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Sample records for brazil petrography mineralogic

  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. Petrography and geochronology of the Sao Jose dos Quatro Marcos granitoids, southwestern Mato Grosso, Brazil

    International Nuclear Information System (INIS)

    An area of about 400Km2 was mapped in the region of Sao Jose dos Quatro Marcos, southwestern State of Mato Grosso, western Brazil. Various granitoid rocks were recognized, intrusive into basement gneisses, and mapped as two distinct units, one of massive late granitoids (mostly 3a and 3b granites) and one of foliated granitoids, with oriented mafic minerals, consisting mainly of tonalites and, to a lesser degree, of granodiorites. The sequence of intrusion is from tonalites to granodiorites to late granites. Magmatic textures are usually preserved in the rocks, with the exception of some clearly recrystallized samples. Field aspects, as well as petrography and mineralogy, suggest a genetic relationship between the various granitoid types, showing overall features commonly cited as typical of 'I' lineages. A Rb/Sr whole-rock isochron obtained from 3b granites (six points) shows an age of 1,472 +- 19 Ma, and Sr8786 initial ratio of 0.7037 +- 0.0004; a nine point isochron (adding two tonalites and one granodiorite) yelds similar results (age of 1,505 +- 20 Ma, initial ratio of 0.7029+- 0.0003). The obtained ages confirm the existence of a thermal-magmatic event at about 1,500 Ma at the southern border of the Amazon Craton. (author)

  4. Mineralogy and Petrography of MIL 090001, a Highly Altered CV Chondrite from the Reduced Sub-Group

    Science.gov (United States)

    Keller, Lindsay P.

    2011-01-01

    MIL 090001 is a large (greater than 6 kg) CV chondrite from the reduced subgroup (CV(sub red)) that was recovered during the 2009-2010 ANSMET field season [1]. The CV(sub red) subgroup meteorites retain primitive characteristics and have escaped the Na and Fe meta-somatism that affected the oxidized (CV(sub ox)) subgroups. MIL 090001 is, however, reported to be altered [1], and thus a major objective of this study is to characterize its mineralogy and petrography and the extent of the alteration.

  5. 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.

  6. 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.

  7. Distribution, Mineralogy, Petrography, Provenance and Significance of Permian Ash-Carrying Deposits in the Paraná Basin

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    José Moacyr Vianna Coutinho

    Full Text Available The study of thin sections taken from drill core samples and outcrops in southern Brazil has demonstrated the occurrenceof repeated ash fall episodes during the Permian period between 280 and 245 Ma. Scattered or concentrated altered volcanicglass shards were detected in strata of Permian sedimentary rocks of the Rio Bonito and Tatui Formations. The shardcarryingsediment is usually a silty or cherty mudstone with variable amounts of calcrete calcite. Burial and alteration ofunstable glass debris led to the development of analcite and less commonly, calcite, silica minerals, zeolites or montmorillonite.Sources of explosive Permian volcanism, responsible for ample ash falls have been sought in South Africa, in the AndeanCordillera and along the Paraná Basin margin. A swarm of rhyolitic centers described in the Cordillera Frontal and in theCentral Argentinian Provincia de La Pampa (Patagonia is here proposed as the most adequate Permian source. In that area,volcanoes must have expelled ashes that traveled thousands of kilometers before settling in deltaic or shallow marineenvironments. Twenty-three occurrences of Permian shard-carrying sediments have been plotted in a Paraná Basin map. Thenumber of ash-carrying sediments decreases northeastward. The authors envisage dense clouds originated in Patagoniatraveling NE, depositing progressively smaller quantities of ashes but reaching Australia in pre-drift Gondwana. Shardcarrying sediments must be distinguished from “tonstein”, ash fall or ash flow tuffs, also recorded in the Permian Gondwana,which would indicate closer ash source area.

  8. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091494 Cai Jianhu(Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China);Wang Liben Mineralogical Features of Rutiles of Different Modes of Occurrence and Genetic Types and Their Research Significance(Mineral Deposits,ISSN0258-7106,CN11-1965/P,27(4),2008,p.531-538,30 refs.)Key words:rutile,ChinaBased on summarizing achievements in the study of rutile mineralogy in China,the authors have dealt systematically with mineralogical characteristics of rutiles of different modes of occurrence and genetic types and their research significance.Relatively comprehensive fundamental knowledge is provided in this paper for further studies of rutile mineralogy,strengthening of rutile resource prospecting and evaluation work,and deep-going discussion of some geological problems related to rutiles.20091495 Cai Mengjun(National Engineering Research Center of Ultrafine Powder,East China University of Science and Technology,Shanghai 200237,China)

  9. 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

  10. 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.)

  11. Petrography and chemistry of basalts from the Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D

    The petrography of the basalts collected in dredge hauls from the Carlsberg Ridge (3 degrees 37'N and 64 degrees 07'E) show systematic variations in their textural and mineralogical assemblages, from an outermost vitreous glassy to a holocrystalline...

  12. Mineralogical aspects of Morro de Seis Lagos deposit (Amazonas, Brazil).

    Science.gov (United States)

    Takehara, Lucy; Almeida, Marcelo; Silveira, Francisco

    2014-05-01

    The alkaline body Morro dos Seis Lagos, situated in the northwest Amazonian region, is a Nb bearing deposit formed by thick lateritic regolith as circular geological feature about 5 km in diameter. The host rock of this deposit is an intensely weathered siderite carbonatite. The alkaline intrusion body was formed during the late Mesozoic and enriched during the Cenozoic by process of denudation of the surrounding rocks and formation of lateritic cover with thickness in the order of hundreds of meters. In this process, enrichment of Nb, Fe, Ti, Mn, P and rare earth elements (REE) occurred where the lateritic regolith represents the major Nb mineralization, with estimated inferred reserves of 2.9 billion ton@ 2.8 % Nb2O5, one of the largest deposits of Nb in the world. The mineralogical composition of the lateritic regolith has the predominance of the goethite and hematite, followed by oxy - hydroxides of Mn, Ti - Nb oxides, pyrochlore, cerianite and phosphates. The lateritic regolith samples showed high contents of Fe2O3 40 %, and is followed by elevated Th concentration, which locally has concentration higher than (18%). Another REE mineral is the cerianite. The main manganese minerals are hollandite, romanechite (BaMn9O16[OH4] - mixtures of manganese oxides) and amorphous Mn oxy - hydroxides. The higher concentration of MnO2 (about 40 %) is restricted to manganesiferous range, where manganese minerals occur as layers and filling voids, indicating strong remobilization by later process.

  13. 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.

  14. 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

  15. The mineralogy department

    International Nuclear Information System (INIS)

    This document aims at making known to CEA geologists the main activity fields of the Mineralogy department by briefly recalling the principles of the implemented methods. It addresses the following methods: petrography, mineral microscopy and metallogeny, mineralogical analysis, autoradiography, thermal analysis, analytical chemistry, chromatography on paper, spectrographic methods (emission spectrography, atomic absorption spectrography), X rays (X ray diffraction, X fluorescence spectroscopy), the techniques of study of radioactive equilibriums or nuclear geology, analysis by neutron activation, and data processing in geology

  16. 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.

  17. 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

  18. Mineralogical characterization of the argillaceous material from the Municipality of Santa Barbara, Para, Brazil

    International Nuclear Information System (INIS)

    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)

  19. Mineralogical characterization of historical portuguese wall tiles of Sao Luis, Maranhao, Brazil

    International Nuclear Information System (INIS)

    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)

  20. Chemical properties and mineralogy of soils with plinthite and petroplinthite in Iranduba (AM, Brazil

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    Cira Hortensia Pérez Garcia

    2013-08-01

    Full Text Available Large areas of Plinthosols with ferruginous materials such as plinthite and/or petroplinthite are fairly common in the Brazilian Amazon basin. This work was carried out to investigate the chemical behavior, mineralogical composition and weathering stage of four representative soil profiles with plinthite and petroplinthite, in Iranduba, AM (Central Amazon. Three well-drained soil profiles at high elevations were studied (P1, Plinthic Vetic Ferralsol; P2 and P3, Vetic Endopetric Plinthosol and a contrasting poorly drained soil (P4 Haplic Plinthosol, located at low elevation. After profile descriptions, soil samples were collected from each horizon, air-dried, sieved (2 mm, and analyzed for particle-size distribution, pH, exchangeable cations (Al3+, Ca2+, Mg2+, K+, and Na+, as well as available P and total organic carbon (TOC content. The minerals present in the clay and sand fractions, as well as in the ferruginous materials were identified by X-ray Diffraction (XRD. The weathering stage of these soils was assessed by means of Ki and Kr indexes, and the amounts of free and amorphous Fe and Al oxides by using dithionite citrate bicarbonate (DBC and ammonium oxalate dissolution procedures, respectively. The results showed that all soils were extremely unfertile, with pH levels ranging between strong and moderate acidity, very low sum of bases and organic matter content, and of available P. The mineralogy of the soil profiles was very similar, mainly of the well-drained soils, with predominance of kaolinite and quartz in the clay and sand fractions, respectively. In the poorly-drained P4, 2:1 clay particles were also observed. These profiles can be considered highly developed according to the Ki index, however, the Ki value of P4 was higher, indicating that this soil was less developed than the others. In summary, these profiles with plinthite and petroplinthite can be characterized as highly developed and infertile soils and are, with exception of

  1. 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.

  2. Petrography and geochronology (U/Pb-Sm/Nd) the Passagem Granite, Pensamiento Granitoid Complex, Paragua Terrane, SW Amazon Craton, Mato Grosso, Brazil

    International Nuclear Information System (INIS)

    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)

  3. 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

  4. 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%.

  5. 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

  6. 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.

  7. Mineralogy, petrology and geochemistry of the Pocos de Caldas analogue study sites, Minas Gerais, Brazil; II. Morro do Ferro

    Energy Technology Data Exchange (ETDEWEB)

    Waber, M. [Bern Univ., Mineralogisch-Petrographisches Inst., Switzerland (Switzerland)

    1991-01-01

    The thorium-rare-earth element deposit at Morro do Ferro is of supergene origin and was formed under lateritic weathering conditions. The ore body forms shallow NW-SE elongated argillaceous lenses that extend from the top of the hill downwards along its south-eastern slope. The deposit is capped by a stockwork of magnetite veins which have protected the underlying, highly argillaceous host rock from excessive erosion. The surrounding country rocks comprise a sequence of subvolcanic phonolite intrusions that have been strongly altered by hydrothermal and supergene processes. From petrological, mineralogical and geochemical studies and mass balance calculations, it is inferred that the highly weathered host rock was originally carbonatic in composition and was initially enhanced in thorium and rare-earth elements compared to the surrounding silicate rocks. Intrusion of the carbonatite produced fenitic alteration of the surrounding phonolites, consisting of an early potassic alteration followed by a vein-type Th-REE mineralization with associated fluorite, carbonate, pyrite and zircon. Subsequent lateritic weathering has completely destroyed the carbonatite, forming a residual supergene enrichment of Th and REEs. Initial weathering of the carbonatite leading to solutions enriched in carbonate and phosphate may have appreciably restricted the dissolution of the primary Th-REE phases. Strongly oxidic weathering has resulted in a fractionation between cerium and the other light rare-earth elements. Ce{sup 3+} is oxidized to Ce{sup 4+} and retained together with thorium by secondary mineral formation and adsorption on poorly crystalline iron- and aluminium-hydroxides. In contrast, the trivalent LREEs are retained to a lesser degree and are thus more available for secondary mineral formation and adsorption at greater depths down the weathering column. (author) figs., tabs., 60 refs.

  8. 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

  9. Syn-collisional peraluminous magmatism in the Rio Doce region: mineralogy, geochemistry and isotopic data of the Neoproterozoic Urucum Suite (eastern Minas Gerais State, Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Nalini Junior, Herminio Arias [Ouro Preto Univ., MG (Brazil). Escola de Minas. Dept. de Geologia]. E-mail: nalini@degeo.ufop.br; Bilal, Essaid [Ecole de Mines de Saint Etienne (France); Neves, Jose Marques Correia [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Inst. de Geociencias

    2000-03-01

    The Urucum Suite granitoids (Rio Doce region southeastern Brazil) contains four main facies: megafeldspar granites, deformed medium-to-coarse-grained granites, tourmaline, and pegmatitic facies. they intrude both the staurolite-garnet-muscovite-biotite schist of the Sao Tome formation (Rio Doce Group) and the Galileia metaluminous suite (596{+-}4 Ma). Detailed structural studies suggest that the Urucum Suite emplaced during an important dextral strike-slip movement (D{sub 1} phase) of the Brasiliano orogeny (650-450 Ma). Modal and chemical mineralogical variations suggest an evolution from the megafeldspar facies to the pegmatitic facies. Whole-rock geochemistry indicates the peraluminous character of the Urucum suite granitoids, the evolution from the megafeldspar facies granites to pegmatite facies granites to pegmatitic facies granites and suggests the syn-collisional character of this suite. U-Pb zircon (582{+-} 2 Ma) and monazite (576-573 {+-}4 Ma) data indicate that the Urucum Suite emplaced during the Brasiliano orogeny. The peraluminous nature of the Suite and isotopic rich character in the Rb-Sr ({sup 87} Sr/{sup 86} Sr = 0.7114 to 0.7165) and Sm Nd (eNd{sub (T)} = -7.4 and -8.2) systems indicate that it formed by partial melting of older intermediate to felsic crustal sources. Based on early Proterozoic model-ages (2.3 to 1.8 Ga) and on 2.0 ga U-Pb inherited signature, granitoids of the Suite are probably derived from a rocks with a long crustal residence (Transamazonian basement), without extensive mantle contribution. (author)

  10. Syn-collisional peraluminous magmatism in the Rio Doce region: mineralogy, geochemistry and isotopic data of the Neoproterozoic Urucum Suite (eastern Minas Gerais State, Brazil)

    International Nuclear Information System (INIS)

    The Urucum Suite granitoids (Rio Doce region southeastern Brazil) contains four main facies: megafeldspar granites, deformed medium-to-coarse-grained granites, tourmaline, and pegmatitic facies. they intrude both the staurolite-garnet-muscovite-biotite schist of the Sao Tome formation (Rio Doce Group) and the Galileia metaluminous suite (596±4 Ma). Detailed structural studies suggest that the Urucum Suite emplaced during an important dextral strike-slip movement (D1 phase) of the Brasiliano orogeny (650-450 Ma). Modal and chemical mineralogical variations suggest an evolution from the megafeldspar facies to the pegmatitic facies. Whole-rock geochemistry indicates the peraluminous character of the Urucum suite granitoids, the evolution from the megafeldspar facies granites to pegmatite facies granites to pegmatitic facies granites and suggests the syn-collisional character of this suite. U-Pb zircon (582± 2 Ma) and monazite (576-573 ±4 Ma) data indicate that the Urucum Suite emplaced during the Brasiliano orogeny. The peraluminous nature of the Suite and isotopic rich character in the Rb-Sr (87 Sr/86 Sr = 0.7114 to 0.7165) and Sm Nd (eNd(T) = -7.4 and -8.2) systems indicate that it formed by partial melting of older intermediate to felsic crustal sources. Based on early Proterozoic model-ages (2.3 to 1.8 Ga) and on 2.0 ga U-Pb inherited signature, granitoids of the Suite are probably derived from a rocks with a long crustal residence (Transamazonian basement), without extensive mantle contribution. (author)

  11. 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.

  12. 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)

  13. The Nussir copper deposit: petrology, mineralogy, geochemistry and distribution of ore mineralization

    OpenAIRE

    Mun, Yulia

    2013-01-01

    The geology, petrography, mineralogy and geochemistry of the Nussir copper deposit in Finnmark, Northern Norway were studied during writing this thesis. The Nussir deposit of copper is a sedimentary-hosted hydrothermal deposit affected by low grade methamorphism and ductile deformation. The copper mineralization includes chalcopyrite, chalcocite, bornite, covellite, and digenite. The deposit contains also economically interesting trace elements, such as silver, gold, and PGE. The deposit show...

  14. 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)

  15. Mineralogical and structural transformations related to alterations in hydrothermal and climatological conditions of basic vulcanic rocks from northern Parana (Ribeirao Preto region, SP, Brazil)

    International Nuclear Information System (INIS)

    Detailed studies of the basic vulcanic rocks of northern Parana basin (Region of Ribeirao Preto, SP) reveled that these rocks were affected by pre-meteoric activity (hydrothermal alteration) before being exposed to the supergene system of alteration linked to the lithosphere/atmosphere interface. Mineralogical and structural transformation are studied. The appearance of sequential crystalline-chemical paragenesis in zones suggest that the hydrothermal activity occurred during two successives processes of alteration: the expulsion of the water from the rock during the later stages of magma cooling and the continous process of dissolution of the rock wall and the ionic diffusion involving the rock sistem of structural voids. The hydro-thermal action was followed by weathering action developing a thin 'front' of superficial alteration. This alteration system, can lead to the formation of three major levels of alteration horizons and superficial accumulations: alterites, glebular and suil surface materials. (C.D.G.)

  16. Sedimentological, textural, mineralogical and geochemical study of surface sediments and suspension material in Baia da Ribeira, Angra dos Reis, RJ, Brazil

    International Nuclear Information System (INIS)

    The geochemistry dispersion of the metals in aquatic environment is related to the physical chemistry proprieties of these elements as to their interaction by sorption on and desorption from solid particles. These interaction must be understood within the environmental dynamic, with its hydrological, sedimentological, chemical, physical and biological processes that may take the toxic elements (stables metals and radionuclides) to the bio alimentary chain. It was observed at the Ribeira Bay, its hydrodynamic behaviour through the suspension material and particulate organic carbon dispersion. And, through the textural, mineralogical and chemical parameters it was observed the behaviour of the geochemistry processes of the sedimentary materials and the influence that they may submit to the metals dispersion. (author)

  17. 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.

  18. Behaviour of zirconium in the weathering of granulites from Salvador-BA/Brazil

    International Nuclear Information System (INIS)

    The weathering related to mineralogy with chemical analysis of Zr in granulites and their weathered equivalents in Salvador - Brazil, is studied. The mineralogical and petrographical characteristics were correlated with analyses for K,Al and Zr. The fresh rocks are quartz-rich pyroxene granulites, the weathered samples were submitted to bromoform and electromagnetic separations to recovery nearly pure zircon from the fraction coarser than 50 micros. These zircons were classified by color, size and shape. Proportions between different colors of zircon were correlated with petrography of fresh granulites. Studies of zircons resistent to acid attack indicated, that the darker colors were due to iron oxide staining. Chemical analyses for Zr in fresh rocks presented values higher than the values corresponding to zircon observed in thin sections, sugesting the presence of Zr as a trace element in ferromagnesian silicates. In the weathered rocks, Zr values are much higher than those corresponding to recovered zircon. Comparisons of K2O, Al2O3 and Zr values in fresh and weathered rocks indicated a loss of K2O, and a gain of Zr by weathering. However, maximum losses of K2O do not coincide with maximum gains of Zr. (author)

  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. Hanford basalt flow mineralogy

    International Nuclear Information System (INIS)

    Mineralogy of the core samples from five core wells was examined in some detail. The primary mineralogy study included an optical examination of polished mounts, photomicrographs, chemical analyses of feldspars, pyroxenes, metallic oxides and microcrystalline groundmasses and determination from the chemical analyses of the varieties of feldspars, pyroxenes and metallic oxides. From the primary mineralogy data, a firm understanding of the average Hanford basalt flow primary mineralogy emerged. The average primary feldspar was a laboradorite, the average pyroxene was an augite and the average metallic oxide was a solid solution of ilmenite and magnetite. Secondary mineralization consisted of vug filling and joint coating, chiefly with a nontronite-beidellite clay, several zeolites, quartz, calcite, and opal. Specific flow units also were examined to determine the possibility of using the mineralogy to trace flows between core wells. These included units of the Pomona, the Umatilla and a high chromium flow just below the Huntzinger. In the Umatilla, or high barium flow, the compositional variation of the feldspars was unique in range. The pyroxenes in the Pomona were relatively highly zoned and accumulated chromium. The high chromium flow contained chromium spinels that graded in chromium content into simple magnetites very low in chromium content. A study of the statistical relationships of flow unit chemical constituents showed that flow unit constituents could be roughly correlated between wells. The probable cause of the correlation was on-going physical-chemical changes in the source magma

  1. Authentication controversies and impactite petrography of the New Quebec Crater

    Science.gov (United States)

    Marvin, Ursula B.; Kring, David A.

    1992-12-01

    The literature reports that led to the current acceptance of New Quebec Crater (Chubb Crater) as an authentic impact crater are reviewed, and it is noted that, for reasons that are not entirely clear, a meteoritic origin for the New Quebec Crater achieved wider acceptance at an earlier data than for the Lake Bosumtwi Crater, for which petrographic and chemical evidence is more abundant and compelling. The petrography of two impact melt samples from the New Quebec Crater was investigated, and new evidence is obtained on the degrees of shock metamorphism affecting the accessory minerals such as apatite, sphene, magnetite, and zircon.

  2. 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.

  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. Petrography and Sulphur Isotope Studies of Pyrites in the Muteh Gold Deposit

    Directory of Open Access Journals (Sweden)

    M. J. Abdollahi

    2009-01-01

    Full Text Available Problem statement: The Muteh mining district is located in 70 km northeast of Golpaygan city within the Sanandaj-Sirjan metamorphic belt. There are 2 gold mines, 7 gold occurrences and numerous mineral indices in the Muteh gold district. There are few researches on Muteh gold district, but a detailed model is not clear yet. The aim of this study is to determine mineralogy of gold-bearing rocks and the role of these rocks in concentration of gold and to improve our knowledge about Muteh model. Approach: Detailed fieldwork carried out at different scales at the Muteh district. About 50 outcrops samples examined petrographically. Fifteen samples containing veinlets of sulfides and quartz selected for H, O and S stable isotope analysis. Petrography characterized by optical microscopy, Scanning Electron Microscopy (SEM and X-Ray powder Diffraction (XRD analysis. Results: Geological studies indicated that the study area show a major poly-phase metamorphism. Since the latest metamorphism was weaker than the earlier ones, the older rocks were affected by more intense metamorphism. The metamorphic rocks mainly consist of schists, quartzite, marble, amphibolite and gneisses. These rocks show two foliations (S1 and S2. The S2 foliation is the major phase in the metamorphic rocks. Pyrite is the most abundant and the important gold-bearing mineral at the study area. Based on evidences of deformation (S2 and crystallization, three main types of pyrites can be distinguished in the Muteh deposit: (1 pre-tectonic or gold bearing pyrite (2 syn-tectonic or disseminated pyrites along the foliation of the host rocks. (3 pyrite aggregates in the host rocks or in the metamorphic segregation quartz veins crosscutting the foliation of the host rocks. The sulfur isotope studies were carried out on pyrites within quartz veinlets, biotite schist and meta-volcanic rocks at the Muteh deposit. Five available data are highly variable even from the same types of hosted rocks

  6. 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)

  7. Development of coal petrography applied in technical processes at the Bergbau-Forschung/DMT during the last 50 years

    Energy Technology Data Exchange (ETDEWEB)

    Steller, Monika; Arendt, Paul; Kuehl, Helmut [Deutsche Montan Technologie GmbH ? Mining Service Division?Essen (Germany)

    2006-06-06

    The paper deals with the activities of the Bergbau-Forschung Coal Petrography Laboratory in Essen (Germany), which, under the influence of Marie-Therese Mackowsky, developed into a stronghold of the industrial application of coal petrology. In 1979, the formerly independent Section for Mineralogy and Petrology was merged with the Chemistry Section. This synergy has widened the research limits and resulted in higher efficiency of projects being carried out within both units. Since 1990, after transforming Bergbau-Forschung into DMT GmbH, a worldwide competition within hard coal and hard coal-based coke markets, together with the switch of the industry towards alternative energy sources, have significantly lowered the importance of the domestic coal mining industry. This in turn resulted in reduction of coal research programs. However, it is stressed that, in spite of transformations of the applied coal petrology experienced during the past 50 years, some achievements are still as applicable as ever. Among them, the method of predicting coke strength using maceral analysis and coal types, published by Mackowsky and Simonis [Mackowsky, M.-Th., Simonis, W., 1969. Die Kennzeichnung von Kokskohlen fur die mathematische Beschreibung der Hochtemperaturverkokung im Horizontalkammerofen bei Schuttbetrieb durch Ergebnisse mikroskopischer Analysen. Gluckauf-Forschungshefte 30, 25-27], is still in use today. The second part of this paper presents some examples of coal petrography applications, which are still important in carbonization processes. Mackowsky discovered that the pyrolytic components were influencing the coke homogeneity in coke ovens and affected coke quality parameters such as CRI and CSR. These highly graphitic layers and lenses prevent gasification of the inner zones of coke lumps, thus lowering the reactivity of metallurgical coke. Moreover, it also seems possible to predict wall load and maximum internal gas pressure as to prevent coke ovens from damage

  8. Development of coal petrography applied in technical processes at the Bergbau-Forschung/DMT during the last 50 years

    International Nuclear Information System (INIS)

    The paper deals with the activities of the Bergbau-Forschung Coal Petrography Laboratory in Essen (Germany), which, under the influence of Marie-Therese Mackowsky, developed into a stronghold of the industrial application of coal petrology. In 1979, the formerly independent Section for Mineralogy and Petrology was merged with the Chemistry Section. This synergy has widened the research limits and resulted in higher efficiency of projects being carried out within both units. Since 1990, after transforming Bergbau-Forschung into DMT GmbH, a worldwide competition within hard coal and hard coal-based coke markets, together with the switch of the industry towards alternative energy sources, have significantly lowered the importance of the domestic coal mining industry. This in turn resulted in reduction of coal research programs. However, it is stressed that, in spite of transformations of the applied coal petrology experienced during the past 50 years, some achievements are still as applicable as ever. Among them, the method of predicting coke strength using maceral analysis and coal types, published by Mackowsky and Simonis [Mackowsky, M.-Th., Simonis, W., 1969. Die Kennzeichnung von Kokskohlen fur die mathematische Beschreibung der Hochtemperaturverkokung im Horizontalkammerofen bei Schuttbetrieb durch Ergebnisse mikroskopischer Analysen. Gluckauf-Forschungshefte 30, 25-27], is still in use today. The second part of this paper presents some examples of coal petrography applications, which are still important in carbonization processes. Mackowsky discovered that the pyrolytic components were influencing the coke homogeneity in coke ovens and affected coke quality parameters such as CRI and CSR. These highly graphitic layers and lenses prevent gasification of the inner zones of coke lumps, thus lowering the reactivity of metallurgical coke. Moreover, it also seems possible to predict wall load and maximum internal gas pressure as to prevent coke ovens from damage

  9. 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.

    1982-04-01

    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.

  10. 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

  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. Mineralogical and geochemical aspects of the sedimentary zeolite occurrences in the Parnaiba Basin

    International Nuclear Information System (INIS)

    The paper presents the petrographical and mineralogical analysis by X-ray diffraction and chemical analysis through electronic microprobe realized in zeolites contained in the Corda Formation sandstones, in the northwestern portion of the Parnaiba Basin, Brazil. The data presented here update and complete the information propagated by Rezende and Angelica (1995) and Angelica et al. (1995)

  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. 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.

  15. Geochemistry and mineralogy

    Energy Technology Data Exchange (ETDEWEB)

    Plecas, I.; Dimovic, S.; Orta, M.M.; Alba, M.D.; Alvero, R.; Becerro, A.I.; Castro, M.A.; Chain, P.; Escudero, A.; Naranjo, M.; Pavon, E.; Trillo, J.M.; Vejsada, J.; Vokal, A.; Zadvernyuk, H.P.; Fedorenko, Y.G.; Zlobenko, B.P.; Koromyslichenko, T.I.; Battaglia, S.; Cervelli, M.; Millot, R.; Girard, J.P.; Missana, T.; Garcia-Gutierrez, M.; Alonso, U.; Muurinen, A.; Carlsson, T.; Chain, P.; Alba, M.D.; Becerro, A.I.; Castro, M.A.; Escudero, A.; Gonzalez-Carrascosa, T.; Hurtado, S.; Pavon, E.; Villa, M.; Bourg, I.C.; Sposito, G.; Bourg, A.C.M.; Marques Fernandes, M.; Rabung, Th.; Dahn, R.; Baeyens, B.; Bradbury, M.H.; Breynaert, E.; Maes, A.; Bruggeman, C.; Maes, I.A.; Vancluysen, J.; Credoz, A.; Bildstein, O.; Jullien, M.; Raynal, J.; Petronin, J.C.; Trotignon, L.; Pokrovsky, O.; Jacquier, P.; Beaucaire, C.; Vuillaume, A.L.; Wittebroodt, Ch.; Ly, J.; Page, J.; Savoye, S.; Pitsch, H.; Jacques, D.; Wang, L.; Galunin, E.; Chain, P.; Alba, M.D.; Vidal, M.; Grandia, F.; Domenech, C.; Arcos, D.; Duro, L.; Bruno, J.; Andre, L.; Pauwels, H.; Azaroual, M.; Albrecht, A.; Romero, M.A.; Aerts, S.; Boven, P.; Van Geet, M.; Boever, P. de; Alonso, U.; Albarran, N.; Missana, T.; Garcia-Gutierrez, M.; Truche, L.; Berger, G.; Guillaume, D.; Jacquot, E.; Tournassat, Ch.; Lerouge, C.; Brendle, J.; Greneche, J.M.; Touzelet, St.; Blanc, Ph.; Gaucher, E.C.; Thoenen, T.; Klinkenberg, M.; Kaufhold, S.; Dohrmann, R.; Siegesmund, S.; Liu, D.J.; Bruggeman, C.; Maes, N.; Weber, T.; Trotignon, L.; Pozo, C.; Bildstein, O.; Combarieu, G. de; Frugier, P.; Menut, D

    2007-07-01

    This session gathers 52 articles (posters) dealing with: the influence of natural sorbents immobilization of spent ion exchange resins in cement; the chemical stability of rare-earth silicate; the mineralogical heterogeneity of Rokle bentonite and radionuclide adsorption: A case study for cesium; the rheological and sorption properties of clay-polymer composites; the clay mineral interactions with leachate solutions in landfills; the lithium isotope fractionation during adsorption onto mineral surfaces; the sorption of Sr{sup 2+} onto mixed smectite / illite clays; Eh and pH in the pore water of compacted bentonite; the chemical interaction of {sup 152}Eu with the clay barrier; the modeling of the acid-base surface chemistry of Montmorillonite; a time resolved laser fluorescence and X-ray absorption spectroscopy study of lanthanide/actinide sorption on clay minerals: influence of carbonate complexation; the structure elucidation and occurrence of Tc(IV) pyrogallol complexes; the geochemistry of Se(0) under boom clay conditions; an experimental and modelling study of pure secondary silicate minerals reactivity in geological CO{sub 2} sequestration conditions; an experimental evaluation of a retention model for major groundwater elements on the Tournemire argillite; modelling the long term interaction of cementitious pore water with Boom clay; the sorption-desorption of radionuclides and analogues in clays suitable for barriers; the modelling of the Redox evolution in the tunnel backfill of a high level nuclear waste repository; the reactivity of nitrates in the different storage compartments of type-b wastes; an investigation into the biodiversity of sulphate reducing bacteria in Boom clay; the colloid generation mechanisms from compacted bentonite under different geochemical conditions; the experimental reduction of aqueous sulphate by hydrogen in the context of the Callovo-Oxfordian argillite; cation exchanged Fe(II) and Sr as compared to other divalent cations

  16. 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.

  17. 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

  18. 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.

  19. Method development in automated mineralogy

    OpenAIRE

    Sandmann, Dirk

    2015-01-01

    The underlying research that resulted in this doctoral dissertation was performed at the Division of Economic Geology and Petrology of the Department of Mineralogy, TU Bergakademie Freiberg between 2011 and 2014. It was the primary aim of this thesis to develop and test novel applications for the technology of ‘Automated Mineralogy’ in the field of economic geology and geometallurgy. A “Mineral Liberation Analyser” (MLA) instrument of FEI Company was used to conduct most analytical studies. T...

