz and calcite. Other minerals (dolomite, ankerite, plagioclase and some sulphates) are present in minor amounts, some occurring as accessory single crystals. Pyrite is them main mineral in these coals and exhibits a large array of textures and morphology. Isolated and clustered euhedral, bacterial and inorganic framboidal, cluster-like, homogeneous and microconcretional massive, infilling and replacing anhedral, and cleat-filling and fracture-filling infiltrational pyrite types were observed. Four stages of mineralization were distinguished: pyrite-kaolinite, pyrite, pyrte-siderite and sulphate stages. The amount of pyrite present in two sections of coal bed A was determined by quantitative powder X-ray diffraction analysis. The concentrations of 37 trace elements were determined. As, Cu, Co, Ni, Zn, Pb, V, Ti, Mo Rb, Cr and Mn are typomorphic for this coal. On the basis of their relation to organic or inorganic matter, four groups of trace elements were subdivided; and on the basis of cluster analysis four associations were differentiated. 19 refs., 31 figs., 2 tabs.

  19. Phase mineralogy studies of solid waste products from coal burning at some Bulgarian themoelectric power plants

    Energy Technology Data Exchange (ETDEWEB)

    Vassilev, S.V. (Bulgarian Academy of Sciences, Sofia (Bulgaria). Institute of Applied Mineralogy)

    1992-06-01

    A combination of methods, including separation, crystallo-optical techniques, SEM, TEM, X-ray, etc., were used to characterize the phase mineralogy, chemical composition, microstructure and some genetic phase peculiarities in solid waste products from coal burning. Fly ashes, bottom ashes and lagooned ashes from the burning of Bobov Dol and East Maritza coal at Bobov Dol and East Maritza thermoelectric power plants, respectively, were studied. These wastes comprise inorganic and organic constituents. The inorganic part consists mainly of non-crystalline (amorphous) components (glass spheres, spheroids and angular particles) and lesser amounts of crystalline components represented by various major (quartz, magnetite, hematite, mullite, feldspar, gypsum, anhydrite, kaolinite-metakaolinite), minor (mica, free CaO, calcite, olivine) and accessory (rutile, svanbergite, iron carbide, chloritoid, zincite, pyrolusite, cuprite, zircon, etc.) mineral phases. The organic constituent consists of unburnt coal components represented by slightly changed, semicoked and coked coal particles. The genesis of the solid phases could be: primary, contained in coal and having undergone no phase transitions (quartz, kaolinite, mica, feldspar, volcanic glass, coal particles); secondary, formed during burning (magnetite, hematite, metakaolinite; mullite, anhydrite, free CaO, glass, semicoke, coke); or tertiary, formed during the transport and storage of fly ashes and bottom ashes (gypsum, calcite, hematite, limonite). 21 refs., 4 figs., 4 tabs.

  20. Mineralogical analysis of dust collected from typical recycling line of waste printed circuit boards.

    Science.gov (United States)

    Wang, Fangfang; Zhao, Yuemin; Zhang, Tao; Duan, Chenlong; Wang, Lizhang

    2015-09-01

    As dust is one of the byproducts originating in the mechanical recycling process of waste printed circuit boards such as crushing and separating, from the viewpoints of resource reuse and environmental protection, an effective recycling method to recover valuable materials from this kind of dust is in urgent need. In this paper, detailed mineralogical analysis on the dust collected from a typical recycling line of waste printed circuit boards is investigated by coupling several analytical techniques. The results demonstrate that there are 73.1wt.% organic matters, 4.65wt.% Al, 4.55wt.% Fe, 2.67wt.% Cu and 1.06wt.% Pb in the dust, which reveals the dust is worthy of reuse and harmful to environment. The concentration ratios of Fe, Mn and Zn can reach 12.35, 12.33 and 6.67 respectively by magnetic separation. The yield of dust in each size fraction is nonuniform, while the yield of -0.75mm size fraction is up to 51.15wt.%; as the particle size decreases, the content of liberated metals and magnetic materials increase, and metals are mainly in elemental forms. The F, Cl and Br elements combing to C in the dust would make thermal treatment dangerous to the environment. Based on these results, a flowsheet to recycle the dust is proposed.

