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Sample records for sub-grain scale mineralogy

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

    Science.gov (United States)

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

    2015-01-01

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

  2. Multivariate analysis of the geochemistry and mineralogy of soils along two continental-scale transects in North America

    Science.gov (United States)

    Drew, L.J.; Grunsky, E.C.; Sutphin, D.M.; Woodruff, L.G.

    2010-01-01

    Soils collected in 2004 along two North American continental-scale transects were subjected to geochemical and mineralogical analyses. In previous interpretations of these analyses, data were expressed in weight percent and parts per million, and thus were subject to the effect of the constant-sum phenomenon. In a new approach to the data, this effect was removed by using centered log-ratio transformations to 'open' the mineralogical and geochemical arrays. Multivariate analyses, including principal component and linear discriminant analyses, of the centered log-ratio data reveal the effects of soil-forming processes, including soil parent material, weathering, and soil age, at the continental-scale of the data arrays that were not readily apparent in the more conventionally presented data. Linear discriminant analysis of the data arrays indicates that the majority of the soil samples collected along the transects can be more successfully classified with Level 1 ecological regional-scale classification by the soil geochemistry than soil mineralogy. A primary objective of this study is to discover and describe, in a parsimonious way, geochemical processes that are both independent and inter-dependent and manifested through compositional data including estimates of the elements and corresponding mineralogy. ?? 2010.

  3. Multivariate analysis of the geochemistry and mineralogy of soils along two continental-scale transects in North America.

    Science.gov (United States)

    Drew, Lawrence J; Grunsky, Eric C; Sutphin, David M; Woodruff, Laurel G

    2010-12-01

    Soils collected in 2004 along two North American continental-scale transects were subjected to geochemical and mineralogical analyses. In previous interpretations of these analyses, data were expressed in weight percent and parts per million, and thus were subject to the effect of the constant-sum phenomenon. In a new approach to the data, this effect was removed by using centered log-ratio transformations to 'open' the mineralogical and geochemical arrays. Multivariate analyses, including principal component and linear discriminant analyses, of the centered log-ratio data reveal the effects of soil-forming processes, including soil parent material, weathering, and soil age, at the continental-scale of the data arrays that were not readily apparent in the more conventionally presented data. Linear discriminant analysis of the data arrays indicates that the majority of the soil samples collected along the transects can be more successfully classified with Level 1 ecological regional-scale classification by the soil geochemistry than soil mineralogy. A primary objective of this study is to discover and describe, in a parsimonious way, geochemical processes that are both independent and inter-dependent and manifested through compositional data including estimates of the elements and corresponding mineralogy. Published by Elsevier B.V.

  4. Continental-scale patterns in soil geochemistry and mineralogy: results from two transects across the United States and Canada

    Science.gov (United States)

    Woodruff, L.G.; Cannon, W.F.; Eberl, D.D.; Smith, D.B.; Kilburn, J.E.; Horton, J.D.; Garrett, R.G.; Klassen, R.A.

    2009-01-01

    In 2004, the US Geological Survey (USGS) and the Geological Survey of Canada (GSC) initiated a pilot study that involved collection of more than 1500 soil samples from 221 sites along two continental transects across Canada and the United States. The pilot study was designed to test and refine protocols for a soil geochemical survey of North America. The two transects crossed a wide array of soil parent materials, soil ages, climatic conditions, landforms, land covers and land uses. Sample sites were selected randomly at approximately 40-km intervals from a population defined as all soils of the continent. At each site, soils representing 0 to 5 cm depth, and the O, A, and C horizons, if present, were collected and analyzed for their near-total content of over 40 major and trace elements. Soils from 0–5 cm depth were also collected for analysis of organic compounds. Results from the transects confirm that soil samples collected at a 40-km spacing reveal coherent, continental- to subcontinental-scale geochemical and mineralogical patterns that can be correlated to aspects of underlying soil parent material, soil age and climate influence. The geochemical data also demonstrate that at the continental-scale the dominance of any of these major factors that control soil geochemistry can change across the landscape. Along both transects, soil mineralogy and geochemistry change abruptly with changes in soil parent materials. However, the chemical influence of a soil’s parent material can be obscured by changing climatic conditions. For the transects, increasing precipitation from west to east and increasing temperature from north to south affect both soil mineralogy and geochemistry because of climate effects on soil weathering and leaching, and plant productivity. Regional anomalous metal concentrations can be linked to natural variations in soil parent materials, such as high Ni and Cr in soils developed on ultramafic rocks in California or high P in soils formed on

  5. Fault Zone Architecture and Mineralogy: Implications in Fluid Flow and Permeability in Crustal Scale Fault Zones in the Southern Andes.

    Science.gov (United States)

    Roquer, T.; Terrón, E.; Perez-Flores, P.; Arancibia, G.; Cembrano, J. M.

    2014-12-01

    Fluid flow in the upper crust is controlled by the permeability and interconnection of fractures in the fault zones. The permeability within the fault zone is determined by its activity, architecture and, in particular, by the mineralogy of the core and the damage zone. Whereas the permeability structure of a fault zone can be defined by the volume proportion of the core with respect to the damage zone, the relationship between the mineralogy and permeability along fault zones still remains obscure. This work examines structural and mineralogical data to show the relationship between the mineral composition of the fault zone with its permeability in the Liquiñe-Ofqui Fault System (LOFS) and the Arc-oblique Long-lived Fault Systems (ALFS), Southern Chile. The LOFS is an active ca. 1200 km long strike-slip Cenozoic intra-arc structure that strikes NNE in its master traces and NE in its subsidiary traces, with dextral and dextral-normal movement mostly developed in the last 6 My. Although the LOFS and the ALFS cross-cut each other, the ALFS is an apparently older basement fault system where seismic and field evidences record sinistral, sinistral-normal and sinistral-reverse movements. One 22-m-long NE transect was mapped orthogonal to a segment of the ALFS, where host rocks are Miocene andesitic rocks. Structural and XRD sampling were conducted in the core and damage zone. Structural mapping shows a multiple core, NW-striking fault zone with foliated gouge and an asymmetric damage zone, where the hanging wall has significantly higher mesoscopic fracture density than the footwall. The hanging wall is characterized by NW-striking, steeply dipping veins. Preliminary XRD results indicate the presence of homogenously distributed Ca-rich zeolite (mainly laumontite) in the core and the veins of the damage zone, which could indicate that the core acted as a conduit for low-temperature (ca. 220°C) fluids.

  6. Lime treatment of an Italian pyroclastic soil: a multi-scale analysis for the correlation of mechanical and chemo-mineralogical effects.

    Science.gov (United States)

    Guidobaldi, Giulia; Cambi, Costanza; Cecconi, Manuela; Comodi, Paola; Zucchini, Azzurra

    2017-04-01

    In recent years, the ever-growing need to minimize costs and environmental impact in the construction of major civil infrastructure has led to the development of a large amount of methods based on the reuse of local materials. In particular, one of the most diffused methods is represented by lime treatment, widely applied in earthwork field to achieve mechanical improvement of otherwise unsuitable fine grained soils. However, unlike fine grained soils, many other types of world-wide common natural soils still represent a geotechnical obstacle. Among these, pyroclastic soils are a typology widely spread in Central and Southern Italy that finds marginal applications in earthworks practice due to the intrinsic complexities in terms of nature, heterogeneity, microstructural features and unsaturated hydro-mechanical behaviour. The need to overcome the described limitations motivates the focus of this work on the geotechnical characterization of pyroclastic deposits along with the increasing attention on the volume-scale and micro-scale features characterization and correlation. The main goal of the present study is to highlight the effects of lime treatment on a zeolite rich pyroclastic soil, focusing on the relationship between macro and micro modifications induced by lime addition. Within this research, an extensive experimental work was developed on a zeolitic pyroclastic soil coming from Orvieto cliff (Vulsini volcanic district, Central Italy). The overall investigation was organized in three phases: the first phase was devoted to the thorough chemo-physical and mineralogical characterization of the raw soil; subsequently, conventional direct shear tests were performed on reconstituted specimens of both raw and lime treated soil (2% and 5% Ca(OH)2) at increasing curing times and stress levels; finally, a wide chemo-mineralogical investigation was carried out on the lime treated samples to gain a more complete knowledge of the reactions responsible for the mechanical

  7. Variability of physicochemical and mineralogical characteristics of biological soil crusts at local scale in the Sahelian zone of western Niger

    Science.gov (United States)

    Cancès, B.; Gommeaux, G.; Marin, B.; Ponthieu, M.; Ralahimanana, C.; Ayachi, S.; Malam Issa, O.

    2012-04-01

    Biological soil crusts (BSC) are organo-mineral complexes resulting from the colonisation of soil surface by living microorganisms, mainly cyanobacteria. Their form, structure and composition vary depending on characteristics related to soils, biological composition and external factors (climate conditions and land uses). This study focussed on the influence of soil characteristics and human activities on BSC properties. BSC samples from Banizoumbou (Niger) taken on protected (ungrazed) and opened (grazed) fallow lands were analysed. BSC characteristics were investigated by using chemical and mineralogical techniques, microscopic and image analysis approach as well as measurements of chlorophyll a content. Hydrophobicity measurements were also performed by the water drop penetration time method. On the basis of their colour, two types of crusts have been identified : black BSC, which occur in protected and unprotected fallow, and red BSC, which only occur in depression zones of the protected fallow. The black crusts are dominated by quartz grains trapped in the network of the filaments of Cyanobacteria. A sandy texture and a reverse grading of mineral particles are typical of physical soil crusts called sieving crusts. The dark surface coloration of the BSC is related to the high density of filamentous Cyanobacteria. Black crusts samples from protected fallow exhibit high biomass related to high cover, whereas samples from grazed fallow lands showed low biomass related to low surface cover. In both cases, hydrophobicity measurements revealed that these BSC are wettable to slightlty water repellent. However, higher values of hydrophobicity were observed on ungrazed samples compared to their grazed counterpart. This variability is likely due to the difference of cover between the two types of samples. This type of BSC corresponds to a later successional stage than the red-coloured BSC. The red BSC has a loamy-sandy texture and a normal grading typical of physical

  8. Mineralogy and cultural heritage.

    Science.gov (United States)

    Artioli, Gilberto

    2010-01-01

    In recent years there has been an escalation in the number of mineralogical studies involving cultural heritage materials. A number of factors have contributed to this exponential growth, including the shrinking budgets in traditional research fields, which forced the expansion of applications of mineralogical methods to novel research areas. Mineralogy as a discipline is traditionally connected to geology, petrology, and geochemistry, although it also has the strong tendency to embody the methods and techniques of modern crystallography and advanced materials science. Arguably, this makes it ideally suited and well equipped to meet the demanding challenges posed by archaeometric analysis and conservation problems. A few case studies linking mineralogy and archaeometry are discussed.

  9. Hydrogeochemical and mineralogical effects of sustained CO2 contamination in a shallow sandy aquifer: A field-scale controlled release experiment

    DEFF Research Database (Denmark)

    Cahill, Aaron Graham; Marker, Pernille Aabye; Jakobsen, Rasmus

    2014-01-01

    were taken pre and postinjection and analyzed to search for effects on mineralogy and sediment properties. Results showed the simulated leak to evolve in two distinct phases; an advective elevated ion pulse followed by increasing persistent acidification. Spatial and temporal differences in evolution...