  20. Mineralogy of the Mercurian Surface

    Science.gov (United States)

    Vander Kaaden, Kathleen E.; McCubbin, Francis M.; Nittler, Larry R.; Peplowski, Patrick N.; Weider, Shoshana Z.; Evans, Larry R.; Frank, Elizabeth A.; McCoy, Timothy

    2016-01-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft orbited Mercury for four years until April 2015, revealing its structure, chemical makeup, and compositional diversity. Data from the mission have confirmed that Mercury is a compositional end-member among the terrestrial planets. The X-Ray Spectrometer (XRS) and Gamma-Ray Spectrometer (GRS) on board MESSENGER provided the first detailed geochemical analyses of Mercury's surface. These instruments have been used in conjunction with the Neutron Spectrometer and the Mercury Dual Imaging System to classify numerous geological and geochemical features on the surface of Mercury that were previously unknown. Furthermore, the data have revealed several surprising characteristics about Mercury's surface, including elevated S abundances (up to 4 wt%) and low Fe abundances (less than 2.5 wt%). The S and Fe abundances were used to quantify Mercury's highly reduced state, i.e., between 2.6 and 7.3 log10 units below the Iron-Wustite (IW) buffer. This fO2 is lower than any of the other terrestrial planets in the inner Solar System and has important consequences for the thermal and magmatic evolution of Mercury, its surface mineralogy and geochemistry, and the petrogenesis of the planet's magmas. Although MESSENGER has revealed substantial geochemical diversity across the surface of Mercury, until now, there have been only limited efforts to understand the mineralogical and petrological diversity of the planet. Here we present a systematic and comprehensive study of the potential mineralogical and petrological diversity of Mercury.

  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. Petrography and sedimentology of Paleogene formations from Nathorstland, Spitsbergen: A diagenetic study of sedimentary facies associations

    OpenAIRE

    Vilberg, Anne Karin

    2011-01-01

    The studied Paleogene successions in the Central Basin Spitsbergen, comprises the Grumantbyen Formation, the Bjørnsonfjellet Member, Battfjellet Formation and the uppermost Aspelin toppen Formation. The objectives have been to describe the petrography and diagenesis relative to sedimentary facies associations. Another minor objective was to compare the reservoir quality of core and outcrop data. This have been done by description,facies interpretation and sampling from the Sysselmannsbreen co...

  3. Petrography Of The Basement Complex Of Maddhapara Mining (Production Level) Dinajpur District, Bangladesh

    OpenAIRE

    Islam, Md. Saidul; Quamruzzaman, Chowdhury; Monir, Md. Minhaj Uddin; Jahan, Sakura; Begum, Momtaj

    2014-01-01

    This research work deals with the petrography of the Palaeoproterozoic Basement Complex (production level) Maddhapara Granite mining project area, Dinajpur district, Bangladesh. Tectonically the study area is a continuation of the Central Indian Tectonic Zone (CITZ), where the Basement Complex is overlain by the Tertiary thin to moderate sediment sequence. The present study has been performed on the basis of collected samples which are taken from the production level at the elevation of about...

  4. 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

  5. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140697Gao Wenyuan(College of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China);Huang Fei The Influence of Different Iron-Sulfur Ratios on Pyrite Formation under Thermal Sulfurization Condition(Earth Science Frontiers,ISSN1005-2321,CN11-3370/P,20(3),2013,p.131-137,6illus.,3tables,19refs.)Key words:pyrite,crystallization

  6. 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)

  7. MINERALOGY

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102235 Cai Yuman(Geological Survey of Jiangsu Province,Nanjing 210018,China);Chen Chong Study on Adsorption Capacity for Ammonium with Natural Zeolite(Journal of Geology,ISSN1674-3636,CN32-1796/P,33(4),2009,p.403-410,8 illus.,9 tables,25 refs.)Key words:zeolite group,cation exchange capacityIn order to discuss the regular absorption rules for ammonium with natural zeolite,the authors took the natural clinoptilolite occurred in Zhenjiang,Jiangsu Province as an experimental sample.Its mineral composition and chemical composition were tested.Their adsorption characteristic for ammonium was studied under batch experiment,and its adsorption isothermal lines were established.It is concluded that the adsorption isothermal lines met the formula Langmuir,and its adsorption capacity for ammonium was determined through mathematic analysis.20102236 Ding Hongrui(School of Earth and Space Sciences,Peking University,Beijing 100871,China);Li Yan Experimental Researches on Photoreduction of Azo Dyes in the Rutile-Cathode Bioelectrochemical System(Acta Petrologica et Mineralogica,ISSN1000-6524,CN11-1966/P,28(6),2009,p.541-546,6 illus.,1 table,17 refs.)Key words:rutileThe reductive decolorization of azo dye wastewater was investigated by using a dual-chambered bioelectrochemical cell equipped with different cathode materials(graphite and rutile-coated graphite).The results demonstrate that the cathodic electron transfer process in the irradiated rutile-cathode system is

  8. 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-

  9. 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

  10. Sediments of Afonso Bezerra belt-Macaiba (meridional border of Potiguar basin, RN, Brazil)

    International Nuclear Information System (INIS)

    The mineralogy of sediments from Potiguar basin, Rio Grande do Norte State, Brazil, is investigated and its origin is determined. Usual sedimentologic methods and X-ray diffraction were used. (M.C.K.)

  11. Reflectance spectroscopy and asteroid surface mineralogy

    Science.gov (United States)

    Gaffey, Michael J.; Bell, Jeffrey F.; Cruikshank, Dale P.

    1989-01-01

    Information available from reflectance spectroscopy on the surface mineralogy of asteroids is discussed. Current spectral interpretive procedures used in the investigations of asteroid mineralogy are described. Present understanding of the nature and history of asteroids is discussed together with some still unresolved issues such as the source of ordinary chondrites.

  12. 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.

  13. 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

  14. Mеthods for investigation in environmental mineralogy

    OpenAIRE

    Sijakova-Ivanova, Tena

    2014-01-01

    Abstract: This paper shows the methods used in investigation in environmental mineralogy. Significant methods used in mineralogical examination are: ICP-AS-inductively coupled plasma atomic emission spectroscopy, IR-Infrared spectroscopy, DTA-differential thermal analysis,TGA-thermogravimetric analysis, EPR–electron paramagnetic resonance, FMR-ferromagnetic resonance, TEM- transmission electron microscopy, SEM- EDS scanning electron microscopy with energy disperzive spectroscopy, CBED-converg...

  15. 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.

  16. Geochemistry and mineralogy of the older (> 40 ka) ignimbrites in the Campanian Plain, southern Italy

    Science.gov (United States)

    Belkin, Harvey E.; Raia, Federica; Rolandi, Giuseppe; Jackson, John C.; de Vivo, Benedetto

    2010-05-01

    The Campanian Plain in southern Italy has been volcanically active during the last 600 ka. The largest and best known eruption at 39 ka formed the Campanian Ignimbrite (CI), which has the largest volume (~310 km3) and the greatest areal extent. However, significant, but scattered deposits of older ignimbrites underlie the CI and document a long history of trachytic eruptions. We examined the geochemistry and mineralogy of 11 older ignimbrite strata by optical petrography, electron microprobe, scanning electron microscope, X-ray diffraction, and various whole-rock geochemical techniques. Strata at Durazzano (116.1 ka), Moschiano (184.7 ka), Seiano Valley A (245.9 ka), Seiano Valley B (289.6 ka), Taurano 7 (205.6 and 210.4 ka), Taurano 9 (183.8 ka), and Taurano 14 (157.4 ka) have been previously dated by the 40Ar/39Ar technique (Rolandi et al., 2003, Min. & Pet., 79) on hand-picked sanidine. The older ignimbrites are trachytic, but are highly altered with LOI from 8 to 17 wt%. Whole-rock compositions reflect variable element mobility during weathering; TiO2, Al2O3, Fe-oxide, and CaO tend to be enriched relative to average CI composition, whereas Na2O and K2O are depleted. X-ray diffraction identified major chabazite, kaolinite, and illite-smectite alteration products in some samples. The phenocryst mineralogy in all of the strata is typical for trachyte magma and consists of plagioclase (~An80 to ~An40), potassium feldspar (~Or50 to ~Or80), biotite (TiO2 = ~4.6 wt%, BaO = ~0.70 wt%, F = ~0.65 wt%), diopside (~Ca47Mg48Fe5 to ~Ca48Mg34Fe18), titanomagnetite, and uncommon Ca-amphibole. Relatively immobile trace elements Zr, Hf, Nb, and Th display similar abundance, linear trends, and ratios as those measured in the Campanian Ignimbrite: Th/Hf = ~4, Zr/Hf = ~50, and Zr/Nb = ~6. The similarity of trace element systematics and phenocryst mineralogy among the Campanian Ignimbrite and the older ignimbrites suggests that the magmagenesis processes and parental source have

  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

    OpenAIRE

    Marcondes Lima da Costa; Dirse Clara Kern; Alice Helena Eleotério Pinto; Jorge Raimundo da Trindade Souza

    2004-01-01

    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,...

  18. The mineralogy of global magnetic anomalies

    Science.gov (United States)

    Haggerty, S. E. (Principal Investigator)

    1984-01-01

    Experimental and analytical data on magnetic mineralogy was provided as an aid to the interpretation of magnetic anomaly maps. An integrated program, ranging from the chemistry of materials from 100 or more km depth within the Earth, to an examination of the MAGSAT anomaly maps at about 400 km above the Earth's surface, was undertaken. Within this framework, a detailed picture of the pertinent mineralogical and magnetic relationships for the region of West Africa was provided. Efforts were directed toward: (1) examining the geochemistry, mineralogy, magnetic properties, and phases relations of magnetic oxides and metal alloys in rocks demonstrated to have originated in the lower crust of upper mantle, (2) examining the assumption that these rocks portray the nature of their source regions; and (3) examining the regional geology, tectonics, gravity field and the MAGSAT anomaly maps for West Africa.

  19. 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

  20. 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)

  1. Mineralogy of Eolian Sands at Gale Crater

    Science.gov (United States)

    Achilles, C. N.; Vaniman, D. T.; Blake, D. F.; Bristow, T. F.; Rampe, E. B.; Ming, D. W.; Chipera, S. J.; Morris, R. V.; Morrison, S. M.; Downs, R. T.; Fendrich, K. V.; Ehlmann, B. L.; Yen, A. S.; Sarrazin, P. C.; Treiman, A. H.; Craig, P. I.; Lapotre, M. G. A.; Edgett, K. S.; Gellert, R.; Crisp, J. A.; Morookian, J. M.; Grotzinger, J. P.; Des Marais, D. J.; Farmer, J. D.

    2016-01-01

    The Mars Science Laboratory rover Curiosity has been exploring outcrop and regolith in Gale crater since August 6, 2012. During this exploration, the mission has collected 10 samples for mineralogical analysis by X-ray diffraction (XRD), using the CheMin instrument. The CheMin (Chemistry and Mineralogy) instrument on the Mars Science Laboratory rover Curiosity uses a CCD detector and a Co-anode tube source to acquire both mineralogy (from the pat-tern of Co diffraction) and chemical information (from energies of fluoresced X-rays). A detailed description of CheMin is provided in [1]. As part of the rover checkout after landing, the first sample selected for analysis was an eolian sand deposit (the Rocknest "sand shadow"). This sample was selected in part to characterize unconsolidated eolian regolith, but primarily to prove performance of the scoop collection system on the rover. The focus of the mission after Rocknest was on the consolidated sediments of Gale crater, so all of the nine subsequent samples were collected by drilling into bedrock com-posed of lithified sedimentary materials, including mudstone and sandstone. No scoop samples have been collected since Rocknest, but at the time this abstract was written the mission stands poised to use the scoop again, to collect active dune sands from the Bagnold dune field. Several abstracts at this conference outline the Bagnold dune campaign and summarize preliminary results from analyses on approach to the Namib dune sampling site. In this abstract we review the mineralogy of Rocknest, contrast that with the mineralogy of local sediments, and anticipate what will be learned by XRD analysis of Bagnold dune sands.

  2. 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

  3. Linkages between mineralogy, fluid chemistry, and microbial communities within hydrothermal chimneys from the Endeavour Segment, Juan de Fuca Ridge

    Science.gov (United States)

    Lin, T. J.; Ver Eecke, H. C.; Breves, E. A.; Dyar, M. D.; Jamieson, J. W.; Hannington, M. D.; Dahle, H.; Bishop, J. L.; Lane, M. D.; Butterfield, D. A.; Kelley, D. S.; Lilley, M. D.; Baross, J. A.; Holden, J. F.

    2016-02-01

    Rock and fluid samples were collected from three hydrothermal chimneys at the Endeavour Segment, Juan de Fuca Ridge to evaluate linkages among mineralogy, fluid chemistry, and microbial community composition within the chimneys. Mössbauer, midinfrared thermal emission, and visible-near infrared spectroscopies were utilized for the first time to characterize vent mineralogy, in addition to thin-section petrography, X-ray diffraction, and elemental analyses. A 282°C venting chimney from the Bastille edifice was composed primarily of sulfide minerals such as chalcopyrite, marcasite, and sphalerite. In contrast, samples from a 300°C venting chimney from the Dante edifice and a 321°C venting chimney from the Hot Harold edifice contained a high abundance of the sulfate mineral anhydrite. Geochemical modeling of mixed vent fluids suggested the oxic-anoxic transition zone was above 100°C at all three vents, and that the thermodynamic energy available for autotrophic microbial redox reactions favored aerobic sulfide and methane oxidation. As predicted, microbes within the Dante and Hot Harold chimneys were most closely related to mesophilic and thermophilic aerobes of the Betaproteobacteria and Gammaproteobacteria and sulfide-oxidizing autotrophic Epsilonproteobacteria. However, most of the microbes within the Bastille chimney were most closely related to mesophilic and thermophilic anaerobes of the Deltaproteobacteria, especially sulfate reducers, and anaerobic hyperthermophilic archaea. The predominance of anaerobes in the Bastille chimney indicated that other environmental factors promote anoxic conditions. Possibilities include the maturity or fluid flow characteristics of the chimney, abiotic Fe2+ and S2- oxidation in the vent fluids, or O2 depletion by aerobic respiration on the chimney outer wall.

  4. 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.

  5. 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

  6. 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.

  7. An unpublished text of Jovellanos about mineralogy

    Directory of Open Access Journals (Sweden)

    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.

  8. An unpublished text of Jovellanos about mineralogy

    OpenAIRE

    Ordaz Gargallo, Jorge; Manuel GUTIÉRREZ CLAVEROL; Lorenzo Álvarez, Elena de

    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...

  9. The Mineralogy of Comet Wild 2

    Science.gov (United States)

    Zolensky, Michael

    2007-01-01

    The nature of cometary solids is of fundamental importance to our understanding of the early solar nebula and protoplanetary history. Samples of Comet Wild 2, provided by the Stardust Mission, have now been examined in terrestrial labs for two years, and are very surprising! Here we describe mainly the critical phases olivine, pyroxene and Fe-Ni sulfides in Wild 2 grains, as a guide to the general mineralogy of the returned comet samples.

  10. Mineralogical characterization of West Chestnut Ridge soils

    International Nuclear Information System (INIS)

    The morphological, physicochemical, and mineralogical properties of the soils and residua from the proposed site of the Central Waste Disposal Facility were characterized. The proposed site is underlain by cherty dolostones, limestones, and shales of the Knox Group covered by a thick residuum. Three diagnostic horizons from four soil profiles and six samples from residuum cores were selected for mineralogical analysis. The coarse fractions (gravel and sand) of the samples included different types of chert, iron-manganese oxide nodules, and quartz. The samples were high in clay content (except those from the A and E horizons) and low in pH and base saturation. The clay fractions were composed of varying amounts of kaolinite, mica, vermiculite, aluminum hydroxy-interlayered vermiculite, amorphous iron and aluminum oxides, gibbsite, and quartz. Aluminum hydroxy-interlayered vermiculite is the major component in surface horizons, but kaolinite becomes dominant in subsurface horizons of the soils. Degradation of kaolinite and formation of aluminum hydroxy-interlayered vermiculite and iron and aluminum oxides are pronounced chemical weathering processes in the surface soils. The aluminum hydroxy interlayering of vermiculite reduces cation exchange and selective sorption capacities of soils. In the residua, micaceous minerals free of aluminum hydroxy interlayering, kaolinite, and amorphous iron and aluminum oxides are major components in the clay fraction. The sorption ratios of 137Cs, 90Sr, 60Co, and the uranium isotopes expected to be in the radioactive wastes should be very high for the clays having such mineralogical composition. The low acid-buffering capacity (base saturation) of the residua suggest that the fragile chemical and mineralogical equilibria can be easily broken if an extreme chemical condition is imposed on the residua

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

    Directory of Open Access Journals (Sweden)

    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

  12. 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

  13. Petrography and composition of Martian regolith breccia meteorite Northwest Africa 7475

    Science.gov (United States)

    Wittmann, Axel; Korotev, Randy L.; Jolliff, Bradley L.; Irving, Anthony J.; Moser, Desmond E.; Barker, Ivan; Rumble, Douglas

    2015-02-01

    The Northwest Africa (NWA) 7475 meteorite is one of the several stones of paired regolith breccias from Mars based on petrography, oxygen isotope, mineral compositions, and bulk rock compositions. Its inventory of lithic clasts is dominated by vitrophyre impact melts that were emplaced while they were still molten. Other clast types include crystallized impact melt rocks, evolved plutonic rocks, possible basalts, contact metamorphosed rocks, and siltstones. Impact spherules and vitrophyre shards record airborne transport, and accreted dust rims were sintered on most clasts, presumably during residence in an ejecta plume. The clast assemblage records at least three impact events, one that formed an impact melt sheet on Mars ≤4.4 Ga ago, a second that assembled NWA 7475 from impactites associated with the impact melt sheet at 1.7-1.4 Ga, and a third that launched NWA 7475 from Mars ~5 Ma ago. Mildly shocked pyroxene and plagioclase constrain shock metamorphic conditions during launch to >5 and <15 GPa. The mild postshock-heating that resulted from these shock pressures would have been insufficient to sterilize this water-bearing lithology during launch. Magnetite, maghemite, and pyrite are likely products of secondary alteration on Mars. Textural relationships suggest that calcium-carbonate and goethite are probably of terrestrial origin, yet trace element chemistry indicates relatively low terrestrial alteration. Comparison of Mars Odyssey gamma-ray spectrometer data with the Fe and Th abundances of NWA 7475 points to a provenance in the ancient southern highlands of Mars. Gratteri crater, with an age of ~5 Ma and an apparent diameter of 6.9 km, marks one possible launch site of NWA 7475.

  14. 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)

  15. Mineralogical Analyses of a Precambrian Stromatolite

    OpenAIRE

    OHARA, Soji; Unno, Wasaburo; Tanaka, Masami; Sato, Yoshiyuki; Tanizawa, Kyoji

    1992-01-01

    [Abstract] Stromatolite is the fossil of the marine life of Infra-Cambrian era (ca.650-800Ma), having layered structure similar to the annual ring of woods. The mineralogy of these ring structures are studied by means of X-ray fluorescence analysis, IR (infra-red) absorption analysis and X-ray diffraction analysis. Dark-colored rings and light brown-colored intermediates are found to be consist of CaCO_3(Calcite) and Ca(FeMg)(CO_3)_2(Ankerite), respectively. Magnesium of chrolophyl origin is ...

  16. Mineralogic Model (MM3.0) Report

    Energy Technology Data Exchange (ETDEWEB)

    A. Sanchez

    2004-09-07

    The purpose of this report is to provide a three-dimensional (3-D) representation of the mineral abundance within the geologic framework model domain. The mineralogic model enables project personnel to estimate mineral abundances at any position, within the model region, and within any stratigraphic unit in the model area. The model provides the abundance and distribution of 10 minerals and mineral groups within 22 stratigraphic sequences or model layers in the Yucca Mountain area. The uncertainties and limitations associated with this model are discussed in Section 6.4. Model validation accomplished by corroboration with data not cited as direct input is discussed in Section 7.

  17. 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

  18. 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.

  19. Magnetic mineralogy of the Mercurian lithosphere

    Science.gov (United States)

    Strauss, Becky; Feinberg, Joshua; Johnson, Catherine

    2016-04-01

    Mercury and Earth are the only inner solar system planets with present-day core-dynamo magnetic fields, in contrast to the past fields of Mars and the Moon and the absence of evidence for a past or present field at Venus. Recently, the MESSENGER mission also measured magnetic fields from lithospheric magnetization on Mercury for the first time. These fields are consistent with remanent magnetization held by rocks exposed to an ancient, internally generated planetary magnetic field. However, the conditions for magnetization in the lithosphere of Mercury are unique among terrestrial planets, and the mechanisms for the acquisition (induced versus remanent) and alteration of magnetization are still unknown. We investigate the physical and chemical environment of Mercury's crust, past and present, to establish the conditions in which magnetization may have been acquired and subsequently modified. Three factors are particularly crucial to the determination of crustal composition and iron mineralogy: the temperature profile of the lithosphere and its evolution over time, redox conditions in the planet's crust and mantle, and the iron content of the lithosphere. We explore potential mechanisms for remanence acquisition and alteration on Mercury, whose surface environment is distinct from that of other inner solar system planets in that it is both very hot and highly reducing. The long-term thermal history of Mercury's crust plays an important role in the longevity of any crustal magnetization, which may be subject to remagnetization through thermal, viscous, and shock mechanisms. This thermal and compositional framework isused to constrain plausible candidate magnetic mineralogies, which can then be analyzed in terms of their capacity to acquire and retain magnetic remanence that is detectable from satellite orbit. We propose a suite of minerals and materials that could be carriers of remanence in the lithosphere of Mercury, including iron alloys, silicides, and sulfides.

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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.

  5. Organic petrography:An approach for identification of maceral groups in Gheshlagh coal area, Eastern Alborz

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    Tahereh Rabani

    2016-07-01

    Full Text Available Introduction Maceral is a term to introduce organic components visible under a microscope (Stopes, 1935. The physical and chemical characteristics of macerals such as elemental composition, moisture content, hardness, density and petrographic characteristics differ. The differences in the physical and chemical characteristics of macerals are reflected in their industrial behavior.(Parkash, 1985. Petrographic analysis provides information on the various physical components of coals (Suwarna and Hemanto, 2007 and determination of quality of coal, coalification rate, composition and characteristics of coke and paleoenvironmental deposition (Taylor et al., 1998. Sampling and methodology Coal samples were collected from freshly mined coal from 11 coal seams of 4 active coal mines (Cheshlagh, Zemestan Yourt, Narges Chal and Cheshmehsaran for organic petrography in the Gheshlagh coal deposits. All samples were collected and stored in plastic bags to prevent contamination and weathering. Samples were prepared for microscopic analysis by reflected light following ASTM Standard procedure D2797-04. For microscopic study, coal samples were crushed to1-mm size fraction (18 mesh size, mounted in epoxy resin and polished. Three polished samples were prepared for each coal seam. The petrographic composition was obtained by maceral analyses under standard conditions (ISO 7404/3, 2009, for maceral analysis. Maceral point counting (based on 400 points analyses were performed using an Olympus BX51 reflected light microscope. The terminology used to identify and describe the organic matter particles is the one proposed by the International Committee for Coal and Organic Petrology (ICCP, 1998; ICCP, 2001; Scott and Glasspool, 2007; Taylor et al., 1998; Stach et al., 1982; Hower et al., 2009; Hower and Wagner, 2012. Organic petrography of theGheshlagh coal seams The vitrinite maceral group is dominant in all coal seams (66.2 to 87.2 vol.% and includes collodetrinite

  6. 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

  7. Mineralogical sources of groundwater fluoride in Archaen bedrock/regolith aquifers: mass balances from the Peninsular Granite Complex, southern India

    Science.gov (United States)

    Hallett, Bethan; Burgess, William; Valsami-Jones, Eugenia

    2014-05-01

    Fluoride in groundwater-sourced drinking water is a widespread concern in India, particularly in the granitic gneiss bedrock/regolith catchments of Andhra Pradesh, one of the most severely affected states. Mobilisation of F- to groundwater is ultimately the consequence of bedrock weathering and regolith development, yet in crystalline bedrock/regolith terrain of the Peninsular Granite Complex, which constitutes a strategically important aquifer environment in India, uncertainties persist in relation to the relative contribution of the different F-bearing minerals and their distribution between the bedrock and the regolith. Even the relative significance of the bedrock and regolith as sources of fluoride to groundwater is disputed, as are explanations of seasonal and/or secular trends in groundwater F-. There are important implications for management of the groundwater resource. Understanding the mechanisms and progress of chemical weathering of the granitic gneiss is key to these questions, ie how effectively is F removed from its primary source(s) as the bedrock weathers? And, to what extent is F- flushed from the weathering profile and/or re-sequestered by secondary mineral phases as the regolith develops? To address these questions we have applied optical petrography, XRD, scanning electron microprobe analysis, whole-rock chemical analysis and leaching experiments to samples of bedrock and regolith from two catchments in Andhra Pradesh. We have quantified the distribution of F between its individual mineralogical sources, and between bedrock and regolith. Experiments show there is no straightforward relationship between whole-rock F content and leached [F-]; in some instances regolith samples leach higher F- concentrations than the fresh granitic gneiss. Results shed light on conflicting conceptual models of F release to groundwater in gneissic bedrock/regolith aquifers. Accounting for groundwater [F-], simple estimates of groundwater flux in the catchments

  8. Sulfur Mineralogy at the Mars Phoenix Landing Site

    Science.gov (United States)

    Ming, Douglas W.; Morris, R.V.; Golden, D.C.; Sutter, B.; Clark, B.C.; Boynton, W.V.; Hecht, M.H.; Kounaves, S.P.

    2009-01-01

    The Mars Phoenix Scout mission landed at the northernmost location (approx.68deg N) of any lander or rover on the martian surface. This paper compares the S mineralogy at the Phoenix landing site with S mineralogy of soils studied by previous Mars landers. S-bearing phases were not directly detected by the payload onboard the Phoenix spacecraft. Our objective is to derive the possible mineralogy of S-bearing phases at the Phoenix landing site based upon Phoenix measurements in combination with orbital measurements, terrestrial analog and Martian meteorite studies, and telescopic observations.

  9. 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

  10. Geology, petrography and geochronology of meridional and oriental regions from Morungaba complex, SP

    International Nuclear Information System (INIS)

    The Morungaba Granitoid Complex, covering about 330 km2, crops out as an elongate irregular Massif trending SW-NE, in the southeast part of the State of Sao Paulo, southeast Brazil. Major constituents are biotite granitoids with subordinate diorites. Over thirty facies types, each with distinctive structural-petrographic features, were recognized during detailed mapping of part of the Massif (about 200 km2), and mapped as groups of facies. Geochronological Rb/Sr data for several groups of associated facies are also presented. (author)

  11. 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.

  12. 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

  13. 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.

  14. About the mineralogical composition of Estonian oil shale ash

    International Nuclear Information System (INIS)

    Results of previous research about the mineralogical composition of Estonian oil shale ash focused on using X-ray diffractometry, problems related to oil shale combustion, and utilization of oil shale ashes were analysed. (author)

  15. Present methods for mineralogical analysis of uranium ores

    International Nuclear Information System (INIS)

    Most promising methods of mineralogic analysis of uranium and uranium-containing minerals, ores and rocks are considered. They include X-ray diffraction, electron microscopy and fluorescence spectroscopy methods. Principle physical basis and capabilities of each method are described; examples of its practical application are presented. Comparative characteristic of method for mineralogic analysis of radioactive ores and their reprocessing products is given. Attention is paid to the equipment and various devices for analysis

  16. The petrography of the Jurassic core from the Harwell research site. Part 1: Kimmeridge Clay, Corallian Beds and Oxford Clay

    International Nuclear Information System (INIS)

    Detailed examination by mineralogical and petrological techniques has enabled a detailed characterisation of the lithologies of the Oxford Clay, Corallian Beds and the Kimmeridge Clay beneath the Harwell Research Site. Information obtained has revealed the nature of the bulk mineralogy, pore-types, pore-surface mineralogy and post-depositional alteration of the rocks. Diagenesis has played an important part in determining the mineralogy, porosity and fabric of the rocks and has had the greatest variation of effects in the Corallian Beds, determining the phases now in contact with groundwater. It is these authigenic phases that are of key interest in assessing the behaviour of radionuclides which may be released into the local groundwater systems. The importance of the different pore-types characterised during this investigation and of the mineral phases lining these potential pathways for groundwater movement are discussed in detail at the end of this report. Diagenesis has reduced primary porosity in many of the Corallian rocks by calcite precipitation. In such rocks where a cohesive cement is present, groundwater flow must occur along large-scale fractures and more slowly along intercrystalline grain-boundary cracks. (author)

  17. Investigations on SYNROC mineralogy. Progress report

    International Nuclear Information System (INIS)

    Progress reports are presented for the following projects: (1) factors influencing the leaching performance of hollandiate; (2) incorporation of uranium and rare earths into zirconolite; (3) reconnaissance studies of the stability relations of Ca-Ti-Al phases in SYNROC C formulations; (4) immobilization of highly aluminous sludges; (5) SYNROC D formulations produced by sintering in air; (6) crystallization behavior of interstitial glass in SYNROC D formulations. Some of the highlights are: (1) leaching performance of all hollandites irrespective of preparation technique, can be improved by hot-pressing under specific controlled redox conditions, below Ni-NiO; (2) there is no satisfactory crystal-chemical reason why the leaching performance of Ti3+-bearing hollandite should be superior to that of Al3+ hollandite; (3) experiments have shown that the zirconolite lattice can accept up to 30% rare earths (Sm2O3) before becoming destabilized in favor of pyrochlore or a related f.c.c. structure; (4) SYNROC zirconolites will therefore be well below their saturation limits in rare earths and trivalent actinides; (5) experiments have established that the Ca-Ti-Al phase (CTA) is compatible with perovskite, hollandite and zirconolite; (6) magnetoplumbite-type phases coexists with hollandite, perovskite, zirconolite and Fe-bearing pseudobrookite, but do not coexist with the CTA phase CaTi3Al8O19; (7) experiments demonstrated that it is not possible to convert highly aluminous sludges to a waste form comprising zirconolite, perovskite, spinel and nepheline plus corundum, by adding appropriate minimum amounts of the inert SYNROC additives (CaO, TiO2, ZrO2, SiO2); (8) sintering of SYNROC D in air at temperatures just above the solidus (1200 to 12500C) produced a dense compact ceramic, but the optimum SYNROC-D mineralogy was not produced

  18. 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

  19. 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. [GTK 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.)

  20. Planosols Developed in Different Geoenvironmental Conditions in Northeastern Brazil

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    José Thales Pantaleão Ferreira

    2016-01-01

    Full Text Available ABSTRACT The semiarid region of northeastern Brazil has a large area occupied by Planosols, where in the State of Pernambuco these soils are mainly used for livestock farming and subsistence crops. The knowledge on these soils is limited, which compromises the understanding on their behavior, potentialities and limitations.This study aimed to analyze morphological, chemical, physical and mineralogical attributes of Planosols developed under different geoenvironmental conditions. Morphological descriptions and chemical, physical and mineralogical analyses were performed in four profiles of Planosols along a rainfall gradient. An increase in rainfall allowed for an increase in the clay content in the Bt horizon and a reduction in ESP, EC, Na+, CEC, S, pH (water and KCl and soil density. Horizons A and E were thicker in Planosols in more humid environments. The increase in ESP associated with the presence of expansive minerals (smectite and vermiculite allowed the development of a prismatic structure in Haplic Planosols and a columnar structure in Natric Planosols. The mineralogical assembly is indicative of poorly weathered soils. The mineralogical assemblies of the silt and clay fractions were similar in the different geoenvironments, while higher contents of easily alterable minerals were observed in the composition of the sand fraction in environments with a drier climate.

  1. 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

  2. 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.

  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. 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.

  5. 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.

  6. 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.

  7. 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.…

  8. 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

  9. The Composition of 433 Eros: A Mineralogical-Chemical Synthesis

    Science.gov (United States)

    McCoy, T. J.; Gaffey, M.; Bell, J. F., III; Boynton, W. V.; Burbine, T. H.; Chapman, C. R.; Cheng, A.; Clark, P. E.; Evans, L. G.; Gorenstein, P.

    2001-01-01

    We report on an effort with the Near-Infrared Spectrometer/Multi-Spectral Imager (NIS/MSI) and X-ray/Gamma-ray Spectrometer (XGRS) teams to synthesize our data sets to constrain the relationship between Eros and meteorites; the mineralogy, abundances and compositions of Eros; and the processes that formed Eros. Additional information is contained in the original extended abstract.

  10. 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

  11. 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。

  12. Skeletal mineralogy of bryozoans: Taxonomic and temporal patterns

    Science.gov (United States)

    Smith, Abigail M.; Key, Marcus M., Jr.; Gordon, Dennis P.