  1. Ice Mineralogy Across and Into the Surfaces of Pluto, Triton, and Eris

    CERN Document Server

    Tegler, S C; Olkin, C B; Young, L A; Romanishin, W; Cornelison, D M; Khodadadkouchaki, R

    2012-01-01

    We present three near-infrared spectra of Pluto taken with the IRTF and SpeX, an optical spectrum of Triton taken with the MMT and the Red Channel Spectrograph, and previously published spectra of Pluto, Triton, and Eris. We combine these observations with a two-phase Hapke model, and gain insight into the ice mineralogy on Pluto, Triton, and Eris. Specifically, we measure the methane-nitrogen mixing ratio across and into the surfaces of these icy dwarf planets. In addition, we present a laboratory experiment that demonstrates it is essential to model methane bands in spectra of icy dwarf planets with two methane phases - one highly-diluted by nitrogen and the other rich in methane. For Pluto, we find bulk, hemisphere-averaged, methane abundances of 9.1 \\pm 0.5%, 7.1 \\pm 0.4%, and 8.2 \\pm 0.3% for sub-Earth longitudes of 10\\degree, 125\\degree, and 257\\degree. Application of the Wilcoxon rank sum test to our measurements finds these small differences are statistically significant. For Triton, we find bulk, hem...

  2. Greenhouse conditions induce mineralogical changes and dolomite accumulation in coralline algae on tropical reefs

    Science.gov (United States)

    Diaz-Pulido, Guillermo; Nash, Merinda C.; Anthony, Kenneth R. N.; Bender, Dorothea; Opdyke, Bradley N.; Reyes-Nivia, Catalina; Troitzsch, Ulrike

    2014-02-01

    Human-induced ocean acidification and warming alter seawater carbonate chemistry reducing the calcification of reef-building crustose coralline algae (CCA), which has implications for reef stability. However, due to the presence of multiple carbonate minerals with different solubilities in seawater, the algal mineralogical responses to changes in carbonate chemistry are poorly understood. Here we demonstrate a 200% increase in dolomite concentration in living CCA under greenhouse conditions of high pCO2 (1,225 μatm) and warming (30 °C). Aragonite, in contrast, increases with lower pCO2 (296 μatm) and low temperature (28 °C). Mineral changes in the surface pigmented skeleton are minor and dolomite and aragonite formation largely occurs in the white crust beneath. Dissolution of high-Mg-calcite and particularly the erosive activities of endolithic algae living inside skeletons play key roles in concentrating dolomite in greenhouse treatments. As oceans acidify and warm in the future, the relative abundance of dolomite in CCA will increase.

  3. A Mineralogical study of nickel mattes from the kalgoorlie nickel smelter, kalgoorlie, western australia

    Science.gov (United States)

    Page, Michael L.

    1982-06-01

    The mineralogy of mattes from Western Mining Corporation Limited’s new nickel flash furnace at Kalgoorlie, Western Australia, are dominated by pentlandite, heazlewoodite and awaruite (Ni-Fe alloy). Magnetite, bornite solid-solution, chromite, and fayalite constitute the minor and trace phases. The optical and scanning electron microscopes, electron microprobe, and the X-ray diffractometer were used to examine the matte samples. Pentlandite and awaruite form subhedral to skeletal crystals and are commonly surrounded by complex intergrowths, some showing exsolution textures, of pentlandite, heazlewoodite, and sometimes bornite. In comparison to products from the old flash furnace, which had separate slag cleaning electric furnaces, these new mattes contain much larger quantities of alloy. The large alloy content results from the incorporation of the slag-cleaning electrodes and the addition of coke to the flash furnace, which produce the strong reducing conditions necessary for significant alloy growth. Matte chemistry not only controls which phases are present, but to some extent also influences the composition of these phases. Even though pentlandite-heazlewooditeawaruite-bornite is the equilibrium assemblage in the Ni-Fe-Cu-S system at temperatures below 550 °C, the variation in mineral composition suggests that disequilibrium was present during crystallization of the samples.

  4. CHEMICAL AND MINERALOGICAL PROPERTIES OF ULTISOLS OF SASAMBA AREA, EAST KALIMANTAN

    Directory of Open Access Journals (Sweden)

    B.H. Prasetyo

    2016-10-01

    Full Text Available Ultisols are a major group of marginal soils extensively found in the upland area of Indonesia. To better understand the potential of the Ultisols developed from claystone and sandstone in the Sasamba Integrated Economical Development Area in East Kalimantan, chemical and mineralogical characteristics of 27 Ultisols pedons consisting of 76 topsoil and 118 subsoil samples were investigated. Besides analysis and interpretation of data, relationships of several soil characteristics were constructed using simple regression. The results indicated that Ultisols showed acid to very acid reaction, had low content of organic matter and low base saturation. Soils generally exhibited net negative charge, and the point of zero charge was reached at pH 3.6. Both potential and available phosphates were low, and there was a trend that amorphous aluminum was responsible for phosphate fixation. The low content of exchangeable potassium in topsoil and subsoil indicated a positive correlation with potential potassium. Clay mineral was composed chiefly of kaolinite, with small amounts of illite, vermiculite, and quartz. The domination of kaolinite and low organic matter content causes the soils to have low cation exchange capacity. Soil management in this area should be focused on building up and maintaining soil fertility, and applying appropriate soil conservation techniques to minimize erosion. To obtain sustained productivity, various soil amendments including the use of farm and/or green manure, liming with agricultural lime, and application of rock phosphate and K fertilizers were highly recommended.