  10. Mineralogy in Geotechnical Engineering

    OpenAIRE

    A. Namdar

    2010-01-01

    The several investigations on soils by different researchers have been executed, but research on soil mechanical propertiesbased on mineralogy is very meager, in this regard the author intention is employee of natural minerals for evaluation of soilcohesion, it may leads to developments of a soil with appropriates characteristics in permeability, transmitting load, resistingagainst deformation and settlement. This paper deals with analysis of soil cohesion based on mineralogy. The result reve...

  11. Mineralogy in Geotechnical Engineering

    Directory of Open Access Journals (Sweden)

    A. Namdar

    2010-01-01

    Full Text Available The several investigations on soils by different researchers have been executed, but research on soil mechanical propertiesbased on mineralogy is very meager, in this regard the author intention is employee of natural minerals for evaluation of soilcohesion, it may leads to developments of a soil with appropriates characteristics in permeability, transmitting load, resistingagainst deformation and settlement. This paper deals with analysis of soil cohesion based on mineralogy. The result revealedcohesion of a plastic soil could be improve by mineral presented in an non plastic soil, and also carbonate has negative affecton soil cohesion and some other soil minerals also have same affect on cohesion that required to be more investigate.

  12. Importance of the Small-Scale Processes Melting, Plate Boundary Formation and Mineralogy on the Large-Scale, Long-Term Thermo-Chemical Evolution of Earth's Mantle-Plate System

    Science.gov (United States)

    Tackley, P.

    2015-12-01

    Seismic observations of the deep Earth reveal the presence of two large low shear velocity provinces (LLSVPs) that are typically inferred to be dense chemically-distinct material, as well as discontinuities that are typically linked to the post-perovskite (pPv) phase transition. Several possible origins of chemically-dense material have been proposed, including recycling of mid-ocean ridge basalt (MORB), primordial differentiation events, crystallisation of a basal magma ocean, or some combination of these creating a basal melange (BAM; Tackley 2012 Earth Sci. Rev.). Each of these possibilities would result in a different composition hence different mineralogy. In order to constrain this we have been running calculations of thermo-chemical mantle evolution over 4.5 billion years that include melting-induced differentiation, plate tectonics induced by strongly temperature-dependent viscosity and plastic yielding, core cooling and compressibility with reasonable assumptions about the pressure-dependence of other material properties. Some of our simulations start from a magma ocean state so initial layering is developed self-consistently. Already-published results (Nakagawa et al., 2009 GCubed, 2010 PEPI, 2012 GCubed) already indicate the importance of exact MORB composition on the amount of MORB segregating above the CMB, which in turn influences mantle thermal structure and the evolution of the core and geodynamo. In more recent results we have been additionally including primordial material. We find that melting-induced differentiation has several first-order effects on the dynamics, including (i) making plate tectonics easier (through stresses associated with lateral variations in crustal thickness) and (ii) reducing heat flux through the CMB (due to the build-up of dense material above the CMB); also (iii) tectonic mode (continuous plate tectonics, episodic lid or stagnant lid) also makes a first-order difference to mantle structure and dynamics. This emphasises

  13. Mineralogy: A Historical Review.

    Science.gov (United States)

    Hazen, Robert M.

    1984-01-01

    Reviews changing concepts of the origins, properties, and classification of minerals. Emphasis is placed on developments of the eighteenth and nineteenth centuries, during which time the interwoven advances of chemistry, physics, crystallography, and high-temperature, high-pressure studies transformed mineralogy from a qualitative to a…

  14. MINERALOGICAL AND PARTICULATE MORPHOLOGICAL ...

    African Journals Online (AJOL)

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    Six representative geophagic clayey soils from Botswana were mineralogically characterized using X-ray powder diffractometry (XRPD), optical microscopy, and environmental scanning electron microscopy (ESEM). Results of identified mineral phases revealed quartz (SiO2) as the most dominant in all samples constituting ...

  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. "Building" 3D visualization skills in mineralogy

    Science.gov (United States)

    Gaudio, S. J.; Ajoku, C. N.; McCarthy, B. S.; Lambart, S.

    2016-12-01

    Studying mineralogy is fundamental for understanding the composition and physical behavior of natural materials in terrestrial and extraterrestrial environments. However, some students struggle and ultimately get discouraged with mineralogy course material because they lack well-developed spatial visualization skills that are needed to deal with three-dimensional (3D) objects, such as crystal forms or atomic-scale structures, typically represented in two-dimensional (2D) space. Fortunately, spatial visualization can improve with practice. Our presentation demonstrates a set of experiential learning activities designed to support the development and improvement of spatial visualization skills in mineralogy using commercially available magnetic building tiles, rods, and spheres. These instructional support activities guide students in the creation of 3D models that replicate macroscopic crystal forms and atomic-scale structures in a low-pressure learning environment and at low cost. Students physically manipulate square and triangularly shaped magnetic tiles to build 3D open and closed crystal forms (platonic solids, prisms, pyramids and pinacoids). Prismatic shapes with different closing forms are used to demonstrate the relationship between crystal faces and Miller Indices. Silica tetrahedra and octahedra are constructed out of magnetic rods (bonds) and spheres (oxygen atoms) to illustrate polymerization, connectivity, and the consequences for mineral formulae. In another activity, students practice the identification of symmetry elements and plane lattice types by laying magnetic rods and spheres over wallpaper patterns. The spatial visualization skills developed and improved through our experiential learning activities are critical to the study of mineralogy and many other geology sub-disciplines. We will also present pre- and post- activity assessments that are aligned with explicit learning outcomes.

  17. Characterization of Mineralogy Across Vesta

    Science.gov (United States)

    De Sanctis, M. C.; Ammannito, E.; Capria, M. T.; Capaccioni, F.; Carraro, F.; Fonte, S.; Frigeri, A.; Magni, G.; Marchi, S.; Palomba, E.; hide

    2012-01-01

    Dawn VIR spectra are characterized by pyroxene absorptions and no clear evidence for abundant other minerals are observed at the scale of the present measurements. Even though Vesta spectra are dominated by pyroxenes, spectral variation at regional and local scales are evident and distinct color units are identified. Although almost all of the surface materials exhibit spectra like those of howardites, some large units can be interpreted to be material richer in diogenite (based on pyroxenes band depths and band centers) and some others like eucrite-rich howardite units. VIR data strongly indicate that the south polar region (Rheasilvia) has its own spectral characteristics, indicating the presence of Mg-pyroxene-rich terrains (diogenite-like), while the equatorial areas have swallower band depths and average band centers at slightly longer wavelengths, consistent with more eucrite rich materials. Vesta surface shows considerable diversity at smaller scales (tens of km), in terms of spectral reflectance and emission, band depths and slopes. Many bright and dark spots are present on Vesta. Dark spots have low reflectance at visible wavelengths and are spectrally characterized by shallower 1 and 2 micron bands with respect the surrounding terrains. Bright materials have high reflectance and are often spectrally characterized by deep pyroxenes absorption bands. Vesta presents complex geology/topography and the mineral distribution is often correlated with geological and topographical structures. Ejecta from large craters have distinct spectral behaviors, and materials exposed in the craters show distinct spectra on floors and rims. VIR reveals the mineralogical variation of Vesta s crustal stratigraphy on local and global scales. Maps of spectral parameters show surface and subsurface unit compositions in their stratigraphic context. The hypothesis that Vesta is the HED parent body is consistent with, and strengthened by, the geologic and spectral context for pyroxene

  18. The Encyclopedia of Mineralogy

    Science.gov (United States)

    Rapp, George, Jr.

    This volume is the tenth in the ambitious Encyclopedia of Earth Science series. In addition to the standard short encyclopedia-style articles, it contains an alphabetical list of 3000 mineral species, groups, varieties, and mineraloids (which, following Fleischer, is called a glossary); this glossary presents basic physical and chemical properties for each entry.Editor Keith Frye has made a major effort, detailed in the preface, to assist the reader/user in avoiding many of the pitfalls in mineral nomenclature. For example, the book presents the names of valid mineral species in lower-case italic type, the names of series or groups in boldface italic letters, while varieties (and synonyms) are set in roman typeface. The worthwhile preface also contains a list, with addresses and date of first publication, of the world's 178 most important journals where mineral data are published. Also included are lists of the important mineral reference books and textbooks on mineralogy. The articles include one on museums with a 32-page table of museums with addresses, size of collection, and specialties.

  19. Mineralogy of asbestos.

    Science.gov (United States)

    Sporn, Thomas A

    2011-01-01

    The term asbestos collectively refers to a group of naturally occurring fibrous minerals which have been exploited in numerous commercial and industrial settings and applications dating to antiquity. Its myriad uses as a "miracle mineral" owe to its remarkable properties of extreme resistance to thermal and chemical breakdown, tensile strength, and fibrous habit which allows it to be spun and woven into textiles. Abundant in nature, it has been mined considerably, and in all continents save Antarctica. The nomenclature concerning asbestos and its related species is complex, owing to the interest held therein by scientific disciplines such as geology, mineralogy and medicine, as well as legal and regulatory authorities. As fibrous silicates, asbestos minerals are broadly classified into the serpentine (chrysotile) and amphibole (crocidolite, amosite, tremolite, anthophyllite, actinolite) groups, both of which may also contain allied but nonfibrous forms of similar or even identical chemical composition, nonpathogenic to humans. Recently, fibrous amphiboles, not historically classified or regulated as asbestos (winchite, richterite), have been implicated in the causation of serious disease due to their profusion as natural contaminants of vermiculite, a commercially useful and nonfibrous silicate mineral. Although generally grouped, classified, and regulated collectively as asbestos, the serpentine and amphibole groups have different geologic occurrences and, more importantly, significant differences in crystalline structures and chemical compositions. These in turn impart differences in fiber structure and dimension, as well as biopersistence, leading to marked differences in relative potency for causing disease in humans for the group of minerals known as asbestos.

  20. About oxide dispersion particles chemical compatibility with areas coherent dissipation/sub-grains of bcc-alloys in Fe - (Cr, V, Mo, W systems

    Directory of Open Access Journals (Sweden)

    Udovsky A.