    2006-10-01

    Skeletal carbonate mineralogy of 1183 specimens of marine bryozoans from the literature was examined for phylogenetic patterns in order to elucidate the effects of bryozoan mineralogy on geochemical and paleoenvironmental analysis. Colonies are composed of calcite (66% of specimens), aragonite (17% of specimens) or various mixtures of the two (17% specimens) (phylum mean = 72.9 wt.% calcite, n = 1051). When calcite is present, it ranges from 0.0 to 13.7 wt.% MgCO 3 (mean = 5.0 wt.% MgCO 3, n = 873). Most (61%) calcitic specimens are formed of intermediate-Mg calcite (4 to 8 wt.% MgCO 3), others (28%) of low-Mg calcite (0 to 4 wt.% MgCO 3), and few of high-Mg calcite (> 8 wt.% MgCO 3). The phylum occupies at least 63% of the theoretical mineralogical "space" available to biomineralisation. Most of this variation occurs in the class Gymnolaemata, order Cheilostomata, suborder Neocheilostomata. Fossil and Recent stenolaemate taxa are generally low- to intermediate-Mg calcite (mean = 99.7 wt.% calcite, 2.6 wt.% MgCO 3, 17% of available biomineral space). Variability among families is related in a general way to first appearance datum: families younger than 100 Ma display greater mineralogical complexity than older ones. The cheilostome infraorder Flustrina includes unusual free-living aragonitic families, dual-calcite skeletons (mainly low-Mg calcite, but with secondary high-Mg calcite), and some genera with considerable mineralogical variability. Families (e.g., Membraniporidae and Phidoloporidae) and species (e.g., Schizoporella unicornis) with the highest degree of variability have potential for environmental correlations with mineralogy, paleoenvironmental interpretation, and possibly molecular investigation for potential cryptic species. Stenolaemate families, genera and species with low variability, on the other hand, are well-suited for geochemical work such as stable isotope analysis. Variability in the skeletal mineralogy of bryozoans suggests that they may be

  13. Some not so obvious reasons to teach optical mineralogy

    Science.gov (United States)

    Gunter, M. E.

    2004-12-01

    Hands-on, interactive, critical thinking, interdisciplinary, spiral learning, and 3-D visualization are familiar words in pedagogy, while Becke lines, dispersion staining, grain mounts, sign of elongation, extinction angle, and optical indicatrix are words seldom used in today's geosciences curriculum. However, the teaching of these seemingly rather historical optical methods, and proper training in the use of the polarized (not petrographic) light microscope (PLM), will by themselves lead to improved learning of our students. And this, if for no other reason, might warrant the inclusion of a semester-long optical mineralogy course. However, another $70 billion per year concern in the U.S. also warrants inclusion of optical mineralogy in a geosciences curriculum. That dollar amount (which would be approximately 10% of annual petroleum sales in the U.S.) centers around the cost spent (wasted?) on asbestos litigation in the U.S. Unfortunately, because we no longer teach PLM skills in the geosciences curriculum, many of the microscopists, regulators, and "expert" witnesses involved in the asbestos issue have little or no formal training in mineralogy or optical mineralogy. This, in turn, often leads to formulation of regulations that make little sense (e.g., that quartz, the most abundant mineral species in the earth's crust is now listed as a human carcinogen) and unsolved mineralogical issues (e.g., OSHA deregulated high-aspect ratio amphibole cleavage fragments in 1994 but did not propose a method to distinguish them from amphibole fibers). The current asbestos issues often deal with tremolite contamination in chrysotile or talc. There are simple PLM methods that we could teach whereby thousands of particles could be screened in minutes to find these possible contaminates, whereas electron beam or X-ray diffraction methods require orders of magnitude more time and cost - and this is only one of many examples. Finally, one might also argue that since minerals

  14. Field characteristics, petrography, and geochronology of the Hohonu Batholith and the adjacent Granite Hill Complex, North Westland, New Zealand

    International Nuclear Information System (INIS)

    Detailed geological mapping, petrography, geochemistry and geochronological studies in the Hohonu Batholith, North Westland, have identified 10 granitoid plutons emplaced during three intrusive episodes. The earliest episode is represented by a single dated Paleozoic pluton, Summit Granite (new) (381.2 ± 7.3 Ma), which is correlated with a discrete pulse of Mid-Late Devonian plutonism recognised in the Karamea Batholith. The undated Mount Graham Granite (new) is also likely to be Paleozoic, based on chemical and petrographic characteristics. The bulk of the batholith (seven plutons) was emplaced in the mid Cretaceous (114-109 Ma) and comprises two related, yet distinct, geochemical suites, which correlate with the previously defined Rahu Suite. The plutons identified are (from north to south): Pah Point Granite; Jays Creek Granodiorite (new); Uncle Bay Tonalite; Te Kinga Monzogranite; Deutgam Granodiorite; Turiwhate Granodiorite (new); and Arahura Granite (new). Mid-Cretaceous plutonism in the Western Province is considered to be the result of crustal thinning and extension following overthickening during collision of the Early Cretaceous Median Tectonic Zone volcanic arc. Late Cretaceous alkaline activity is represented by the emplacement of the A-type French Creek Granite at 1.7 ± 1.8 Ma, contemporaneous with intrusion of a major swarm of doleritic-lamprophyric dikes - the Hohonu Dike Swarm. These events correlate with the first appearance of oceanic crust in the Tasman Sea. The Granite Hill Complex is a suite of amphibolite facies gneisses occurring as an uplifted wedge between the Alpine Fault nd the Hohonu Batholith. These gneisses are considered to represent an extension of the Fraser Complex to the south. A detailed understanding of their geological affinities and history is yet to be established. (author). 66 refs., 7 figs., 3 tabs

  15. Chemical and mineralogical soil atributes from Comperj area due to variations in lithotype, landscape position and vegetation cover

    Directory of Open Access Journals (Sweden)

    João Bosco Vasconcellos Gomes

    2014-04-01

    Full Text Available Establishing Comperj (petrochemical complex Petrobras and partner companies at Itaboraí city, Rio de Janeiro State, Brazil involves a great impact on natural environment, while it is an opportunity for actions of environmental compensation. The objectives of this study were to characterize soil chemistry and mineralogy of Comperjarea, based on landscape, particle size distribution and soil morphology, also considering different parent materials, landscape positions (shoulder, backslope and footslope at the hillslope and toeslope at floodplain and vegetation cover groups. Different landscape positions, comparing toeslope and average hillslope, have differential behavior on several chemical attributes, besides those associated with landscape position itself (topography and water regime. Along the hillslope, differences on surface soil samples also occurred, considering studied attributes, among different parent materials and vegetation covergroups. Sites of both vegetation cover groups (forest and pasture along the hillslope showed differences on many chemical attributes, except for organic C average valuesthat were not differentiated among them. Soil mineralogy on all samples was extremely kaolinitic and there were small differences among parent material groups. Soilconsistencies observed were very to extremely hard on both soil parent material groups, Proterozoic and Tertiary.

  16. Contributions to the petrography, geochemistry and geochronology (U-Pb and Sm-Nd) of the Paleoproterozoic effusive rocks from Iricoume Group, Amazonian Craton, Brazil

    International Nuclear Information System (INIS)

    The southernmost region of the Guyana shield, Amazonian craton, hosts large record of Paleoproterozoic effusive rocks of the Iricoume Group. They present remarkably well-preserved igneous textures and structures. The SiO2 contents reveal a bimodal association marked by a compositional gap between acid (SiO2 > 67 wt%) and intermediate (SiO2 2, alkali, Rb, Zr, Nb + Ta, La + Ce and 104 Ga/Al content and low Fe2O3tot, TiO2, CaO, Sr and Co content. They exhibit subalkaline, metaluminous-to-peraluminous compositions, and geochemically compatible to A-type magmatism emplaced in post-collisional to within-plate tectonic settings. The intermediate rocks are andesitic/basalt to andesite relatively high contents of TiO2, Al2O3, Fe2O3total, MgO, CaO, Sr and Co; low SiO2, K2O, Rb, Zr, Nb + Ta, La + Ce. They have subalkaline and metaluminous geochemical composition and plot on within-plate basalt field. The acid rocks crystallized at 1882 ± 11 Ma in U-Pb analyses for LA-MC-ICPMS zircon data. The Sm-Nd isotopic data on all rocks reveal a Nd TDM model ages between 2.59 and 2.16 Ga and εNd(t) values between -5.78 and 0.03, indicate that the magmatic evolution was related to the reworking of older Paleoproterozoic at the Rhyacian-Siderian period, continental crust (Transamazonian crust-forming event) with some mixing with a limited amount mantle-derived magmas or with contamination by Archean crust. The petrographic, geochemical and geochronological data presented in this paper suggest a within-plate to post-collisional tectonic setting for the Iricoume volcanism, involving lower crust uplift and generation of basalt magma in an extensional regime. (author)

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

    Directory of Open Access Journals (Sweden)

    TRAVERSA GIANBOSCO

    2001-01-01

    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.

  18. Contributions to the petrography, geochemistry and geochronology (U-Pb and Sm-Nd) of the Paleoproterozoic effusive rocks from Iricoume Group, Amazonian Craton, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Suelen Nonata de Souza; Nascimento, Rielva Solimairy Campelo do, E-mail: suelen-marques@hotmail.com, E-mail: rielva@ufam.edu.br [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Inst. de Geociencias; Souza, Valmir da Silva; Dantas, Elton Luiz, E-mail: vsouza@unb.br, E-mail: elton@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Inst. de Geociencias; Valerio, Cristovao da Silva, E-mail: cristovao@igeo.ufrr.br [Universidade Federal de Roraima (UFRR), Boa Vista, RR (Brazil). Inst. de Geociencias

    2014-07-01

    The southernmost region of the Guyana shield, Amazonian craton, hosts large record of Paleoproterozoic effusive rocks of the Iricoume Group. They present remarkably well-preserved igneous textures and structures. The SiO{sub 2} contents reveal a bimodal association marked by a compositional gap between acid (SiO{sub 2} > 67 wt%) and intermediate (SiO{sub 2} < 57.7 wt%) rocks. The acid effusive rocks are rhyolites to rhyodacites with high SiO{sub 2}, alkali, Rb, Zr, Nb + Ta, La + Ce and 104 Ga/Al content and low Fe{sub 2}O{sub 3tot}, TiO{sub 2}, CaO, Sr and Co content. They exhibit subalkaline, metaluminous-to-peraluminous compositions, and geochemically compatible to A-type magmatism emplaced in post-collisional to within-plate tectonic settings. The intermediate rocks are andesitic/basalt to andesite relatively high contents of TiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3total}, MgO, CaO, Sr and Co; low SiO{sub 2}, K{sub 2}O, Rb, Zr, Nb + Ta, La + Ce. They have subalkaline and metaluminous geochemical composition and plot on within-plate basalt field. The acid rocks crystallized at 1882 ± 11 Ma in U-Pb analyses for LA-MC-ICPMS zircon data. The Sm-Nd isotopic data on all rocks reveal a Nd TDM model ages between 2.59 and 2.16 Ga and ε{sub Nd}(t) values between -5.78 and 0.03, indicate that the magmatic evolution was related to the reworking of older Paleoproterozoic at the Rhyacian-Siderian period, continental crust (Transamazonian crust-forming event) with some mixing with a limited amount mantle-derived magmas or with contamination by Archean crust. The petrographic, geochemical and geochronological data presented in this paper suggest a within-plate to post-collisional tectonic setting for the Iricoume volcanism, involving lower crust uplift and generation of basalt magma in an extensional regime. (author)

  19. 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)

  20. On the relationship between luminescence excitation spectra and feldspar mineralogy

    DEFF Research Database (Denmark)

    Poolton, N.R.J.; Bøtter-Jensen, L.; Johnsen, O.

    1996-01-01

    Feldspar minerals can be used as naturally occurring radiation dosemeters, with dose assessment commonly using luminescence techniques. Since many feldspars contain radioactive K-40, knowledge of the mineralogy of the luminescent samples being measured is of high importance. Most feldspars contain...... more than trace amounts of highly luminescent Fe3+ impurities, and this article examines the relationship between features of the luminescence excitation spectrum of this ion with sample mineralogy. It is demonstrated that there is a near linear correspondence between the plagioclase feldspar...... groups. The results are compared with properties of the excitation spectra dose-dependent optically stimulated luminescence (OSL) in order to compare the chemical environment of the OSL donor defect, and the isolated Fe3+ centres....

  1. 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

  2. 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.

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

    OpenAIRE

    Alexandra Giurgiu; Tudor Tămaş

    2013-01-01

    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, leucoph...

  4. Petrology and mineralogy of the Y-793605 martian meteorite

    OpenAIRE

    Yukio, Ikeda

    1997-01-01

    Yamato-793605 is a lherzolitic shergottite and very similar in texture and mineralogy to other two lherzolitic shergottites, ALHA77005 and LEW88516,but is not a pair with the latter two. It consists mainly of olivine, pyroxene, maskelynite, chromite, ilmenite, and pyrrhotite. Small silicate inclusions occur in olivine and pyroxene. Olivine has a wide compositional range from Fo_ to Fo_, that included in pyroxene is more magnesian, and that in contact with maskelynite is more ferroan. Chromite...

  5. Mineralogy and chemical compositions of Colomera (IIE) silicate inclusions

    OpenAIRE

    Hsu, W.; H. Takeda; Huss, G. R.; Wasserburg, G. J.

    1997-01-01

    Irons of groups lAB and IIE contain silicate inclusions. In IAB irons, these inclusions are basically chondritic, but in IIE they vary from chondritic to highly differentiated [1,2]. In this work, we present detailed studies of mineralogy and trace-element geochemistry of eight silicate inclusions from Colomera with the goal of better understanding early planetary differentiation and possible genetic relationships between iron and stony meteorites.

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

    International Nuclear Information System (INIS)

    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

  7. 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

  8. 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

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

    OpenAIRE

    Ordaz Gargallo, Jorge; Manuel GUTIÉRREZ CLAVEROL; Lorenzo Álvarez, Elena de

    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...

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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

  15. Petrography, age, and paleomagnetism of basalt lava flows in coreholes Well 80, NRF 89-04, NRF 89-05, and ICPP 123, Idaho National Engineering Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Lanphere, M.A.; Champion, D.E. [Geological Survey, Menlo Park, CA (United States); Kuntz, M.A. [Geological Survey, Denver, CO (United States)

    1993-12-31

    The petrography, age, and paleomagnetism were determined on basalt from 23 lava flows comprising about 1200 feet of core from four coreholes in the Idaho National Engineering Laboratory (ML). The four coreholes are located in the southwestern part of the INEL. Paleomagnetic measurements were made on 192 samples of basalt, and K-Ar ages were measured on 19 basalt samples. All of the samples have normal magnetic polarity and were erupted during the Brunhes Normal Polarity Epoch. Basalt lava flows in ICPP 123 can be satisfactorily correlated with lava flows in the previously studied corehole at Site E, but correlations cannot be made with confidence between ICPP 123 and the other three coreholes studied in this investigation.

  16. Radiopharmacy education in Brazil

    OpenAIRE

    Ralph Santos-Oliveira; Marta De Souza Albernaz

    2014-01-01

    The number of schools of pharmacy has been increasing each year in Brazil. From 2002 to 2013 over 300 new schools were opened in Brazil with a final number of 415 schools of pharmacy in operation around the country. Of these schools, only 28 schools offer a course in radiopharmacy (7.77%). However, the demand for such trained professionals has grown exponentially in Brazil, especially following amendment 49 (February 2006) that broke the monopoly on the production, distribution, and marketing...

  17. Mineralogical Mapping in the Cuprite Mining District, Nevada

    Science.gov (United States)

    Goetz, A. F. H.; Srivastava, V.

    1985-01-01

    The airborne imaging spectrometer (AIS) has provided for the first time, the possibility to map mineralogical constituents in the Earth's surface and thus has enormously increased the value of remote-sensing data as a tool in the solution of geologic problems. The question addressed with AIS at Cuprite was how well could the mineral components at the surface of a hydrothermal alteration zone be detected, identified and mapped? The question was answered positively and is discussed. A relatively rare mineral, buddingtonie, that could not have been detected by conventional means, was discovered and mapped by the use of AIS.

  18. 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...... Ocean. In this project, we studied samples of dust and topsoils in various agroecological zones, from the north to the south of Ghana, focussing mainly on the mineralogy of these materials. Some data about grain sizes and morphology of the samples are also presented. Feldspars, together with quartz...

  19. Mineralogy-swelling potential relationships for expansive shales

    Science.gov (United States)

    Olsen, H.W.; Krosley, L.; Nelson, K.; Chabrillat, S.; Goetz, A.F.H.; Noe, D.C.

    2000-01-01

    The extent to which mineralogy and swelling potential is correlated in the expansive clays and shales is studied. Sites are selected in Cretaceous shales, including Pierre Shale, that are uplifted into steeply dipping strata near the foothills of the Rocky Mountains. Swelling potentials are obtained on limited suites of samples with conventional and labor-intensive schemes including Seed and Chen's schemes, and with swell-consolidation measurements in response to saturation, consolidation, and rebound in an oedometer. The results showing the percent total smectite provide a useful index of swelling potential concept defined by Seed and correlates well with the swelling potential indices developed by Seed, Chen, and McKeen.

  20. 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.

  1. Nano-mineralogy of suspended sediment during the beginning of coal rejects spill.

    Science.gov (United States)

    Civeira, Matheus S; Ramos, Claudete G; Oliveira, Marcos L S; Kautzmann, Rubens M; Taffarel, Silvio R; Teixeira, Elba C; Silva, Luis F O

    2016-02-01

    Ultrafine and nanometric sediment inputs into river systems can be a major source of nutrients and hazardous elements and have a strong impact on water quality and ecosystem functions of rivers and lakes regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in South America. The objective of this work was to study the coal cleaning rejects (CCRs) spill that occurred from a CCRs impoundment pond into the Tubarão River, South Brazil, provided a unique occasion to study the importance and role of incidental nanoparticles associated with pollutant dispersal from a large-scale, acute aquatic pollution event. Multifaceted geochemical research by 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 Raman spectroscopy, provided an in-depth understanding of importance of a nano-mineralogy approach of Aqueous Pollution Scenarios. The electron beam studies showed the presence of a number of potentially hazardous elements (PHEs) in nanoparticles (amorphous and minerals). Some of the neoformed ultrafine/nanoparticles found in the contaminated sediments are the same as those commonly associated with oxidation/transformation of oxides, silicates, sulfides, and sulfates. These data of the secondary ultra/nanoparticles, puts in evidence their ability to control the mobility of PHEs, suggesting possible presentations in environmental technology, including recuperation of sensitive coal mine. The developed methodology facilitated the sediment transport of the catchment providing consistent results and suggesting its usefulness as a tool for temporary rivers management. PMID:26688250

  2. Rare earth elements and titanium in plants, soils and groundwaters in the alkaline-ultramafic complex of Salitre, MG, Brazil

    OpenAIRE

    Ceccantini, G.; Figueiro, A.M.G.; Sondag, Francis; Soubiès, François

    1997-01-01

    The contents of Rare Earth Elements (REE) and titanium in various species of plants, in groundwaters and in soils from the ultramafic complex of Salitre, MG, Brazil, were determined. Due to the particular mineralogy of the bedrock, REE and Ti present high concentrations in the soils. The transfer factors of the REE from soil to plants were calculated, giving values ranging from 0.0001 to 0.0028, much lower than the values reported elsewhere in Brazil. Furthermore, as suggested by other author...

  3. Distribution and petrography of the mesozoic basic dykes of the San Gregorio de Polanco, Parana magmatic province, Uruguay

    International Nuclear Information System (INIS)

    The tectonomagmatic events developed in the lower Cretaceous, predating the South Atlantic Ocean opening, generated an intensive magmatic activity that covered an important surface of the South American platform (Parana-Etendeka Magmatic Province). Both the instability and rupture of the continental crust, as well as magma rising are registered by the presence of basic intrusions (dykes and sills), and lava flows located in the central-north portion of Uruguay. This paper deals with a detailed petrologic study focused on the San Gregorio de Polanco Dyke Swarm (Department of Tacuarembo). As result of semidetailed geological mapping, 17 dyke segments with 12km length and 20m width maximum have been identified. These dykes are concentrated in four main geographic zones named: Achar, San Gregorio de Polanco, La Paloma and San Jorge. The dykes define parallel to sub parallel trends, with a zig-zag pattern (N140°-170° and N080°-110°) controlled by basement lineaments. Their mineralogy includes calcic plagioclases (labradorite and andesine), calcic clinopyroxene (augite-pigeonite), opaques minerals (two populations), olivine; glass and apatite as accessories. In turn, the SEM-EDS analyses of the opaque minerals (modal 15%) of both populations allowed their classification as titanomagnetite correspondent to different crystallisation stages. The first population of titanomagnetite would correspond to the main crystallisation stage while the second one would be generated by partial dissolution of the former under low oxygen fugacity conditions and temperatures around 450°C

  4. Characterizing the Mineralogy of Potential Lunar Landing Sites

    Science.gov (United States)

    Pieters, Carle; Head, James W., III; Mustard, Jack; Boardman, Joe; Buratti, Bonnie; Clark, Roger; Green, Rob; Head, James W, III; McCord, Thomas B.; Mustard, Jack; Runyon, Cassandra; Staid, Matt

    2006-01-01

    Many processes active on the early Moon are common to most terrestrial planets, including the record of early and late impact bombardment. The Moon's surface provides a record of the earliest era of terrestrial planet evolution, and the type and composition of minerals that comprise a planetary surface are a direct result of the initial composition and subsequent thermal and physical processing. Lunar mineralogy seen today is thus a direct record of the early evolution of the lunar crust and subsequent geologic processes. Specifically, the distribution and concentration of specific minerals is closely tied to magma ocean products, lenses of intruded or remelted plutons, basaltic volcanism and fire-fountaining, and any process (e.g. cratering) that might redistribute or transform primary and secondary lunar crustal materials. The association of several lunar minerals with key geologic processes is illustrated in Figure 1. The geologic history of potential landing sites on the Moon can be read from the character and context of local mineralogy.

  5. Mineralogy of interplanetary dust particles from the 'olivine' infrared class

    Science.gov (United States)

    Christoffersen, R.; Buseck, P. R.

    1986-01-01

    Analytical electron microscopy observations establish that olivine is abundant and the predominant silicate phase in three interplanetary dust particles (IDPs) from the 'olivine' infrared spectra category. Two of the particles have microstructures resembling those of most nonhydrous chondritic IDPs, consisting of micron to submicron grains together with a matrix composed of amorphous carbonaceous material and sub-500 A grains. In addition to olivine these particles respectively contain enstatite and magnetite, and pentlandite plus Ca-rich clinopyroxene. The third IDP consists mostly of olivine and pyrrhotite with little or no matrix material. Olivine grains in this particle contain prominent solar-flare ion tracks with densities corresponding to a space-exposure age between 1000 to 100,000 years. Although the three particles have olivine-rich mineralogies in common, other aspects of their mineralogies and microstructures suggest that they experienced different formation histories. The differences between the particles indicate that the olivine infrared spectral category is a diverse collection of IDPs that probably incorporates several genetic groups.

  6. Automated mineralogical logging of coal and coal measure core

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Fraser; Joan Esterle; Colin Ward; Ruth Henwood; Peter Mason; Jon Huntington; Phil Connor; Reneta Sliwa; Dave Coward; Lew Whitbourn [CSIRO Exploration & Mining (Australia)

    2006-06-15

    A mineralogical core logging system based on spectral reflectance (HyLogger{trademark}) has been used to detect and quantify mineralogies in coal and coal measure sediments. The HyLogger{trademark} system, as tested, operates in the visible-to-shortwave infrared spectral region, where iron oxides, sulphates, hydroxyl-bearing and carbonate minerals have characteristic spectral responses. Specialized software assists with mineral identification and data display. Three Phases of activity were undertaken. In Phase I, carbonates (siderite, ankerite, calcite) and clays (halloysite, dickite) were successfully detected and mapped in coal. Repeat measurements taken from one of the cores after three months demonstrated the reproducibility of the spectral approach, with some spectral differences being attributed to variations in moisture content and oxidation. Also, investigated was HyLogger{trademark} ability to create a 'brightness-profile' on coal materials, and these results were encouraging. In Phase II, geotechnically significant smectitic clays (montmorillonite) were detected and mapped in cores of clastic roof and floor materials. Such knowledge would be useful for mine planning and design purposes. In Phase III, our attempts at determining whether phosphorus-bearing minerals such as apatite could be spectrally detected were less than conclusive. A spectral index could only be created for apatite, and the relationships between the spectrally-derived apatite-index, the XRD results and the analytically-derived phosphorus measurements were ambiguous.

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

    Science.gov (United States)

    Stegen, James C; Konopka, Allan; McKinley, James P; Murray, Chris; Lin, Xueju; Miller, Micah D; Kennedy, David W; Miller, Erin A; Resch, Charles T; Fredrickson, Jim K

    2016-01-01

    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, richness, and 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 richness-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. PMID:27469056

  8. 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.

  9. Mineralogic Model (MM3.0) Analysis Model Report

    Energy Technology Data Exchange (ETDEWEB)

    C. Lum

    2002-02-12

    The purpose of this report is to document the Mineralogic Model (MM), Version 3.0 (MM3.0) with regard to data input, modeling methods, assumptions, uncertainties, limitations and validation of the model results, qualification status of the model, and the differences between Version 3.0 and previous versions. A three-dimensional (3-D) Mineralogic Model was developed for Yucca Mountain to support the analyses of hydrologic properties, radionuclide transport, mineral health hazards, repository performance, and repository design. Version 3.0 of the MM was developed from mineralogic data obtained from borehole samples. It consists of matrix mineral abundances as a function of x (easting), y (northing), and z (elevation), referenced to the stratigraphic framework defined in Version 3.1 of the Geologic Framework Model (GFM). The MM was developed specifically for incorporation into the 3-D Integrated Site Model (ISM). The MM enables project personnel to obtain calculated mineral abundances at any position, within any region, or within any stratigraphic unit in the model area. The significance of the MM for key aspects of site characterization and performance assessment is explained in the following subsections. This work was conducted in accordance with the Development Plan for the MM (CRWMS M&O 2000). The planning document for this Rev. 00, ICN 02 of this AMR is Technical Work Plan, TWP-NBS-GS-000003, Technical Work Plan for the Integrated Site Model, Process Model Report, Revision 01 (CRWMS M&O 2000). The purpose of this ICN is to record changes in the classification of input status by the resolution of the use of TBV software and data in this report. Constraints and limitations of the MM are discussed in the appropriate sections that follow. The MM is one component of the ISM, which has been developed to provide a consistent volumetric portrayal of the rock layers, rock properties, and mineralogy of the Yucca Mountain site. The ISM consists of three components: (1

  10. Chemical and mineralogical characterization of iron concretions of some Brazilian soils

    International Nuclear Information System (INIS)

    Chemical and physical analyses of concretionary materials were carried out, with the purpose of getting chemical and mineralogical characteristics of concretions found in some Brazilian soils in different ecosystems spectrophotometry was used for the chemical characterization, and x-ray diffraction and Moessbauer spectroscopy for the mineralogical characterization of the materials studied. (A.R.H.)

  11. Petrography, palynology, and paleoecology of the Lower Pennsylvanian Bon Air coal, Franklin County, Cumberland Plateau, southeast Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Shaver, Stephen A.; Saussy, Frederick L. [Department of Forestry and Geology, University of the South, Sewanee, TN 37383 (United States); Eble, Cortland F. [Kentucky Geological Survey, 228 MMRB, University of Kentucky, Lexington, KY 40506-0107 (United States); Hower, James C. [Center for Applied Energy Research, University of Kentucky, 2540 Research Park Drive, Lexington, KY 40511-8433 (United States)

    2006-05-03

    Stratigraphy, palynology, petrography, and geochemistry of the Bon Air coal from the Armfield, Dotson, Rutledge, and Shakerag mine sites of Franklin County, Tennessee suggest that Bon Air seams at all sites were small (=1.0 mile, 1.6 km), spatially distinct paleomires that evolved from planar to domed within the fluviodeltaic Lower Pennsylvanian Raccoon Mountain Formation. Of observed palynoflora, 88?97% are from lycopsids prevalent in the Westphalian. Densosporites palynomorphs of small lycopsids (e.g., Omphalophloios) dominate at the shale-hosted Armfield site, while Lycospora palynoflora of large arboreous lycopsids (especially Lepidodendron, with lesser Lepidophloios harcourtii and Lepidophloios hallii) dominate where intercalated siltstone/sandstone/shale hosts the coal (all other sites). Palynoflora of other lycopsids (Sigillaria and Paralycopodites), tree ferns, seed ferns, small ferns, calamites, and cordaites are generally minor. Genera of clastic-associated Paralycopodites are most common in Shakerag's coal (=10%), yet quite rare in Rutledge or Dotson coals. Overall, the palynomorph assemblages suggest that the Bon Air paleomires were forest swamps, and Early Pennsylvanian in age (Westphalian A, Langsettian). Dominant macerals at all sites are vitrinites, with fine collodetrinite (from strongly decomposed plant debris) more common than coarser collotelinite (from well-preserved plant fragments), and with lesser inertinites (fusinite and semifusinite) and liptinites (dominantly sporinite). Shakerag's coal has greatest abundance (mineral-matter-free) of collotelinite (up to 47%) and total vitrinite (74?79%) of any sites, but lowest liptinite (12?14.5%) and inertinite (7?11%). The Dotson and Rutledge seams contain moderate liptinite (21?23%) and highest inertinite (36?37%), lowest vitrinite (=41%), and lowest collotelinite (13?15%). Armfield's seam has relatively high liptinite (26?28%) and vitrinite (56.5?62%), but rather low inertinite (12

  12. 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

  13. Archean spherule classification of CT3 drill core, Barberton Greenstone Belt (South Africa) based on petrography and mineral chemistry

    Science.gov (United States)

    Ozdemir, Seda; Koeberl, Christian; Mohr-Westheide, Tanja; Reimold, W. Uwe; Hofmann, Axel

    2016-04-01

    The impact history of the Early Archean Earth is not well documented. The oldest known impact structure is about 2 Ga years old; impact-related signatures in Precambrian rocks are scarce. The possible impact signature might be the Archean spherule layers that occur in the Barberton Greenstone Belt (BGB), Kaapvaal Craton, South Africa, and in the Pilbara Craton Western Australia, with ages of 3.2-3.4 and around 2.5 Ga [1]. These spherules were interpreted as impact-generated and ballistically emplaced silicate melt droplets [2]. This study is focused on petrographic and mineralogical characteristics from a set of newly drilled Archean spherule layers in drill core CT3 from the northeastern part of the BGB. The investigation of the three main intervals (A, B, and C, which include 2, 13, and 2 individual spherule layers, respectively) within CT3, contains the classification of spherules based on their shapes, textural features, deformation types, and mineral content. All of the intervals show spherule variation in those features. Therefore, the classification helps to understand if the spherules underwent processes such as tectonic deformation or if multiple impact events occurred in the area, which both might a reason of spherule layer duplications. The aim of the work is to differentiate various spherule types and the groundmasses in which they are embedded. The spherules within 17 identified spherule layers have been examined by optical microscopy (polarized and reflected) and secondary electron microscopy and were classified by shape and textural features. Subsequently, mineral phases and the chemical composition of the spherules and their matrices were investigated by using electron microprobe analysis. Regarding the shapes of the spherules they were divided into two main groups: undeformed and deformed. Undeformed spherules have spherical to ovoid as well as tear-drop shapes; deformed spherules were further subdivided into three main groups; flattened, crushed

  14. Petrography of isotopically-dated clasts in the Kapoeta howardite and petrologic constraints on the evolution of its parent body

    International Nuclear Information System (INIS)

    Detailed mineralogic and petrographic data are presented for four isotopically-dated basaltic rock fragments separated from the howardite Kapoeta. Clasts C and rho have been dated at approximately 4.55 AE and approximately 4.60 AE respectively, and Clast rho contains 244Pu and 129I decay products. These are both igneous rocks that preserve all the features of their original crystallization from a melt. They thus provide good evidence that the Kapoeta parent body produced basaltic magmas shortly after its formation ( 40Ar/39Ar age. This sample is extensively recrystallized, and the ages are interpreted as a time of recrystallization, and not the time of original crystallization from a melt. Clast B has yielded a Rb-Sr age of approximately 3.63 AE, and an 40Ar/39Ar age of > approximately 4.50 AE. This sample is moderately recrystallized, and the Rb-Sr age probably indicates a time of recrystallization, whereas the 40Ar/39Ar age more closely approaches the time of crystallization from a melt. Thus, there is no clearcut evidence for 'young' magmatism on the Kapeota parent body. The FeO and MnO contents of all pyroxenes in Kapeota fall near a line with FeO/MnO approximately 35, suggesting that the source rocks are fundamentally related. The FeO/MnO value in lunar pyroxenes (approximately 60) is distinct from that of the pyroxenes in Kapoeta. Anorthositic rocks were not observed in Kapoeta, suggesting that plagioclase was not important in the evolution of the Kapoeta parent body, in contrast to the Moon. Both objects appear to have originated in chemically-distinct portions of the solar system, and to have undergone differentiation on different time scales involving differing materials. (author)

  15. 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

  16. 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.