  5. Mineralogical and textural characterization of mortars and plasters from the archaeological site of Barsinia, northern Jordan

    Directory of Open Access Journals (Sweden)

    Mustafa Mohammad AL-Naddaf

    2014-12-01

    Full Text Available Twelve mortar and plaster samples excavated in the archaeological site of Barsinia were mineralogically and petrographically examined by XRay Diffraction (XRD and Stereo and Polarized Light Microscopy, while the total carbonate content was measured using a DietrichFruhling Calcimeter. The physical properties of the samples, such as water uptake under atmospheric pressure and under vacuum, together with density and porosity, were measured. Only twelve samples were available for the purposes of this study: 8 plaster samples and 4 mortar samples. Eleven samples out of the total number of samples were mortars or plasters with lime binder and silica aggregate; calcite and quartz were identified in all of these samples. In most of the samples one or more pozzolanic components were detected; a hydraulic effect therefore exists in practically most of the studied mortars. Excluding the plasters taken from waterbearing constructions such as cisterns, and the mortar sample from the compact floor, the binder content is high; in general, the overall porosity of the studied samples is high. Porosity and petrographic investigation results suggest that the burning temperature of the limestone was low and/or the duration of the combustion was short; such preparation conditions produce a desirable quicklime. Owing to the significant compositional and textural differences between the samples that were reported, there is consequently no suitable general mortar that can be adopted for the restoration of the whole site.

  6. Critical zone study in Korea: integration of hydrogeology, mineralogy, sedimentology and molecular biogeochemistry

    Science.gov (United States)

    Lee, J. Y.; Kwon, K.; Jo, K. N.; Lee, J. S.

    2015-12-01

    Critical Zone (CZ) is the topmost layer of the Earth ranging from the vegetation canopy down to the soil, groundwater, and bedrock that sustains our ecosystem including human life. This CZ is being greatly influenced by the climate change and anthropogenic forces. We introduce the Critical Zone Frontier Research Laboratory (CFRL), a critical zone research lab recently funded by the Korean government for 2015-2020. The objective of CFRL is to unravel the relationships between climate and CZ changes to propose a prediction model for future responses of CZ to climate change. For this ultimate goal, we establish multiple CZ observatories in Kangwon areas and investigate soil, groundwater, and cave environments by integration of hydrogeology, mineralogy, sedimentology and molecular biogeochemistry. This study will enhance our understanding about CZ and local resolution of a climate change model. This research is financially supported by the Basic Research Laboratory Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning.

  7. Organo-mineral Interactions in Ultisols and Andosols with Contrasting Mineralogy

    Science.gov (United States)

    Sparks, D. L.

    2015-12-01

    Organo-mineral associations play an important role in long-term stabilization of soil organic matter. To understand the role of soil minerals and major cations in organo-mineral interactions, we applied STXM-NEXAFS spectroscopy at C, N, Al and Si K-edges, as well as Ca and Fe L-edges, to conduct submicron-level investigations of the associations of C and C forms with Ca, Fe, Al and Si in soil clay fraction of Ultisols and Andosols with contrasting mineralogy. Ultisols were under agricultural use receiving input of limestone and mushroom compost, whereas Andosols were under natural vegetation. The poorly crystalline minerals such as allophane and ferrihydrite were rich in Andosols, while Ultisols were dominated by vermiculite, illite and kaolinite. STXM analysis showed a high spatial correlation between C and Ca in the Utisols. The major Ca forms in agricultural Ultisols were organic Ca. A variety of C forms such as phenols, heterocyclic compounds, carboxylamides were found in Ca-rich "hot spots" in Ultisols. In contrast a relatively uniform distribution of C and C forms on mineral surfaces was observed in Andosols, revolutionizing our view of heterogeneous distribution of OM in natural soil. The C forms associated with minerals were aromatic and carboxyl C. These results demonstrates the importance of Ca containing organic compounds in soil C sequestration in agricultural Ultisols, and highlights the important role of the poorly-crystalline soil minerals in soil organic matter sequestration in Andosols.

  8. The "chessboard" classification scheme of mineral deposits: Mineralogy and geology from aluminum to zirconium

    Science.gov (United States)

    Dill, Harald G.