    2016-01-01

    Full Text Available A concept of partial magnetic moments (PMM of the iron atoms located in the first ч four coordination spheres (1÷4 CS for bcc lattice have been introduced based on analysis of results obtained by quantum-mechanical calculations (QMC for volume dependence of the average magnetic moment ferromagnetic (FM Fe. The values of these moments have been calculated for pure bcc Fe and bcc - Fe-Cr alloys. This concept has been used to formulate a three sub-lattice model for binary FM alloys of the Fe-M systems (M is an alloying paramagnetic element. Physical reason for sign change dependence of the short-range order and mixing enthalpy obtained by QMCs for Fe-(Cr, V bcc phases has been found. Using this model it has been predicted that static displacements of Fe - atoms in alloy matrix increase with increasing the of CS number and result in reducing of the area of coherent dissipation (ACD size with growth of the dimension factor (DF in the Fe-(Cr, V, Mo, W systems in agreement with the X-ray experiments. It has been shown theoretically that anisotropy of spin- density in bcc lattice Fe and DF in binary Fe - (Cr, V, Mo, W systems is main factor for origins of segregations on small angle boundaries of ACD and sub-grains boundaries To prevent the coagulation of both ACD and sub-grains, and to increase the strength of alloys, it is advisable to add oxide dispersion particles into ferrite steel taking into account their chemical compatibility and coherent interfacing with the crystalline lattice of a ferrite matrix. Application of phase diagrams for binary and ternary the Fe-(Y, Zr-O systems to verify chemical compatibility of oxide dispersion particles with ferrite matrix have been discussed

  1. Advances and Opportunities in Ore Mineralogy

    Directory of Open Access Journals (Sweden)

    Nigel J. Cook

    2017-11-01

    Full Text Available The study of ore minerals is rapidly transforming due to an explosion of new micro- and nano-analytical technologies. These advanced microbeam techniques can expose the physical and chemical character of ore minerals at ever-better spatial resolution and analytical precision. The insights that can be obtained from ten of today’s most important, or emerging, techniques and methodologies are reviewed: laser-ablation inductively-coupled plasma mass spectrometry; focussed ion beam-scanning electron microscopy; high-angle annular dark field scanning transmission electron microscopy; electron back-scatter diffraction; synchrotron X-ray fluorescence mapping; automated mineral analysis (Quantitative Evaluation of Mineralogy via Scanning Electron Microscopy and Mineral Liberation Analysis; nanoscale secondary ion mass spectrometry; atom probe tomography; radioisotope geochronology using ore minerals; and, non-traditional stable isotopes. Many of these technical advances cut across conceptual boundaries between mineralogy and geochemistry and require an in-depth knowledge of the material that is being analysed. These technological advances are accompanied by changing approaches to ore mineralogy: the increased focus on trace element distributions; the challenges offered by nanoscale characterisation; and the recognition of the critical petrogenetic information in gangue minerals, and, thus the need to for a holistic approach to the characterization of mineral assemblages. Using original examples, with an emphasis on iron oxide-copper-gold deposits, we show how increased analytical capabilities, particularly imaging and chemical mapping at the nanoscale, offer the potential to resolve outstanding questions in ore mineralogy. Broad regional or deposit-scale genetic models can be validated or refuted by careful analysis at the smallest scales of observation. As the volume of information at different scales of observation expands, the level of complexity

  2. Mineralogy of meteorite groups

    Science.gov (United States)

    Rubin, Alan E.

    1997-03-01

    Approximately 275 mineral species have been identified in meteorites, reflecting diverse redox environments, and, in some cases, unusual nebular formation conditions. Anhydrous ordinary, carbonaceous and R chondrites contain major olivine, pyroxene and plagioclase; major opaque phases include metallic Fe-Ni, troilite and chromite. Primitive achondrites are mineralogically similar. The highly reduced enstatite chondrites and achondrites contain major enstatite, plagioclase, free silica and kamacite as well as nitrides, a silicide and Ca-, Mg-, Mn-, Na-, Cr-, K- and Ti-rich sulfides. Aqueously altered carbonaceous chondrites contain major amounts of hydrous phyllosilicates, complex organic compounds, magnetite, various sulfates and sulfides, and carbonates. In addition to kamacite and taenite, iron meteorites contain carbides, elemental C, nitrides, phosphates, phosphides, chromite and sulfides. Silicate inclusions in IAB/IIICD and IIE irons consist of mafic silicates, plagioclase and various sulfides, oxides and phosphates. Eucrites, howardites and diogenites have basaltic to orthopyroxenitic compositions and consist of major pyroxene and calcic plagioclase and several accessory oxides. Ureilites are made up mainly of calcic, chromian olivine and low-Ca clinopyroxene embedded in a carbonaceous matrix; accessory phases include the C polymorphs graphite, diamond, lonsdaleite and chaoite as well as metallic Fe-Ni, troilite and halides. Angrites are achondrites rich in fassaitic pyroxene (i.e., Al-Ti diopside); minor olivine with included magnesian kirschsteinite is also present. Martian meteorites comprise basalts, lherzolites, a dunite and an orthopyroxenite. Major phases include various pyroxenes and olivine; minor to accessory phases include various sulfides, magnetite, chromite and Ca-phosphates. Lunar meteorites comprise mare basalts with major augite and calcic plagioclase and anorthositic breccias with major calcic plagioclase. Several meteoritic phases formed

  3. Mineralogy of Meteorite Groups

    Science.gov (United States)

    Rubin, Alan E.

    1997-01-01

    Approximately 275 mineral species have been identified in meteorites, reflecting diverse redox environments, and, in some cases, unusual nebular formation conditions. Anhydrous ordinary, carbonaceous and R chondrites contain major olivine, pyroxene and plagioclase; major opaque phases include metallic Fe-Ni, troilite and chromite. Primitive achondrites are mineralogically similar. The highly reduced enstatite chondrites and achondrites contain major enstatite, plagioclase, free silica and kamacite as well as nitrides, a silicide and Ca-, Mg-, Mn-, Na-, Cr-, K- and Ti-rich sulfides. Aqueously altered carbonaceous chondrites contain major amounts of hydrous phyllosilicates, complex organic compounds, magnetite, various sulfates and sulfides, and carbonates. In addition to kamacite and taenite, iron meteorites contain carbides, elemental C, nitrides, phosphates, phosphides, chromite and sulfides. Silicate inclusions in IAB/IIICD and lIE iron meteorites consist of mafic silicates, plagioclase and various sulfides, oxides and phosphates. Eucrites, howardites and diogenites have basaltic to orthopyroxenitic compositions and consist of major pyroxene and calcic plagioclase and several accessory oxides. Ureilttes .are made up mainly of calcic, chromian olivine and low-Ca clinopyroxene embedded in a carbonaceous matrix; accessory phases include the C polymorphs graphite, diamond, lonsdaleite and chaoite as well as metallic Fe-Ni, troilite and halides. Angrites are achondrites rich in fassaitic pyroxene (i.e. , AI-Ti diopside); minor olivine with included magnesian kirschsteinite is also present. Martian meteorites comprise basalts, Iherzolites, a dunite and an orthopyroxenite. Major phases include various pyroxenes and olivine; minor to accessory phases include various sulfides, magnetite, chromite and Ca-phosphates. Lunar meteorites comprise mare basalts with major augite and calcic plagioclase and anorthositic breccias with major calcic plagioclase. Several meteoritic

  4. Impact of mineralogical heterogeneity on reactive transport modelling

    Science.gov (United States)

    Liu, Min; Shabaninejad, Mehdi; Mostaghimi, Peyman

    2017-07-01

    Impact of mineralogical heterogeneity of rocks in reactive modelling is investigated by applying a pore scale model based on the Lattice Boltzmann and Finite Volume Methods. Mass transport, chemical reaction and solid structure modification are included in the model. A two-dimensional mineral map of a sandstone rock is acquired using the imaging technique of QEMSCAN SEM with Energy-Dispersive X-ray Spectroscopy (EDS). The mineralogical heterogeneity is explored by conducting multi-mineral reaction simulations on images containing various minerals. The results are then compared with the prediction of single mineral dissolution modelling. Dissolution patterns and permeability variations of multi-mineral and single mineral reactions are presented. The errors of single mineral reaction modelling are also estimated. Numerical results show that mineralogical heterogeneity can cause significant errors in permeability prediction, if a uniform mineral distribution is assumed. The errors are smaller in high Péclet regimes than in low Péclet regimes in this sample.

  5. CHEMICAL AND MINERALOGICAL CHARACTERIZATION AND ...

    African Journals Online (AJOL)

    Preferred Customer

    The chemical and mineralogical characterization of raw feldspathic materials from Dschang. (Cameroon) was realized by means of X-ray ... and F2 were collected from the pegmatite of south west of Dschang city indicated by a dark thick arrow. ... in static air with heating rate 10 °C/min. Chemical analysis were performed at ...

  6. GEOCHEMISTRY AND MINERALOGICAL EVALUATION OF ...

    African Journals Online (AJOL)

    Dr Osondu

    2011-11-05

    Nov 5, 2011 ... removal of muscovite and reduction of hematite is successful, and this would be necessary if the deposit is to be exploited. Conclusion. The Chemical and mineralogical analyses after beneficiation shows that the kyanite found in the study area even though not completely consistent with the British and ...

  7. GEOCHEMISTRY AND MINERALOGICAL EVALUATION OF ...

    African Journals Online (AJOL)

    Dr Osondu

    2011-11-05

    Nov 5, 2011 ... samples, quartz, mulite and silliminite 45%. Evaluation of the indusrial suitability show inconsistent of the Kuta kyanite with BSI and ASTM standards specification for industrial mineral, it can be use as refractory material based on the alumina content. Keywords: Geochemistry, Mineralogy, Quartzite, Kyanite, ...

  8. Mapping the physico-chemical properties of mineral dust in western Africa: mineralogical composition

    National Research Council Canada - National Science Library

    Formenti, P; Caquineau, S; Desboeufs, K; Klaver, A; Chevaillier, S; Journet, E; Rajot, J. L

    2014-01-01

    ... and transport areas worldwide. In this paper, we explore the synthesis of these observations to provide a large-scale quantitative view of the mineralogical composition and its variability according to source region and time after transport...

  9. 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...

  10. 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.

  11. Environmental mineralogy - Understanding element behavior in ecosystems

    Science.gov (United States)

    Brown, Gordon E., Jr.; Calas, Georges

    2011-02-01

    Environmental Mineralogy has developed over the past decade in response to the recognition that minerals are linked in many important ways with the global ecosystem. Minerals are the main repositories of the chemical elements in Earth's crust and thus are the main sources of elements needed for the development of civilization, contaminant and pollutant elements that impact global and local ecosystems, and elements that are essential plant nutrients. These elements are released from minerals through natural processes, such as chemical weathering, and anthropogenic activities, such as mining and energy production, agriculture and industrial activities, and careless waste disposal. Minerals also play key roles in the biogeochemical cycling of the elements, sequestering elements and releasing them as the primary minerals in crustal rocks undergo various structural and compositional transformations in response to physical, chemical, and biological processes that produce secondary minerals and soils. These processes have resulted in the release of toxic elements such as arsenic in groundwater aquifers, which is having a major impact on the health of millions of people in South and Southeast Asia. The interfaces between mineral surfaces and aqueous solutions are the locations of most chemical reactions that control the composition of the natural environment, including the composition of natural waters. The nuclear fuel cycle, from uranium mining to the disposition of high-level nuclear waste, is also intimately related to minerals. A fundamental understanding of these processes requires molecular-scale information about minerals, their bulk structures and properties such as solubility, their surfaces, and their interactions with aqueous solutions, atmospheric and soil gases, natural organic matter, and biological organisms. Gaining this understanding is further complicated by the presence of natural, incidental, and manufactured nanoparticles in the environment, which are

  12. Vesta Mineralogy: VIR maps Vesta's surface

    Science.gov (United States)

    Coradina, A.; DeSanctis, M.; Ammannito, E.; Capaccioni, F.; Capria, T.; Carraro, F.; Cartacci, M.; Filacchione, G.; Fonte, S.; Magni, G.; hide

    2011-01-01

    The Dawn mission will have completed Survey orbit around 4 Vesta by the end of August 2011. We present a preliminary analysis of data acquired by the Visual and InfraRed Spectrometer (VIR) to map Vesta mineralogy. Thermal properties and mineralogical data are combined to provide constraints on Vesta's formation and thermal evolution. delivery of exogenic materials, space weathering processes, and origin of the howardite. eucrite, and diogenite (HED) meteorites.