  17. 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 calcareous soils of the region. SEM observations indicated a wide range of particle morphologies over the 1-50 μm size range, with spherical, platy, cubic, elongate and prismatic shapes and rounding from angular to rounded. Energy dispersive X-ray analysis of TSP samples from both sites for non-dusty periods indicated that the sampled mineral suite contained 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.

  18. Environmental Mineralogy of the Kursk Iron Ore Deposit

    Science.gov (United States)

    Posukhova, Tatiana V.; Riakhovskaya, Sofiya K.

    The development of new technologies is one of the most effective ways to solve environmental problems related to ore-dressing. Complex mineralogical investigations are able to help in improving this process. In collaboration with researchers from the IPKON institute, we have developed an electrochemical method to improve the properties of crushed ores prepared for the wet magnetic separation. This article studies the samples before and after application of the electrochemical method. Surfaces of mineral grains investigated by the scanning electron microscopy show differences in flocculation. Measured polarization curves showed unequal electrochemical processes on surfaces of magnetite, hematite, and martite particles. X-ray analysis and Mössbauer data also confirmed the changes in compositions of the ores before and after using the electrochemical method. Magnetic properties of the studied species to be compared before and after the application of method showed relevant increase in parameters such as magnetic viscosity (Svo), breaking saturation field (Hcr), magnetic susceptibility (χ), and specific magnetization (Is).

  19. 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

  20. 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).

  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. Chemistry and mineralogy of garnet pyroxenites from Sabah, Malaysia

    Science.gov (United States)

    Morgan, B.A.

    1974-01-01

    Garnet pyroxenites and corundum-garnet amphibolites from the Dent peninsula of eastern Sabah (North Borneo) occur as blocks in a slump breccia deposit of late Miocene age. The earliest formed minerals include pyrope-almandine garnet, tschermakitic augite, pargasite, and rutile. Cumulate textures are present in two of the six specimens studied. The earlier fabric has been extensively brecciated and partly replaced by plagioclase, ilmenite, and a fibrous amphibole. The bulk composition and mineralogy of these rocks are similar to those of garnet pyroxenite lenses within ultramafic rocks. Estimated temperature and pressure for the origin of the Sabah garnet pyroxenites is 850??150?? C and 19??4 kbar. ?? 1974 Springer-Verlag.

  3. Hydrothermal synthesis as a route to mineralogically-inspired structures.

    Science.gov (United States)

    McMillen, Colin D; Kolis, Joseph W

    2016-02-21

    The use of high temperature hydrothermal reactions to prepare crystals having mineralogically-related structures is described. Complex naturally occurring minerals can have fascinating structures and exhibit important features like low dimensionality, noncentrosymmetry, or ion channels that can provide excellent guideposts for the designed synthesis of new materials. Actual minerals, even though they may have intriguing physical properties, are often unsuitable for study because of the persistent impurities inevitably present in natural samples. Hydrothermal fluids at relatively high temperatures provide access to large, high quality single crystals of structures with mineral-like structures. This enables the study of physical properties like ionic conduction, magnetic spin frustration and non-linear optical behavior. Some fundamental considerations of the hydrothermal technique are discussed in the context of synthesizing mineralogically-inspired materials. The metal vanadates provide a surprisingly rich and diversified range of compounds and are selected to illustrate many of the concepts described here. A series of low dimensional mineral analogs featuring isolated units, chains, and layers have been prepared in the laboratory as large single crystals using a high temperature hydrothermal synthetic methods, and their physical properties are under investigation. The metal silicates are also highlighted as another promising field of exploration, since their hydrothermal synthesis surprisingly lags behind the enormous literature of the natural silicate minerals. The introduction of heteroelements, such as boron to make borosilicates, appears to also open the door to additional new materials. Many of these new materials have direct equivalents in the mineral kingdom, while others have no known analogs but are reminiscent of minerals and can be classified in the same ways. From these initial results there appears to be a very rich vein of synthetic minerals waiting

  4. 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.

  5. 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.

  6. 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.

  7. 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. PMID:25590704

  8. Focus on Brazil

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-11-01

    Brazil, the largest country in South America with a population of almost 140 million, has been plagued since the early 1980s by high foreign debt (approximately US$121 billion at present) and hyperinflation (nearly 600 percent over the past 12 months). These factors, in combination with the slower than anticipated growth in electricity demand, have been instrumental in curtailing nuclear power development in the country. Following recommendations advanced in a commissioned study for improving Brazil`s nuclear program, Brazilian President Jose Sarney announced on August 31st the restructuring of the country`s nuclear industry.

  9. Brazil Agriculture Policy Review

    OpenAIRE

    Quiroga, Jose; Brooks, Jonathan; Melyukhina, Olga

    2005-01-01

    In June 2005, OECD members met with senior government officials from Brazil to discuss Brazilian agricultural policies and future directions, as a part of a comprehensive agricultural policy review. Ongoing dialogue with Brazil on policy issues is important to fostering a better understanding of global challenges and opportunities that lie ahead. Results of the review will be published by the OECD in 2005. This policy note provides a preview of key findings.

  10. Energy in Brazil

    International Nuclear Information System (INIS)

    To prepare the Gross Domestic Product increase of 4 % in the next years, it is necessary to increase the capacity in Brazil. The government decided actions in favor of the installed capacity growth speeding up and planed investments. This document takes stock on the energy situation in Brazil, the human, political and geographical constraints and the decided measures in favor the energy development. (A.L.B.)

  11. 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

  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. High-resolution X-ray CT for 3D petrography of ferruginous sandstone for an investigation of building stone decay.

    Science.gov (United States)

    Cnudde, Veerle; Dewanckele, Jan; Boone, Matthieu; de Kock, Tim; Boone, Marijn; Brabant, Loes; Dusar, Michiel; de Ceukelaire, Marleen; de Clercq, Hilde; Hayen, Roald; Jacobs, Patric

    2011-11-01

    Diestian ferruginous sandstone has been used as the dominant building stone for monuments in the Hageland, a natural landscape in east-central Belgium. Like all rocks, this stone type is sensitive to weathering. Case hardening was observed in combination with blackening of the exterior parts of the dressed stones. To determine the 3D petrography and to identify the structural differences between the exterior and interior parts, X-ray computed tomography was used in combination with more traditional research techniques like optical microscopy and scanning electron microscopy. The 3D characterization of the ferruginous sandstone was performed with a high-resolution X-ray CT scanner (www.ugct.ugent.be) in combination with the flexible 3D analysis software Morpho+, which provides the necessary petrophysical parameters of the scanned samples in 3D. Besides providing the required 3D parameters like porosity, pore-size distribution, grain size, grain orientation, and surface analysis, the results of the 3D analysis can also be visualized, which enables to understand and interpret the analysis results in a straightforward way. The complementarities between high-quality X-ray CT images and flexible 3D software and its relation with the more traditional microscopical research techniques are opening up new gateways in the study of weathering processes of natural building stones.

  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. Learning Activities for an Undergraduate Mineralogy/Petrology Course-"I Am/We Are."

    Science.gov (United States)

    Goodell, Philip C.

    2001-01-01

    Introduces an entry level mineralogy/igneous petrology course designed for undergraduate students and presents a series of learning activities based on individual and cooperative learning. Includes 18 references. (Author/YDS)

  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 a compact and lightweight X-Ray Diffraction (XRD) / X-Ray Fluorescence (XRF) instrument for analysis of mineralogical composition of regolith,...

  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. Mineralogical Characteristics and The Pedogenetic Processes of Soils on Coral Reefs in Ambon

    Directory of Open Access Journals (Sweden)

    Rina Devnita

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol4no1.20093The mineralogical characteristics of soils developed on coral reef parent materials in Hitu and Wailiha, Ambon, were investigated regarding to the relationship to pedogenesis. The analyses concerned with the characteristics of soil chemical, physical, and mineralogy of the rock fragment and sand, silt and clay fractions are to investigate the pedogenesis processes. Both soil profiles indicate the clayey texture, slightly neutral reaction, high cation exchange capacity, base saturation, and iron oxide. The mineralogical analyses of rock fragments and sand fractions indicate that besides carbonate minerals, silicate minerals were also found. The clay mineralogy showing the domination of kaolinite, gibbsite, and goethite, reflects that the soil is intensely weathered. Pedogenesis process showing the clay translocation, indicates that the weathering process has been occuring under the tropical influence.    

  19. 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...

  20. 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.

  1. Spectroscopic Characterization of Mineralogy Across Vesta: Evidence of Different Lithologies

    Science.gov (United States)

    De Sanotis, M. C.; Ammannito, E.; Filacchione, G.; Capria, M. T.; Tosi, F.; Capaccioni, F.; Zambon, F.; Carraro, F.; Fonte, S.; Frigeri, A.; Jaumann, R.; Magni, G.; Marchi, S.; McCord, T. B.; McFadden, L. A.; McSween, H. Y.; Mittlefehldt, D. W.; Nathues, A.; Palomba, E.; Pieters, C. M.; Raymond, C. A.; Russell, C. T.; Turrini, D.

    2012-01-01

    The average spectrum of Vesta, obtained by VIR in the range 0.25-5.1 microns, shows clear evidence of absorption bands due to pyroxenes and thermal emissions beyond 3.5 11m. Vesta shows considerable variability across its surface in terms of spectral reflectance and emission, band depths, bands widths and bands centers, reflecting a complex geological history. Vesta's average spectrum and inferred mineralogy resemble those of howardite meteorites. On a regional scale, significant deviations are seen: the south polar 500km Rheasilvia impact crater has a higher diogenitic component, and equatorial regions show a higher eucritic component. This lithologic distribution, with a concentration of Mg-pyroxenes in the Rheasilvia area, reinforces the hypothesis of a deeper diogenitic crust excavated by the impact that formed the Rheasilvia crater, and an upper eucritic crust, whose remnants are seen in the equatorial region. This scenario has implications for Vesta differentiation, consistent with magma ocean models. However, serial magmatism models could also have concentrated pyroxene cumulates in plutons emplaced within the lower crust,

  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. Lunar highland melt rocks - Chemistry, petrology and silicate mineralogy

    Science.gov (United States)

    Vaniman, D. T.; Papike, J. J.

    1980-01-01

    A selected suite containing several of the largest samples of lunar highland melt rocks includes impact melt specimens (anorthositic gabbro, low-K Fra Mauro) and volcanic specimens (intermediate-K Fra Mauro). Although previous assumptions of LKFM volcanism have fallen into disfavor, no fatal arguments against this hypothesis have been presented, and the evidence of a possibly 'inherited igneous' olivine-plagioclase cosaturation provides cause for keeping a volcanic LKFM hypothesis viable. Comparisons of silicate mineralogy with melt rock compositions provide information on the specimen's composition and cooling history. Plagioclase-rock compositions can be matched to the experimentally determined equilibria for appropriate samples to identify melt rocks with refractory anorthitic clasts. Olivine-rock compositions indicate that melt rock vitrophyres precipitate anomalously Fe-rich olivine; the cause of this anomaly is not immediately evident. The Al-Ti and Ca-Fe-Mg zonation in pyroxene provide information on relative cooling rates of highland melt rocks, but Cr- and Al-content (where Al-rich low-Ca pyroxene cores are preserved in rapidly cooled samples) can be correlated with composition of the host rock.

  4. Mineralogical record of the redox conditions on early Mars

    Science.gov (United States)

    Dehouck, Erwin; Gaudin, Anne; Chevrier, Vincent; Mangold, Nicolas

    2016-06-01

    Sulfates and Fe-oxides identified on the martian surface by orbital and in situ missions indicate that oxidizing conditions have existed on early Mars, at least locally and/or episodically. In the context of rock alteration and weathering, redox conditions are especially critical for the behavior of iron, which is soluble in its divalent state but insoluble in its trivalent state. Here, we combine results from a series of laboratory experiments conducted under Mars-like conditions to address the influence of highly-oxidizing compounds such as hydrogen peroxide (H2O2) on the alteration pathways of primary materials. We show that, if early Mars had a dense CO2 atmosphere allowing for relatively "warm and wet" conditions and surface weathering, highly-oxidizing conditions would have strongly inhibited the formation of Fe/Mg-smectite clays from alteration of igneous ferromagnesian minerals, and possibly enhanced the formation of carbonates. But a decade of mineral mapping of the martian surface show abundant, widespread Fe/Mg-clays and rare carbonates, which we interpret here as a mineralogical record of poorly-oxidizing (or even reducing) conditions during most of the Noachian era. Oxidizing conditions would have occurred later in martian history as a consequence of a higher rate of H2 escape or of a lower rate of volcanic outgassing, or both.

  5. 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.

  6. Ooid mineralogy and diagenesis of upper Mississippian Pitkin Formation, Arkansas

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, E.; Snelling, R.D.; Dawson, W.C.; Machain, M.L. (Louisiana State Univ., Baton Rouge (USA))

    1989-08-01

    The Pitkin formation is a marine oolitic-bioclastic limestone exhibiting shoal, lagoonal, beach, and tidal-channel facies. Ooids formed on the Pitkin carbonate shelf show lateral and vertical variations in original mineralogy. In a section south of Mountain View, Arkansas, the lower marine shoal and shoreface facies are composed of originally aragonitic ooids. These ooids are replaced by neomorphic calcite and exhibit elevated strontium and low magnesium concentrations. The overlying lagoonal facies are composed of originally calcite ooids that have retained their original radial fabrics. These ooids exhibit low strontium and high magnesium concentration. Ooids in sections to the west of Mountain View are all calcitic. Early diagenesis of the formation is dominated by marine cementation. Postdepositional diagenesis encompasses extensive dissolution of originally aragonite and magnesian calcite components, precipitation of a late unzoned ferroan calcite, and minor amounts of saddle dolomite. Grainstone units lack any intergranular porosity. Pressure solution contacts among grains in grainstones are generally uncommon. Cementation alone is responsible for destruction of all of the original porosity in these rocks. Intensive pressure solution is observed only in packstone units not affected by early marine cementation.

  7. 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.

  8. 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.

  9. 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.

  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. Clay Mineralogy, Organic Carbon Burial, and Redox Evolution in Proterozoic Oceans

    OpenAIRE

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

    2010-01-01

    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 sedimenta...

  12. The mineralogy, geochemistry and surface area of mudrocks from the London Clay Formation of southern England

    OpenAIRE

    Kemp, S.J.; Wagner, D.

    2006-01-01

    This report describes the results of mineralogical and geochemical analysis of a suite of mudstones from the London Clay Formation of southern and south-eastern England. The work was carried out as part of the ongoing ‘Ground Movements: Shrink/Swell’ project under the Physical Hazards Programme. The first part of the report gives an introduction to the geology of the London Clay Formation and a summary of previous mineralogical studies of these rocks. A summary of analytical methods employ...

  13. The mineralogy, surface area and geochemistry of samples from the Wealden Group of southern England

    OpenAIRE

    Kemp, S.J.; Wagner, D.; Ingham, M.N.

    2012-01-01

    This report describes the results of mineralogical and geochemical analysis of a suite of mudstones from the Wealden Group of southern England. The work was carried out as part of the ongoing „Ground Shrinkage Hazards‟ project under the Land Use, Planning and Development Programme. The first part of the report gives an introduction to the geology of the Wealden Group and a summary of previous mineralogical studies of these rocks. A summary of analytical methods employed (X-ray diffraction ...

  14. 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.

  15. Mineralogical characteristics of copper flotation products from Cayeli mine, Turkey and their influence to mineral processing

    OpenAIRE

    Strashimirov, S.; Dobrev, S.; Stamenov, S.; GAYDARDZHIEV, Stoyan; Aksani, B.

    2004-01-01

    The paper presents mineralogical characteristics and pecularities of minerals distribution in products from Cu cycle of clastic ore mineral processing in Cayeli concentrator, Turkey. Special attention has been drawn to the mineralogical pecularities of sphalerite. The study has covered 16 samples from Cu flotation feed, Cu rougher concentrate, Cu final concentrate and tailing, each sieved in 4 granulometric classes. Significant quantity of sphalerite charactarized by higher amount of Cu and F...

  16. 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.

  17. Technical characterization by image analysis: an automatic method of mineralogical studies

    International Nuclear Information System (INIS)

    The application of a modern method of image analysis fully automated for the study of grain size distribution modal assays, degree of liberation and mineralogical associations is discussed. The image analyser is interfaced with a scanning electron microscope and an energy dispersive X-rays analyser. The image generated by backscattered electrons is analysed automatically and the system has been used in accessment studies of applied mineralogy as well as in process control in the mining industry. (author)

  18. Towards mineralogical and geochemical reference groups for some Bronze Age ceramics 
from Transylvania (Romania)

    OpenAIRE

    Volker Hoeck; Corina Ionescu; Lucretia Ghergari; Carmen Precup

    2009-01-01

    Based on their chemical composition ceramic shards from three Bronze Age sites in Transylvania, i.e., Copăceni, Derşida and Palatca respectively, were distinguished by major, trace, and RE elements. Within the Copăceni samples, two subgroups (A and B) showing different chemistry and mineralogy were additionally separated out. The link between chemistry and mineralogy showed clearly the important contribution of the temper to the overall chemistry of the ceramic shards. In turn, the chemistry ...

  19. Corporate Governance Country Assessment : Brazil

    OpenAIRE

    World Bank

    2012-01-01

    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...

  20. 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

  1. [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.

  2. Liver Transplantation in Brazil.

    Science.gov (United States)

    Bittencourt, Paulo Lisboa; Farias, Alberto Queiroz; Couto, Claudia Alves

    2016-09-01

    Over 1700 liver transplantations (LTs) are performed annually in Brazil. In absolute terms, the country performs more LT surgeries than anywhere else in Latin America and is third worldwide. However, due to its increasing population and inadequate donor organ supply, the country averages 5-10 LTs per million population, far lower than required. There is a marked heterogeneity in organ donation and LT activity throughout the country. Access to LT in the underprivileged North, Midwest, and Northeast regions of Brazil is scarce. Major challenges for the future of LT in Brazil will be to increase organ donation and access to LT. The reduction of those geographical disparities in donation, organ procurement, and LT due to political and financial constraints is of utmost importance. Liver Transplantation 22 1254-1258 2016 AASLD. PMID:27228568

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Mineralogical Characteristics of Carbonate Rock-Hosted Naturally Occurring Asbestos

    Science.gov (United States)

    Shin, E.; Roh, Y.

    2012-12-01

    Naturally Occurring Asbestos (NOA) occurs in rocks and soils as a result of natural weathering and human activities. The parent rocks of asbestos have been associated with ultramafic and mafic rocks, and carbonate rock. The previous studies on naturally occurring asbestos were mainly limited to ultramafic and mafic rock-hosted asbestos and studies on carbonate rock-hosted asbestos are relatively rare in South Korea. Therefore, this study was aimed to characterize mineralogy of carbonate rock-hosted NOA at Muju and Jangsu, Jeonbuk province and Seosan and Asan, Chungnam province. The rock types at the four sites are consisting mainly of Precambrian metasedimentary rock. XRD and PLM analyses showed fibrous minerals in the sites were tremolite and actinolite of acicular and columnar forms. SEM-EDS analyses showed that asbestiform tremolite and actinolite had various ratios of length and diameters over 12:1, and needle and columnar forms. A columnar forms of tremolite and actinolite were showed small acicular at the edge of the particle. Its main chemical compositions are mainly Si, O, Mg, Ca, which were identical to tremolite. Actinolite contains Fe in addition to Si, O, Mg, Ca. EPMA analyses of asbestos occurred at Muju indicated that chemical composition are 55% SiO2, 23.2% MgO, 13.1 % CaO, and 0.61 % FeO and the chemical formula calculated as (K0.01Na0.01)Ca2.01(Mg4.94Fe0.05) (Al0.004Si7.98)O22(OH)2, which is close to ideal tremolite. In addition to tremolite, actinolite was also occurred at Seosan, Chungnam. XRD analyses showed that antigorite was existed at Muju, but PLM and SEM analyses showed the antigorite was platy structure, not asbestiform. These results indicate that asbestiform tremolite and actinolite with acicular forms contains in carbonate rocks at Muju and Jangsu, Jeonbuk and Seosan and Asan, Chungnam province South Korea.

  9. 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. PMID:16574393

  10. Mineralogy of dust emissions from the Bodele Depression

    Science.gov (United States)

    Millham, Rosemary Assunta

    Scope and method of study. This study focused on identifying the minerals in the dust emitted from the Bodele Depression in northern Chad in the Saharan Desert. Understanding the mineralogy provides the information needed to assess the effects that mineral dust has on climate and climate change relative to the energy budget and radiative forcings, and cloud characteristics and properties, and assists in providing critical information for assessing amounts of nutrients delivered to oceans and lands. There is a question of health issues related to dust emissions not addressed in this study. Using a traditional X-Ray diffractometer (XRD), scanning electron microscope (SEM) with chemical analysis capabilities, French geological survey maps, and a new instrument for detecting d-spacings and K-fluorescence in unprepared samples called the XRD XRF (CCDXRD) that couples a CCD with traditional X-Ray diffractometer, mineral identification is possible. Findings and conclusions. The samples from the Bodele in situ aerosol and bulk ground materials produce the dust emissions occurring from the region ˜40% of the days in a year. The results from literature review, X-Ray diffractometer data, SEM data, geological survey maps, and the CCD XRD data provided concrete identification of the Bodele minerals as typical crustal silicate minerals with small amounts of calcium carbonate, dolomite, silica, desiccated diatoms, and possible iron oxides. The silicate minerals are primarily ferromagnesian and framework silicates typical of low-lying depositional basins and the weathering processes occurring in alternating wet and dry periods. Clays minerals halloysite, kaolinite, and smectites (montmorillite) are the most common. Exotic materials were detected in two of the bulk samples. A reading of 25.75% titanium in one sample, and elevated isolated silicon data (considered cosmic silicon) provided the only anomalies in the study.

  11. Petrography, fine stratigraphy and petrofacies of the Stassfurt rock salt (Zechstein 2) in the development region of ASSE II salt mine near Brunswick

    International Nuclear Information System (INIS)

    The Stassfurt rock salt (Na2) in the Asse II salt mine constitutes a saline sequence of the sub-Hercynian basin. In the anticline of the Asse II the Na2 constitutes a core of the anticline with an interior special folding. The combination of underground mapping with the investigations of the salt petrography permits the recognition of stratigraphic unities and with it sedimentary and early diagenetic formation processes for the stratigraphic beds of the Hauptsalz (Na2β), the Speisesalz (Na2SP) and the Polyhalitbaenkchensalz (Na2P). An additional postdiagenetic new formation of minerals from the overlying Stassfurt potash layer (K2C) can be recognized in the kieseritic region of the ''Carnallitisch-Kieseritische Ueberganssalz (Na2K+C)'' and in the ''Tonliniensalz'' (Na2TL). The lower part of the Na2β belongs to a saline basin facies. In the upper part of the Na2β structural and textural characteristics refer to the swallowing of the saline sedimentation room. Simultaneously, more and more terrestrial influences of the saline sedimentation become conspicuous in the northwestern part of the Asse II. They have their clearest facies in the only locally formed Tonliniensalz (Na2TL). The petrographic review of the ''polyhalite region'', which encloses the upper part of the Na2β, the Na2SP and the Na2P, rendered obvious indications for a pseudomorphic origin of polyhalite from primarily sedimened gypsum. The replacement of anhydrite by polyhalite was compared to it as being of unimportant significance. The quantitative parts of the accessory minerals (polyhalite, anhydrite, kieserite, sylvite, carnallite) were determined by means of geochemical investigations in the stratigraphic horizons of Na2 in the mine Asse II. A regional comparison with the saline sedimentation of Zechstein 2 in the sub-Hercynian basin shows a progressive saline sedimentation cycle of the Stassfurt type for the fine stratigraphic division of the Na2 in Asse II. (orig./HP)

  12. 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.

  13. 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.

  14. 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…

  15. 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…

  16. 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

  17. 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

  18. 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

  19. Mineralogy and Geochemistry at the Meridiani Landing Site, Mars

    Science.gov (United States)

    Johnson, J. R.

    2004-05-01

    The Mars Exploration Rover (MER) Opportunity landed in Meridiani Planum on January 24, 2004 (PST). The scientific rationale for selecting this landing site (1.95 S, 354.47 E) centered on the discovery by the orbiting Thermal Emission Spectrometer of 10-20% grey crystalline hematite in association with basaltic rocks in this region. Formation of hematite requires either precipitation in iron-rich waters or thermal oxidation of iron-bearing volcanic rocks. Each MER rover carries instruments well suited for in situ and remote analyses of iron-rich materials. The mast-mounted visible/near-infrared multispectral Pancam system and thermal infrared Mini-TES spectrometer in combination with the arm-mounted alpha particle x-ray spectrometer (APXS), Moessbauer spectrometer (MB), Microscopic Imager (MI), and Rock Abrasion Tool (RAT) deliver complementary detailed information on the morphology, mineralogy and composition of the materials at this site. The exposure of relatively high albedo bedrock materials on the western crater rim and low albedo soils in the crater have been the main focus during the first 25 sols of rover operations. Results thus far include: (1) Subtle variability in the ferric and ferrous absorption features observed by Pancam in the soil and bedrock, consistent with poorly crystalline iron phases; (2) Confirmation by Mini-TES of gray hematite-rich soils, with hematite-free soils consistent with basalt; (3) Discovery of small (1-5 mm) grayish spherules embedded in and weathering from the bedrock, with as yet undetermined composition; (4) Moessbauer spectra consistent with olivine and a weak magnetic phase in the soils; (5) APXS soil data consistent with a basaltic composition and with S and Cl levels similar to other landing sites. Among current hypotheses for the bedrock formation, some involve fine-grained basaltic sediments as starting materials that underwent either (a) cementation by minerals and growth of spherical concretions; (b) alteration by

  20. 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.

  1. 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.

  2. A new data set of soil mineralogy for dust-cycle modeling

    Directory of Open Access Journals (Sweden)

    E. Journet

    2013-09-01

    Full Text Available The mineralogy of airborne dust affects the impact of dust particles on direct and indirect radiative forcing, on atmospheric chemistry and on biogeochemical cycling. It is determined partly by the mineralogy of the dust-source regions and partly by size-dependent fractionation during erosion and transport. Here we present a data set that characterizes the clay and silt sized fractions of global soil units in terms of the abundance of 12 minerals that are important for dust-climate interactions: quartz, feldspars, illite, smectite, kaolinite, chlorite, vermiculite, mica, calcite, gypsum, hematite and goethite. The basic mineralogical information is derived from the literature, and is then expanded following explicit rules, in order to characterize as many soil units as possible. We present three alternative realisations of the mineralogical maps that account for the uncertainties in the mineralogical data. We examine the implications of the new database for calculations of the single scattering albedo of airborne dust and thus for dust radiative forcing.

  3. 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)

  4. Mineralogical and lithochemical studies of strata beneath the Harwell research site

    International Nuclear Information System (INIS)

    Determinations have been made of the mineralogy and lithochemistry of the principal lithological units of the Mesozoic and Palaeozoic rocks penetrated by boreholes at the Harwell Research Site. Samples were taken at approximately 9m intervals from the Upper Greensand to the Coal Measures, together with a number from the Chalk. Mineralogical analyses were carried out using X-ray diffraction, with thermal analysis and surface area measurements aiding quantification. Major and trace element determinations were made using direct electron excitation X-ray spectrometry and X-ray fluorescence respectively. Other chemical determinations included organic carbon, sulphate and 'exchangeable' cations. The mineralogical and lithochemical variations within and between the major litho-stratigraphic units are discussed and compared with published data for other localities. (author)

  5. Towards mineralogical and geochemical reference groups for some Bronze Age ceramics 
from Transylvania (Romania

    Directory of Open Access Journals (Sweden)

    Volker Hoeck

    2009-09-01

    Full Text Available Based on their chemical composition ceramic shards from three Bronze Age sites in Transylvania, i.e., Copăceni, Derşida and Palatca respectively, were distinguished by major, trace, and RE elements. Within the Copăceni samples, two subgroups (A and B showing different chemistry and mineralogy were additionally separated out. The link between chemistry and mineralogy showed clearly the important contribution of the temper to the overall chemistry of the ceramic shards. In turn, the chemistry facilitated the provenance study of the raw materials, which were collected in the vicinity of the sites. In combination with the mineralogy of the ceramics, the chemical analyses can serve as a basis for a geochemical reference set used by further studies.

  6. Deforestation, Rondonia, Brazil

    Science.gov (United States)

    1992-01-01

    This view of deforestation in Rondonia, far western Brazil, (10.0S, 63.0W) is part of an agricultural resettlement project which ultimately covers an area about 80% the size of France. The patterns of deforestation in this part of the Amazon River Basin are usually aligned adjacent to highways, secondary roads, and streams for ease of access and transportation. Compare this view with the earlier 51G-37-062 for a comparison of deforestation in the region.

  7. Heliostat tailored to Brazil

    OpenAIRE

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

    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...

  8. Mineralogy of an unusual Cr-rich inclusion in the Los Martinez (L6) chrondritic breccia

    Science.gov (United States)

    Brearley, Adrian J.; Casanova, Ignacio; Miller, M. L.; Keil, Klaus

    1991-01-01

    During the petrological study of the L6 chondritic breccia, Los Martinez, we discovered a large, highly unusual Cr-rich inclusion whose mineralogy appears to be unique in both terrestrial and extraterrestrial occurrences. We carried out electron microprobe, scanning electron microscopy, and transmission electron microscopy investigations of this inclusion in order to determine its composition and mineralogy in detail and to establish its origin and possible relationship to other Cr-rich objects in chondritic meteorites. Details of the chemical composition, origin, and thermal history are given.

  9. Magnetic mineralogy of heavy metals-contaminated soils

    Science.gov (United States)

    Shenggao, L.

    2012-04-01

    Soils around mine and in urban areas are often contaminated by heavy metals derived from industrial and human activities [1, 2]. These contaminated soils are often characterized by a magnetic enhancement on topsoils. Many studies demonstrated that there are significant correlations between heavy metals and various magnetic parameters in contaminated soils, indicating a strong affinity of heavy metals to magnetic minerals. The magnetic particles in contaminated soils were separated by a magnetic separation technique. The rock magnetism, XRD, field emission scanning electron microscopy equiped with an energy-dispersive X-ray analyzer (FESEM/EDX) were used to characterize their magnetic mineralogy. Results of XRD analysis indicated that the magnetic particles separated from heavy metal-contaminated soils are composed of quartz, magnetite, and hematite. Based on the X-ray diffraction peak intensity, the Fe3O4 was identified as the predominant magnetic mineral phase. The high-temperature magnetization (Ms-T) curves of magnetic particles extracted from contaminated soils show a sharp Ms decrease at about 580C (the Curie temperature of magnetite), suggesting that magnetite is the dominant magnetic carrier. The hysteresis loops of contaminated soils are closed at about 100-200 mT which is consistent with the presence of a dominant ferrimagnetic mineral phase. The FESEM analysis showed a great variety of shapes of magnetic particles in contaminated soils. The most common morphology are observed in the form of spherules, with the sizes ranging from 20 to 100 um. The chemical composition of magnetic particles consist mainly of Fe, Si, Al, and Ca with minor heavy metal elements (Cu, Zn, Hg, and Cr). The semi-quantitative Fe content identified by FESEM/EDX ranged from 40 to 90%. Combined studies of rock magnetism, XRD, and FESEM/EDX indicated that magnetic mineral phases responsible for the magnetic enhancement of contaminated soils are anthropogenic origin which are coarse

  10. Radiopharmacy education in Brazil

    Directory of Open Access Journals (Sweden)

    Ralph Santos-Oliveira

    2014-01-01

    Full Text Available The number of schools of pharmacy has been increasing each year in Brazil. From 2002 to 2013 over 300 new schools were opened in Brazil with a final number of 415 schools of pharmacy in operation around the country. Of these schools, only 28 schools offer a course in radiopharmacy (7.77%. However, the demand for such trained professionals has grown exponentially in Brazil, especially following amendment 49 (February 2006 that broke the monopoly on the production, distribution, and marketing of short half-life radiopharmaceuticals, and the recent constitutional amendment project 517/2010, which was approved in the last instance and is waiting for final approval by the President. Thus, in this scenario, there are a total of 417 radiopharmacy services across the country waiting for qualified professionals to fill posts. However, while there are insufficient trained professionals, radiopharmacy services under the aegis of Agencia Nacional de Vigilancia Sanitaria - Brazilian Health Surveillance Agency allow biomedical scientists and biologists to perform specialized functions as developed in radiopharmacy services without the presence of radiopharmacists.