    2010-06-01

    Economic geology is a mixtum compositum of all geoscientific disciplines focused on one goal, finding new mineral depsosits and enhancing their exploitation. The keystones of this mixtum compositum are geology and mineralogy whose studies are centered around the emplacement of the ore body and the development of its minerals and rocks. In the present study, mineralogy and geology act as x- and y-coordinates of a classification chart of mineral resources called the "chessboard" (or "spreadsheet") classification scheme. Magmatic and sedimentary lithologies together with tectonic structures (1 -D/pipes, 2 -D/veins) are plotted along the x-axis in the header of the spreadsheet diagram representing the columns in this chart diagram. 63 commodity groups, encompassing minerals and elements are plotted along the y-axis, forming the lines of the spreadsheet. These commodities are subjected to a tripartite subdivision into ore minerals, industrial minerals/rocks and gemstones/ornamental stones. Further information on the various types of mineral deposits, as to the major ore and gangue minerals, the current models and the mode of formation or when and in which geodynamic setting these deposits mainly formed throughout the geological past may be obtained from the text by simply using the code of each deposit in the chart. This code can be created by combining the commodity (lines) shown by numbers plus lower caps with the host rocks or structure (columns) given by capital letters. Each commodity has a small preface on the mineralogy and chemistry and ends up with an outlook into its final use and the supply situation of the raw material on a global basis, which may be updated by the user through a direct link to databases available on the internet. In this case the study has been linked to the commodity database of the US Geological Survey. The internal subdivision of each commodity section corresponds to the common host rock lithologies (magmatic, sedimentary, and

  9. Technical note: Mineralogical, chemical, morphological, and optical interrelationships of mineral dust re-suspensions

    Science.gov (United States)

    Engelbrecht, Johann P.; Moosmüller, Hans; Pincock, Samuel; Jayanty, R. K. M.; Lersch, Traci; Casuccio, Gary

    2016-08-01

    This paper promotes an understanding of the mineralogical, chemical, and physical interrelationships of re-suspended mineral dusts collected as grab samples from global dust sources. Surface soils were collected from arid regions, including the southwestern USA, Mali, Chad, Morocco, Canary Islands, Cabo Verde, Djibouti, Afghanistan, Iraq, Kuwait, Qatar, UAE, Serbia, China, Namibia, Botswana, Australia, and Chile. The particulate mass fractions, an aerodynamic particle size analyzer, and a three-wavelength (405, 532, 781 nm) photoacoustic instrument with integrating reciprocal nephelometer for monitoring absorption and scattering coefficients during the dust re-suspension process. Filter sampling media included Teflon® membrane and quartz fiber filters for chemical analysis and Nuclepore® filters for individual particle analysis by scanning electron microscopy (SEM). The 75, material. Also shown are differences in SSA of the kaolinite/hematite/goethite samples from Mali and those from colloidal soils elsewhere. Results from this study can be integrated into a database of mineral dust properties, for applications in climate modeling, remote sensing, visibility, health (medical geology), ocean fertilization, and impact on equipment.

  10. Mineralogy and geochemistry of xenoliths in the Eocene volcanic rocks from southwest of Jandaq

    Directory of Open Access Journals (Sweden)

    Samineh Rajabi

    2013-04-01

    Full Text Available The Eocene volcanic rocks from the southwest of the Jandaq (Kuh-e-Godar-e-Siah, Central-East Iran micro-continent are andesitic basalt and andesite in composition. These rocks contain xenoliths with granulitic mineralogy. Mineral assemblage of these xenoliths is plagioclase + phlogopite + corundum + sillimanite + chlorite + phengite with granublastic, poiklioblastic and foliated textures in the pick metamorphic condition. Thermometry of phlogopite in these xenoliths suggests the average temperature 782oC. The characteristics of the xenoliths are consistent with the granolitic facies metamorphism of the Al-saturated Si-undersaturated crustal sediments at the lower crust condition. Melting of these granulites forms the magma which crystallized the S-type granitoids. Differentiation and crystallization of this magma causes the S-type granite formation. Therefore, the S-type granites in the study area are probably generated from melting of the granulites parts of which brought to the surface as xenoliths by Eocene magmatism in south of the Jandaq (Kuh-e-Godar-e-Siah. S-type granites in the study area are located along the Doruneh, Chupanan and Aeirakan faults in the Aeirakan area and Jandaq ophiolite. These granites are the source of uranium, thorium and uranium ore in southwest of the Aeirakan mountain.

  11. Constraints on the Mineralogy of Gale Crater Mudstones from MSL SAM Evolved Water

    Science.gov (United States)

    McAdam, A. C.; Sutter, B.; Franz, H. B.; Hogancamp, J. V. (Clark); Knudson, C. A.; Andrejkovicova, S.; Archer, P. D.; Eigenbrode, J. L.; Ming, D. W.; Mahaffy, P. R.