  13. Landslide: Mineralogical and Physical Investigation

    Science.gov (United States)

    Tudor, Viluș; Grozav, Adia; Rogobete, Gheorghe

    2017-10-01

    In order to construct a road bed foundation, if land has moved, on an area with old landslides, there is a high chance of it moving again. The investigation was made in a region with hilly relief, in which the parent materials of soils are argillaceous marls of Pliocene age. Because the slope is scarped and the versant has been cut, the soil mass slide favoured of the particle-size distribution dominated by heavy clay. With a reiteratedly percolative moisture regime, the soil material is saturated in water fora long period (700-800 mm precipitation/year), and that can increase the slope mass, thereby increasing the driving forces. In a soil profile situated on the top of the hill, with landslide for about 40 m length of the road, disturbed and undisturbed soil samples were analysed physic-chemical and mineralogical. For the heavy and light minerals from the sand fraction a polarized light analyser is used, and for clay minerals X-ray, differential thermal and infrared absorption method are used. The particle-size distribution in the soil profile is dominated by the clay fraction, which reached 53.2% in the ABt horizon and 63.0% in the Bt horizon (67-93 cm depth). The structure of the light minerals, consists of quartz (41-58%); feldspar (10.16-18.10%); muscovite (14.10-26.04). The heavy minerals are oxides (2.61-15.26%), hornblende (0.58-2.87%) and biotite (0.51-2.68%). It must be mentioned the presence of the metamorphic minerals, with the source of the Poiana Rusca mountains. These minerals are epidote (1.01-1.86%), disthene (0.70-1.86%), staurolite (0.73-2.46%) and sillimanite (0.35-0.45%). The clay minerals, inherited from the parent material or formed during the soil-forming process are dominated by smectite, which represent (71-85%) from the total clay minerals, illite 10-21%, and Kaolinite, 4-12%. Rheological properties, like plastic index (53.8%), activity index (1.01%) and consistency index (0.99-1.00%) show that the shrinkage – swelling processes are

  14. Mineralogy of Galvanic Corrosion By-products in Domestic Drinking Water Pipes

    Science.gov (United States)

    This study presents the results of a visual and mineralogical characterization of scales developed over long time periods at galvanically coupled lead-brass and lead-copper pipe joints from several different drinking water distribution systems. The long-term exposure aspect of t...

  15. Petrography and mineralogy of archaeological finds from Al Zubarah, Qatar

    DEFF Research Database (Denmark)

    Kinzel, Moritz; Sølling, Theis Ivan; Sobott, Robert

    The contribution presents results of mineralogical analyses of finds which are nit originating from Al Zubarah, mainly diving weights.......The contribution presents results of mineralogical analyses of finds which are nit originating from Al Zubarah, mainly diving weights....

  16. 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.

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

    Science.gov (United States)

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

    2014-01-01

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

  18. Strategies and Technologies for In Situ Mineralogical Investigations on Mars

    Science.gov (United States)

    Marshall, J. R.; Bratton, C.; Koppel, L.; Hecht, M.; Metzger, E.

    1999-01-01

    Surface landers on Mars (Viking and Pathfinder) have not revealed satisfying answers to the mineralogy and lithology of the planet's surface. In part, this results from their prime directives: Viking focused on exobiology, Pathfinder focused on technology demonstration. The analytical instruments on board the landers made admirable attempts to extract the mineralogy and geology of Mars, as did countless modeling efforts after the missions. Here we suggest a framework for elucidating martian, or any other planetary geology, through an approach that defines (a) type of information required, (b) explorational strategy harmonious with acquisition of these data, (c) interpretation approach to the data, (d) compatible mission architecture, (e) instrumentation for interrogating rocks and soil. (a) Data required: The composition of a planet is ordered at scales ranging from molecules to minerals to rocks, and from geological units to provinces to planetary-scale systems. The largest ordering that in situ compositional instruments can attempt to interrogate is rock type "aggregate" information. This is what the geologist attempts to identify first. From this, mineralogy can be either directly seen or inferred. From mineralogy can be determined elemental abundances and perhaps the state of the compounds as being crystalline or amorphous. Knowledge of rock type and mineralogy is critical for elucidating geologic process. Mars landers acquired extremely valuable elemental data, but attempted to move from elements to aggregates, but this can only be done by making many assumptions and sometimes giant leaps of faith. Data we believe essential are elements, minerals, degree of ordering of compounds, and the aggregate or rock type that these materials compose. (b) Explorational strategy: A lander should function as a surrogate geologist. Of the total landscape, a geologist sees much, but gives detailed attention to an infinitesimally small amount of what is seen. To acquire

  19. Mineralogical, Geochemical, Physical And Industrial Potentials Of ...

    African Journals Online (AJOL)

    %) and shrinkage limit (8.30 – 8.70%) as well as low vitrification. The shale is also characterized by high loss on ignition (16.8%). Keywords: mineralogy, chemical, physical, industrial potential, shale. Journal of Mining and Geology Vol.

  20. Chemical and mineralogical characterization and ceramic suitability ...

    African Journals Online (AJOL)

    The chemical and mineralogical characterization of raw feldspathic materials from Dschang (Cameroon) was realized by means of X-ray diffraction, differential thermal analyses, optical and scanning electron microscopies, and analytical techniques. It was found that these materials consist of albite (43 ± 3 wt.%), microcline ...

  1. Mineralogical, geochemical and geomechanical characterization of ...

    African Journals Online (AJOL)

    This work focuses on the mineralogical and chemical analysis of two alluvial clays from the Sanaga River, four lateritic clays from Monatele and Ebebda regions in southern Cameroon and, on the physicomechanical characterization of these clayey mixtures. The exploitation of XRD patterns reveals that quartz, muscovite, ...

  2. Mineralogical and particulate morphological characterization of ...

    African Journals Online (AJOL)

    Six representative geophagic clayey soils from Botswana were mineralogically characterized using X-ray powder diffractometry (XRPD), optical microscopy, and environmental scanning electron microscopy (ESEM). Results of identified mineral phases revealed quartz (SiO2) as the most dominant in all samples constituting ...

  3. *Corresponding author Mineralogical Appraisal of Sediments of ...

    African Journals Online (AJOL)

    MICHAEL

    Mineralogical Appraisal of Sediments of Duricrust Suites and Pans around Jwaneng. Area, Botswana. 1*ATLHOPHENG, JULIUS R; 2GEORGES-IVO E. EKOSSE. 1. Department of Environmental Science, University of Botswana, Private Bag UB0704. Gaborone. 2. Geology, Mining and Minerals Programs, University of ...

  4. Studies on Mineralogy, Micromorphology and Relationships of

    African Journals Online (AJOL)

    were described and sampled from suiface and subsuiface horizons for mineralogical, micromorphological and fertility studies. X-ray diffraction studies indicated that the soils have different mineral components in the suiface and subsuiface horizons. Quartz is the dom- inant mineral in topsoils of both lbushi and Luseni soils.

  5. 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.; hide

    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.

  6. Diagenetic Mineralogy at Gale Crater, Mars

    Science.gov (United States)

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

    2015-01-01

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

  7. Iron mineralogy as a fingerprint of former steelmaking activities in river sediments.

    Science.gov (United States)

    Kanbar, Hussein Jaafar; Montargès-Pelletier, Emmanuelle; Losson, Benoit; Bihannic, Isabelle; Gley, Renaud; Bauer, Allan; Villieras, Frederic; Manceau, Luc; El Samrani, Antoine G; Kazpard, Veronique; Mansuy-Huault, Laurence

    2017-12-01

    Submerged sediment cores were collected upstream of a dam in the Orne River, northeastern France. This dam was built in the context of steelmaking to constitute a water reservoir for blast furnace cooling and wet cleaning of furnace smokes. The dam also enhanced sediment deposition in the upstream zone. This study was performed to unravel the contamination status of sediments and to evidence possible contribution sources. The sediment layers were analyzed for water content, grain size, chemical composition, crystalline phases at a bulk scale and poorly crystalline and amorphous phases at a sub-micrometer scale. Visual aspect, texture, color, and chemical and mineralogical analyses showed that the settled sediments were mainly composed of fine black matter, certainly comprising steelmaking by-products. Those materials were highly enriched with Fe, Zn, Pb and other trace metals, except for a relatively thin layer of surficial sediments that had settled more recently. Bulk mineralogy revealed crystalline iron minerals, such as magnetite, goethite, wuestite and pyrite, in the deep layers of the sediment cores. Furthermore, microscopic investigations evidenced the presence of ferrospheres, goethite nanoparticles and newly formed Fe-aluminosilicates; all originating from the former steelmaking facilities. The variation of iron mineralogy, combined with specific chemical profiles and other sediment features, demonstrate the different contributions that constitute the sediment deposit. Furthermore, chemical and mineralogical features of goethite and Fe-aluminosilicates could be used as a fingerprint for such contaminated sediments. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Mineralogical analysis of pan concentrates from Nigeria

    OpenAIRE

    Kemp, S. J.; Wagner, D.; Noble, S.; Mounteney, I.

    2009-01-01

    This report presents the results of mineralogical characterisation of a small suite of seven pan concentrate samples from Nigeria. The samples were submitted for analysis by Drs Roger Key and John Ridgway (BGS) as part of the ‘Technical Assistance Services for the Geochemical Mapping of Nigeria’ project which aims to provide baseline geoscientific information for mineral exploration and environmental management through a study of the distribution of important metallic elements.

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

    Science.gov (United States)

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

    2010-07-01

    This paper presents an investigation of the mineralogy and pore water chemistry of a boiler ash sampled from a municipal solid waste fluidized-bed incinerator, subject to 18 months of dynamic leaching in a large percolation column experiment. A particular focus is on the redox behaviour of Cr(VI) in relation to metal aluminium Al(0), as chromium may represent an environmental or health hazard. The leaching behaviour and interaction between Cr(VI) and Al(0) are interpreted on the basis of mineralogical evolutions observed over the 18-month period and of saturation indices calculated with the geochemical code PhreeqC and reviewed thermodynamic data. Results of mineralogical analyses show in particular the alteration of mineral phases during leaching (e.g. quartz and metal aluminium grains), while geochemical calculations suggest equilibria of percolating fluids with respect to specific mineral phases (e.g. monohydrocalcite and aluminium hydroxide). The combination of leaching data on a large scale and mineralogical analyses document the coupled leaching behaviour of aluminium and chromium, with chromium appearing in the pore fluids in its hexavalent and mobile state once metal aluminium is no longer available for chromium reduction. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  10. 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.