  11. Health promotion in Brazil.

    Science.gov (United States)

    Ivo de Carvalho, Antonio; Westphal, Marcia Faria; Pereira Lima, Vera Lucia Góes

    2007-01-01

    Brazil, a Latin American country of continental proportions and contrasts, demographic inequalities, and social inequities, concomitantly faces the challenge of preventing and controlling infectious diseases, injuries, and non-communicable diseases. The loss of strength of the biomedical paradigm, the change in epidemiological profile, and the sociopolitical and cultural challenges of recent decades have fostered the emergence of new formulations about public health thinking and practice. Among them, are the paradigms of Brazilian Collective Health and Health Promotion. The former provides philosophical support for Brazil's Unified Health System (SUS). The aim of this article is to discuss the development of public health within the country's history, and to analyze and compare the theoretical assumptions of Health Promotion and Collective Health. We conclude that health promotion, based on the principles and values disseminated by the international Charters and concerned with social actors and social determinants of the health-disease process, has significant potential to promote the improvement of living and health conditions of the population. This frame of reference guided the formulation of the National Policy of Health Promotion within the Unified Health System, which was institutionalized by a ministerial decree. The importance and application of evaluating the effectiveness of health promotion processes and methodologies in Brazil have been guided by various frames of reference, which we clarify in this article through describing historical processes. PMID:17596091

  12. 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.

  13. Elementary and isotopic geochemistry of vein goethite in laterite-gossanic crusts from the Igarape Bahia gold mine (Carajas, Brazil)

    International Nuclear Information System (INIS)

    The lateritic crusts of the gold mine from the Igarape Bahia, in Carajas, situated at Para state, Brazil, present themselves frequently sectioned by the goethite sub-vertical veins. The veins have the following measures: until 10 cm of thickness and more than 6 m of length. This work aims to characterize the textural, mineralogical and chemical aspects of these veins, in order to understand its evolution, mainly the relation with the laterites and its geological importance, including the aspects referents to the mineral prospecting. (author)

  14. Characterization of indoor dust from Brazil and evaluation of the cytotoxicity in A549 lung cells.

    Science.gov (United States)

    Deschamps, E; Weidler, P G; Friedrich, F; Weiss, C; Diabaté, S

    2014-04-01

    Over the past decade, ambient air particulate matter (PM) has been clearly associated with adverse health effects. In Brazil, small and poor communities are exposed to indoor dust derived from both natural sources, identified as blowing soil dust, and anthropogenic particles from mining activities. This study investigates the physicochemical and mineralogical composition of indoor PM10 dust samples collected in Minas Gerais, Brazil, and evaluates its cytotoxicity and inflammatory potential. The mean PM10 mass concentration was 206 μg/m(3). The high dust concentration in the interior of the residences is strongly related to blowing soil dust. The chemical and mineralogical compositions were determined by ICP-OES and XRD, and the most prominent minerals were clays, Fe-oxide, quartz, feldspars, Al(hydr)oxides, zeolites, and anatase, containing the transition metals Fe, Cr, V, Ni, Cu, Zn, Ti, and Mn as well as the metalloid As. The indoor dust samples presented a low water solubility of about 6 %. In vitro experiments were carried out with human lung alveolar carcinoma cells (A549) to study the toxicological effects. The influence of the PM10 dust samples on cell viability, intracellular formation of reactive oxygen species (ROS), and release of the pro-inflammatory cytokine IL-8 was analysed. The indoor dust showed little effects on alamarBlue reduction indicating unaltered mitochondrial activity. However, significant cell membrane damage, ROS production, and IL-8 release were detected in dependence of dose and time. This study will support the implementation of mitigation actions in the investigated area in Brazil. PMID:23990125

  15. 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,…

  16. BRAZIL'S CARBON BUDGET FOR 1990

    Science.gov (United States)

    The recent history of deforestation in the Amazon region of Brazil is well known. ajor reason for alarm over the rate and magnitude of deforestation in Brazil has been concern that the reduction in vegetation releases carbon dioxide (CO2) and other greenhouse gases that may contr...

  17. Nuclear material control in Brazil

    International Nuclear Information System (INIS)

    A general view about the safeguards activities in Brazil is presented. The national system of accounting for and control of nuclear materials is described. The safeguards agreements signed by Brazil are presented, the facilities and nuclear material under these agreements are listed, and the dificulties on the pratical implementation are discussed. (E.G.)

  18. Comparisons of Mineralogy Between Cumulate Eucrites and Lunar Meteorites Possibly from the Farside Anorsothitic Crust

    Science.gov (United States)

    Takeda, H.; Yamaguchi, A.; Hiroi, T.; Nyquist, L. E.; Shih, C.-Y.; Ohtake, M.; Karouji, Y.; Kobayashi, S.

    2011-01-01

    Anorthosites composed of nearly pure anorthite (PAN) at many locations in the farside highlands have been observed by the Kaguya multiband imager and spectral profiler [1]. Mineralogical studies of lunar meteorites of the Dhofar 489 group [2,3] and Yamato (Y-) 86032 [4], all possibly from the farside highlands, showed some aspects of the farside crust. Nyquist et al. [5] performed Sm-Nd and Ar-Ar studies of pristine ferroan anorthosites (FANs) of the returned Apollo samples and of Dhofar 908 and 489, and discussed implications for lunar crustal history. Nyquist et al. [6] reported initial results of a combined mineralogical/chronological study of the Yamato (Y-) 980318 cumulate eucrite with a conventional Sm-Nd age of 4567 24 Ma and suggested that all eucrites, including cumulate eucrites, crystallized from parental magmas within a short interval following differentiation of their parent body, and most eucrites participated in an event or events in the time interval 4400- 4560 Ma in which many isotopic systems were partially reset. During the foregoing studies, we recognized that variations in mineralogy and chronology of lunar anorthosites are more complex than those of the crustal materials of the HED parent body. In this study, we compared the mineralogies and reflectance spectra of the cumulate eucrites, Y-980433 and 980318, to those of the Dhofar 307 lunar meteorite of the Dhofar 489 group [2]. Here we consider information from these samples to gain a better understanding of the feldspathic farside highlands and the Vesta-like body.

  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. Elemental, mineralogical, and pore-solution compositions of selected Canadian clays

    International Nuclear Information System (INIS)

    Clay materials will be an important component of a barrier and sealing system in a nuclear fuel waste disposal vault in Canada. In this report the elemental, mineralogical, and pore-solution compositions of candidate clay sealing materials for the Canadian Nuclear Fuel Waste Management Program are presented

  1. 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.

  2. 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

  3. Remote In-Situ Quantitative Mineralogical Analysis Using XRD/XRF

    Science.gov (United States)

    Blake, D. F.; Bish, D.; Vaniman, D.; Chipera, S.; Sarrazin, P.; Collins, S. A.; Elliott, S. T.

    2001-01-01

    X-Ray Diffraction (XRD) is the most direct and accurate method for determining mineralogy. The CHEMIN XRD/XRF instrument has shown promising results on a variety of mineral and rock samples. Additional information is contained in the original extended abstract.

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. Social Psychotherapy in Brazil.

    Science.gov (United States)

    Fleury, Heloisa J; Marra, Marlene M; Knobel, Anna M

    2015-10-01

    This paper describes the practice of sociodrama, a method created by J. L. Moreno in the 1930s, and the Brazilian contemporary socio-psychodrama. In 1970, after the Fifth International Congress of Psychodrama was held in Brazil, group psychotherapy began to flourish both in private practice and hospital clinical settings. Twenty years later, the Brazilian health care system added group work as a reimbursable mental health procedure to improve social health policies. In this context, socio-psychodrama became a key resource for social health promotion within groups. Some specific conceptual contributions by Brazilians on sociodrama are also noteworthy. PMID:26401805

  10. 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.

  11. 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.

  12. 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. PMID:22795764

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

    Science.gov (United States)

    Foster, T.; Clode, P. L.

    2016-03-01

    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 may leave 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 Ma. 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 1-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 the investigation of the combined impact of high pCO2 and reduced Mg / Ca ratio on coral skeletal mineralogy.

  14. 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

  15. Microbial Metabolic Landscapes Derived from Complementary Mineralogical, Aqueous Geochemical, and Gas Data Associated with High pH, Actively Serpentinizing Springs in the Coast Range Ophiolite (CA,USA) and Zambales and Palawan Ophiolites (Philippines)

    Science.gov (United States)

    Cardace, D.; Meyer-Dombard, D. R.; Arcilla, C. A.; Hoehler, T. M.; McCollom, T. M.; Schrenk, M. O.

    2013-12-01

    We applied x-ray diffraction and thin section petrography to profile the mineralogy of serpentinites and relict peridotites pertinent to the Coast Range Ophiolite Microbiological Observatory (CROMO, an array of 8 water monitoring wells installed in serpentinizing ultramafic rocks, sited at the UC-Davis McLaughlin Natural Reserve, Lower Lake, CA) and Zambales and Palawan ophiolites in the Philippines. In general, serpentinization in near surface samples was extensive, obscuring many protolith characteristics, but relict olivine grains are apparent. Upwelling serpentinizing formation fluids react to varying degrees with shallow hydrological regimes impacted by meteoric inputs. In the vicinity of CROMO, modest pH (7 to 8.5) waters form spring deposits. In the Philippines ophiolites, high pH (10.8 to 11. 3) waters form extensive travertines near Manleluag Springs and newly faulted sections of the Poon Bato River. Travertine fabric and chemistry indicate episodic spring flow and suggest that ambient water chemistry shifts over time. A multiprobe meter simultaneously measured pH, temperature, conductivity, oxidation-reduction potential, and dissolved oxygen at selected springs. Filtered water samples from monitoring wells and springs were analyzed for major elements and some ions. Dissolved gases and gas bubbles were captured and transported for analysis of H2, CO, and CH4. Aqueous and gas geochemistry data were transformed into activity data using EQ3: A Computer Program for Geochemical Aqueous Speciation-Solubility Calculations (Wolery, 1992) and the Gibbs Energy values for selected metabolic reactions, given the environmental conditions, were calculated. Metabolisms considered were: methanogenesis, methane oxidation, ferric iron reduction, ferrous iron oxidation, oxidation of S in pyrite, nitrification, denitrification, and N-fixation. At all sites tapping waters sourced in actively serpentinizing systems, regardless of geography, ferrous iron oxidation was the most

  16. The mechanism of myrmekite formation deduced from steady-diffusion modeling based on petrography: Case study of the Okueyama granitic body, Kyushu, Japan

    Science.gov (United States)

    Yuguchi, Takashi; Nishiyama, Tadao

    2008-12-01

    Myrmekite is an intergrowth texture consisting of vermicular quartz and albitic plagioclase (Ab 93An 7 in this study), typically occurring between K-feldspar and plagioclase. It occurs ubiquitously in both metamorphic and granitic rocks; however, its genesis has been an enigma. This paper describes myrmekite's petrography and discusses its genesis from the Okueyama granitic body (OKG), which is a young (14 Ma) granite in Southwest Japan with no evidence of deformation after solidification. The genesis of a newly observed texture, the 'reaction rim', will be also discussed in relation to myrmekite. The reaction rim is an albite layer (Ab 95An 5) with no vermicular quartz between K-feldspar and plagioclase, and it occasionally makes a composite texture with myrmekite. Both myrmekite and the reaction rim are accompanied by a diffusive boundary layer (Olg-layer) with a mean composition of oligoclase (Ab 75An 25) in the rim of neighboring plagioclase rim. The overall reactions in an open system for the formation of myrmekite and that for the reaction rim are derived based on the following two models: 1) one based on the assumption of conservation of solid volume with arbitrarily specified closure components, and 2) the other based on the assumption of closure of AlO 3/2 together with an arbitrarily specified volume factor. Steady diffusion modeling in an open system based on the overall reaction thus derived defines the stability field of myrmekite and of the reaction rim in terms of the ratios of phenomenological coefficients ( L-ratios). The steady diffusion models for the above two models have essentially the same features. Myrmekite is stable for large values (> 10) of LAlAl/ LCaCa, for moderate values of LAlAl/ LSiSi, and for only small values (vs. LAlAl/ LNaNa, and its dependence on LAlAl/ LSiSi is stronger than that of myrmekite. The reaction rim is stable only for large values of LAlAl/ LCaCa, which is consistent with the case of myrmekite. Exchange cycles for

  17. 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.

  18. 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.

  19. The Byzantine ceramics from Pergamon excavations. Characterization of local and imported productions by elementary analysis using PIXE and INAA methods and by petrography

    International Nuclear Information System (INIS)

    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

  20. Space activities in Brazil

    Science.gov (United States)

    Carvalho, H.; Kono, J.; Quintino, M.; Perondi, L.

    Brazilian space activities develop around three main programs, namely, the China-Brazil Earth Resources Satellite (CBERS) , the Applications Satellite program, comprising the Multi-Mission Platform and associated remote sensing payloads (radar and optical), and the Scientific Satellites program. Increasing national industry participation and acquiring new technology are strategic goals established for all programs. CBERS program is the result of successful long term cooperation between China and Brazil for the development of remote sensing satellites. Initially comprising two satellites, launched in 1999 and 2003, and now extended to four, this cooperation fulfills the needs of both countries in earth imagery. CBERS satellites are designed for global coverage and include cameras for high spatial resolution and wide field of view, in the visible, near infrared spectrum, an infrared multi-spectral scanner, and a Transponder for the Brazilian Environmental Data Collection System to gather data on the environment. They are unique systems due to the use of onboard cameras which combine features that are specially designed to resolve the broad range of space and time scales involved in our ecosystem. Applications satellites, mainly devoted to optical and radar remote sensing, are being developed in the frame of international cooperation agreements, and will be based on the use of a recurrent Multi-Mission Platform (MMP), currently under development. The MMP will be 3-axes stabilized and will have a fine pointing capability, in several pointing modes, such as Earth, Inertial or Sun pointing. Missions will be focused on natural resources observation and monitoring.. The Program for Scientific Satellites is based on low-cost micro-satellites and aims at providing frequent flight opportunities for scientific research from space, whilst serving as a technological development platform, involving Research Institutes, Universities and National Industry. Current projects are FBM

  1. Brazil: public health genomics.

    Science.gov (United States)

    Castilla, E E; Luquetti, D V

    2009-01-01

    Brazil represents half of South America and one third of Latin America, having more than 186 million inhabitants. After China and India it is the third largest developing country in the world. The wealth is unequally distributed among the states and among the people. Brazil has a large and complex health care system. A Universal Public Health System (SUS: Sistema SPACEnico de Saúde) covers the medical expenses for 80% of the population. The genetic structure of the population is very complex, including a large proportion of tri- hybrid persons, genetic isolates, and a panmictic large majority. Genetic services are offered at 64 genetic centers, half of them public and free. Nationwide networks are operating for inborn errors of metabolism, oncogenetics, and craniofacial anomalies. The Brazilian Society of Medical Genetics (SBGM) has granted 120 board certifications since 1986, and 7 recognized residences in medical genetics are operating in the country. Three main public health actions promoted by the federal government have been undertaken in the last decade, ultimately aimed at the prevention of birth defects. Since 1999, birth defects are reported for all 3 million annual live births, several vaccination strategies aim at the eradication of rubella, and wheat and maize flours are fortified with folic acid. Currently, the government distributes over 2 million US dollars to finance 14 research projects aimed at providing the basis for the adequate prevention and care of genetics disorders through the SUS. Continuity of this proactive attitude of the government in the area of genomics in public health is desired. PMID:19023184

  2. 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.

  3. 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.

  4. Amazonian anthrosols support similar microbial communities that differ distinctly from those extant in adjacent, unmodified soils of the same mineralogy.

    Science.gov (United States)

    Grossman, Julie M; O'Neill, Brendan E; Tsai, Siu Mui; Liang, Biqing; Neves, Eduardo; Lehmann, Johannes; Thies, Janice E

    2010-07-01

    We compared the microbial community composition in soils from the Brazilian Amazon with two contrasting histories; anthrosols and their adjacent non-anthrosol soils of the same mineralogy. The anthrosols, also known as the Amazonian Dark Earths or terra preta, were managed by the indigenous pre-Colombian Indians between 500 and 8,700 years before present and are characterized by unusually high cation exchange capacity, phosphorus (P), and calcium (Ca) contents, and soil carbon pools that contain a high proportion of incompletely combusted biomass as biochar or black carbon (BC). We sampled paired anthrosol and unmodified soils from four locations in the Manaus, Brazil, region that differed in their current land use and soil type. Community DNA was extracted from sampled soils and characterized by use of denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism. DNA bands of interest from Bacteria and Archaea DGGE gels were cloned and sequenced. In cluster analyses of the DNA fingerprints, microbial communities from the anthrosols grouped together regardless of current land use or soil type and were distinct from those in their respective, paired adjacent soils. For the Archaea, the anthrosol communities diverged from the adjacent soils by over 90%. A greater overall richness was observed for Bacteria sequences as compared with those of the Archaea. Most of the sequences obtained were novel and matched those in databases at less than 98% similarity. Several sequences obtained only from the anthrosols grouped at 93% similarity with the Verrucomicrobia, a genus commonly found in rice paddies in the tropics. Sequences closely related to Proteobacteria and Cyanobacteria sp. were recovered only from adjacent soil samples. Sequences related to Pseudomonas, Acidobacteria, and Flexibacter sp. were recovered from both anthrosols and adjacent soils. The strong similarities among the microbial communities present in the anthrosols for

  5. Mineralogy of the Ibitira eucrite and comparison with other eucrites and lunar samples

    Science.gov (United States)

    Steele, I. M.; Smith, J. V.

    1976-01-01

    The mineralogy of the Ibitira meteorite is studied using single-crystal X-ray and energy-dispersive electron-probe techniques. It is shown that this strongly metamorphosed unbrecciated vesicular eucrite has a primary variolitic and secondary hornfelsic texture dominated by equant grains of pale-brown pyroxene (60%) set in an irregular matrix of plagioclase (30%). Minor phases are detected which indicate igneous crystallization, a prolonged metamorphic history, and vapor deposition. The following sequence of events is suggested as the simplest explanation for the mineralogical features observed: (1) crystallization of the meteorite in a lava flow; (2) prolonged annealing, reduction of primary spinel, and vapor deposition; (3) strong shock sufficient to modify the texture of the plagioclase grains; and (4) sufficient annealing to allow crystallization of the plagioclase as a subparallel mosaic and partial conversion to the low structural state. Evidence for this sequence is examined in detail, particularly in relation to the general features of eucrites, howardites, and mesosiderites

  6. Clay Minerals – Mineralogy and Phenomenon of Clay Swelling in Oil

    Directory of Open Access Journals (Sweden)

    Karpiński B.

    2015-03-01

    Full Text Available Among the minerals found in the earth's crust, clay minerals are of the widest interest. Due to the specific properties such as plasticity, absorbing and catalytic properties clay minerals are used in many industries (oil & gas, chemistry, pharmacy, refractory technology, ceramics etc.. In drilling, a phenomenon of swelling clays is frequently observed. It has an important impact on the cementing quality. During the last few decades clays have been the subject of research on a scale unprecedented in the history of mineralogy. This paper presents review literature on mineralogy of clay minerals and phenomenon of swelling in oil and gas industry. Unique ion exchange properties and clay swelling mechanisms are also considered.

  7. Mineralogical characterization of selected shales in support of nuclear waste repository studies: Progress report

    International Nuclear Information System (INIS)

    Because baseline characterization of shale mineralogy is critical to the interpretation of results from experiments on radionuclide retardation, groundwater-shale interactions, and physicochemical characteristics, a protocol for quantitative mineralogical analyses has been developed by integrating geochemical and instrumental techniques for the investigation of properties related to repository performance. Thermal analyses were used to estimate total organic matter and carbonate mineral contents. Scanning electron microscope backscattering and elemental mapping of polished sectors and particle-size distribution data were used to estimate the amounts of quartz plus feldspar and pyrite in the shales. X-ray diffraction, neutron activation, and size-distribution data were utilized to estimate phyllosilicate mineral contents. High-resolution transmission electron microscopy was used to identify clay mineral components

  8. 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

  9. 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.

  10. A comprehensive physico-chemical, mineralogical and morphological characterization of Indian mineral wastes.

    Science.gov (United States)

    Gedam, Vidyadhar V; Jha, Rajesh; Labhasetwar, Pawan; Engelsen, Christian J

    2013-08-01

    This paper provides a comprehensive characterization of mineral waste such as fly ash, bottom ash, slag and construction demolition (C&D) collected from four different thermal power plants, three steel plants and three C&D waste generation sites in India. To determine utilisation potential and environmental concerns, as received fly ash, bottom ash, slag and C&D waste were analysed for physico-chemical, mineralogical and morphological properties. The physico-chemical properties analysed include pH, moisture content, acid insoluble residue, loss on ignition(LOI), carbon content, fineness, chloride content, sulphate content, reactive silica content, XRF and heavy metal analysis. Morphological and mineralogical characteristics were investigated using scanning electron microscopy-energy dispersive X-ray. Particle size distribution was obtained using particle size analyser. The material analysed has different compositions and were selected with a view to determine their suitability for different applications in cement and concrete industry and for further research studies. PMID:23255170

  11. 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.

  12. 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.

  13. Estimating the buoyancy field for Earth's lower mantle using seismic and mineralogical models

    Science.gov (United States)

    Colli, Lorenzo; Ghelichkhan, Siavash; Chust, Thomas; Steinle-Neumann, Gerd; Simmons, Nathan; Schuberth, Bernhard S. A.

    2016-04-01

    Many geophysical phenomena, such as mantle convection, dynamic topography, geoid undulations, and plate motions, arise as a balance between driving gravitational forces and resisting viscous stresses within the Earth's mantle. A good characterization of the present-day buoyancy field of the mantle would allow for tighter constraints on its viscosity. It is possible to derive an estimate for the present-day buoyancy field of the lower mantle using seismically-derived global tomographic models together with thermodynamically self-consistent models of mantle mineralogy. However, given the uncertainties affecting both seismic and mineralogical models, different choices can be made, which lead to different estimates. Here we explore some of the possible endmembers, looking at the different buoyancy structure they produce and the different implications they have for the dynamic Earth.

  14. Mineralogical Characterization of Copper Slag from Tongling Nonferrous Metals Group China

    Science.gov (United States)

    Chun, Tiejun; Ning, Chao; Long, Hongming; Li, Jiaxin; Yang, Jialong

    2016-09-01

    In this paper, the mineralogical characterization of typical copper slag supplied by the Tongling Nonferrous Metals Group China was performed based on x-ray fluorescence, x-ray diffraction, and scanning electron microscopy with energy dispersive spectroscopy. The results show that the dominant phases of the slag are fayalite, glassy substance and magnetite. The minor accessory phases consist of copper matte, metallic copper and other complex lead and zinc minerals. The contents of iron, copper, lead and zinc in copper slag are 40.21%, 0.79%, 0.24%, and 2.80%, respectively. The mineralogy of copper slag indicates that these valuable elements are difficult to recover by beneficiation processes due to the complicated occurrences. Instead, the pyro-metallurgical processes appear promising in recovering the valuable metals from copper slag.

  15. 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.

  16. Mineralogical test as a preliminary step for metallurgical proses of Kalan ores

    International Nuclear Information System (INIS)

    Mineralogical tests as a preliminary step for hydrometallurgy of Kalan ores, including Eko Remaja and Rirang have been carried out to identify the elements and minerals content which affect the metallurgical process, especially the leaching and purification of uranium. Mineralogical tests have been done by means of radioactive and radioluxugraph tests to identify radioactive minerals; thin specimen analysis, Scanning Electron Microscopy (SEM) to identify elements and morphology, EPMA to analyse qualitatively the elements, X-ray Diffractometer (XRD) to identify of minerals content; and X-ray Fluorescence (XRF) and chemical analyses to determine total elements qualitatively and quantitatively. The experimental results show that the Eko Remaja ores contain uraninite and brannerite, iron and titan oxides, sulfides, phosphates and silicates minerals, while the Rirang ores contain uraninite, monazite and molybdenite

  17. Mineralogy and technological properties of some kaolin types used in the ceramic industry

    Directory of Open Access Journals (Sweden)

    Marcel Benea

    2004-04-01

    Full Text Available Three different kaolin types used in ceramic industry were analyzed by different methods in order to obtain a complete mineralogical and technological characterisation. Studies were carried out by using a combination of analyses (XRD, SEM, methylene blue absorption, particle size distribution of both the bulk sample, and the fine fraction. The main technological characteristics (drying and firing shrinkage, Pfefferkorn plasticity index, rheology, resistance, and colour after firing of the ceramic masses prepared by using the analyzed kaolin types were also established. As a result, a direct relationship between the mineralogical composition and particle size distribution of different kaolin types vs. the technological properties of the raw and fired ceramic products was evidenced.

  18. 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.

  19. 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.

  20. 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.

  1. Mineralogy of Layered Outcrops at Mawrth Vallis and Implications for Early Aqueous Geochemistry on Mars

    Science.gov (United States)

    Bishop, J. L.; Gross, C.; Rampe, E. B.; Wray, J. J.; Parente, M.; Horgan, B.; Loizeau, D.; Viviano-Beck, C. E.; Clark, R. N.; Seelos, F. P.; Ehlmann, B. L.; Murchie, S. L.

    2016-01-01

    Recently developed CRISM parameters and newly available DTMs are enabling refined characterization of the mineralogy at Mawrth Vallis. A stratigraphy including 5 units is mapped using HRSC DTMs across 100s of kms and using HiRISE DTMs across 100s of meters. Transitions in mineralogic units were characterized using spectral properties and surface morphology. The observations point to an ancient wet and warm geologic record that formed the thick nontronite unit, a period of wet/dry cycling to create acid alteration, followed by leaching or pedogenesis to result in Al-phyllosilicates, and finally a drier, colder climate that left the altered ash in the form of nanophase aluminosilicates, rather than crystalline clays.

  2. 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.

  3. The Espinharas uranium occurrence, Brazil

    International Nuclear Information System (INIS)

    Nuclam has been exploring for uranium in Brazil since 1976. During this period one uranium ore body has been found in the vicinity of Espinharas, a village in Paraiba State, northeast Brazil. According to present knowledge, the mineralized ore body is caused by metasomatic action. The history of discovery and the exploration work until the end of 1979 is given, showing the conceptual change with increasing knowledge of the mineralized zone. (author)

  4. Aqueous Alteration Rinds in Basalt: Mineralogic Characterization from Hand Sample to Outcrop with Hyperspectral Imaging and Implications for Mars 2020

    Science.gov (United States)

    Greenberger, R. N.; Mustard, J. F.; Cloutis, E. A.; Mann, P.; Wilson, J. H.

    2014-07-01

    Hydrothermally altered lacustrine pillow basalts show strong gradients in mineralogy, chemistry, and redox state from interior to exterior at thick section, hand sample, and outcrop scales identified with hyperspectral imaging and elemental mapping.

  5. Morphology and Mineralogy of Libya Montes Layered Delta Deposits, Mars: Implications for Long-Term Aqueous Alteration

    Science.gov (United States)

    Erkeling, G.; Reiss, D.; Poulet, F.; Carter, J.; Loizeau, D.; Hiesinger, H.; Ivanov, M. A.; Hauber, E.; Jaumann, R.

    2011-03-01

    We present the first results of our morphologic and mineralogic investigation of layered delta-deposits in the Libya Montes, where our observations suggest long-term availability of water and aqueous alteration.

  6. Notas inéditas de Jovellanos sobre mineralogía

    OpenAIRE

    Ordaz Gargallo, Jorge; Manuel GUTIÉRREZ CLAVEROL; Lorenzo Álvarez, Elena de

    2010-01-01

    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. Christian Herrgen y la institucionalización de la mineralogía en Madrid

    OpenAIRE

    Parra, Dolores; Pelayo, Francisco

    1996-01-01

    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 ...

  8. Petrology and mineralogy of CK chondrites: Implications for the metamorphism of the CK chondrite parent body

    OpenAIRE

    Takaaki, Noguchi

    1993-01-01

    The petrology and mineralogy of four CK chondrites, Karoonda (CK4), Maralinga (CK4), Yamato(Y)-693(CK4), and Elephant Moraine (EET) 87507 (CK5) were investigated in detail to estimate the origin of their quite heterogeneous plagioclases and the metamorphic history of CK chondrite parent body. EPMA analyses and SEM observations revealed that plagioclases in chondrules, CAIs, and matrices in CK chondrites have different compositional variations and that plagioclases in matrices display distinct...

  9. Mineralogy of the Asuka 87 and 88 eucrites and crustal evolution of the HED parent body

    OpenAIRE

    Takeda,Hiroshi/Ishii,Teruaki/Arai,Tomoko/Miyamoto,Masamichi

    1997-01-01

    Mineralogical study of three apparently crystalline eucrites, Asuka (A)-87272,A-881388 and A-881394 revealed that their textures are not primary crystallization products from a magma. A-87272 is a monomict breccia, but the finegrained matrix is recrystallized to a granulitic texture with fine, rounded pyroxene crystals set in a plagioclase matrix. Large fragments of pyroxene are inverted to orthopyroxene with coarse exsolution lamellae on (001) and fine ones on (100). A-881388 contains a larg...

  10. Mineralogical and Geochemical Controls of Arsenic in an Active Tailings Dam

    OpenAIRE

    Samuel A. Ndur; William K. Buah

    2015-01-01

    The aim of this study was to assess arsenic (As) mobilization in an active tailings dam through mineralogical and geochemical characterization study. Arsenite is the predominant As species in the dam with more than 50% of the arsenic bound to the organic fraction. Pyrite and arsenopyrite are the principal opaque minerals remaining in the tailings with relic grains showing rims of oxidation (hematite/goethite). Illite, kaolinite and carbonates act as pH buffers and consume the acid generated d...

  11. Hydrothermal carbonate chimneys from a continental rift (Afar Rift): Mineralogy, geochemistry, and mode of formation

    OpenAIRE

    Dekov, V. M.; Egueh, N. M.; Kamenov, G.D.; Bayon, G.; Lalonde, S. V.; Schmidt, Mark; Liebetrau, Volker; Munnik, F.; Fouquet, Y.; Tanimizu, M.; Awaleh, M. O.; Guirreh, I.; Le Gall, B.

    2014-01-01

    International audience Carbonate chimney-like deposits up to 60 m high are scattered or arranged in rows at the shores of a desiccating hypersaline and alkaline lake from a continental rift setting (Lake Abhé, Afar Rift, Djibouti). The chimneys formed sub-aqueously in the lake water body at a higher water level than observed today. Alternating calcite and low-Mg calcite + silica concentric layers compose the chimney structures. Mineralogical and geochemical investigations of the chimneys, ...

  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 Lower Silurian Osmundsberg K-bentonite. Part II: Mineralogy, geochemistry, chemostratigraphy and tectonomagmatic significance

    Science.gov (United States)

    Huff, W.D.; Bergstrom, Stig M.; Kolata, Dennis R.; Sun, H.

    1998-01-01

    The Lower Silurian Osmundsberg K-bentonite is a widespread ash bed that occurs throughout Baltoscandia and parts of northern Europe. This paper describes its characteristics at its type locality in the Province of Dalarna, Sweden. It contains mineralogical and chemical characteristics that permit its regional correlation in sections elsewhere in Sweden as well as Norway, Estonia, Denmark and Great Britain. The Baltica as part of the subduction complex associated with the closure of Iapetus.