    2017-01-01

    The Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments on the Mars Science Laboratory (MSL) have analysed more than 150 micron fines from 14 sites at Gale Crater. Here we focus on the mudstone samples. Two were drilled from sites John Klein (JK) and Cumberland (CB) in the Sheepbed mudstone. Six were drilled from Murray Formation mudstone: Confidence Hills (CH), Mojave (MJ), Telegraph Peak (TP), Buckskin (BK), Oudam (OU), Marimba (MB). SAM's evolved gas analysis mass spectrometry (EGA-MS) detected H2O, CO2, O2, H2, SO2, H2S, HCl, NO, and other trace gases, including organic fragments. The identity and evolution temperature of evolved gases can support CheMin mineral detection and place constraints on trace volatile-bearing phases or phases difficult to characterize with X-ray diffraction (e.g., amorphous phases). Here we will focus on SAM H2O data and comparisons to SAM-like analyses of key reference materials.

  12. Characterization of the Effects of Precursor Mineralogy on Hematite Spectra: Application to Martian Hematite Mineralization

    Science.gov (United States)

    Glotch, Timothy D.; Morris, Richard V.; Sharp, Thomas G.; Christensen, Philip R.

    2003-01-01

    The Thermal Emission Spectrometer (TES) instrument aboard Mars Global Surveyor discovered several isolated deposits of gray, crystalline hematite in Sinus Meridiani, Aram Chaos, and Valles Marineris. A variety of formation mechanisms has been proposed for the martian hematite deposits, including aqueous and nonaqueous processes. Comparison of the average Sinus Meridiani hematite spectrum measured by TES to laboratory emissivity spectra for a variety of naturally occurring hematites shows small but potentially important differences. In particular, the emissivity minimum at 300 and 445/cm in the Sinus Meridiani (SM) spectrum is displaced 10-25/cm to lower frequencies compared to some natural hematite samples. In addition, these bands in the TES data are narrower than the broad bands seen in many natural hematite spectra. These differences may imply that the natural variability of hematite spectra has not been fully characterized, especially with respect to the reaction pathway (precursor mineralogy and temperature of hematite formation) and crystal morphology. Here, we describe the thermal infrared spectral characteristics of several series of synthetic hematite samples derived by direct precipitation, dehydroxylation of fine-grained goethite and the oxidation of magnetite. Several natural hematite sample spectra are also presented for comparison. Transmission electron microscopy (TEM) and Mossbauer spectral analyses of selected samples were performed in order to help determine the causes of the changes seen in the infrared spectra.

  13. Mineralogical and Geochemical Compositions of the No. 5 Coal in Chuancaogedan Mine, Junger Coalfield, China

    Directory of Open Access Journals (Sweden)

    Ning Yang

    2015-11-01

    Full Text Available This paper reports the mineralogy and geochemistry of the Early Permian No. 5 coal from the Chuancaogedan Mine, Junger Coalfield, China, using optical microscopy, scanning electron microscopy (SEM, Low-temperature ashing X-ray diffraction (LTA-XRD in combination with Siroquant software, X-ray fluorescence (XRF, and inductively coupled plasma mass spectrometry (ICP-MS. The minerals in the No. 5 coal from the Chuancaogedan Mine dominantly consist of kaolinite, with minor amounts of quartz, pyrite, magnetite, gypsum, calcite, jarosite and mixed-layer illite/smectite (I/S. The most abundant species within high-temperature plasma-derived coals were SiO2 (averaging 16.90%, Al2O3 (13.87%, TiO2 (0.55% and P2O5 (0.05%. Notable minor and trace elements of the coal include Zr (245.89 mg/kg, Li (78.54 mg/kg, Hg (65.42 mg/kg, Pb (38.95 mg/kg, U (7.85 mg/kg and Se (6.69 mg/kg. The coal has an ultra-low sulfur content (0.40%. Lithium, Ga, Se, Zr and Hf present strongly positive correlation with ash yield, Si and Al, suggesting they are associated with aluminosilicate minerals in the No. 5 coal. Arsenic is only weakly associated with mineral matter and Ge in the No. 5 coals might be of organic and/or sulfide affinity.

  14. Greenhouse conditions induce mineralogical changes and dolomite accumulation in coralline algae on tropical reefs.

    Science.gov (United States)

    Diaz-Pulido, Guillermo; Nash, Merinda C; Anthony, Kenneth R N; Bender, Dorothea; Opdyke, Bradley N; Reyes-Nivia, Catalina; Troitzsch, Ulrike

    2014-01-01

    Human-induced ocean acidification and warming alter seawater carbonate chemistry reducing the calcification of reef-building crustose coralline algae (CCA), which has implications for reef stability. However, due to the presence of multiple carbonate minerals with different solubilities in seawater, the algal mineralogical responses to changes in carbonate chemistry are poorly understood. Here we demonstrate a 200% increase in dolomite concentration in living CCA under greenhouse conditions of high pCO2 (1,225 μatm) and warming (30 °C). Aragonite, in contrast, increases with lower pCO2 (296 μatm) and low temperature (28 °C). Mineral changes in the surface pigmented skeleton are minor and dolomite and aragonite formation largely occurs in the white crust beneath. Dissolution of high-Mg-calcite and particularly the erosive activities of endolithic algae living inside skeletons play key roles in concentrating dolomite in greenhouse treatments. As oceans acidify and warm in the future, the relative abundance of dolomite in CCA will increase.