  11. Mapping the physico-chemical properties of mineral dust in western Africa: mineralogical composition

    OpenAIRE

    Formenti, P.; S. Caquineau; K. Desboeufs; Klaver, A.; Chevaillier, S.; Journet, E.; Rajot, J.L.

    2014-01-01

    In the last few years, several ground-based and airborne field campaigns have allowed exploring the properties and impacts of mineral dust in western Africa, one of the major emission and transport areas worldwide. In this paper, we explore the synthesis of these observations to provide with a large-scale quantitative view of the mineralogical composition and its variability with source region and time after transport. This work reveals that mineral dust...

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

    Science.gov (United States)

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

    2013-01-01

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

  13. 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

  14. Application of mineralogical techniques in the study of human lithiasis.

    Science.gov (United States)

    Aguilar-Ruiz, Jose; Arrabal-Polo, Miguel Angel; Sierra, Manuel; Arrabal-Martin, Miguel

    2012-12-01

    The authors review the mineralogical methods and techniques of analyzing calculi, stony concretions in the body. They discuss the main types of kidney stones (prostate, testicular, salivary, and bile) and the different diagnostic methods in mineralogy. By applying the techniques of optical microscopy and electron microscopy, they describe the different characteristics of human stones, based on extensive experience as evidenced by their numerous studies.

  15. Mineralogy and composition of the oceanic mantle

    Science.gov (United States)

    Putirka, Keith; Ryerson, F.J.; Perfit, Michael; Ridley, W. Ian

    2011-01-01

    The mineralogy of the oceanic basalt source region is examined by testing whether a peridotite mineralogy can yield observed whole-rock and olivine compositions from (1) the Hawaiian Islands, our type example of a mantle plume, and (2) the Siqueiros Transform, which provides primitive samples of normal mid-ocean ridge basalt. New olivine compositional data from phase 2 of the Hawaii Scientific Drilling Project (HSDP2) show that higher Ni-in-olivine at the Hawaiian Islands is due to higher temperatures (T) of melt generation and processing (by c. 300°C) related to the Hawaiian mantle plume. DNi is low at high T, so parental Hawaiian basalts are enriched in NiO. When Hawaiian (picritic) parental magmas are transported to shallow depths, olivine precipitation occurs at lower temperatures, where DNi is high, leading to high Ni-in-olivine. Similarly, variations in Mn and Fe/Mn ratios in olivines are explained by contrasts in the temperatures of magma processing. Using the most mafic rocks to delimit Siqueiros and Hawaiian Co and Ni contents in parental magmas and mantle source compositions also shows that both suites can be derived from natural peridotites, but are inconsistent with partial melting of natural pyroxenites. Whole-rock compositions at Hawaii and Siqueiros are also matched by partial melting experiments conducted on peridotite bulk compositions. Hawaiian whole-rocks have elevated FeO contents compared with Siqueiros, which can be explained if Hawaiian parental magmas are generated from peridotite at 4-5 GPa, in contrast to pressures of slightly greater than 1 GPa for melt generation at Siqueiros; these pressures are consistent with olivine thermometry, as described in an earlier paper. SiO2-enriched Koolau compositions are reproduced if high-Fe Hawaiian parental magmas re-equilibrate at 1-1·5 GPa. Peridotite partial melts from experimental studies also reproduce the CaO and Al2O3 contents of Hawaiian (and Siqueiros) whole-rocks. Hawaiian magmas have TiO2

  16. 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

  17. 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.; hide

    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,

  18. Relating the Mineralogical Characteristics of Tampakan Ore to Enargite Separation

    National Research Council Canada - National Science Library

    Maedeh Tayebi-Khorami; Emmanuel Manlapig; Elizaveta Forbes

    2017-01-01

    The mineralogical characteristics of enargite-bearing copper ores from the Tampakan deposit have been investigated as the means to understanding the separation of enargite from other copper sulphides...

  19. Unraveling the mineralogy of delta deposits on Mars

    Science.gov (United States)

    Osterloo, Mikki; Kierein-Young, Kathryn

    2017-04-01

    and preservation processes between the fan delta deposits. Our initial survey of the deltas indicates that almost all sites contain minor phyllosilicate detections, however only nine sites have significant abundances (i.e., spatially cohesive mapped deposits). Most of the phyllosilicate deposits consist of Fe/Mg clays such as nontronite and saponite, with a few sites showing detections of minor amounts of Al clays. Geologic observations indicate that most of the clays outcrop along the bottom edge of the deltas with a few sites showing a larger band of clays located just beyond the base of the delta. HiRISE images provide additional small-scale geologic context and indicate that most of the clay deposits are exposed as thin erosional layers. When clay deposits are located beyond the base of the delta they are typically more massive in outcrop. Our ongoing morphological, watershed, and catchment basin investigations will provide additional constraints on the style and extent of hydrologic activity. Coupling our detailed spectroscopic characterization with our ongoing work will provide key information on the geologic processes that produced the mineralogical diversity of martian deltas and will likely provide important clues regarding the past habitability of these environments.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel I., E-mail: daniel.kaplan@srnl.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Kukkadapu, Ravi [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Seaman, John C. [Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802 (United States); Arey, Bruce W.; Dohnalkova, Alice C. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Buettner, Shea [Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802 (United States); Li, Dien [Savannah River National Laboratory, Aiken, SC 29808 (United States); Varga, Tamas [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Scheckel, Kirk G. [US Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH 45224 (United States); Jaffé, Peter R. [Princeton University, Princeton, NJ 08540 (United States)

    2016-11-01

    Wetlands mitigate the migration of groundwater contaminants through a series of biogeochemical gradients that enhance multiple contaminant-binding processes. The hypothesis of this study was that wetland plant roots contribute organic carbon and release O{sub 2} within the rhizosphere (plant-impact soil zone) that promote the formation of Fe(III)-(oxyhydr)oxides. In turn, these Fe(III)-(oxyhydr)oxides stabilize organic matter that together contribute to contaminant immobilization. Mineralogy and U binding environments of the rhizosphere were evaluated in samples collected from contaminated and non-contaminated areas of a wetland on the Savannah River Site in South Carolina. Based on Mössbauer spectroscopy, rhizosphere soil was greatly enriched with nanogoethite, ferrihydrite-like nanoparticulates, and hematite, with negligible Fe(II) present. X-ray computed tomography and various microscopy techniques showed that root plaques were tens-of-microns thick and consisted of highly oriented Fe-nanoparticles, suggesting that the roots were involved in creating the biogeochemical conditions conducive to the nanoparticle formation. XAS showed that a majority of the U in the bulk wetland soil was in the + 6 oxidation state and was not well correlated spatially to Fe concentrations. SEM/EDS confirm that U was enriched on root plaques, where it was always found in association with P. Together these findings support our hypothesis and suggest that plants can alter mineralogical conditions that may be conducive to contaminant immobilization in wetlands. - Highlights: • Uranium concentrated in wetland environments • Hypothesized that plant roots change mineralogy and contaminant binding environment, promoting contaminant immobilization • Field study showed sharp dissolved U concentration profiles over the centimeter scale. • Spectroscopy identified unique mineralogy in rhizosphere compared to non-rhizosphere soil. • Uranium concentrated in root plaques in the + 6

  1. Possible space experiment "Mineralogical mapping of the Moon's surface"

    Science.gov (United States)

    Morozhenko, O. V.; Vidmachenko, A. P.

    2017-08-01

    We proposed a spectropolarimetric method for mineralogical mapping of Moon's surface. It based on measurements of the real part of refractive index from analysis of the empirical relation between maximum value of degree of linear polarization and normal albedo, obtained from the orbital polar spacecraft. Processing of the obtained observation material will allow the global mineralogical mapping of the Moon's surface with a sufficiently high accuracy.

  2. COMPAS: Compositional mineralogy with a photoacoustic spectrometer

    Science.gov (United States)

    Smith, W. Hayden

    1992-01-01

    There is an important need for an in situ method of mineral and rock identification and quantification that provides true absorption spectra for a wide spectral range for lunar lander/rover missions. Many common minerals such as feldspars, magnetite, ilmenite, and amorphous fine solids or glasses, can exhibit flat spectral reflectances in the 400-2500 nm spectral region that render inaccurate or difficult their spectral detection and quantitative analysis. Ideal rock and mineral spectra are, of course, pure absorption spectra that are independent of the spectral effects of scattering, particle size, and distribution that can result in a suppression or distortion of their spectral features. This ideal seldom pertains to real samples. Since sample preparation is difficult and may fundamentally alter the observed diffuse spectral reflectance, an in situ spectral measurement method for rocks and minerals on the Moon, insensitive to the sample morphology, would be invaluable. Photoacoustic spectroscopy is a well-established technique appropriate for this task that has been widely applied in condensed-phase spectral studies of complex, highly light scattering, unprepared samples of everything from coal to whole blood, including rock and mineral characterization. A Compositional Mineralogy Photoacoustic Spectrometer, or COMPAS, can enable in situ spectral measurement of rocks and minerals, bypassing the major limitations of diffuse reflectance spectroscopy. COMPAS spectral capabilities for rock and mineral samples will be incorporated into an instrument prototype specifically for lunar measurements, compatible with rover capabilities.

  3. Revised mineralogic summary of Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-03-01

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

  4. The importance of mineralogical input into geometallurgy programs

    Science.gov (United States)

    Hoal, K. Olson; Woodhead, J.D.; Smith, Kathleen S.

    2013-01-01

    Mineralogy is the link between ore formation and ore extraction. It is the most fundamental component of geomet programs, and the most important aspect of a life-of-project approach to mineral resource projects. Understanding orebodies is achieved by understanding the mineralogy and texture of the materials, throughout the process, because minerals hold the information required to unlock the value they contain. Geomet mineralogy programs absolutely require the appropriate expertise and at least three steps of mineral characterisation prior to using semi-automated or other methods: field examination, thorough core logging, and optical microscopy. Economic geological inputs for orebody characterisation are necessary for orebody understanding, and are exemplified by current research in the Zambian Copperbelt, where revised sequence stratigraphy and understanding of alteration, metasomatism and metamorphism can be used to predict topical issues at mine sites. Environmental inputs for sustainability characterisation are demonstrated by recent work on tailings from the Leadville, Colorado, USA area, including linking mineralogy to water quality issues. Risk assessments need to take into account the technical uncertainties around geological variability and mineral extractability, and mineralogy is the only metric that can be used to make this risk contribution.

  5. Belite Portland Clinkers. Synthesis and Mineralogical Analysis

    Directory of Open Access Journals (Sweden)

    de la Torre, A. G.

    2005-06-01

    Full Text Available The quaternary system CaO-SiO2-Al2O3-Fe2O3 has been taken into account to design five compositions of belite Portland clinkers with belite (Ca2SiO4 contents ranging from 60 to 65 wt%, located in its primary phase field of crystallization. The synthesis of these belite clinkers has been studied by high temperature microscopy, dilatometry, differential thermal analysis and thermogravimetric analysis. As a result, the optimum clinkerization temperature has been established at 1360 ± 5ºC. The quantitative phase analyses of the clinkers were carried out by X-ray powder diffraction with the Rietveld methodology. The mineralogical composition depends on the initial dosages, on the highest temperature achieved and on the time of residence at this temperature. The reaction was completed at 1365ºC during 15 min (free CaO < 0.5 wt%, in those conditions the β-belite form is stabilized and the harmful transformation β→γ is avoided.