  14. Mineralogical impact on long-term patterns of soil nitrogen and phosphorus enzyme activities

    Science.gov (United States)

    Mikutta, Robert; Turner, Stephanie; Meyer-Stüve, Sandra; Guggenberger, Georg; Dohrmann, Reiner; Schippers, Axel

    2014-05-01

    Soil chronosequences provide a unique opportunity to study microbial activity over time in mineralogical diverse soils of different ages. The main objective of this study was to test the effect of mineralogical properties, nutrient and organic matter availability over whole soil pro-files on the abundance and activity of the microbial communities. We focused on microbio-logical processes involved in nitrogen and phosphorus cycling at the 120,000-year Franz Josef soil chronosequence. Microbial abundances (microbial biomass and total cell counts) and enzyme activities (protease, urease, aminopeptidase, and phosphatase) were determined and related to nutrient contents and mineralogical soil properties. Both, microbial abundances and enzyme activities decreased with soil depth at all sites. In the organic layers, microbial biomass and the activities of N-hydrolyzing enzymes showed their maximum at the intermediate-aged sites, corresponding to a high aboveground biomass. In contrast, the phosphatase activity increased with site age. The activities of N-hydrolyzing enzymes were positively correlated with total carbon and nitrogen contents, whereas the phosphatase activity was negatively correlated with the phosphorus content. In the mineral soil, the enzyme activities were generally low, thus reflecting the presence of strongly sorbing minerals. Sub-strate-normalized enzyme activities correlated negatively to clay content as well as poorly crystalline Al and Fe oxyhydroxides, supporting the view that the evolution of reactive sec-ondary mineral phases alters the activity of the microbial communities by constraining sub-strate availability. Our data suggest a strong mineralogical influence on nutrient cycling par-ticularly in subsoil environments.

  15. Influence of the chemical, physical and mineralogical characteristics on the three latosoils compacting

    International Nuclear Information System (INIS)

    This work studies the behavior of three brazilian latosoils (Purple, Una and yellow latosoils) concerning to the tendency of compacting, by using the trail analysis for evaluation of the physical, chemical, mineralogical and other compacting estimation effects on this process. Two conditions of soil use were considered: intensive cultivation, with field evaluation which indicates the compacting and not worked area, with natural forest or old and abandoned reforesting

  16. Qualitative mineralogical characterization of the sinter by X-ray diffraction

    International Nuclear Information System (INIS)

    This paper aims the qualitative mineralogical characterization of sinters and raw materials employed on its fabrication, via X-ray diffraction technique. Thus, sample with constant coke breeze content and variable contents of sand, limestone, dunite and dolomite were prepared to obtain current sinter compositions, with variable basicity. The tests were performed at the research of the following institutions: Companhia Siderurgica Nacional, Centro de Tecnologia Mineral and Instituto Nacional de Tecnologia. (author)

  17. Study of bismuth minerals belonging to the mineralogical collection from the National Museum

    International Nuclear Information System (INIS)

    With the purpose of searching the presence of Tellurium minerals in the Ouro Preto-Mariana country, Minas Gerais State, and considering the existence of a great number of minerals in which this element come across allied with Bismuth, samples of the mineralogical collection of the Museu Nacional, proceeding that region and classified as Bismuth minerals were studied by X-ray fluorescence analysis and diffractometric analysis. In this report the results of this research are presented. (Author)

  18. 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.

  19. 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.

  20. 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.

  1. Moessbauer Spectroscopy for Lunar Resource Assessment: Measurement of Mineralogy and Soil Maturity

    Science.gov (United States)

    Morris, R. V.; Agresti, D. G.; Shelfer, T. D.; Pimperl, M. M.; Shen, M.-H.; Gibson, M. A.; Wills, E. L.

    1992-01-01

    First-order assessment of lunar soil as a resource includes measurement of its mineralogy and maturity. Soils in which the mineral ilmenite is present in high concentrations are desirable feedstock for the production of oxygen at a lunar base. The maturity of lunar soils is a measure of their relative residence time in the upper 1 mm of the lunar surface. Increasing maturity implies increasing load of solar wind species (e.g., N, H, and He-3), decreasing mean grain size, and increasing glass content. All these physicochemical properties that vary in a regular way with maturity are important parameters for assessing lunar soil as a resource. For example, He-3 can be extracted and potentially used for nuclear fusion. A commonly used index for lunar soil maturity is I(sub s)/FeO, which is the concentration of fine-grained metal determined by ferromagnetic resonance (I(sub s)) normalized to the total iron content (as FeO). I(sub s)/FeO has been measured for virtually every soil returned by the Apollo and Luna missions to the Moon. Because the technique is sensitive to both oxidation state and mineralogy, iron Moessbauer spectroscopy (FeMS) is a viable technique for in situ lunar resource assessment. Its utility for mineralogy is apparent from examination of published FeMS data for lunar samples. From the data published, it can be inferred that FeMS data can also be used to determine soil maturity. The use of FeMS to determine mineralogy and maturity and progress on development of a FeMS instrument for lunar surface use are discussed.

  2. 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.)

  3. Mineralogy and technological properties of some kaolin types used in the ceramic industry

    OpenAIRE

    Marcel Benea; Maria Gorea

    2004-01-01

    Three different kaolin types used in ceramic industry were analyzed by different methods in order to obtain a complete mineralogical and technological characterisation. Studies were carried out by using a combination of analyses (XRD, SEM, methylene blue absorption, particle size distribution) of both the bulk sample, and the fine fraction. The main technological characteristics (drying and firing shrinkage, Pfefferkorn plasticity index, rheology, resistance, and colour after firing) of the c...

  4. 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...

  5. 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.

  6. Sub-grain scale mineralogy of Hanford sand after reaction with caustic tank wastes

    Science.gov (United States)

    Crandell, L. E.; Peters, C. A.; Um, W.; Lindquist, W.

    2010-12-01

    Reactions of caustic tank waste with vadose-zone sediments at the DOE Hanford, WA site cause dissolution of quartz and aluminosilicate minerals and precipitation of secondary minerals, sodalite and cancrinite. In this study, Hanford sediments from reactive column experiments were examined using 2-D imaging technologies. Mineralogy was examined at the sub-grain scale through image analysis of SEM backscattered electron (BSE) images supplemented with elemental mapping from energy-dispersive X-ray spectroscopy (EDS). The thin sections were made from cross-sections of epoxied sediments in the experimental columns, before and after reaction with simulated tank waste leachate. The image analysis method developed for this work identifies the important minerals and quantifies their accessibility to pore fluids, information that may be used to improve reactive transport modeling of water-rock reactions. Current reactive transport models use mineralogical information obtained through X-ray diffraction (XRD) analysis of crushed samples. Such analysis provides reliable information on the relative quantities of minerals present in macroscopic samples. However, the absence of information on sub-grain scale mineralogy may lead to erroneous interpretation in the context of reactive transport. Preliminary findings indicate the presence of grain inclusions and secondary mineral coatings which may significantly impact the accessibility of minerals to pore waters and thus alter the predicted water -rock reactions.

  7. 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.

  8. 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.

  9. Mineralogical characterization of selected shales in support of nuclear waste repository studies

    International Nuclear Information System (INIS)

    One objective of the Sedimentary Rock Program at the Oak Ridge National Laboratory has been to examine end-member shales to develop a data base that will aid in evaluations if shales are ever considered as a repository host rock. Five end-member shales were selected for comprehensive characterization: the Chattanooga Shale from Fentress County, Tennessee; the Pierre Shale from Gregory County, South Dakota; the Green River Formation from Garfield County, Colorado; and the Nolichucky Shale and Pumpkin Valley Shale from Roane County, Tennessee. Detailed micromorphological and mineralogical characterizations of the shales were completed by Lee et al. (1987) in ORNL/TM-10567. This report is a supplemental characterization study that was necessary because second batches of the shale samples were needed for additional studies. Selected physical, chemical, and mineralogical properties were determined for the second batches; and their properties were compared with the results from the first batches. Physical characterization indicated that the second-batch and first-batch samples had a noticeable difference in apparent-size distributions but had similar primary-particle-size distributions. There were some differences in chemical composition between the batches, but these differences were not considered important in comparison with the differences among the end-member shales. The results of x-ray diffraction analyses showed that the second batches had mineralogical compositions very similar to the first batches. 9 refs., 9 figs., 4 tabs

  10. 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.

  11. 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.

  12. Magnetic mineralogy analyses on greigite-bearing sediments with inconsistent magnetic polarity (Adana Basin, Southern Turkey)

    Science.gov (United States)

    Lucifora, S.; Cifelli, F.; Mattei, M.; Cosentino, D.; Sagnotti, L.; Roberts, A.

    2012-04-01

    A paleomagnetic study has been carried out, in the framework of the VAMP (Vertical Anatolian Movement Project) project, on 4 stratigraphic sections and 1 site from the Adana basin in the southern margin of the Anatolian Plateau. About 300 standard cylindrical samples have been analysed for paleomagnetism and rock magnetism. All the sections have been deposited in the upper Messinian"lago-mare" post-evaporitic event, which occurred in the Mediterranean basin, during the reverse polarity Chron C3r. Paleomagnetic results, presented in this work, are in contrast with these data, showing both normal and reverse polarities along the sections. Standard magnetic mineralogy investigations, integrated with SEM analyses and FORC diagrams, show that magnetite and ferrimagnetic iron sulphides (greigite) are the main magnetic carriers. Moreover, we find an interesting correlation between the magnetic mineralogy of the sediments and the magnetic polarities, being magnetite the magnetic carrier in the normal polarity samples and greigite in the reverse ones. Reversal and fold tests demonstrate that normal polarity samples have been subjected to a pervasive magnetic overprint and acquired their remanent magnetization after bedding tilt. Whereas samples with a reverse polarity acquired their remanent magnetization before bedding tilt, but after syn-sedimentary soft deformation. This work is proposed as a contribution aimed to improve the understanding of the relationship between the magnetic mineralogy and the remagnetization phenomena in order to avoid misinterpretation of magnetostratigraphic and paleomagnetic data.

  13. The in situ exobiological investigation of the Martian surface mineralogy during unmanned missions. [Abstract only

    Science.gov (United States)

    Mancinelli, Rocco L.; White, Melisa R.

    1994-01-01

    An important goal of exobiological research is to determine if life arose on planets other than Earth. The only other planet known, to date, on which life may have arisen is Mars. The data suggest that the physical environment of early Mars (i.e., temperature, pressure, and radiation regimes) was suitable for life to arise. Thus far, the data also suggest that early Mars possessed sufficient quantities of the required building blocks and a number of the chemical compounds necessary for life to arise. It is not known, however, if water existed in the appropriate state (i.e., liquid) in sufficient quantities long enough for life to arise. Determining the mineralogy and components of the Martian soil through in situ analyses during missions to Mars will provide information from which an assessment can be made for the probability of the origin of life on Mars. Missions to Mars in the near future will be unmanned and capable of in situ analyses. Our studies have shown that differential thermal analysis coupled with gas chromatography (DTA/GC) is a more appropriate analytical technique than, x-ray fluorescence, x-ray diffraction, alpha-proton backscatter, gamma-ray spectrometry, differential scanning calorimetry coupled with mass spectrometry (DSC/MS), or DSC/GC to identify the mineralogy of the Martian surface material in situ. DTA/GC is an advancement over the pyrolytic techniques flown on previous missions that have supplied only limited mineralogical information (Biemann et al. 1977).

  14. 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

  15. 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)

  16. 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.

  17. Petrology and geochemistry of the marbles and calcosilicated rocks from Ipira, Bahia - Brazil

    International Nuclear Information System (INIS)

    This work explains a study of marbles and diopsitites from Serra das Panelas, Ipira, Bahia, Brazil. Petrographic analysis, chemistry some elements, trace elements and rare earths, isotopic analysis of Strontium, carbon and oxigen, and geochronological determinations were done. The ages founded correspond to Transamazonic Orogenetic cicle, with Archean age, confirmed by the 18O values found, which give to marble, ages about 2.500 my. The mineralogy and the texture give to marble an invulgar aspect, making a confusion with carbonate. The petrochemical data and the geochemistry of 13C and 18O isotopes showed that the marble and diopsitites was formed from the old marine carbonates. The geochemistry of rare earth suggests a strong correlation with carbonitic and alkaline rocks. An hybrid origem to this rocks is proposed. (C.D.G.)

  18. 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.

  19. 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.

  20. THE ENGINEERING PETROGRAPHY OF GRANITE IN ZHEJIANG PROVINCE, SOUTHEAST OF CHINA%浙江花岗岩的工程岩石学研究

    Institute of Scientific and Technical Information of China (English)

    Moustafa El Omella; C.A. Tang; T. Xu

    2005-01-01

    In this paper, the petrographical characteristics and mechanical properties of Zhejiang granite are studied to elucidate the relationships between them. Close scrutiny of the mineralogy and mechanical properties of the granite provides a good signs of metasomatic alteration in these rocks. Engineering properties of rock material, which depend on the physical properties, can be predicated when the relevant parameters are defined quantitatively. Microscopical observation, hardness, density, porosity and point load strength values can be used as quantititative indicies of studied granite, and each of these factors gives a reliable indication of the engineering case of the rock. The engineering properties and mechanical behavior are functions of the physical properties of the rock constituents and controlled by the alteration state.%对浙江省花岗岩的岩相学特征及力学性质进行了研究以确定它们之间的关系.矿物学研究显示出花岗岩的交代蚀变特征,这可以反映在岩石的力学性质上.岩石材料的物理性质决定其工程学性质,在相关定量参数确定的情况下,可以预测岩石材料的工程学性质.镜下观察、硬度、密度、孔隙度及点负荷强度均可作为所研究花岗岩的定量参数.上述每个因素都可提供岩石工程学的可靠预测.岩石的物理性质受岩石成分及蚀变状态控制,而岩石的工程学性质和力学特征是其物理性质的函数.

  1. 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

  2. Ethanol fuels in Brazil

    International Nuclear Information System (INIS)

    The largest alternative transportation fuels program in the world today is Brazil's Proalcool Program. About 6.0 million metric tons of oil equivalent (MTOE) of ethanol, derived mainly from sugar cane, were consumed as transportation fuels in 1991 (equivalent to 127,000 barrels of crude oil per day). Total primary energy consumed by the Brazilian economy in 1991 was 184.1 million MTOE, and approximately 4.3 million vehicles -- about one third of the total vehicle fleet or about 40 percent of the total car population -- run on hydrous or open-quotes neatclose quotes ethanol at the azeotropic composition (96 percent ethanol, 4 percent water, by volume). Additional transportation fuels available in the country are diesel and gasoline, the latter of which is defined by three grades. Gasoline A (regular, leaded gas)d has virtually been replaced by gasoline C, a blend of gasoline and up to 22 percent anhydrous ethanol by volume, and gasoline B (premium gasoline) has been discontinued as a result of neat ethanol market penetration

  3. 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. PMID:12295035

  4. 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.

  5. The Evolution of Reforestation in Brazil

    OpenAIRE

    Bacha, Carlos

    2003-01-01

    This paper analyzes the evolution of reforestation in Brazil and makes an evaluation of federal government policies used to stimulate that activity. Despite the huge increase of reforestation areas in Brazil since the 1970s, what put up Brazil as the sixth large country with reforested areas, a scarcity of roundwood from reforested areas is happing in that country during the first decade of the 21st century. Federal government implemented three programs to foster the reforestation in Brazil d...

  6. Islam in Brazil or the Islam of Brazil?

    Directory of Open Access Journals (Sweden)

    Vitória Peres de Oliveira

    2006-01-01

    Full Text Available This article is about the Islam lived and practiced by Muslim communities in Brazil. It attempts to understand the identity that this religion is acquiring in the Brazilian religious field. It discusses the discrepancy between figures presented by the official census and Muslim sources and offers models to think about the emergence of Muslim communities and possible changes due to the entrance of "new Muslims" (converted Brazilians without Muslim origin. Based on empirical data, it discusses the difficulties found and strategies used by the communities. It suggests that Islam in Brazil is starting to put down roots and to have a profile of its own.

  7. 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.

  8. OUT Success Stories: Rural Electrification in Brazil

    International Nuclear Information System (INIS)

    The United States and Brazil are collaborating to bring electricity to some 5 million households in rural Brazil. Over the next decade, there is a potential to install approximately 500 megawatts (MW) of solar home systems and 1000 MW of community systems, bringing light to households, schools, and health clinics throughout rural Brazil

  9. 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.

  10. Sexuality education in Brazil.

    Science.gov (United States)

    Suplicy, M

    1994-01-01

    The development of a comprehensive program of sex education in Brazilian schools is described in the context of Brazil's culture and traditions such as the Carnival. The influence of Catholicism is explored as is the effect of the behavioral restrictions called for by scientists concerned about sexually transmitted diseases. The Brazilian response to homosexuality is described, and the emergence of a public discussion of sexuality in the media is traced. It is noted that improvements in the status of women have been held in check by a public ridicule of feminism and by the strength of the traditional patriarchal structures which dominate the culture. With this picture given of how the issue of sexuality fits into Brazilian life, the 1980s initiative on the part of the Work and Research Group for Sex Education is described. Opposition to this effort has largely taken the form of passive resistance; even the Catholic Church has not officially protested the sex education program. Details are provided about 1) the selection of teachers, teacher training, and weekly supervisory teacher meetings; 2) the way in which parental permission for student participation was gained; 3) the implementation of the program; 4) the successes achieved; and 5) the difficulties encountered. Finally, it is noted that plans were made to expand the sex education project from the Sao Paulo area to 6 additional large cities in 1994. Also planned is the publication of the Brazilian Guidelines for Comprehensive Sexuality which will explain the sex education methodology and be extremely valuable in the establishment of new projects. PMID:12287356

  11. 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. PMID:12346918

  12. 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

    2016-02-01

    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. PMID:26927450

  13. 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.

  14. 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.

  15. 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.

  16. Mineralogical and geochemical patterns of urban surface soils, the example of Pforzheim, Germany

    International Nuclear Information System (INIS)

    This study presents a combined geochemical and mineralogical survey of urban surface soils. Many studies on urban soils are restricted to purely chemical surveys in order to investigate soil pollution caused by anthropogenic activities such as traffic, heating, industrial processing, waste disposal and many more. In environmental studies, chemical elements are often distinguished as lithogenic and anthropogenic elements. As a novel contribution to those studies, the authors combined the analysis of a broad set of chemical elements with the analysis of the main mineralogical phases. The semi-quantification of mineralogical phases supported the assignment of groups of chemical elements to lithogenic or anthropogenic origin. Minerals are important sinks for toxic elements. Thus, knowledge about their distribution in soils is crucial for the assessment of the environmental hazards due to pollution of urban soils. In Pforzheim, surface soils (0-5 cm depth) from various land use types (forest, agriculture, urban green space, settlement areas of various site densities) overlying different geological units (clastic and chemical sediments) were investigated. Urban surface soils of Pforzheim reflect to a considerable degree the mineral and chemical composition of parent rocks. Irrespective of the parent rocks, elevated concentrations of heavy metals (Zn, Cu, Pb, Sn, Ag) were found in soils throughout the whole inner urban settlement area of Pforzheim indicating pollution. These pollutants will tend to accumulate in inner urban surface soils according to the available adsorption capacity, which is normally higher in soils overlying limestone than in soils overlying sandstone. However, inner urban surface soils overlying sandstone show elevated concentrations of carbonates, phyllo-silicates and Fe and elevated pH values compared with forest soils overlying sandstone. Thus, in comparison to forest soils overlying sandstones, inner urban soils overlying sandstone affected by

  17. Morphological and mineralogical forms of technogenic magnetic particles in industrial dusts

    Science.gov (United States)

    Magiera, T.; Jabłońska, M.; Strzyszcz, Z.; Rachwal, M.

    2011-08-01

    The morphology, mineralogy, and magnetic properties of technogenic magnetic particles (TMPs) were analysed in four kinds of industrial dust produced during high temperature technological processes of different branches of industry (lignite and hard coal burning, cement production, coke production). The study was carried out by means of magnetic susceptibility measurement, energy dispersive spectroscopy (EDS), scanning electron microscope (SEM), X-ray diffraction, Mössbauer spectroscopy, and thermomagnetic analysis. To assess the total content of the magnetic fraction in bulk dust samples, mass specific magnetic susceptibility (χ) was measured and then a physical separation of magnetic particles (mostly of technogenic origin) was conducted. The dusts revealed high diversity of the χ value, which was dependent on the magnetic particles' concentration and mineralogical composition. Significant differences in the magnetic mineralogy of dusts coming from different branches of industry were observed. In fly ashes from coal combustion, spherical forms (typical ferromagnetic spherules) of magnetite, magnesioferrite, and maghemite were mostly observed. In dusts after lignite combustion a higher content of antiferromagnetic hematite and maghemite was observed due to the lower temperature of lignite combustion. In cement dusts a large variety of iron minerals were observed including magnetite, maghemite, hematite, ferrites, and goethite. The characteristic mineral forms for cement dusts were Ca-ferrites and co-occurrence of calcite, anhydrite, gypsum, and bassanite with a magnetic mineral fraction. The magnetic fraction produced by the coke industry was mostly in the form of tightly compacted aggregates with well-formed crystal structures where ferromagnetic pyrrhotite was characteristic feature. The TMPs could be distinctive for pollution source identification and serve as a tracer of dust origin and (if found in topsoil) identification of soil pollution sources.

  18. Quantitative mineralogical characterization of chrome ore beneficiation plant tailing and its beneficiated products

    Science.gov (United States)

    Das, S. K.

    2015-04-01

    Mineralogical characterization and liberation of valuable minerals are primary concerns in mineral processing industries. The present investigation focuses on quantitative mineralogy, elemental deportment, and locking-liberation characteristics of the beneficiation of tailings from a chrome ore beneficiation plant in the Sukinda region, Odisha; methods used for the study of the beneficiated tailings are QEMSCAN®, X-ray diffraction (XRD), and mineral chemistry by a scanning electron microscope equipped with an energy-dispersive spectrometer (SEM-EDS). The tailing sample was fine grained (69.48wt% below 45 μm size), containing 20.25wt% Cr2O3 and 39.19wt% Fe2O3, with a Cr:Fe mass ratio of 0.51. Mineralogical investigations using QEMSCAN studies revealed that chromite, goethite, and gibbsite are the dominant mineral phases with minor amounts of hematite, kaolinite, and quartz. The sample contained 34.22wt% chromite, and chromite liberation is more than 80% for grains smaller than 250 μm in size. Based on these results, it was predicted that liberated chromite and high-grade middling chromite particles could be separated from the gangue by various concentration techniques. The tailing sample was beneficiated by hydrocyclone, tabling, wet high-intensity magnetic separation (WHIMS), and flotation in order to recover the chromite. A chromite concentrate with 45.29wt% Cr2O3 and a Cr:Fe mass ratio of 1.85 can be produced from these low-grade chromite ore beneficiation plant rejects.

  19. 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

  20. 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.

  1. Geochemical and Mineralogical Composition of Bima Sandstone Deposit, Yola Area, NE Nigeria

    Directory of Open Access Journals (Sweden)

    D.M. Orazulike

    2011-03-01

    Full Text Available The aim of this study is to determine the geochemical and mineralogical composition of Bima Sandstone deposite of northeastern Nigeria. A total number of sixteen (16 sandstone samples were collected in Yola area inorder to classify the deposit of the Bima Sandstone exposed in this area on the basis of its chemical and mineralogical make-up. All the samples were selected randomly and subjected to both geochemical and petrographic studies. Relative concentration of the major oxide groups such as silica and alumina alkali oxides, iron oxide and magnesia has been used to classify the deposit. The results of the log of ratio of the m ajor oxide groups indicate that Bima Sandstone of the study area can be classified as greywackes, arkoses and lithic arenites including sub-greywackes and protoquartzites. The abundant alkali values as shown by the relatively high log K2O/Na2O ratio in most of the samples indicated immature sandstones whereas low alkali values in sam ples F, H and M revealed mature sandstones. The enrichment of silica (quartz over Al2O3 (log SiO2/Al2O3<1.5 indicate that Bima Sandstone has undergone long period of transportation and have been subjected to intense weathering resulting in the destruction of other minerals especially plagioclase and potassium feldspars during transportation. Microscopic examination of about sixteen slides (16 of Bima Sandstone under both plane and cross polars revealed the following average mineralogical composition: quartz (65% feldspars (14%, mica (9%, iron oxide (5%, calcite (3% further confirms quartz/lithic arenites and greywackes as some of the predominant sedimentary rocks in the study area.

  2. Notas inéditas de Jovellanos sobre mineralogía

    OpenAIRE

    Ordaz Gargallo, Jorge; Gutiérrez Claverol, Manuel Alberto; Lorenzo Álvarez, Elena de

    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 ...

  3. The postglacial Stuoragurra Fault, North Norway - A textural and mineralogical study.

    Science.gov (United States)

    Roaldset, E.

    2012-04-01

    The postglacial Stuoragurra Fault, North Norway - A textural and mineralogical study Elen Roaldset(1), Mari Åm (2), and Oddleiv Olesen(3) 1) Natural History Museum, University of Oslo, P.O.Box 1172 Blindern, 0318 Oslo, Norway 2) Statoil R &D, P. O. Box 2470, 7005 Trondheim, Norway 3) Norwegian Geological Survey, P.O.Box 6315 Sluppen, 7491 Trondheim, Norway The Stuoragurra Fault is part of the Lapland province of postglacial faults and was identified in 1983 during a colloborative project between the Geological Surveys of Finland Norway and Sweden. The Stuoragurra Fault is an 80 km long fault zone which contains three main segments of eastward dipping faults (30-55 deg.) with up to 10 m of reverse displacement and a 7 m high escarpment. It cross-cuts glaciofluvial deposits and consequently being younger than 10.000 years. The postglacial fault segments follow to a large extent older fault zones represented by lithified breccias and diabases of Proterozoic age. In this paper we will present textural and mineralogical study of a 135 m continous core drilled across the fault zone. The investigation methods include quality assessments by rock quality designation methods (RQD and Q- methods), textural and petrological descriptions visually and by thin section microscopy, and mineralogical analysis by X-ray diffraction. Special attention is drawn to neoformed and/or degraded minerals like clay minerals and iron oxides/hydroxides. The quality assessments of the cored material reflect the degree of rock deformation and fragmentation and show the quality of the bedrock generally to be of very poor (about 60%) to poor quality" (25%) The main minerals in the fresh rock are quarts, feldspar, mica and iron oxides (magnetite and ilmenite). Throughout the cored borehole products of weathering have formed on fissures, fractures and in strongly deformed, gravelly, zones. The neoformed minerals include kaolinite, smectite, and vermiculite, as well as goethite. The mineralogical

  4. 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.

  5. 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

  6. Mineralogical Composition of the Urinary Stones from Different Provinces in Iraq

    Directory of Open Access Journals (Sweden)

    Adnan H. Afaj

    2005-01-01

    Full Text Available For this study, 25 samples of urinary stones were chosen from different provinces in Iraq as representative sampling localities. These samples of urinary stones were collected to represent kidney, urate, and bladder stones. The main objectives of this study are to try to shed some light on the possibilities of tracking down the effective environmental factors that determine the mineralogical and chemical composition of these stones. The stones were examined using several techniques, the most important of which was the use of the X-ray diffraction (XRD technique to determine the mineralogical composition of these stones. A scanning electron microscopy (SEM test was conducted to determine the crystallographic forms and structures for the minerals forming these stones. Optical properties of these minerals were studied using a polarizing microscope. All these techniques revealed that the calcium oxalate, represented in Whewellite mineral, is the most dominant type of these stones, in addition to other minerals such as Hydroxy apatite, Struvite, and Uricite. Dittmarite was pointed out for the first time ever in some samples. This mineral has not been determined in any previous study worldwide.Considering the results of mineralogical and chemical examinations of the urinary stones in question, and the statistical information gathered from the Iraqi Health Ministry, statistical analyses were applied. The ratio of male-female cases in this study happened to be 4:1, which was higher than the ratio in the years 1988––1989 and 1993–1994, 2:1; 3:1 respectively. The highest percentage of the cases was in the 15–50 age group, which is considered as the most productive years of human lifetime. This study showed that one of the most significant factors was that the mineralogical variation of urinary stones in some Iraqi provinces was due to geographical differences, which reflect the variation in lithogenic factors and also climatological factors. Other

  7. 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

  8. 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.

  9. The uranium source-term mineralogy and geochemistry at the Broubster natural analogue site, Caithness

    International Nuclear Information System (INIS)

    The British Geological Survey (BGS) has been conducting a coordinated research programme at the Broubster natural analogue site in Caithness, north Scotland. This work on a natural radioactive geochemical system has been carried out with the aim of improving our confidence in using predictive models of radionuclide migration in the geosphere. This report is one of a series being produced and it concentrates on the mineralogical characterization of the uranium distribution in the limestone unit considered as the 'source-term' in the natural analogue model

  10. IMPACT OF POLLUTION ON THE CLAY MINERALOGICAL COMPOSITION OF SOME SOILS FROM ZLATNA AREA (ROMANIA)

    OpenAIRE

    C. Craciun; Alexandrina Manea; Laura Paulette; Marius Eftene; Victoria Mocanu

    2008-01-01

    Zlatna area is a high polluted zone with heavy metals due to industrial activity (extraction and processing of non-ferrous area). In spite of the fact that industrial activity was stoped for 2-3 years, the effect of pollution are still obvious. The aim of this paper is to make evident some aspects concerning the impact of pollution on the mineralogical composition of the clay fraction (below 2μ) from some soils belonging to dystric cambisol and luvisol type. From the chemical point of view, ...

  11. Relating Optical Properties of Dusts to their Mineralogical and Physical Interrelationships

    Science.gov (United States)

    Engelbrecht, J. P.; Moosmuller, H.; Jayanty, R. K. M.; Casuccio, G.; Pincock, S. L.

    2015-12-01

    The purpose of the project was to provide information on the mineralogical, chemical and physical interrelationships of re-suspended mineral dust samples collected as grab samples from global dust sources. Surface soil samples were collected from about 65 desert sites, including the southwestern USA (12), Mali (3), Chad (3), Morocco (1), Canary Islands (8), Cape Verde (1), Djibouti (1), Afghanistan (3), Iraq (6), Kuwait (5), Qatar (1), UAE (1), Serbia (3), China (5), Namibia (3), Botswana (4), Australia (3), and Chile (1). The 38 μm, health (medical geology), ocean fertilization, and damage to equipment.

  12. Mineralogy and geochemistry of efflorescent minerals on mine tailings and their potential impact on water chemistry.

    Science.gov (United States)

    Grover, B P C; Johnson, R H; Billing, D G; Weiersbye, I M G; Tutu, H

    2016-04-01

    In the gold mining Witwatersrand Basin of South Africa, efflorescent mineral crusts are a common occurrence on and nearby tailings dumps during the dry season. The crusts are readily soluble and generate acidic, metal- and sulphate-rich solutions on dissolution. In this study, the metal content of efflorescent crusts at an abandoned gold mine tailings dump was used to characterise surface and groundwater discharges from the site. Geochemical modelling of the pH of the solution resulting from the dissolution of the crusts was used to better understand the crusts' potential impact on water chemistry. The study involved two approaches: (i) conducting leaching experiments on oxidised and unoxidised tailings using artificial rainwater and dilute sulphuric acid and correlating the composition of crusts to these leachates and (ii) modelling the dissolution of the crusts in order to gain insight into their mineralogy and their potential impact on receiving waters. The findings suggested that there were two chemically distinct discharges from the site, namely an aluminium- and magnesium-rich surface water plume and an iron-rich groundwater plume. The first plume was observed to originate from the oxidised tailings following leaching with rainwater while the second plume originated from the underlying unoxidised tailings with leaching by sulphuric acid. Both groups of minerals forming from the respective plumes were found to significantly lower the pH of the receiving water with simulations of their dissolution found to be within 0.2 pH units of experimental values. It was observed that metals in a low abundance within the crust (for example, iron) had a stronger influence on the pH of the resulting solutions than metals in a greater abundance (aluminium or magnesium). Techniques such as powder X-ray diffraction (PXRD) and in situ mineral determination techniques such as remote sensing can effectively determine the dominant mineralogy. However, the minerals or metals

  13. 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...

  14. [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.

  15. Violence in Schools in Brazil.

    Science.gov (United States)

    Pino, Angel

    1995-01-01

    The causes of violence in schools, as in society, are multiple and complex; they are rooted in the intolerable economic and social conditions created by Brazil's development model, characterized by unequal wealth distribution, widespread poverty, and an exclusive society. By mirroring this exclusionary process, the educational system is inherently…

  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. 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.

  18. 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.

  19. IMPACT OF POLLUTION ON THE CLAY MINERALOGICAL COMPOSITION OF SOME SOILS FROM ZLATNA AREA (ROMANIA

    Directory of Open Access Journals (Sweden)

    C. Craciun

    2008-10-01

    Full Text Available Zlatna area is a high polluted zone with heavy metals due to industrial activity (extraction and processing of non-ferrous area. In spite of the fact that industrial activity was stoped for 2-3 years, the effect of pollution are still obvious. The aim of this paper is to make evident some aspects concerning the impact of pollution on the mineralogical composition of the clay fraction (below 2μ from some soils belonging to dystric cambisol and luvisol type. From the chemical point of view, the effect of pollution is the acidifiation and depletion of bases, reflected by the decrease of values of indices which express soil reaction (pH and soil exchange properties, especially in the surface horizon. From mineralogical point of view, the acidifiation determines a strong alteration of primary minerals (micas and feldspars and just of secondary minerals (illite, evolution beeing towards hydroxy interlayered minerals (intergrade and kaolinite. As result of this alteration the content of kaolinite increases, achiving a double content in the surface horizon of some polluted soils. Sometimes kaolinite becomes the dominant mineral in the clay fraction of some strong polluted soil.