  15. Mineralogy of SNC Meteorite EET79001 by Simultaneous Fitting of Moessbauer Backscatter Spectra

    Science.gov (United States)

    Morris, Richard V.; Agresti, D. G.

    2010-01-01

    We have acquired M ssbauer spectra for SNC meteorite EET79001 with a MIMOS II backscatter M ssbauer spectrometer [1] similar to those now operating on Mars as part of the Mars Exploration Rover (MER) missions. We are working to compare the Fe mineralogical composition of martian meteorites with in-situ measurements on Mars. Our samples were hand picked from the >1 mm size fraction of saw fines on the basis of lithology, color, and grain size (Table 1). The chips were individually analyzed at approx.300K by placing them on a piece of plastic that was in turn supported by the contact ring of the instrument (oriented vertically). Tungsten foil was used to mask certain areas from analysis. As shown in Figure 1, a variety of spectra was obtained, each resulting from different relative contributions of the Fe-bearing minerals present in the sample. Because the nine samples are reasonably mixtures of the same Fe-bearing phases in variable proportions, the nine spectra were fit simultaneously (simfit) with a common model, adjusting parameters to a single minimum chi-squared convergence criterion [2]. The starting point for the fitting model and values of hyperfine parameters was the work of Solberg and Burns [3], who identified olivine, pyroxene, and ferrous glass as major, and ilmenite and a ferric phase as minor (<5%), Fe-bearing phases in EET79001.

  16. PERMEABILITY AND CONSOLIDATION OF SEDIMENT MIXTURES AS FUNCTION OF SAND CONTENT AND CLAY MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The current study is the first step in a systematic experimental research on the erosion behaviour of sand-mud mixtures. It concerns the effect of a varying sand content and clay mineralogy on the porosity, structure, strength and permeability of artificially generated sediment mixtures. The permeability of a sediment mixture is an especially significant parameter concerning the type of erosion that occurs. It determines ifthe erosion of the bed is either a drained or an undrained process,respectively indicating surface erosion or mass erosion. Measurements on various mixtures concerning the consolidation coefficient and the permeability have been executed. Results show a distinct transition of behaviour between a sand-silt dominated network structure and a clay-water matrix. The occurrence of these two types of structures appears to depend on the porosity of the volume fraction of sand related to silt, which is, therefore, an important parameter concerning the type of erosion. Finally, the study provides a valuable data set that can be used as a reference for following stages of this research on the erosion behaviour of natural cohesive sediments.

  17. Stratigraphy and mineralogy of a carbonate-hosted gold deposit: Kings Mountain gold mine, NC

    Energy Technology Data Exchange (ETDEWEB)

    Supplee, J.; Lapoint, D.; Feiss, P.G.

    1985-01-01

    The Kings Mountain Gold Mine, Cleveland Company, North Carolina, is unique in the Appalachians in that it is carbonate-hosted, with a distinctive ore mineralogy. The mine stratigraphy is upright, younging east to west. The basal unit is a volcanic to subvolcanic chlorite, feldspar, quartz-eye porphyry, cut by a silicic porphyry, interpreted as a shallow level intrusion. Above and gradational to the chloritic porphyry, unless separated by the intrusive silicic porphyry, is a sericitic, quartz-eye porphyry, probably a metatuff. A north-thinning, graphite schists is above the sericitic porphyry. Carbonates overlie the graphite schist except to the north where they are above the sericitic porphyry. The carbonates consist of basal and upper sequences separated by a sericite, quartz-eye schists (metatuff) which is capped by a chlorite-sericite-graphite schist. Mineralization occurs within each carbonate sequence. This is overlain by interbedded chlorite and graphite schists with two horizons of exhalative iron formation (I.F.). Above the I.F. is a thick sequence of sericitic chlorite schists (turbidites). The mineralized carbonates are pervasively silicified with a disseminated assemblage of pyrite, pyrrhotite, sphalerite, chalcopyrite, galena, gold, altaite (PbTe), tetrahedrite, and pyrargyrite in quartz and dolomite +/- fluorite gangue. We suggest that the mineralization is associated with hydrothermal activity during emplacement of the silicic porphyry and following carbonate diagenesis. Mineralization was syn- or post-depositional with respect to the I.F.