    Teniendo en cuenta el sistema cuaternario CaO-SiO2-Al2O3-Fe2O3, se han diseñado cinco composiciones de clínqueres Pórtland belíticos, con contenidos del 60 y del 65% en peso de belita (Ca2SiO4, situadas en su campo primario de cristalización. La síntesis de estos clínqueres belíticos se ha estudiado “in situ” por microscopía de alta temperatura, dilatometría y análisis térmico diferencial y termogravimétrico. La temperatura óptima de clinquerización, determinada con estas técnicas, ha sido de 1360 ± 5ºC. Los análisis cuantitativos de los clínqueres se llevaron a cabo por difracción de rayos-X con la metodología Rietveld. Los porcentajes de las diferentes fases dependen de las dosificaciones iniciales, de la temperatura alcanzada y del tiempo de residencia a dicha temperatura. Se ha conseguido una reacción total (%CaO libre < 0.5% en peso tratando a 1365ºC durante 15 min, en cuyas condiciones se estabiliza la forma β de la belita y se evita la transformación perjudicial β→γ.

  6. Automated quantitative micro-mineralogical characterization for environmental applications

    Science.gov (United States)

    Smith, Kathleen S.; Hoal, K.O.; Walton-Day, Katherine; Stammer, J.G.; Pietersen, K.

    2013-01-01

    Characterization of ore and waste-rock material using automated quantitative micro-mineralogical techniques (e.g., QEMSCAN® and MLA) has the potential to complement traditional acid-base accounting and humidity cell techniques when predicting acid generation and metal release. These characterization techniques, which most commonly are used for metallurgical, mineral-processing, and geometallurgical applications, can be broadly applied throughout the mine-life cycle to include numerous environmental applications. Critical insights into mineral liberation, mineral associations, particle size, particle texture, and mineralogical residence phase(s) of environmentally important elements can be used to anticipate potential environmental challenges. Resources spent on initial characterization result in lower uncertainties of potential environmental impacts and possible cost savings associated with remediation and closure. Examples illustrate mineralogical and textural characterization of fluvial tailings material from the upper Arkansas River in Colorado.

  7. Spectroscopic characterization of mineralogy and its diversity across Vesta.

    Science.gov (United States)

    De Sanctis, M C; Ammannito, E; 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; Toplis, M J; Turrini, D

    2012-05-11

    The mineralogy of Vesta, based on data obtained by the Dawn spacecraft's visible and infrared spectrometer, is consistent with howardite-eucrite-diogenite meteorites. There are considerable regional and local variations across the asteroid: Spectrally distinct regions include the south-polar Rheasilvia basin, which displays a higher diogenitic component, and equatorial regions, which show a higher eucritic component. The lithologic distribution indicates a deeper diogenitic crust, exposed after excavation by the impact that formed Rheasilvia, and an upper eucritic crust. Evidence for mineralogical stratigraphic layering is observed on crater walls and in ejecta. This is broadly consistent with magma-ocean models, but spectral variability highlights local variations, which suggests that the crust can be a complex assemblage of eucritic basalts and pyroxene cumulates. Overall, Vesta mineralogy indicates a complex magmatic evolution that led to a differentiated crust and mantle.

  8. The mineralogy of mudrocks from the Lias Group of England

    OpenAIRE

    Kemp, S.J.; McKervey, J.A.

    2001-01-01

    This report describes the results of mineralogical analysis of a suite of sedimentary rocks from the Lias Group of England. The work was carried out as part of the ongoing BGS research programme, ‘Engineering Geology of UK Rocks and Soils.’ The first part of the report gives an introduction to the Lias Group geology and a summary of previous mineralogical studies of these rocks. A summary of analytical methods employed (X-ray diffraction analysis and surface area determinations) is then pr...

  9. 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...

  10. Spectral classification and mineralogical characterization of Nili Fossae for a better understanding of hydrated mineralogies.

    Science.gov (United States)

    Serventi, Giovanna; Carli, Cristian; Altieri, Francesca; Geminale, Anna; Sgavetti, Maria; Grassi, Davide; Orosei, Roberto; Bellucci, Giancarlo

    2017-04-01

    The presence of hydrated minerals on Mars provides a record of water-related processes and, in particular, the identification of phyllosilicates puts constraints on the evolution of Mars (Poulet et al., 2005). Even if data from the Observatoire pour la Minèralogie, l'Eau, les Glaces, et l'Activitè (OMEGA) and from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) show the presence of different hydrated minerals, on Mars the spectral regions where hydrated minerals absorb are also affected by atmospheric features due to gaseous components, mostly CO2 and H2O. Among the different methods that have been proposed to separate the atmospheric signatures from the hydrated absorptions, we use the Surface Atmosphere Separation (SAS) method proposed by Geminale et al. (2015) to analyze the Nili Fossae region (in particular, four MEX orbit have been selected and a mosaic have been created). In this work, we spectrally classify the Nili Fossae region using the Spectral Angle Mapping (SAM, Kruse et al., 1993) classification and using a spectral library iteratively built from the image though the Pixel Purity Index (PPI, Boardman, 1995). Mainly, we recognized five spectral regions dominated by: iron-hydroxides, pyroxenes (both orthopyroxene and clinopyroxene), olivine and phyllosilicates, in accordance with the literature. Then, we focused on the hydrated regions: absorptions in the 1.9-2.3 µm are fundamental to recognize a hydrated mineralogy, and to discriminate between phyllosilicates characterized by different cations in the octahedral environment. Comparing our results with maps from Mangold et al. (2007) and Poulet et al (2007), we demonstrated that the SAS+SAM technique permits to identify hydrated regions that cannot be easily recognized using the spectral mapping applied to images corrected with Mons Olympus method (Langevin et al., 2005). Furthermore, applying the MGM algorithm to a set of spectra selected from hydrated regions, we recognized the

  11. Mineralogical and chemical characteristics of newer dolerite dyke ...

    Indian Academy of Sciences (India)

    The newer dolerite dykes around Keonjhar within the Singbhum Granite occur in NE–SW, NW–SE and NNE–SSW trends. The mafic dykes of the present study exhibit several mineralogical changes like clouding of plagioclase feldspars, bastitisation of orthopyroxene, and development of fibrous amphibole.

  12. Mineralogy and geochemistry of granitoids from Kinnaur region ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 125; Issue 7. Mineralogy and geochemistry of granitoids from Kinnaur region, Himachal .... of Geology, Kumaun University, Nainital 263 002, Uttarakhand, India. Department of Earth and Environmental Sciences, Yamagata University, 990 8560, Yamagata, Japan.

  13. 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

  14. chemical and mineralogical characteristics of lateritic iron ore ...

    African Journals Online (AJOL)

    DJFLEX

    CHEMICAL AND MINERALOGICAL CHARACTERISTICS OF. LATERITIC IRON ORE DEPOSIT AT IYUKU, ... transported to the laboratory. 2.4. SAMPLE TREATMENTThe samples were air- dried in the ... Irabor E. E. I. Department of Chemistry, University of Benin, Benin City, Nigeria. Okolo P. O. Department of Chemistry, ...

  15. 49 The Geology and Mineralogy of Clay Occurrences Around Kutigi ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    Abstract. This paper reports the geology and mineralogy of the clay occurrences around Kutigi. The methodology of research includes detailed mapping of the area, collection of clay samples and laboratory analysis using X- ray diffraction. Field results show that clays in Kutigi are deposited as alluvial deposit from braided ...

  16. Clay mineralogy of the mud banks of Cochin

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, R.R.; Murty, P.S.N.

    The mineralogy of the sediments constituting the mud banks formed off Cochin, Kerala, India was studied. The clay mineral composition was used as a means of understanding the nature and source of origin of the muds. Fine fraction of the mud samples...

  17. The Geology and Mineralogy of Clay Occurrences Around Kutigi ...

    African Journals Online (AJOL)

    This paper reports the geology and mineralogy of the clay occurrences around Kutigi. The methodology of research includes detailed mapping of the area, collection of clay samples and laboratory analysis using X- ray diffraction. Field results show that clays in Kutigi are deposited as alluvial deposit from braided and ...

  18. Palynology and clay mineralogy of the Deccan volcanic associated ...

    Indian Academy of Sciences (India)

    Palynology and clay mineralogy of the Deccan volcanic associated sediments of Saurashtra, Gujarat: Age and paleoenvironments. Bandana Samant. 1,∗. , D M Mohabey. 2. , P Srivastava. 3 and Deepali Thakre. 1. 1. Department of Geology, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur 440 001, India. 2.

  19. Studies on Mineralogy, Micromorphology and Relationships of soils ...

    African Journals Online (AJOL)

    Selected typical soils were described and sampled from surface and subsurface horizons for mineralogical, micromorphological and fertility studies. X-ray diffraction studies indicated that the soils have different mineral components in the surface and subsurface horizons. Quartz is the dominant mineral in topsoils of both ...

  20. Mineralogical and chemical character-istics of newer Dolerite Dyke ...

    Indian Academy of Sciences (India)

    The mafic dykes of the present study exhibit several mineralogical changes like clouding of plagioclase feldspars, bastitisation of orthopyroxene, and development of fibrous amphibole (tremolite–actinolite) from clinopyroxene, which are all considered products of hydrothermal alterations. This alteration involves addition ...

  1. Mineralogical Results from the Mars Science Laboratory Rover Curiosity

    Science.gov (United States)

    Blake, David Frederick.

    2017-01-01

    NASA's CheMin instrument, the first X-ray Diffractometer flown in space, has been operating on Mars for nearly five years. CheMin was first to establish the quantitative mineralogy of the Mars global soil (1). The instrument was next used to determine the mineralogy of a 3.7 billion year old lacustrine mudstone, a result that, together with findings from other instruments on the MSL Curiosity rover, documented the first habitable environment found on another planet (2). The mineralogy of this mudstone from an ancient playa lake was also used to derive the maximum concentration of CO2 in the early Mars atmosphere, a surprisingly low value that calls into question the current theory that CO2 greenhouse warming was responsible for the warm and wet environment of early Mars. CheMin later identified the mineral tridymite, indicative of silica-rich volcanism, in mudstones of the Murray formation on Mt. Sharp. This discovery challenges the paradigm of Mars as a basaltic planet and ushers in a new chapter of comparative terrestrial planetology (3). CheMin is now being used to systematically sample the sedimentary layers that comprise the lower strata of Mt. Sharp, a 5,000 meter sequence of sedimentary rock laid down in what was once a crater lake, characterizing isochemical sediments that through their changing mineralogy, document the oxidation and drying out of the Mars in early Hesperian time.

  2. Effect of Chemical and Mineralogical Composition of Rocks on the ...

    African Journals Online (AJOL)

    The study was conducted in Hewanie and its surrounding areas of 169.82 km2 with a major objective of identifying the effect of chemical and mineralogical composition of rocks on the chemistry of the groundwater quality. This was conducted by taking 11 groundwater and 5 rock samples from the main geological units of ...