  20. Mineralogical and sedimentological study of gypsiferous sands from the Saharian Desert

    Science.gov (United States)

    Somma, Roberta; Bella, Francesca

    2016-04-01

    A mineralogical and sedimentological study was carried out in Quaternary aeolian sands from the Sahara Desert (Tunisia and Libya). Gypsum resulted to be the dominant mineral (65%), whereas quartz resulted to be in significant amount (25%) in all samples. Aragonite and calcite, related to marine organisms, was found especially in the Libyan sands. Gypsum grains appear in euhedral crystals or as polycrystalline twinned crystals. Crystal habitus is pseudo-octahedric or tabular. Due to the euhedral habitus, the forms of the grains is discoid or bladed but with a low roundness. Quartz grains are mostly ialin or orange as the grain surfaces are coated with thin hematite films. Quartz grains dominantly appear as subhedral crystals. Habitus is prismatic or hexagonal. Due to the subhedral habitus, quartz grain forms can be classified as bladed with a low roundness. A minor amount of quartz grains is formed by well rounded and spherical grains showing frosted and pitted surfaces. The particle size analysis indicated that the studied sediments consist of well sorted very fine sands. The studied Quaternary aeolian sands can be classified as gypsiferous sands. Notwithstanding sands are well sorted, they are immature under a mineralogical and textural point of view. Particularly, gypsum formed in present or past sabkha and the amount of marine bioclasts should suggest that the source area of the Lybian gypsum grains could be a sabkha near the sea.

  1. Significance of mineralogy in the development of flowsheets for processing uranium ores

    International Nuclear Information System (INIS)

    This report has been prepared from material developed at and subsequent to a consultants' meeting held in Vienna in January 1978. The main purpose of the meeting was to prepare a document in the form of a guide for planning and developing treatment flowsheets for uranium ore processing. It was apparent that ore mineralogy, analysed, described and interpreted in ways most meaningful to the metallurgist, is the most essential information required for forming the basis of such planning. This topic, here termed metallurgical mineralogy, is therefore a major theme of this publication. In preparing the report the Agency has borne in mind the important need to impart the experience and knowledge gained in the more developed countries to those who are in the early stages of exploiting their uranium resources. The contents may be criticized as lacking, in some respects, the requisite depth and detail of treatment. The Agency and the consultants are conscious of the need to expand the information in a number of ways. However, the report is presented in its present form in the belief that, as the first attempt to correlate, on a world-wide basis, ore type with processing, it will be considered as a useful basis for future development of these themes

  2. Mineralogy, geochemistry and genesis of the Gheshlagh bauxite deposit, southeast of Gorgan

    Directory of Open Access Journals (Sweden)

    Razgar Faramarzi

    2012-04-01

    Full Text Available The Gheshlagh bauxite deposit is located 110 km southeast of Gorgan. The deposit has been developed as a stratiform horizon with more than 2 km length and a thickness of about 25 m along the contact of Ruteh and Elika carbonate formations. Textural analysis indicates both allochthonous and autochtonous origins for the bauxites. Bohemite, diaspore, anatase, rutile, hematite, goethite, kaolinite, svanbergite, pyrite, and quartz were identified in the ore paragenesis. Based on textural and mineralogical evidence, the deposit can be divided into five distinct units including upper bauxite, upper kaolinite, hard bauxite, lower kaolinite and lower bauxite. Accumulation coefficients of trace elements and geochemical indices such as Ti/Cr, TiO2/Al2O3, Zr/Ti and Nb/Y, combined with the geological evidence suggest the basaltic rocks of the Soltanmeidan Formation as the main source of bauxite materials. Combination of mineralogical and geochemical data shows that the deposit formed in two main stages. First, bauxite materials, Fe and Ti oxides and clay minerals developed as authigenic bauxitization processes of basaltic parent rock. Then, these materials were transported to karst depressions and were accumulated as a bauxite horizon.

  3. 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.

  4. Mineralogical characterization of ambient fine/ultrafine particles emitted from Xuanwei C1 coal combustion

    Science.gov (United States)

    Lu, Senlin; Hao, Xiaojie; Liu, Dingyu; Wang, Qiangxiang; Zhang, Wenchao; Liu, Pinwei; Zhang, Rongci; Yu, Shang; Pan, Ruiqi; Wu, Minghong; Yonemochi, Shinich; Wang, Qingyue

    2016-03-01

    Nano-quartz in Xuanwei coal, the uppermost Permian (C1) coal deposited in the northwest of Yuanan, China, has been regarded as one of factors which caused high lung cancer incidence in the local residents. However, mineralogical characterization of the fine/ultrafine particles emitted from Xuanwei coal combustion has not previously been studied. In this study, PM1 and ultrafine particles emitted from Xuanwei coal combustion were sampled. Chemical elements in the ambient particles were analyzed by inductively coupled plasma mass spectrometry (ICP-MS), and mineralogical characterization of these ambient particles was investigated using scanning electronic microscopy (SEM/EDX) and transmission electronic microscopy, coupled with energy-dispersive spectroscopy (TEM/EDX). Our results showed that the size distribution of mineral particles from the coal combustion emissions ranged from 20 to 200 nm. Si-containing particles and Fe-containing particles accounted for 50.7% of the 150 individual particles measured, suggesting that these two types of particles were major minerals in the ambient particles generally. The nano-mineral particles were identified as quartz (SiO2) and gypsum (CaSO4) based on their crystal parameters and chemical elements. Additionally, there also existed unidentified nano-minerals. Armed with these data, toxicity assessments of the nano-minerals will be carried out in a future study.

  5. 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.

  6. Sedimentology and mineralogy of Libertad formation (late pleistocene) related to local fauna La Paz (Montevideo- Uruguay)

    International Nuclear Information System (INIS)

    The Local Fauna La Paz (Montevideo, Uruguay) includes skeletal remains of taxa that are characteristic of the Late Pleistocene: Glyptodon clavipes, Doedicurus sp., Panochthus sp., Lestodon sp., Macrauchenia patachonica, Stegomastodon waringi, Toxodon platensis, among others. This paper aims to contribute to the understanding of sedimentary processes acting, considering litofaciological and mineralogical aspects of sediment involved, responsible for the accumulation of bonebed. To meet the targets was lifted a detail stratigraphic section; for mineralogical studies were collected representative samples from each individual litofacies and clays were treated for the purposes of being subjected to analysis by X-ray diffractometer. The study was supplemented with a textural and compositional observation of silt and sand fraction through binocular magnifier and petrographic microscope. According to the sedimentological aspects and some taphonomic features of the bonebed such as: facies settling, the absence of sedimentary structures (massive deposit) and grainselection, along with the complete dismantling and chaotic disposal of materials, and the degree of angularity of the largest clasts, it follows that a mud flow was the last reason on the transportation and deposition of remains. The results of the X-ray diffraction reveal the predominance of chlorites and smectites on sepiolite. Previous studies suggested that the lithostratigraphic unit including the remains was the Dolores Formation. However, considering the evolutionary Quaternary model and geomorphological appearance, we consider these sediments belonging to the Libertad Formation

  7. Spectral characteristics of the iron oxides with application to the Martian bright region mineralogy

    Science.gov (United States)

    Sherman, D. M.; Burns, R. G.; Mee Burns, V.

    1982-01-01

    Reflectance spectra of eight polymorphs of FeOOH and Fe2O3 are determined in order to clarify the nature and significance of the iron oxide mineralogy on Mars. The effect of other components that might interfere with iron oxide absorption features is qualitatively constrained through the use of the Kebulka-Munk theory. It is found that the effect of temperature complicates the identification of a given Fe(3+) phase based on the position of the 6A1-4T1 absorption feature. While the Fe(3+) crystal field transitions are spin forbidden, most of the iron oxide polymorphs exhibit anomalously intense crystal field absorption features due to magnetic coupling between adjacent FeO6 octahedra. It is suggested that the resulting deviations from observed remotely sensed reflectance spectra of Mars may provide a basis for the exclusion of many iron oxide phases as significant components of the Martian Fe(3+) mineralogy. A comparison of these results with the visible region spectra of Martian bright regions indicates that the predominant Fe(3+)-bearing phase may be a magnetically disordered material, such as amorphous gels, some ferric sulphates, and other minerals in which Fe(3+) ions in the crystal structure are not magnetically coupled.

  8. Effects of rock mineralogy and pore structure on stress-dependent permeability of shale samples.

    Science.gov (United States)

    Al Ismail, Maytham I; Zoback, Mark D

    2016-10-13

    We conducted pulse-decay permeability experiments on Utica and Permian shale samples to investigate the effect of rock mineralogy and pore structure on the transport mechanisms using a non-adsorbing gas (argon). The mineralogy of the shale samples varied from clay rich to calcite rich (i.e. clay poor). Our permeability measurements and scanning electron microscopy images revealed that the permeability of the shale samples whose pores resided in the kerogen positively correlated with organic content. Our results showed that the absolute value of permeability was not affected by the mineral composition of the shale samples. Additionally, our results indicated that clay content played a significant role in the stress-dependent permeability. For clay-rich samples, we observed higher pore throat compressibility, which led to higher permeability reduction at increasing effective stress than with calcite-rich samples. Our findings highlight the importance of considering permeability to be stress dependent to achieve more accurate reservoir simulations especially for clay-rich shale reservoirs.This article is part of the themed issue 'Energy and the subsurface'. PMID:27597792

  9. Iron Mineralogy and Uranium-Binding Environment in the Rhizosphere of a Wetland Soil

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-12

    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.

  10. 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.

  11. The population question in Brazil.

    Science.gov (United States)

    1992-01-01

    Population control programs were instituted in Brazil in the 1960s and resulted in as 50% reduction of the fertility rate in 20 years with a reduction in population growth from 2.9%/year in the 1960s to 2.1% in the 1980s. The rapid urbanization which has occurred in Brazil also contributed to this process. While the Brazilian government has eschewed foreign intervention, it encourages the population control programs which are funded by international agencies. The women's movement became involved in policies relating to reproductive rights in 1980, and attempts were made to change the focus of women's health care and the right of women to make reproductive choices. 71% of Brazilian women of reproductive age who are married or living in consensual union use contraception. This compares with 70% of women in developed countries. In Brazil, however, 44% of the women have been sterilized, 41% use oral contraceptives (OCs), and 12% use natural or barrier methods, compared to 7, 13, and 41%, respectively, in developed countries. Sterilization is illegal in Brazil, although it is widespread; the high number of Cesarean section births may determine a medical need for sterilization (after three such deliveries, for example). Abortion is also illegal (except in cases of rape or if the mother's life is in danger) and widespread. The 2 to 3 million abortions each year are thought to be the third cause of maternal mortality. Studies of OC use have shown that Brazilian women often use OCs without medical monitoring or in cases when the contraceptive is absolutely contraindicated. In the past few years, Brazilian women's groups have demanded that the government deal with the issue of family planning in order to stop the intervention of international population control agencies. Brazil has never had the sufficiently modern and effective policy to help women to use contraception safely during the various stages of their reproductive lives. PMID:12286343

  12. 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.

  13. 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.

  14. 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.

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

    International Nuclear Information System (INIS)

    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. 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.

  17. Geology, mineralogy, and genesis of palygorskite clay from Borshchevka deposit in the Kaluga Region and outlook for its technological use

    Science.gov (United States)

    Nasedkin, V. V.; Vasiliev, A. L.; Boeva, N. M.; Belousov, P. E.

    2014-05-01

    In this paper we consider localization and paleogeographic conditions of palygorskite deposition in the Moscow Syneclise, which is regarded as a palygorskite province. The geology and mineralogy of the Borshchevka deposit are also characterized. Mineralogical and chemical analyses of rocks from the Steshevo Horizon (C1st), which is the most promising for palygorskite and associated smectite, have been carried out. The morphology and crystal structure of palygorskite varieties differing in origin are characterized, as well as possible use of palygorskite from the Borshchevka deposit as a drilling mud, foundry sand, and sorbent.

  18. 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

  19. 76 FR 30195 - Brazil: Competitive Factors in Brazil Affecting U.S. and Brazilian Agricultural Sales in Selected...

    Science.gov (United States)

    2011-05-24

    ... COMMISSION Brazil: Competitive Factors in Brazil Affecting U.S. and Brazilian Agricultural Sales in Selected... No. 332-524, Brazil: Competitive Factors in Brazil Affecting U.S. and Brazilian Agricultural Sales in... competitive factors in Brazil affecting U.S. and Brazilian agricultural sales in third country markets....

  20. 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

  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. 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

  3. Mineralogically triggered strain localization: inferences from ductile paired shear zones (Tauern Window, Eastern Alps)

    Science.gov (United States)

    Duprat-Oualid, Sylvia; Grasemann, Bernhard; Huet, Benjamin; Yamato, Philippe; Habler, Gerlinde

    2016-04-01

    Lithosphere is mainly constituted by polyphase rocks whose mineralogical, structural and textural characteristics control the spatial distribution of strain, and so, its effective mechanical strength. Variations in local mineralogical compositions may lead to drastic changes in the local microstructures and texture leading, by mechanical feedback processes, to strain hardening or weakening. Understanding these small-scale relations between the petrological characteristics, the rheological properties and the development of progressive deformation is thus of fundamental importance for understanding the strength of rocks at large-scale, especially the mechanical behavior of plates boundaries. We acknowledge the importance of brittle precursors for the localization of strain in the viscous deforming part of the crust. In this study, we focus in centimeter-wide paired ductile shear zones shaped nearby along on both sides of ep-grt-qtz veins within a late Variscan metagranodiorite of the "Zentralgneis" in the Tauern Window (Berlinerhütte, Zillertal, Austria). The paired shear zones, underlined by biotite bands, localized at some centimeters away from the veins associated with a metasomatic domain, within the relatively undeformed host rock. According to their spatial orientations, they exhibit different intensities of shearing (from incipient linking of biotites to anastomosing ultra-mylonitic bands) and thus can be explored as successive strain domains of a shear zone developing in space and time. Here, we present a combination of high-resolution petro-chemical section across the paired shear zones with microstructural and textural measurements in order to constrain mineral reactions and deformation processes associated with the development of localized shear zones. Whole rock chemical analyzes combined with continuous mineralogical mapping revealed small chemical variations induced by fluid-rock interactions in the vicinity of the veins. Although macroscopically

  4. 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.

  5. Brazil, oil and statoil: challenges and opportunities

    OpenAIRE

    Linchausen, Harald Christoffer

    2010-01-01

    This thesis aims to shed some light on what challenges Brazil faces concerning its oil reserves. It also considers Statoil’s situation and attempts to analyse the challenges both face. Hotelling’s rule and Dunning’s OLI framework are presented and used in order to complete this analysis. The thesis starts by looking at the history of petroleum in Brazil and Norway. Next, the theoretical framework is outlined. The challenges for both Brazil and Statoil are presented and anal...

  6. Brazil: The Future of Modern Agriculture?

    OpenAIRE

    Holger Matthey; Fabiosa, Jacinto F.; Fuller, Frank H.

    2004-01-01

    In an attempt to understand better Brazil's future role in agricultural markets, the authors of this report traveled to Brazil on a fact-finding mission in September 2003. The goal was to get a first-hand impression of Brazil's agricultural sector and especially its future potential. In this report we provide a general description of crop and livestock production, government policies, public and private cooperation, and transportation and biotechnology issues. The most striking observations m...

  7. 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...

  8. 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.

  9. Brazil: Mechanisms of Direct Democracy

    OpenAIRE

    Bovo, Raquel

    2008-01-01

    In the structure of Brazilian Government, regarding both the executive as well as the executive powers, the increase in ways in which society can participate in decisions of public interest, stands out. Among the shared or participatory managerial policies implemented in Brazil, the following are noteworthy: the participatory budget, managerial councils, committees dealing with watersheds, thematic conferences, plebiscites, public meetings and referenda. However, if compared to the size of Br...

  10. State Government Bailouts in Brazil

    OpenAIRE

    Bevilaqua, Afonso S.

    2002-01-01

    As a result of the consolidation of democracy after the end of the military regime in the mid-1980s, Brazil has gone through a period of remarkable decentralization both in fiscal and political terms. The move towards decentralized management and control of public finances has been followed by a series of bailouts of state governments by the federal government. The lack of effective control on borrowing, coupled with reputational effects originating from these repeated bailout operations, red...

  11. 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)

  12. 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)

  13. 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.

  14. Brazil-Africa geological links

    Science.gov (United States)

    Torquato, Joaquim Raul; Cordani, Umberto G.

    1981-04-01

    In this work, the main evidence and conclusions regarding geological links between Brazil and Africa are summarized, with emphasis on the geochronological aspects. Taking into account the geographical position, as well as the similarities in the geochronological pattern, the following main provinces of the two continents are correlated: The Imataca and Falawatra complexes in the Guayana Shield and the Liberian Province of West Africa. The Paraguay-Araguaia and the Rockelide Fold Belts. The Sa˜o Luiz and the West African cratonic areas. The Caririan Fold Belt of northeastern Brazil and the Pan-Africa Belt of Nigeria and Cameroon. The JequiéComplex of Bahia, the Ntem Complex of Cameroon and similar rocks of Gabon and Angola. The Ribeira Fold Belt in Brazil and the West Congo and Damara Belts in West and South Africa. In addition, other geological links are considered, such as some of the major linear fault zones which can be traced across the margins of South America and Africa, in the pre-drift reconstructions. Correlations are also made of the tectonic and stratigraphic evolution of the Paranáand Karroo syneclises, and the Brazilian and African marginal basins around the South Atlantic, during their initial stages. Finally, several similarities in the tectonic evolution of South America and Africa, during and after the onset of drifting, are shown to be compatible with a recent origin for the South Atlantic floor, as required by sea-floor spreading and continental drift between South America and Africa.

  15. An AIDS campaign in Brazil.

    Science.gov (United States)

    Janoff, D

    1987-01-01

    The Acquired Immune Deficiency Syndrome (AIDS) distribution program in Brazil, spearheaded by the National Division of Sanitary Surveillance in Ports, Airports, and Borders, was part of the government's massive education campaign to prevent the transmission of HIV-AIDS in Brazil. Beginning in February 1987, the climate was sufficiently favorable to operate a coordinated information campaign during the Carnival celebration, and tourists arriving in the cities of Brazil for the annual Carnival celebration were handed an educational brochure in Portugese, Spanish, English, and French. Yet, beyond reaching the tourist populations, it is particularly important to reach large portions of the Brazilian population. Planners of the national AIDS campaign intend to use television, radio, and all major newspapers in their effort to cover the country. Initial television coverage is comprised of short informational messages directed at high-risk groups. There also are plans to use radio and the print media in order to reach a wider audience. It is estimated that US $6 million will be needed to adequately meet the costs of AIDS prevention and medical care, but due to extreme budget constraints, only $45,000 has been earmarked for ongoing AIDS activities at this time. PMID:12281284

  16. 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.

  17. Chemical and mineralogical characterization on glazes of ceramics from Coimbra (Portugal) from the sixteenth to nineteenth centuries.

    Science.gov (United States)

    Guilherme, A; Coroado, J; Carvalho, M L

    2009-12-01

    Chemical, mineralogical and textural characterizations were performed on glazed pieces prepared in laboratory as well as on faiences fragments collected from the existing remains in "Santa Clara-a-Velha" monastery (Coimbra, Portugal). The chemical investigation was carried out using micro X-ray fluorescence (micro-EDXRF) and wavelength dispersive X-ray fluorescence (WDXRF); the mineralogical results using X-ray diffraction (XRD) and the textural profile was obtained by scanning electron microscopy coupled with an energy dispersive spectroscopy system (SEM-EDS). Attention has been drawn to the glaze mineralogical changes during the firing temperature process, where three different types of glazes were submitted to three different firing temperatures (800 degrees C, 900 degrees C and 1,000 degrees C). Under these conditions, it is possible to relate the mineralogical content of the fragments to their firing temperature. Furthermore, we focused our purposes on identifying the technological aspects of the ceramic production in Coimbra, such as the raw materials, manufacture techniques and firing temperature adopted for the glaze. The latter aspect is highly dependent on the ceramic materials. In the framework of a more general project, this survey has as premise the recognition of a pattern, which is thought to be exclusively typical from the region of Coimbra. The perspective developed in the present work is towards reliable archaeometric criteria, which can be used to characterise scientifically the ceramics from Coimbra. PMID:19768663

  18. Mineralogy and Genesis of the Windjana Sandstone, Kimberley Area, Gale Crater, Mars

    Science.gov (United States)

    Treiman, A. H.; Bish, D.; Ming, D. W.; Grotzinger, J.; Vaniman, D. T.; Baker, M. B.; Farmer, J.; Chipera, S.; Downs, R. T.; Morris, R. V.; Rampe, E.; Blake, D. F.; Berger, J.; Cavanagh, P. D.; Gellert, R.; Glazner, A. F.; Schmidt, M.; Yen, A. S.; Filiberto, J.

    2015-01-01

    MSL Curiosity investigated the Windjana sandstone outcrop, in the Kimberley area of Gale Crater, and obtained mineralogical analyses with the CheMin XRD instrument. Windjana is remarkable in containing an abundance of potassium feldspar (and thus K in its bulk chemistry) combined with a low abundance of plagioclase (and low Na/K in its chemistry). The source of this enrichment in K is not clear, but has significant implications for the geology of Gale Crater and of Mars. The high K could be intrinsic to the sediment and imply that the sediment source area (Gale Crater rim) includes K-rich basalts and possibly more evolved rocks derived from alkaline magmas. Alternatively, the high K could be diagenetic and imply that the Gale Crater sediments were altered by K-rich aqueous fluids after deposition.

  19. An X-ray diffraction method for semiquantitative mineralogical analysis of Chilean nitrate ore

    Science.gov (United States)

    Jackson, J.C.; Ericksent, G.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.

  20. 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 ...

  1. Mineralogy, Geochemistry, and Origin of Buyukmahal Manganese Mineralization in the Artova Ophiolitic Complex, Yozgat, Turkey

    Directory of Open Access Journals (Sweden)

    Nursel Öksüz

    2014-01-01

    Full Text Available The Artova ophiolite complex (AOC is exposed along the northwestern and eastern margins of Yozgat area in Turkey. The Mn-deposit in the Buyukmahal area is part of this ophiolite complex. The deposit is in banded and lenticular forms and hosted by a radiolarite unit overlying the volcanics. Pyrolusite and magnetite are the main minerals of the manganese ore in the Buyukmahal (Yozgat area. The gang minerals in the deposit are composed only of quartz and calcite. In this study, mineralogy, major oxide, trace element and REE contents of Buyukmahal manganese mineralization are evaluated. The geochemical data indicate that Buyukmahal mineralization does not originate from a pure hydrothermal or pure hydrogenous source but from a system consisting of both sources. It is also asserted that the mineralization was first developed on a sea floor spreading center within the Alpine Ophiolite System and then obducted as part of the AOC.

  2. Mineralogy and Chemistry of Coronadite from Middle Cambrian Manganese Deposits at Wadi Dana, Southern Jordan

    Directory of Open Access Journals (Sweden)

    Ahmad Al-Malabeh

    2009-01-01

    Full Text Available Coronadite was reported from the upper-most horizons of the Middle Cambrian sediments at two locations in Wadi Dana, central Wadi Araba and Jordan. The unit is composed of dolomite, limestone and shale. Geochemical investigations show appreciable variations in Mn, Pb, Fe, K and Ba contents in the coronadite between the two studied sites. Pb was found to increase downward in both sites in spite of the lateral distance between them. Fe does not vary vertically, but its concentration decreases eastward. This can be attributed to the nature and mobilization direction, duration of the process, as well as the mechanism of both Fe and Pb bearing solutions. Mineralogical analysis has revealed the presence of hollandite-coronadite, cryptomelane-coronadite and psilomelane-coronadite in solid solutions. These petrographical and geochemical characteristics of the coronadite-bearing samples indicated that they formed epigenetically.

  3. 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.

  4. Mineralogical and Moessbauer studies on the paramagnetic separate of Al-Kidirate meteorite

    Energy Technology Data Exchange (ETDEWEB)

    Gismelseed, A.M.; Worthing, M.A.; Yousif, A.A.; Elzain, M.E.; Al-Rawas, A.D. [College of Science, Sultan Qaboos University, Box 36 Alkhoud, 123 Sultanate of Oman (Oman); Kamal, H.M. [Faculty of Education, University of Khartoum, Khartoum (Sudan)

    2004-02-01

    The paramagnetic fraction of the chondritic meteorite (Al Kidirate) has been studied by scanning electron microscopy (SEM) and Moessbauer spectroscopy at different temperatures. The mineralogical analysis indicates that the fraction consists mostly of olivine and pyroxene. The pyroxene is present in two restricted compositions; bronzitic orthopyroxene and clinopyroxene in the diopside-endiopside range. The Moessbauer measurements confirm the above characterization showing two paramagnetic doublets for olivine and pyroxene. The Moessbauer relative area under the resonance curve together with the atomic concentration derived from the microprobe data are used to derive the chemical formulae for orthopyroxene and clinopyroxene. The formulae derived using the two methods show good agreement. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. 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...

  6. Chemical and mineralogical characterization of two commercial cements and its evolution in function of time

    International Nuclear Information System (INIS)

    Mineralogical evolution of Portland cement is studied during hydration process using materials characterization techniques as X-ray diffraction (XRD) and scanning electron microscopy (Sem) in order to analyze the changes in the various cement minerals as alite, belite, celite, during processing to the hydrated phases of tobermorite gel, portlandite and ettringite, respectively, in the cement paste setting at different ages (3, 7 and 28 days). It was found that the hydration process occurs differently in each mineral because of their reaction rates or changes they experience in their crystals during processing of anhydrous to hydrated phase. You may notice changes in the appearance of the dough as you go hydration and the formation of tobermorite gel, portlandite and ettringite. (Author)

  7. Mineralogical and Geochemical Controls of Arsenic in an Active Tailings Dam

    Directory of Open Access Journals (Sweden)

    Samuel A. Ndur

    2015-05-01

    Full Text Available The aim of this study was to assess arsenic (As mobilization in an active tailings dam through mineralogical and geochemical characterization study. Arsenite is the predominant As species in the dam with more than 50% of the arsenic bound to the organic fraction. Pyrite and arsenopyrite are the principal opaque minerals remaining in the tailings with relic grains showing rims of oxidation (hematite/goethite. Illite, kaolinite and carbonates act as pH buffers and consume the acid generated during pyrite oxidation and raise the pH to near neutral measured in the tailings dam. At near neutral conditions As is mobilized, which likely combines with the Fe and Ca oxides formed to form ferric-calcium arsenates and deposited in the tailings dam. Some As appear to equilibrate with atmospheric CO2 and are converted into calcium carbonates with release of arsenic into solution.

  8. Mineralogy and crystal chemistry of iron in the Timan bauxite and products of their technological processing

    Science.gov (United States)

    Kotova, O.; Silaev, V.; Lutoev, V.; Vakhrushev, A.

    2016-04-01

    Mineralogical and geochemical features of two series of samples of typical bauxites from two deposits of Middle Timan mining area (Vezhayu-Vorykva and Svetlinskoe) were studied. The phase composition of ferrous bauxites generally is boehmite, hematite, ultradisperse low-ordered goethite and berthierine. In a boehmite and kaolinite structural impurity of iron to 10%, and in the iron oxidehydroxides aluminum impurity is revealed. On iron content bauxites are subdivided into three mineral types for which quantitative data on valence states of ions of iron and proportions of their distribution last on nonequivalent structural positions in hematite, goethite and berthierine are obtained. Noble metals (Ag, Au, Ir, Rh, Pd) concentrating in bauxites are revealed for the first time. Obtained data can lead to decrease of power consumption during aluminum production and high quality ceramics, to provide production of valuable iron oxide, and also to minimize the ecological harm from accumulation of bauxite wastes.

  9. Mineralogical Response of the Post harvest Mango (Mangifera Indica L.) to Different Levels of Bavistin DF

    International Nuclear Information System (INIS)

    This study was carried out with the post harvest mangoes (viz., the Langra and the Khirshapat) treating with different levels of Bavistin DF solution (namely, 250, 500, and 750 PPM) for obtaining results on the mineral content changes as well as storability of post harvest mango. The results of the experiments exhibited that only the single effect of varieties was found to be significant in most of the parameters studied. The Langra enriched a greater quantity of magnesium, iron and manganese constituents over the Khirshapat. On the other hand, Khirshapat enriched higher quantities of calcium, copper and zinc content at all the storage duration. Different post harvest treatments subjected to the investigation demonstrated significant variation in most of the mineralogical properties of mango at different days of storage. The result explored that calcium, magnesium, iron, and manganese contents were rapidly increased. On the other hand copper and zinc content drastically decreased from untreated mangoes. (author)

  10. 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.

  11. Solidus and liquidus temperatures and mineralogies for anhydrous garnet-lherzolite to 15 GPa

    Science.gov (United States)

    Herzberg, C. T.

    1983-01-01

    Strong convergence is noted, in experimental data for systems pertaining to anhydrous fertile garnet-lherzolite in the 6.5-15 GPa range, either to a common temperature or to temperatures differing by only about 100 C. The major element composition of magmas generated by even minor degrees of partial melting may be similar to the composition of the primordial, bulk silicate earth in an upper mantle stratigraphic column more than 160 km deep. Whether or not the solidus and liquidus intersect, the liquidus mineralogy for undepleted garnet-lherzolite compositions is found to change from olivine, at low pressures, to pyroxene, garnet, or a solid solution of both, at pressures greater than 10-15 GPa.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Mineralogía aplicada para la pequeña minería

    OpenAIRE

    Castroviejo Bolibar, Ricardo; Berrezueta, Edgar

    2003-01-01

    La pequeña minería puede beneficiarse de una forma muy directa de los recientes avances en el campo de la mineralogía aplicada y técnicas relacionadas. La definición tipológica y la modelización de yacimientos han alcanzado tal nivel que pueden permitir derivar conclusiones de alcance práctico, para exploración o incluso para la consecución de créditos, con estudios petrológicos y mineralógicos relativamente sencillos y baratos. Igualmente la aplicación rigurosa de técnicas como el análisis d...

  18. Clay mineralogy of lithofacies of northland allochthon rocks, north island, new zealand

    International Nuclear Information System (INIS)

    Northland Allochthon, a bathyal depth sediments, comprises an originally fining-upwards passive margin wedge which accumulated adjacent to northeastern New Zealand between mid-Cretaceous and latest Oligocene. The Northland Allochthon is overlain by Miocene arc and arc-basin deposits. This paper provides clay mineralogy and its transformation of different lithofacies of the Northland Allochthon rocks of North Island, New Zealand to understand the processes of precipitation during deposition and diagenesis of these rocks and possible later effects associated with obduction and re-burial of these rocks. The clay mineral sequence observed in the study area is from smectite to illite through illite/smectite interstratified mixed-layered clays. X-Ray diffractometry and Scanning Electron Microscopy of mixed-layer illite/smectite (I/S) clay from sandstone and shale shows a progressive increase in illite layers with increasing age. (author)

  19. Mineralogy in the Waste Isolation Pilot Plant (WIPP) facility stratigraphic horizon

    International Nuclear Information System (INIS)

    Forty-six samples were selected for this study from two cores, one extending 50 ft up through the roof of the WIPP facility and the other penetrating 50 ft below the facility floor. These samples, selected from approximately every other foot of core length, represent the major lithologies present in the immediate vicinity of the WIPP facility horizon: ''clean'' halite, polyhalitic halite, argillaceous halite, and mixed polyhalitic-argillaceous halite. Samples were analyzed for non-NaCl mineralogy by determining weight percents of water- and EDTA-insoluble residues, which were then identified by x-ray diffraction. In general, WIPP halite contains at most 5 wt % non-NaCl residue. The major mineral constituents are quartz, magnesite, anhydrite, gypsum, polyhalite, and clays. Results of this study confirm that, in previous descriptions of WIPP core, trace mineral quantities have been visually overestimated by approximately an order of magnitude. 9 refs., 5 figs., 5 tabs

  20. 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.