  18. Río Tinto: A Geochemical and Mineralogical Terrestrial Analogue of Mars

    Directory of Open Access Journals (Sweden)

    Ricardo Amils

    2014-09-01

    Full Text Available The geomicrobiological characterization of the water column and sediments of Río Tinto (Huelva, Southwestern Spain have proven the importance of the iron and the sulfur cycles, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals, but also in maintaining the high level of microbial diversity detected in the basin. It has been proven that the extreme acidic conditions of Río Tinto basin are not the product of 5000 years of mining activity in the area, but the consequence of an active underground bioreactor that obtains its energy from the massive sulfidic minerals existing in the Iberian Pyrite Belt. Two drilling projects, MARTE (Mars Astrobiology Research and Technology Experiment (2003–2006 and IPBSL (Iberian Pyrite Belt Subsurface Life Detection (2011–2015, were developed and carried out to provide evidence of subsurface microbial activity and the potential resources that support these activities. The reduced substrates and the oxidants that drive the system appear to come from the rock matrix. These resources need only groundwater to launch diverse microbial metabolisms. The similarities between the vast sulfate and iron oxide deposits on Mars and the main sulfide bioleaching products found in the Tinto basin have given Río Tinto the status of a geochemical and mineralogical Mars terrestrial analogue.

  19. Peridotite xenoliths from the Jagersfontein kimberlite pipe: I. Primary and primary-metasomatic mineralogy

    Energy Technology Data Exchange (ETDEWEB)

    Harte, B. (Univ. of Edinburgh (England)); Gurney, J.J. (Univ. of Cape Town (South Africa)); Winterburn, P.A. (Univ. of Edinburgh (England) Isotope Geochemistry Facility, Pretoria (South Africa))

    1990-02-01

    The geochemistry and textures of peridotite xenoliths from the Jagersfontein kimberlite pipe are reported. The xenoliths have a primary mineralogy of olivine {plus minus} orthopyroxene {plus minus} clinopyroxene {plus minus} garnet {plus minus} spinel. They are subdivided into coarse and deformed xenoliths corresponding to high- and low-temperature estimates, respectively. Coarse-grained xenoliths are further subdivided into low- and medium-temperature groups. Mineral chemistry of these two groups is distinct, e.g., clinopyroxene 100 Al/(Al + Cr) 24 to 60 and 60 to 70 in the medium- and low-temperature groups, respectively. Low-temperature xenoliths have undergone exsolution of pyroxene, spinel, and garnet in their pyroxenes. Primary modal metasomatism has occurred in the coarse xenoliths with the replacement of orthopyroxene by edenitic amphibole in the low-temperature xenoliths and of clinopyroxene by low-Ti phlogopite in the medium-temperature xenoliths. The amphibole stability limit confines it to shallower depths. Metasomatized xenoliths have been enriched in K, Na, Al, and Ca, and trace incompatible elements. Metasomatism is considered to have occurred at round 1 Ga by the infiltration of, and reaction with, ascending H{sub 2}O-rich fluids with Sr and Nd isotopic characteristics similar to group II kimberlites. The widespread chemical equilibrium seen in metasomatized xenoliths suggests that the particularly distinctive features of the low-temperature Jagersfontein xenoliths, namely exsolution and very low equilibration temperatures, may also be a result of the primary metasomatism.

  20. Brazil in the global energy world

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Frank D.; Vossoughi, Shapour [University of Kansas (KU), KS (United States)

    2012-07-01

    Brazil is the 10th largest energy consumer in the world and the third largest in the Western Hemisphere, behind the United States and Canada. Total primary energy consumption in Brazil has increased significantly in recent years; and over the past decade, Brazil has made great strides in increasing its total energy production, particularly oil. Brazil has the second-largest crude oil reserves in South America (behind Venezuela), and is one of the fastest growing oil producers in the world. According to United States Energy Information Administration (EIA), Brazil had 12.2 billion barrels of proven oil reserves in 2008. In 2007, Brazil's state owned Petroleo Brasileiro S.A. (PETROBRAS) announced that it had discovered an estimated 5-8 billion barrels of recoverable reserves (including both oil and natural gas) in the Tupi field, located in the Santos Basin. In 2008, subsequent discoveries were announced, to include Jupiter and Carioca (aka Sugar Loaf). Although PETROBRAS has yet to confirm the size of the discoveries, some industry analysts estimate the total extent of recoverable oil and natural gas reserves in the entire pre-salt layer have approached 40 to 80 billion barrels of oil equivalent. The reserves occur below a salt zone that is estimated to be 7,000 meters below the ocean surface. However, Brazil faces many challenges to recover the hydrocarbons to include technical, political, fiscal, and infrastructure hurdles. In spite of the challenges ahead, these discoveries transformed the nature and focus of Brazil's oil industry, economy, and future; and the potential impact of the pre-salt discoveries upon world oil markets is vast. The purpose of this paper is to discuss how the recent discoveries will affect Brazil's future and the impact it will have on the global energy world. (author)