  3. effect of chemical and mineralogical composition of rocks

    African Journals Online (AJOL)

    Osondu

    The study was conducted in Hewanie and its surrounding areas of 169.82 km2 with a major objective of identifying the effect of chemical and mineralogical composition of rocks on the chemistry of the groundwater quality. This was conducted by taking 11 groundwater and 5 rock samples from the main geological units of ...

  4. mineralogical and geochemical trends in lateritic weathering profiles ...

    African Journals Online (AJOL)

    Three soil profiles on the basement rocks in Awa-Oru-Ijebu Igbo area of southwestern Nigeria were investigated for the formation secondary minerals and the comparison of the mineralogical and geochemical patterns in the weathering profiles overlying the rocks during the humid tropical weathering. X-ray data showed that ...

  5. Mineralogical Appraisal of Sediments of Duricrust Suites and Pans ...

    African Journals Online (AJOL)

    A mineralogical investigation of duricrust suites in Letlhakeng valley, and five pans around Jwaneng in Botswana was undertaken in order to know the mineral assemblages and infer on their landscape formation. In Letlhakeng, duricrusts comprised calcretes, silcretes and ferricretes. Calcretes were dominated by the ...

  6. Mineralogy and pedogenesis in a soil chronosequence on a ...

    African Journals Online (AJOL)

    Studies on soils of the floodplain of lower Niger river are scanty although this floodplain forms a very important agricultural resource base in Nigeria. The objective of this study is to provide comprehensive information on the characteristics of the soils with respect to their mineralogy and the effect of seasonal flooding on their ...

  7. Application of Tablet PCs to Lecture Demonstrations on Optical Mineralogy

    Science.gov (United States)

    Hoisch, Thomas D.; Austin, Barbara A.; Newell, Shawn L.; Manone, Mark F.

    2010-01-01

    Learning optical mineralogy requires students to integrate a complex theory with microscope manipulations and image interpretation. To assist student learning, we performed lecture demonstrations during which digital photomicrographs were taken and delivered to students using Tablet PCs, whereupon they were imported into note-taking software and…

  8. Mineralogical controls on dust emissions in the Bodele Depression, Chad

    Science.gov (United States)

    Surface mineralogy is critical in the understanding of aeolian processes, however its role in dust production is currently underestimated. Recent research indicates that discrepancies between predicted and observed dust loads by dust models may be attributed to inadequacies within their associated d...

  9. Mineralogy and trace element chemistry of the Siliceous Earth of ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    We report the presence of a 3–5 cm thick loose fragmental layer in the Siliceous Earth at Matti ka. Gol in the Barmer basin of Rajasthan. Petrographic, chemical and mineralogical study reveals the presence of abundant volcanic debris such as glass shards, agglutinates, hollow spheroids, kinked biotites, feldspars showing ...

  10. Geophagic clays: Their mineralogy, chemistry and possible human ...

    African Journals Online (AJOL)

    Geophagic clays: Their mineralogy, chemistry and possible human health effects. ... African Journal of Biotechnology ... of the study were to qualitatively and quantitatively identify the mineral constituents and to determine selected elemental compositions in the clay samples in order to infer on possible human health effects.

  11. Mineralogy of Tailings Dump around Selebi Phikwe Nickel-Copper ...

    African Journals Online (AJOL)

    This study aimed at mineralogically characterizing the tailings dump emanating from the mining and smelting of nickel-copper (Ni-Cu) at Selebi Phikwe, Botswana, Southern Africa. Samples of tailings dump around the Selebi Phikwe Ni-Cu plant were studied using petrographic microscopy and X-ray Powder Diffraction ...

  12. Mineralogy and trace element chemistry of the Siliceous Earth of ...

    Indian Academy of Sciences (India)

    We report the presence of a 3-5 cm thick loose fragmental layer in the Siliceous Earth at Matti ka Gol in the Barmer basin of Rajasthan. Petrographic, chemical and mineralogical study reveals the presence of abundant volcanic debris such as glass shards, agglutinates, hollow spheroids, kinked biotites, feldspars showing ...

  13. Mineralogical maturity in dunefields of North America, Africa and Australia

    Science.gov (United States)

    Muhs, D.R.

    2004-01-01

    Studies of dunefields in central and western North America show that mineralogical maturity can provide new insights into the origin and evolution of aeolian sand bodies. Many of the world's great sand seas in Africa, Asia and Australia are quartz-dominated and thus can be considered to be mineralogically mature. The Algodones (California) and Parker (Arizona) dunes in the southwestern United States are also mature, but have inherited a high degree of mineralogical maturity from quartz-rich sedimentary rocks drained by the Colorado River. In Libya, sediments of the Zallaf sand sea, which are almost pure quartz, may have originated in a similar fashion. The Fort Morgan (Colorado) and Casper (Wyoming) dunefields in the central Great Plains of North America, and the Namib sand sea of southern Africa have an intermediate degree of mineralogical maturity because their sources are large rivers that drained both unweathered plutonic and metamorphic rocks and mature sedimentary rocks. Mojave Desert dunefields in the southwestern United States are quite immature because they are in basins adjacent to plutonic rocks that were their sources. Other dunefields in the Great Plains of North America (those in Nebraska and Texas) are more mature than any possible source sediments and therefore reflect mineralogical evolution over time. Such changes in composition can occur because of either of two opposing long-term states of the dunefield. In one state, dunes are stable for long periods of time and chemical weathering depletes feldspars and other weatherable minerals in the sediment body. In the other state, which is most likely for the Great Plains, abrasion and ballistic impacts deplete the carbonate minerals and feldspars because the dunes are active for longer periods than they are stable. ?? 2003 Elsevier B.V. All rights reserved.

  14. The Mineralogy of Microbiologically Influenced Corrosion

    Science.gov (United States)

    2015-01-01

    increase in alkalinity shifts the equilibrium to the following reactions, where hydroxyl ions cause the precipitation of magnesium hydroxide if the...soluble salt that has exceeded its equilibrium solubility concentration. Most scales are minerals, e.g., MgC03 ( magnesium carbonate) or Fe2(C03h...of amorphous FeS (iron sulfide), FeC03 (siderite), magnesium carbonate, and calcium carbonate. They concluded that the conductivity was due to iron

  15. 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

  16. Geochemistry and mineralogy of the Oligo-Miocene sediments of the Valley of Lakes, Mongolia.

    Science.gov (United States)

    Richoz, Sylvain; Baldermann, Andre; Frauwallner, Andreas; Harzhauser, Mathias; Daxner-Höck, Gudrun; Klammer, Dietmar; Piller, Werner E

    2017-01-01

    The Valley of Lakes is approximately a 500-km elongate depression in Central Mongolia, where Eocene to Miocene continental sediments are long known for their outstanding fossil richness. The palaeontological record of this region is an exceptional witness for the evolution of mammalian communities during the Cenozoic global cooling and regional aridification. In order to precisely elucidate the climatic evolution of the region, we studied the mostly siliciclastic sediments with several levels of paleosols for their sedimentology, mineralogy, major and trace element composition and δ13C and δ18O composition. The obtained results show that temperate hydrothermal fluids induced a strong illitization of the fluvial and lacustrine sediments. This finding contradicts the current conceptual view that the fine fraction of the sediments is of aeolian origin. Moreover, the diagenetic growth of illite resulted in a strong overprinting of the sediments and, subsequently, largely disturbed the pristine mineralogical and geochemical composition of the sediments that could have carried any palaeo-climatic information. An exception is the δ13C (and δ18O) isotope values of authigenic carbonate found in calcrete horizons that still record the ambient climatic conditions prevailing during paleosol formation. Our novel δ13C and δ18O record suggests an early Oligocene aridification in Central Asia at ∼31 Ma, whereas the Oligocene glacial maximum shows no increase in aridification. A second, regional-scale aridification occurs at ~25 Ma and corresponds to a late Oligocene marked mammalian turnover in the Valley of Lakes sediments.

  17. Mineralogy of Rocks and Sediments at Gale Crater, Mars

    Science.gov (United States)

    Achilles, Cherie; Downs, Robert; Blake, David; Vaniman, David; Ming, Doug; Rampe, Elizabeth; Morris, Dick; Morrison, Shaunna; Treiman, Allan; Chipera, Steve; Yen, Albert; Bristow, Thomas; Craig, Patricia; Hazen, Robert; Crisp, Joy; Grotzinger, John; Des Marias, David; Farmer, Jack; Sarrazin, Philippe; Morookian, John Michael

    2017-04-01

    The Mars Science Laboratory rover, Curiosity, is providing in situ mineralogical, geochemical, and sedimentological assessments of rocks and soils in Gale crater. Since landing in 2012, Curiosity has traveled over 15 km, providing analyses of mudstones and sandstones to build a stratigraphic history of the region. The CheMin X-ray diffraction (XRD) instrument is the first instrument on Mars to provide quantitative mineralogical analyses of drilled powders and scooped sediment based on X-ray crystallography. CheMin identifies and determines mineral abundances and unit-cell parameters of major crystalline phases, and identifies minor phases at abundances >1 wt%. In conjunction with elemental analyses, CheMin-derived crystal chemistry allows for the first calculations of crystalline and amorphous material compositions. These mineralogy, crystal chemistry, and amorphous chemistry datasets are playing central roles in the characterization of Gale crater paleoenvironments. CheMin has analyzed 17 rock and sediment samples. In the first phase of the mission, Curiosity explored the sedimentary units of Aeolis Palus (Bradbury group), including two mudstones from Yellowknife Bay. CheMin analyses of the Yellowknife Bay mudstones identified clay minerals among an overall basaltic mineral assemblage. These mineralogical results, along with imaging and geochemical analyses, were used to characterize an ancient lacustrine setting that is thought to have once been a habitable environment. Following the investigations of the Bradbury group, Curiosity arrived at the lower reaches of Aeolis Mons, commonly called Mt. Sharp. A strategic sample campaign was initiated, drilling bedrock at <25 m elevation intervals in order to compile a comprehensive stratigraphic column of Mt. Sharp sedimentary units. Two formations have been sampled thus far, the lower-most Murray formation and the Stimson formation, which lies unconformably over the Murray. The Stimson formation is a cross

  18. Morphology Dependent Flow Stress in Nickel-Based Superalloys in the Multi-Scale Crystal Plasticity Framework

    Directory of Open Access Journals (Sweden)

    Shahriyar Keshavarz

    2017-11-01

    Full Text Available This paper develops a framework to obtain the flow stress of nickel-based superalloys as a function of γ-γ’ morphology. The yield strength is a major factor in the design of these alloys. This work provides additional effects of γ’ morphology in the design scope that has been adopted for the model developed by authors. In general, the two-phase γ-γ’ morphology in nickel-based superalloys can be divided into three variables including γ’ shape, γ’ volume fraction and γ’ size in the sub-grain microstructure. In order to obtain the flow stress, non-Schmid crystal plasticity constitutive models at two length scales are employed and bridged through a homogenized multi-scale framework. The multi-scale framework includes two sub-grain and homogenized grain scales. For the sub-grain scale, a size-dependent, dislocation-density-based finite element model (FEM of the representative volume element (RVE with explicit depiction of the γ-γ’ morphology is developed as a building block for the homogenization. For the next scale, an activation-energy-based crystal plasticity model is developed for the homogenized single crystal of Ni-based superalloys. The constitutive models address the thermo-mechanical behavior of nickel-based superalloys for a large temperature range and include orientation dependencies and tension-compression asymmetry. This homogenized model is used to obtain the morphology dependence on the flow stress in nickel-based superalloys and can significantly expedite crystal plasticity FE simulations in polycrystalline microstructures, as well as higher scale FE models in order to cast and design superalloys.