  1. Mineralogy, petrology and whole-rock chemistry data compilation for selected samples of Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    Petrologic, bulk chemical, and mineralogic data are presented for 49 samples of tuffaceous rocks from core holes USW G-1 and UE-25a number-sign 1 at Yucca Mountain, Nevada. Included, in descending stratigraphic order, are 11 samples from the Topopah Spring Member of the Paintbrush Tuff, 12 samples from the Tuffaceous Beds of Calico Hills, 3 samples from the Prow Pass Member of the Crater Flat Tuff, 20 samples from the Bullfrog Member of the Crater Flat Tuff and 3 samples from the Tram Member of the Crater Flat Tuff. The suite of samples contains a wide variety of petrologic types, including zeolitized, glassy, and devitrified tuffs. Data vary considerably between groups of samples, and include thin section descriptions (some with modal analyses for which uncertainties are estimated), electron microprobe analyses of mineral phases and matrix, mineral identifications by X-ray diffraction, and major element analyses with uncertainty estimates

  2. 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

  3. 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

  4. 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.

  5. Petrological mineralogical and geochemical characterization of the granitoids and fracture fillings developed in Ratones Mines (Spain)

    International Nuclear Information System (INIS)

    The petrological, mineralogical and geochemical characterisation of the granitoids and fracture fillings developed in the Ratones Mine (Caceres, Spain) has been done in order to understand rock-water interaction processes which control water geochemical parameters. Special interest has been devoted to the analysis and interpretation of REE patterns in the solid phase (granitoids and fracture fillings) because they constitute geochemical tracers in water-rock interaction process. Moreover, REE are considered as actinide analogues. In order to characterise the solid phase (granitoids and fracture fillings) several investigation scales (system, outcrop, whole rock, mineral and geochemical components) have been considered and different types of samples have been analysed. These factors control the methodological approach used in this investigation. The analytical methods we have used in this investigation are microscope, qualitative and semi-quantitative methods (XRD, SEM,EDAX) and quantitative methods (ICP-MS, XRF, EM, LAM-IC-MS). The bulk of the granitoids located around the Ratones Mine Belongs to the alkaline feldspar granite-sienogranite lihotype and they show a peraluminous and subalkaline pattern. From the mineralogical point of view, they are composed by quartz, K-feldspar (Or>90%), showing sericitation, moscovitization and turmolinization altherations, alkaline plagioclase (An-=-3%), usually altered to sericite, saussirite and less frequently affected by moscovitization processes, Fe-Al biotite, frequently affected by chloritization processes and sometimes replaced by muscovite, and finally muscovite (>2% celadonite and <4% paragonite) both of primary and secondary origin. The differences observed between the different lithotypes are related with the modal proportion of the principal minerals,with the presence or absence of certain accessory minerals ( turmaline, cordierite), with specific textural patterns, grain size and also with the richness in specific

  6. 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. PMID:19079803

  7. The letter, the dictionary and the laboratory: translating chemistry and mineralogy in eighteenth-century France.

    Science.gov (United States)

    Bret, Patrice

    2016-04-01

    Eighteenth-century scientific translation was not just a linguistic or intellectual affair. It included numerous material aspects requiring a social organization to marshal the indispensable human and non-human actors. Paratexts and actors' correspondences provide a good observatory to get information about aspects such as shipments and routes, processes of translation and language acquisition (dictionaries, grammars and other helpful materials, such as translated works in both languages), texts acquisition and dissemination (including author's additions and corrections, oral presentations in academic meetings and announcements of forthcoming translations). The nature of scientific translation changed in France during the second half of the eighteenth century. Beside solitary translators, it also happened to become a collective enterprise, dedicated to providing abridgements (Collection académique, 1755-79) or enriching the learned journals with full translations of the most recent foreign texts (Guyton de Morveau's 'Bureau de traduction de Dijon', devoted to chemistry and mineralogy, 1781-90). That new trend clearly had a decisive influence on the nature of the scientific press itself. A way to set up science as a social activity in the provincial capital of Dijon, translation required a local and international network for acquiring the linguistic and scientific expertise, along with the original texts, as quickly as possible. Laboratory results and mineralogical observations were used to compare material facts (colour, odour, shape of crystals, etc.) with those described in the original text. By providing a double kind of validation - with both the experiments and the translations - the laboratory thus happened to play a major role in translation. PMID:27391665

  8. 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.

  9. 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.

  10. 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

  11. Effects of Subsurface CO2 Reservoir Leaks on Overlying Groundwater Aquifer Geochemistry and Mineralogy

    Science.gov (United States)

    Qafoku, N. P.; Lawter, A.; Harvey, O. R.; Wang, G.; Bacon, D. H.; Gartman, B.; Brown, C.

    2012-12-01

    Carbon dioxide (CO2) sequestration in deep subsurface reservoirs has been recognized as a viable way to store anthropogenic CO2. However, not all potential risk factors associated with this technology have been identified. In an attempt to identify one of these risks, we studied the potential impacts of CO2 leaks from deep reservoirs on aquifer geochemistry and mineralogy. A series of wet chemical extractions and batch experiments were conducted with the objective to determine: i) time-dependent changes in groundwater pH, total dissolved solids, and contaminant concentrations; ii) the extent of mineral dissolution and solid phase transformations; and iii) contaminant(s) interactions with existing minerals and/or neophases formed during the experiments. Solid materials and simulated groundwater from two sites, the Edwards aquifer in Texas and the High Plains aquifer in Kansas, were used in this study. The solid materials were initially extracted with a concentrated nitric acid solution to determine total contaminant concentrations in these materials. The results showed that these materials had substantial concentrations of a variety of contaminants that may be mobilized during CO2 exposure. For example, the levels of Pb found in some nitric acid extraction samples were nearly 200 times the EPA drinking water limit. The results from batch experiments conducted with different flow rates of CO2 gas demonstrated that the groundwater pH decreased from a starting pH of 8.1 to a pH of 5.8, promoting mineral dissolution and contaminant release from the sediments. Additional studies are underway to understand the release of metals and contaminants under relevant field conditions (e.g., pH 5.0-8.5), determine changes in sediment mineralogy, and study mineral:contaminant interactions in the aquifer sediments exposed to the CO2 gas using a variety of microscopic and spectroscopic techniques.

  12. 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 (coatings are present as an open fabric, resulting in a large surface area in contact with pore water. Significant correlations between the amount of goethite in the grain coatings and the concentration of sediment-bound SO42- were observed, indicative of anion sorption. Other mineral-chemical relations indicate that negatively charged surfaces and competition with SO 42- results in exclusion of NO3- from inner sphere exchange sites. The observed NO3- storage may be a result of matrix forces within the grain coatings and outer sphere complexation. The results of this study indicate that the mineralogy of grain coatings can have demonstrable effects on the storage of NO 3- and SO42- in the unsaturated zone. ?? Soil Science Society of America. All rights reserved.

  13. Mineralogy and sealing properties of various bentonites and smectite-rich clay materials

    International Nuclear Information System (INIS)

    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

  14. 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

  15. Radiocesium sorption in relation to clay mineralogy of paddy soils in Fukushima, Japan.

    Science.gov (United States)

    Nakao, Atsushi; Ogasawara, Sho; Sano, Oki; Ito, Toyoaki; Yanai, Junta

    2014-01-15

    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 (137)Cs retention ability of soils (half-life 30.1 y). Of all the fission products released by the Fukushima accident, (137)Cs is the most important long-term contributor to the environmental contamination. The RIP, a quantitative index of the (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(-1), and ranged from 2.4 mol kg(-1) to 19.4 mol kg(-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 (137)Cs retention ability of the soil clays, but also could be used to predict the (137)Cs retention ability of soil clays for other paddy fields in Fukushima and other areas.

  16. 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 < 0.10 (varying from 0.04 to 0.08) or Tmax values < 435 oC (ranging from 410 to 435 oC). Keywords: Yeşilyuva coals (Acı payam/Denizli), 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)

  17. Mineralogy and geochemistry of base-metal deposits at Halilar area, NW Turkey

    Science.gov (United States)

    Kiran Yildirim, D.; Abdelnasser, A.; Doner, Z.; Kumral, M.

    2015-12-01

    This study focuses on the base-metal deposits at Halilar area (NW Turkey) by reporting new data obtained from mineralogical, petrographical and geochemical investigation of this deposit. It is to determine key features of the host rocks, mineralogical changes and alteration zones related to this mineralization. Halilar area is located about 25-30 km NE of Edremit in Balikseir district (NW Turkey). This area contains Halilar group that overlies pre-Late Triassic metamorphic rocks and Permian limestone in the surrounding areas. This Halilar group consists of Bagcagiz and Sakarkaya Formations; later intruded by Duztarla granitic rocks. The base metal deposits at study area represent locally Cu-Pb with some Zn vein type deposits. These deposits restricted to fault gouge zone directed NE-SW as well as occurred at the lower boundary of Bagcagiz and Duztarla granite. It also closely associated with intense hydrothermal alteration within brecciation, and quartz stockwork veining. The mineral assemblage includes chalcopyrite, galena, and some sphalerite, with covellite, and goethite in an abundant gangue of quartz and pyrite. Paragenetic relationships reveal three stages of mineralization; pre-ore, ore, and supergene. Wall-rock hydrothermal alteration includes pervasive silicification, sulfidation, carbonatization, and selective chloritization, sericitization and muscovitization. The geochemical studies refer to the altered samples have high CIA relative to the least altered rocks. The relationship between Na2O and K2O with the Ishikawa alteration index refers to the data plot close to chlorite/sericite. Also, based on alteration box plotting (Ishikawa alteration index vs. chlorite-carbonate-pyrite index), they mostly plotted in the field of the hydrothermal alteration close to chlorite and pyrite minerals with more hydrothermal trends; Intense sericite-chlorite ± pyrite alteration, chlorite ± sericite ± pyrite alteration, and sericite-carbonate alteration.

  18. 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.

  19. 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.

  20. Mineralogical Controls over Carbon Storage and Residence Times in Grassland Soils

    Science.gov (United States)

    Dwivedi, D.; Riley, W. J.; Torn, M. S.; Spycher, N.

    2014-12-01

    Globally, soil organic matter (SOM) contains approximately three times more carbon than the atmosphere and terrestrial vegetation contain combined. However, it is not well understood why some SOM persists for a long time while other SOM decomposes quickly. For future climate predictions, representing soil organic matter (SOM) dynamics accurately in Earth system models is essential. Soil minerals stabilize organic carbon in soil; however, there are gaps in our understanding of how soil mineralogy controls the quantity and turnover of long-residence-time organic carbon. To investigate the impact of soil mineralogy on SOM dynamics, we used a new model (Biotic and Abiotic Model of SOM—BAMS1 [Riley et al., 2014]) integrated with a three-dimensional, multiphase reactive transport solver (TOUGHREACT). The model represents bacterial and fungal activity, archetypal polymer and monomer carbon substrate groups, aqueous chemistry, gaseous diffusion, aqueous advection and diffusion, and adsorption and desorption processes. BAMS1 can predict bulk SOM and radiocarbon signatures without resorting to an arbitrary depth-dependent decline in SOM turnover rates. Results show a reasonable match between observed and simulated depth-resolved SOM and ∆14C in grassland ecosystems (soils formed on terraces south of Eureka, California, and the Central Chernozem Region of Russia) and were consistent with expectations of depth-resolved profiles of lignin content and fungi:aerobic bacteria ratios. Results also suggest that clay-mineral surface area and soil sorption coefficients constitute dominant controls over organic carbon stocks and residence times, respectively. Bibliography: Riley, W.J., F.M. Maggi, M. Kleber, M.S. Torn, J.Y. Tang, D. Dwivedi, and N. Guerry (2014), Long residence times of rapidly decomposable soil organic matter: application of a multi-phase, multi-component, and vertically resolved model (BAMS1) to soil carbon dynamics, Geoscientific Model Development, vol. 7, 1335

  1. 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)

  2. 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

  3. Mineralogical characterization of arsenic in gold mine tailings from three sites in Nova Scotia

    Energy Technology Data Exchange (ETDEWEB)

    M Corriveau; H Jamieson; M Parsons; G Hall

    2011-12-31

    Chronic exposure to high concentrations of arsenic (As) in windblown and vehicle-raised dust from tailings sites in Nova Scotia poses a potential health risk to recreational users of these areas and to nearby residents. The exposure may involve inhalation of dust, as well as oral ingestion of particles. It is important to understand the mineralogy and morphology of As-bearing dust particles in order to evaluate the risk posed by near-surface particulates in As-bearing tailings fields, as this will influence the stability and toxicity of As in the wastes. Optical mineralogy, scanning electron microscopy, electron microprobe, X-ray diffraction, synchrotron-based micro-X-ray diffraction ({mu}XRD) and micro-X-ray absorption near edge structure ({mu}XANES), and sequential leach extractions were applied to tailings samples from three sites in eastern Nova Scotia. Arsenic occurs naturally in these gold deposits mainly in arsenopyrite (FeAsS). In the near-surface material of the tailings fields, sulphide minerals have almost completely oxidized to secondary minerals such as scorodite (FeAsO{sub 4}{center_dot}2H{sub 2}O) and Ca-Fe arsenates. Iron oxyhydroxides contain variable amounts of As{sub 2}O{sub 5} from trace to 30 wt.% and CaO up to 8 wt.%. The presence of multiple As-hosting solid phases, including relatively soluble Ca-Fe arsenates and Fe oxyhydroxides with adsorbed As has important implications for human health risk assessment and remediation design.

  4. Mineralogy and chemistry of altered Icelandic basalts: Application to clay mineral detection and understanding aqueous environments on Mars

    Science.gov (United States)

    Ehlmann, B. L.; Bish, D. L.; Ruff, S. W.; Mustard, J. F.

    2012-10-01

    We used a suite of techniques, including those emulating compositional data sets obtained from Mars orbit and obtainable at the Mars surface, to examine aqueous alteration of basaltic rocks from Iceland as a mineralogic and geochemical analog for Noachian environments on Mars. A sample suite was collected for laboratory measurement of (1) whole-rock visible/near-infrared (VNIR) reflectance and thermal infrared (TIR) emission spectra; (2) VNIR and TIR reflectance spectra of particle-size separates derived from the bulk rock and from materials extracted from fractures/vesicles; (3) X-ray diffraction (XRD) patterns for determination of quantitative modal mineralogy; (4) major element chemistry using flux fusion of whole-rock powders; and (5) electron microprobe analyses of minerals in thin sections. Conclusions about aqueous alteration can be influenced by technique. For these basalts, whole-rock chemical data showed scant evidence for chemical fractionation, but TIR, VNIR, and XRD measurements identified distinctive assemblages of hydrous silicate minerals, differing by sample. XRD provided the most complete and accurate quantitative determination of sample mineralogy. However, VNIR spectroscopy was the technique most useful for determining composition of low-abundance smectite clays, and TIR spectroscopy was the most useful for recognizing hydrated silicates in thin surface coatings. High spatial resolution mineralogical and chemical data sets were useful for understanding the texture and distribution of alteration products and variations in fluid chemistry. No single approach provides a complete assessment of the environment of alteration, demonstrating the importance of employing multiple, synergistic mineralogical and geochemical techniques and instruments in exploration of rock strata from aqueous paleoenvironments on Mars.

  5. 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 <2 micron) to confirm the mineralogical constituents of the rock. Clay mineralogy has been the main focus, as their presence within the shale may affect the 'frackability' of the shale. Clay 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.

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

    OpenAIRE

    Flávio Adriano Marques; Márcia Regina Calegari; Pablo Vidal-Torrado; Peter Buurman

    2011-01-01

    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 tha...

  7. 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

  8. 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;…

  9. 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)

  10. Inequality and Economic Development in Brazil

    OpenAIRE

    World Bank

    2004-01-01

    This study addresses three questions : why do inequalities matter for Brazil's development? Why does Brazil occupy a position of very high inequality in the international community? And, What should public policy do about it? Excessive income inequality is unfair, and undesirable on ethical grounds, and can bring adverse effects on economic growth, health outcomes, social cohesion, and cri...

  11. 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...

  12. 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…

  13. 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…

  14. 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…

  15. Brazil Low Carbon Case Study : Waste

    OpenAIRE

    World Bank

    2010-01-01

    This report synthesis the findings for the waste sector of a broader study, the Brazil low carbon study, which was undertaken by the World Bank in its initiative to support Brazil's integrated effort towards reducing national and global emissions of Greenhouse Gases (GHG) while promoting long term development. The purpose of the present report is to assist in the preparation of public poli...

  16. 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…

  17. Aspergillus bertholletius sp. nov. from Brazil Nuts

    DEFF Research Database (Denmark)

    Taniwaki, Marta H.; Pitt, John I.; Iamanaka, Beatriz T.;

    2012-01-01

    During a study on the mycobiota of brazil nuts (Bertholletia excelsa) in Brazil, a new Aspergillus species, A. bertholletius, was found, and is described here. A polyphasic approach was applied using morphological characters, extrolite data as well as partial beta-tubulin, calmodulin and ITS sequ...

  18. 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…

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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

  5. The Influence of Glass Leachate on the Hydraulic, Physical, Mineralogical and Sorptive Properties of Hanford Sediment

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel I.; Serne, R. Jeffrey; Schaef, Herbert T.; Lindenmeier, Clark W.; Parker, Kent E.; Owen, Antionette T.; McCready, David E.; Young, James S.

    2003-08-26

    The Immobilized Low Activity Waste (ILAW) generated from the Hanford Site will be disposed of in a vitrified form. It is expected that leachate from the vitrified waste will have a high pH and high ionic strength. The objective of this study was to determine the influence of glass leachate on the hydraulic, physical, mineralogical, and sorptive properties of Hanford sediments. Our approach was to put solutions of NaOH, a simplified surrogate for glass leachate, in contact with quartz sand, a simplified surrogate for the Hanford subsurface sediment, and Warden soil, an actual Hanford sediment. Following contact with three different concentrations of sodium hydroxide solutions, changes in hydraulic conductivity, porosity, moisture retention, mineralogy, aqueous chemistry, and soil-radionuclide distribution coefficients were determined. Under chemical conditions approaching the most caustic glass leachate conditions predicted in the near-field of the ILAW disposal site, approximated by 0.3 M NaOH, significant changes in mineralogy were observed. The clay minerals of the Hanford sediment evidenced the greatest dissolution thereby increasing the relative proportions of the more resistant minerals, e.g., quartz, feldspar, and calcite, in the remaining mass. Some re-precipitation of solids (mostly amorphous gels) was observed after caustic contact with both solids; these precipitates increased the moisture retention in both sediments, likely because of water retained within the gel coatings. The hydraulic conductivities were slightly lower but, because of experimental artifacts, these reductions should not be considered significant. Thus, there does not seem to be large differences in the hydraulic properties of the quartz sand or Warden silt loam soil after 192 days of contact with caustic fluids similar to glass leachate. The long term projected impact of the increased moisture retention has not been evaluated but likely will not make past simplified performance

  6. "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

  7. 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

  8. 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 .

  9. The effects of impure CO2 on reservoir sandstones: results from mineralogical and geomechanical experiments

    Science.gov (United States)

    Marbler, H.; Erickson, K. P.; Schmidt, M.; Lempp, Ch.; Pöllmann, H.

    2012-04-01

    An experimental study of the behaviour of reservoir sandstones from deep saline aquifers during the injection and geological storage of CO2 with the inherent impurities SOX and NOX is part of the German national project COORAL*. Sample materials were taken from outcrops of possible reservoir formations of Rotliegend and Bunter Sandstones from the North German Basin. A combination of mineralogical alteration experiments and geomechanical tests was carried out on these rocks to study the potential effects of the impurities within the CO2 pore fluid. Altered rock samples after the treatment with CO2 + SOX/NOX in an autoclave system were loaded in a triaxial cell under in-situ pressure and temperature conditions in order to estimate the modifications of the geomechanical rock properties. Mineralogical alterations were observed within the sandstones after the exposure to impure supercritical (sc)CO2 and brine, mainly of the carbonatic, but also of the silicatic cements, as well as of single minerals. Besides the partial solution effects also secondary carbonate and minor silicate mineral precipitates were observed within the pore space of the treated sandstones. These alterations affect the grain structure of the reservoir rock. Results of geomechanical experiments with unaltered sandstones show that the rock strength is influenced by the degree of rock saturation before the experiment and the chemical composition of the pore fluid (scCO2 + SOX + NOX). After long-term autoclave treatment with impure scCO2, the sandstone samples exhibit modified strength parameters and elastic deformation behaviour as well as changes in porosity compared to untreated samples. Furthermore, the injected fluid volume into the pore space of sandstones from the same lithotype varies during triaxial loading depending on the chemistry of the pore fluid. CO2 with NOX and SOX bearing fluid fills a significantly larger proportion of the sandstone pore space than brine with pure scCO2. * The

  10. 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

  11. Mineralogy of the Lunar Crust through Complex Craters and Links to Lunar Meteorite Geologic Context

    Science.gov (United States)

    Isaacson, P.; Hiroi, T.; Lucey, P. G.; Hawke, B. R.; Pieters, C. M.; Liu, Y.; Patchen, A.; Taylor, L. A.

    2012-12-01

    Orbital measurements allow the composition of planetary surfaces to be mapped globally, something not possible with returned samples. Optical instruments such as reflectance spectrometers, which are sensitive to the very uppermost surface (~1-2 mm depth), provide the highest spatial resolution of the various compositional remote sensing techniques. Major lunar rock-forming minerals exhibit diagnostic absorptions across visible to near-infrared (VNIR) wavelengths, and data returned by VNIR reflectance spectrometers enable global mineralogical mapping. Focused analyses of central peaks eliminate two of the drawbacks of remote VNIR reflectance spectroscopy. The steep slopes of central peaks inhibit the development of a thick regolith layer, meaning that central peaks are relatively optically immature and thus preserve the diagnostic spectral absorption features critical to compositional analyses. Furthermore, the crater formation process brings to the surface materials from depth [e.g., Melosh, 1989, Cintala and Grieve, 1998], exposing materials that would otherwise be inaccessible to optical remote sensing. We will present a survey of lunar crater central peaks, following the work of Tompkins and Pieters [1999] and Cahill et al. [2009], who used Clementine UVVIS multispectral data. We employ a band fitting procedure that gives estimates of the position, strength, and width of the mafic 1 μm absorption feature, which are used to evaluate the mineralogy of the central peaks. In addition to the central peaks survey, we will present laboratory spectroscopy data for a suite of lunar meteorite samples. The lunar meteorites offer an important opportunity for "new-sample science" due to their diverse source regions from across the Moon, as opposed to the very limited coverage of manned exploration missions. However, the scientific utility of the lunar meteorites is limited by a lack of geologic context for the samples. Our sample suite includes a range of compositions

  12. The Color of Small Bodies: Mineralogy, Surface Properties, History and Future Prospects

    Science.gov (United States)

    McFadden, L. A.

    2002-12-01

    The technique of spectral reflectance was first applied to the brightest asteroids in 1970. Spectral reflectance of 4 Vesta demonstrated the technique's usefulness for identifying mineralogy of asteroid surfaces. A survey of asteroids was made using 25 interference filters spanning 0.33-1.0 μm. Spectral characteristics were grouped. Concurrently, laboratory measurements of minerals, rocks and meteorites were acquired and mineralogical interpretation of asteroid surfaces was made. Telescope apertures increased, IR detectors and thin film filters became available and spectrometers extending into the near-infrared were developed. With increasing knowledge of absorption and spectral features came more detailed knowledge of the surface composition of asteroids. New technology of the 1980's brought us the 52-color asteroid survey. The availability of CCD's enabled studies of smaller, fainter asteroids in the visible and resulted in good characterization of narrower and shallower absorption bands that are often the only bands found on dark asteroid surfaces. The 8-color asteroid filters were selected to measure fainter asteroids. This approach was based on color differences and permitted asteroid surveys to sample a larger population. With time, specific regions of the asteroid belt have been studied. Hildas, Trojans, asteroids near resonances, e.g. the 3:1 Kirkwood gap, and asteroid families. Most recently colors and reflectance spectra of TNO's and Centaurs are available. Similarities and differences between asteroids and other small bodies in the solar system permit us to derive information about the surface processes and compositional variation providing clues to the formation and processes in the early Solar System. As we understand the limits of this technique, we go to different spectral regions where different physical processes are active. Combining remote sensing techniques can provide constraints on compositional interpretations that are ambiguous when based

  13. Mineralogy and thermal properties of kaolin from the San José (Oruro, Bolivia)

    Science.gov (United States)

    Alfonso, Pura; Garcia-Valles, Maite; Martínez, Salvador; Amando Penedo, Lucio; Elvys Trujillo, Juan

    2016-04-01

    The San José mine, Oruro, Bolivia is known for provided a broad diversity of minerals. The San José Sn deposit is a Sn-Ag deposit composed of veins hosted in a complex of Miocene domes from monzonitic to dioritic composition within rhyolitic volcanic rocks hosted in Tertiary sedimentary rocks. Advanced argillitic alteration. is widespread in the surroundings of the deposit. Kaolinitization reach industrial importance and the kaolinitized rock is exploited, however it was not already been characterised. In this study we present a preliminary mineralogical and thermal characterization to determine the industrial applications of these kaolinitic materials. A sampling of the kaolinitized rocks in outcrops from the mining area was undertaken. The chemical composition of major and trace elements was determined by X-ray fluorescence (XRF). Mineralogy was obtained by powder diffraction X-ray (XRD) and infrared spectroscopy (FTIR). Quantitative determination of phases was obtained by the Rietveld refinement method using the Fullprof software. Thermal properties were determined by differential thermal analysis-thermo gravimetry (DTA -TG) and dilatometry. Mineral phases determined are mainly quartz (54-55 wt. %), kaolinite (7-8 wt. %), K-feldspar (8-19 wt. %), muscovite (16-17 wt. %), plagioclase up to 3 wt. %, alunite up to 8 wt% and gypsum up to 4 wt%. DTA -TG show a first endothermic event related to the dehydration of gypsum, with a loss weight of 0.4 wt%. An endothermic peak corresponding to the loss of the OH- groups of kaolinite occurs about 520 °C and an exothermic, at 980 °C, due to the crystallization of the mullite phase. The endothermic peak is attributed to the transformation of kaolinite in metakaolinite: Al2Si2O5 (OH)4  Al2Si2O7 + 2H2O and the dehydroxilation of alunite; the loss weight associated with this event is 2.9-3.2 wt%. The exothermic peak is caused by the formation of mullite: 3Al2Si2O7  Al6Si2O13 + 4SiO2. Another loss weight, of 3wt%, is

  14. Mineralogy, Degree of Brecciation, and Aqueous Alteration of CI Chondrites Orgueil, Ivuna, and Alais

    Science.gov (United States)

    Endress, M.; Bischoff, A.

    1993-07-01

    The textural and mineralogical properties of the CI-chondrites Orgueil, Ivuna, and Alais were studied by electron microscopy in order to obtain new insights into the history and evolution of the CI parent body. Degree of Brecciation. The electron optical investigation of Orgueil, Ivuna, and Alais revealed that the three samples experienced different degrees of brecciation: (1) Orgueil is highly brecciated. It consists of abundant clastic matrix (clasts usually modal abundance of carbonates (up to 10 vol%) and a lack of sulfates; the second is enriched in sulfates, but contains no carbonates, and the third lithology can be characterized by its high abundance of coarse-grained phyllosilicate fragments. Mineralogy. As phases >5 micrometers in size we observed magnetite, sulfides, carbonates, Ca-phosphate, olivine (Fachunks (up to 300 micrometers in size; especially in Ivuna). The Ca-phosphates contain small amounts of FeO (1-2 wt%), MnO (1 wt%), and Na2O (up to 3 wt%). Sulfates mostly occur as vein fillings in Alais (mainly gypsum) and Orgueil (mainly epsomite), but such veins are lacking in our Ivuna sample. Here, single sulfate grains (<10 micrometers) are rarely dispersed throughout the matrix. Aqueous alteration. Based on a study of Orgueil and Y-82162, [1,2] proposed a model, that during late stage aqueous alteration Fe-rich solutions readily decompose coarse-grained phyllosilicate clusters to fine-grained phyllosilicates and ferrihydrite and that contemporaneously sulfates were formed. Since Y-82162 contains abundant phyllosilicate clusters, but no ferrihydrite and no sulfate, Y-82162 should be less altered than Orgueil [1]. Considering this model we can distinguish between Orgueil, Ivuna, and Alais based on the degree of alteration. The abundance of phyllosilicate fragments is low in Orgueil, but high in Ivuna and Alais. In contrast to Orgueil, Ivuna contains no ferrihydrite [3,4] and very little sulfate. Therefore, the degree of aqueous alteration appears to

  15. 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

  16. 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

  17. Semantic Interoperability for Computational Mineralogy: Experiences of the eMinerals Consortium

    Science.gov (United States)

    Walker, A. M.; White, T. O.; Dove, M. T.; Bruin, R. P.; Couch, P. A.; Tyer, R. P.

    2006-12-01

    The use of atomic scale computer simulation of minerals to obtain information for geophysics and environmental science has grown enormously over the past couple of decades. It is now routine to probe mineral behavior in the Earth's deep interior and in the surface environment by borrowing methods and simulation codes from computational chemistry and physics. It is becoming increasingly important to use methods embodied in more than one of these codes to solve any single scientific problem. However, scientific codes are rarely designed for easy interoperability and data exchange; data formats are often code-specific, poorly documented and fragile, liable to frequent change between software versions, and even compiler versions. This means that the scientist's simple desire to use the methodological approaches offered by multiple codes is frustrated, and even the sharing of data between collaborators becomes fraught with difficulties. The eMinerals consortium was formed in the early stages of the UK eScience program with the aim of developing the tools needed to apply atomic scale simulation to environmental problems in a grid-enabled world, and to harness the computational power offered by grid technologies to address some outstanding mineralogical problems. One example of the kind of problem we can tackle is the origin of the compressibility anomaly in silica glass. By passing data directly between simulation and analysis tools we were able to probe this effect in more detail than has previously been possible and have shown how the anomaly is related to the details of the amorphous structure. In order to approach this kind of problem we have constructed a mini-grid, a small scale and extensible combined compute- and data-grid that allows the execution of many calculations in parallel, and the transparent storage of semantically-rich marked-up result data. Importantly, we automatically capture multiple kinds of metadata and key results from each calculation. We

  18. Chemical and Mineralogical Characterization of Arsenic, Lead, Chromium, and Cadmium in a Metal-contaminated Histosol

    Energy Technology Data Exchange (ETDEWEB)

    Gao, X.; Schulze, D

    2010-01-01

    The chemical and mineralogical forms of As, Pb, Cr, and Cd were studied in a metal-contaminated organic soil (Histosol) that received runoff and seepage water from a site that was once occupied by a lead smelter. Soil samples were collected from different depth intervals during both wet and dry seasons and analyzed using bulk powder X-ray diffraction (XRD), synchrotron-based micro X-ray diffraction ({mu}-XRD), and micro X-ray fluorescence ({mu}-SXRF) spectroscopy. There was a clear pattern of mineral distribution with depth that indicated the presence of an intense redox gradient. The oxidized reddish brown surface layer (0-10 cm) was dominated by goethite ({alpha}-FeOOH) and poorly crystalline akaganeite ({beta}-FeOOH). Lead and arsenic were highly associated with these Fe oxides, possibly by forming inner-sphere surface complexes. Gypsum (CaSO{sub 4} {center_dot} 2H{sub 2}O) was abundant in the layer as well, particularly for samples collected during dry periods. Fe(II)-containing minerals, such as magnetite (Fe{sub 3}O{sub 4}) and siderite (FeCO{sub 3}), were identified in the intermediate layers (10-30 cm) where the reductive dissolution of Fe(III) oxides occurred. A number of high-temperature minerals, such as mullite (3Al{sub 2}O{sub 3} {center_dot} 2Si{sub 2}O), corundum ({alpha}-Al{sub 2}O{sub 3}), hematite ({alpha}-Fe{sub 2}O{sub 3}), and wustite (FeO) were identified in the subsurface and they probably formed as a result of a burning event. Several sulfide minerals were identified in the most reduced layers at depths > 30 cm. They included realgar (AsS), alacranite (As{sub 4}S{sub 4}), galena (PbS), and sphalerite (Zn, Fe{sup 2+})S, and a series of Fe sulfides, including greigite (Fe{sup 2+}Fe{sub 2}{sup 3+} S{sub 4}), pyrrhotite (Fe{sub 1-x}S), mackinawite (FeS), marcasite (FeS{sub 2}), and pyrite (FeS{sub 2}). Most of these minerals occurred as almost pure phases in sub-millimeter aggregates and appeared to be secondary phases that had precipitated from

  19. 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

  20. 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)