  1. Mineralogy of the clay fraction of alfisols in two slope curvatures: IV - spatial correlation with physical properties

    Directory of Open Access Journals (Sweden)

    Livia Arantes Camargo

    2013-04-01

    Full Text Available Although the influence of clay mineralogy on soil physical properties has been widely studied, spatial relationships between these features in Alfisols have rarely been examined. The purpose of this work was to relate the clay minerals and physical properties of an Alfisol of sandstone origin in two slope curvatures. The crystallographic properties such as mean crystallite size (MCS and width at half height (WHH of hematite, goethite, kaolinite and gibbsite; contents of hematite and goethite; aluminium substitution (AS and specific surface area (SSA of hematite and goethite; the goethite/(goethite+hematite and kaolinite/(kaolinite+gibbsite ratios; and the citrate/bicarbonate/dithionite extractable Fe (Fe d were correlated with the soil physical properties through Pearson correlation coefficients and cross-semivariograms. The correlations found between aluminium substitution in goethite and the soil physical properties suggest that the degree of crystallinity of this mineral influences soil properties used as soil quality indicators. Thus, goethite with a high aluminium substitution resulted in large aggregate sizes and a high porosity, and also in a low bulk density and soil penetration resistance. The presence of highly crystalline gibbsite resulted in a high density and micropore content, as well as in smaller aggregates. Interpretation of the cross-semivariogram and classification of landscape compartments in terms of the spatial dependence pattern for the relief-dependent physical and mineralogical properties of the soil proved an effective supplementary method for assessing Pearson correlations between the soil physical and mineralogical properties.

  2. Feasibility of ASD AgriSpec analysis to indicate mineralogy of a potential shale gas reservoir from west Lancashire, UK

    Science.gov (United States)

    Fleming, Claire; Hough, Edward; Kemp, Simon; Cave, Mark

    2016-04-01

    Mudrocks rich in organic matter present an attractive exploration target for unconventional gas and oil. The mid-Carboniferous (Visean - Bashkirian) Bowland Shale is developed in a series of fault-bound basins and is considered the principal accumulation of gas-prone shales in the UK. One risk with exploitation of shales is that the rocks may exhibit ductile behaviour and will not respond in an optimal way to hydraulic stimulation programmes. The brittle behaviour of the rock is strongly influenced by mineralogical composition. Approximately 15 m of core from the lower part of the Bowland Shale, has been used to test the feasibility of using Natural Infra-Red (NIR) Spectrometry to characterise the mineralogy of the shale, and compared to analysis using standard XRD techniques (both whole-rock and minerals are also easily detected using NIR spectrometry as they display distinctive absorption features in the Short Wave Infrared region of the electromagnetic spectrum. The benefits of using a handheld NIR spectrometer (AgriSpec) is that it provides a rapid, non-destructive and highly portable method for characterising clay mineralogy. This method may represent a simple solution to the initial characterisation of what are challenging rocks to characterise: thick accumulations (locally in excess of 3500 m) with few marker horizons to enable correlation between basins. Results demonstrate that clay minerals such as dickite, kaolinite and smectite (as well as other characteristic minerals such as siderite; calcite and gypsum) can be identified within the Bowland Shale using this technique.

  3. Mineralogical response of the Mediterranean crustose coralline alga Lithophyllum cabiochae to near-future ocean acidification and warming

    Science.gov (United States)

    Nash, Merinda C.; Martin, Sophie; Gattuso, Jean-Pierre

    2016-11-01

    Red calcareous coralline algae are thought to be among the organisms most vulnerable to ocean acidification due to the high solubility of their magnesium calcite skeleton. Although skeletal mineralogy is proposed to change as CO2 and temperature continue to rise, there is currently very little information available on the response of coralline algal carbonate mineralogy to near-future changes in pCO2 and temperature. Here we present results from a 1-year controlled laboratory experiment to test mineralogical responses to pCO2 and temperature in the Mediterranean crustose coralline alga (CCA) Lithophyllum cabiochae. Our results show that Mg incorporation is mainly constrained by temperature (+1 mol % MgCO3 for an increase of 3 °C), and there was no response to pCO2. This suggests that L. cabiochae thalli have the ability to buffer their calcifying medium against ocean acidification, thereby enabling them to continue to deposit magnesium calcite with a significant mol % MgCO3 under elevated pCO2. Analyses of CCA dissolution chips showed a decrease in Mg content after 1 year for all treatments, but this was affected neither by pCO2 nor by temperature. Our findings suggest that biological processes exert a strong control on calcification on magnesium calcite and that CCA