  19. 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

  20. chemical and mineralogical characterization of lateritic iron ore ...

    African Journals Online (AJOL)

    DJFLEX

    2010-04-22

    Apr 22, 2010 ... CHEMICAL AND MINERALOGICAL CHARACTERIZATION OF. LATERITIC IRON ORE ... results of the chemical assay are moisture (0.02 - 1.11%), L. O. I. (2.31 – 2.93%), Fe2O3 (50.40 – 66.29%), Al2O3. (17.25 – 25.50%), CaO (0.32 .... Aliquot of this was taken for Ca, Mg, Ni, Mn and. Cr determinations.

  1. Elemental and Clay Mineralogical Compositions of Dustfall in the ...

    African Journals Online (AJOL)

    Although the phenomenon of harmattan dustfall in Nigeria has covered many centuries, information as to the total elemental compositions and the type of clay mineralogy in the dust are very scanty. This study was carried out in the Lower Benue Valley (Latitude 7.250N – 8.250N and Longitude 8.000E – 8.500E) to ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-15

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

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

    Science.gov (United States)

    Morris, Richard V.

    2016-01-01

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

  4. Mineralogical, Chemical, and Optical Interrelationships of Airborne Mineral Dusts

    Science.gov (United States)

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

    2014-12-01

    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, < 125 μm soil fractions were mineralogically characterized by optical microscopy. We will be presenting results on the optical measurements, also showing the relationship between single scattering albedo (SSA) at three different wavelengths, and chemical as well as mineralogical content and interdependencies of the entrained dust samples. Examples showing the relationships between the single scattering albedos of airborne dusts, and iron (Fe) in hematite, goethite, and clay minerals (montmorillonite, illite, palygorskite), will be discussed. Differences between the clay minerals in samples from Mali and those from other localities are demonstrated. We intend establishing a data base for applications in climate modeling, remote sensing, visibility, health (medical geology), ocean fertilization, and damage to equipment.

  5. Vesta Mineralogy after Dawn Global Observations

    Science.gov (United States)

    ChristinaDeSanctis, Maria; Ammannito, E.; Capaccioni, F.; Cparia, M. T.; Carraro, F.; Fonte, S.; Frigeri, A.; Longobardo, A.; Marchi, S.; Palomba, E.; hide

    2012-01-01

    The Dawn mission has completed its mapping phases at Vesta and millions of spectra have been acquired by the Visible and InfraRed Mapping Spectrometer, VIR(1). VIR characterizes and maps the mineral distribution on Vesta -strengthening the Vesta HED linkage- and provides new insights into Vesta s formation and evolution(2,3). VIR spectra are dominated by pyroxene absorptions near 0.9 and 2.0 m and large thermal emission beyond 3.5 m. Although almost all surface materials exhibit howardite-like spectra, some large regions can be interpreted to be richer in eucritic (basaltic) material and others richer in diogenititic (Mg-orthopyroxenitic) material. The Rheasilvia basin contains Mg-pyroxene-rich terrains for example. Vesta' s surface shows considerable diversity at local scales. Many bright and dark areas(3,4) are associated with various geological features and show remarkably different morphology. Moreover, VIR detected statistically significant, but weak, variations at 2.8 m that have been interpreted as indicating the presence of OH-bearing phases on the surface(5). The OH distribution is uneven with large regions lacking this absorption feature. Associations of 2.8 m band with morphological structures indicate complex process responsible for OH. Vesta exhibits large spectral variations that often correlate with geological structures, indicating a complex geological and evolutionary history, more similar to that of the terrestrial planets than to other asteroids visited by spacecrafts.

  6. 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.

  7. Mineralogy, paragenesis, and mineral zoning of the Bulldog Mountain vein system, Creede District, Colorado

    Science.gov (United States)

    Plumlee, Geoffrey S.; Heald Whitehouse-Veaux, Pamela

    1994-01-01

    assemblage marked the transition to stage E. During stage E, the final sulfide stage, abundant botryoidal pyrite and marcasite with lesser stibnite, sphalerite, and sulfosalts were deposited primarily along the top of the Bulldog Mountain ore zone. Stage F, the final mineralization stage along the vein system, is marked by wire silver and concurrent leaching of earlier sulfides and sulfosalts; this stage may reflect the transition to a supergene environment.The sequence of mineralization stages identified in this study along the Bulldog Mountain system can be correlated with corresponding stages identified by other researchers along the OH and P veins, and the southern Amethyst vein system. Mineral zoning patterns identified along the Bulldog Mountain vein system also parallel larger scale zoning patterns across the central and southern Creede district.The complex variations in mineral assemblages documented in time and space along the Bulldog Mountain vein system were produced by the combined effects of many processes. Large-scale changes in vein mineralogy over time produced discrete mineralization stages. Short-term mineralogical fluctuations produced complex interbanding of mineralogically distinct generations. Fluid chemistry evolution within the vein system produced large-scale lateral zoning patterns within certain stages. Hypogene leaching substantially modified the distributions of some minerals. Finally, structural activity, mineral deposition, and mineral leaching modified fluid flow pathways repeatedly during mineralization, and so added to the complex mineral distribution patterns within the vein system.

  8. 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.

  9. Abiotic dechlorination of chlorinated ethenes in natural clayey soils: Impacts of mineralogy and temperature.

    Science.gov (United States)

    Schaefer, Charles E; Ho, Paul; Gurr, Christopher; Berns, Erin; Werth, Charles

    2017-11-01

    Laboratory batch experiments were performed to assess the impacts of temperature and mineralogy on the abiotic dechlorination of tetrachloroethene (PCE) or trichloroethene (TCE) due to the presence of ferrous minerals in natural aquifer clayey soils under anaerobic conditions. A combination of x-ray diffraction (XRD), magnetic susceptibility, and ferrous mineral content were used to characterize each of the 3 natural soils tested in this study, and dechlorination at temperatures ranging from 20 to 55°C were examined. Results showed that abiotic dechlorination occurred in all 3 soils examined, yielding reduced gas abiotic dechlorination products acetylene, butane, ethene, and/or propane. Bulk first-order dechlorination rate constants (kbulk), scaled to the soil:water ratio expected for in situ conditions, ranged from 2.0×10-5day-1 at 20°C, to 32×10-5day-1 at 55°C in the soil with the greatest ferrous mineral content. For the generation of acetylene and ethene from PCE, the reaction was well described by Arrhenius kinetics, with an activation energy of 91kJ/mol. For the generation of coupling products butane and propane, the Arrhenius equation did not provide a satisfactory description of the data, likely owing to the complex reaction mechanisms associated with these products and/or diffusional mass transfer processes associated with the ferrous minerals likely responsible for these coupling reactions. Although the data set was too limited to determine a definitive correlation, the two soils with elevated ferrous mineral contents had elevated abiotic dechlorination rate constants, while the one soil with a low ferrous mineral content had a relatively low abiotic dechlorination rate constant. Overall, results suggest intrinsic abiotic dechlorination rates may be an important long-term natural attenuation component in site conceptual models for clays that have the appropriate iron mineralogy. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Coralline algae in a naturally acidified ecosystem persist by maintaining control of skeletal mineralogy and size.

    Science.gov (United States)

    Kamenos, N A; Perna, G; Gambi, M C; Micheli, F; Kroeker, K J

    2016-10-12

    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. © 2016 The Authors.

  11. Abiotic dechlorination of chlorinated ethenes in natural clayey soils: Impacts of mineralogy and temperature

    Science.gov (United States)

    Schaefer, Charles E.; Ho, Paul; Gurr, Christopher; Berns, Erin; Werth, Charles

    2017-11-01

    Laboratory batch experiments were performed to assess the impacts of temperature and mineralogy on the abiotic dechlorination of tetrachloroethene (PCE) or trichloroethene (TCE) due to the presence of ferrous minerals in natural aquifer clayey soils under anaerobic conditions. A combination of x-ray diffraction (XRD), magnetic susceptibility, and ferrous mineral content were used to characterize each of the 3 natural soils tested in this study, and dechlorination at temperatures ranging from 20 to 55 °C were examined. Results showed that abiotic dechlorination occurred in all 3 soils examined, yielding reduced gas abiotic dechlorination products acetylene, butane, ethene, and/or propane. Bulk first-order dechlorination rate constants (kbulk), scaled to the soil:water ratio expected for in situ conditions, ranged from 2.0 × 10- 5 day- 1 at 20 °C, to 32 × 10- 5 day- 1 at 55 °C in the soil with the greatest ferrous mineral content. For the generation of acetylene and ethene from PCE, the reaction was well described by Arrhenius kinetics, with an activation energy of 91 kJ/mol. For the generation of coupling products butane and propane, the Arrhenius equation did not provide a satisfactory description of the data, likely owing to the complex reaction mechanisms associated with these products and/or diffusional mass transfer processes associated with the ferrous minerals likely responsible for these coupling reactions. Although the data set was too limited to determine a definitive correlation, the two soils with elevated ferrous mineral contents had elevated abiotic dechlorination rate constants, while the one soil with a low ferrous mineral content had a relatively low abiotic dechlorination rate constant. Overall, results suggest intrinsic abiotic dechlorination rates may be an important long-term natural attenuation component in site conceptual models for clays that have the appropriate iron mineralogy.

  12. The Spatial Distribution and Mineralogical Association of Organics in the Tagish Lake and Bells Carbonaceous Chondrites

    Science.gov (United States)

    Clemett, S. J.; Nakamura-Messenger, K.; Thomas-Keprta, K. L.; Messenger, S.

    2010-01-01

    Chondritic meteorites represent some of the most primitive Solar System materials available for laboratory analysis. While the presence of simple organic molecules has been well documented in such materials [1], little is known about their spatial distribution and to what extent, if any, they exhibit specific mineralogical associations. This dichotomy arises since organic analysis typically involves solvent extraction as a preliminary step. To address these issues we have used two-step laser mass spectrometry (L 2MS) to map in situ the spatial distribution of aromatic and conjugated organics at the micron scale in freshly exposed surfaces of the Tagish Lake and Bells carbonaceous chondrites. Our specific goals are two-fold; firstly to investigate if and how abundance of organic species varies within the meteorite matrix both as an ensemble, and with respect to functional group (e.g., R-OH vs. RCH3) and between members of the same homologous series (e.g., R-H vs. R-(CH2)H). Secondly, to determine whether observed spatial variations can be related to specific mineralogical and/or physical characteristics of the host matrix. In regard to the latter we are particularly interested in the role that carbonaceous nanoglobules [2] play as reservoirs of organic matter. Such globules, which are believed to have formed by photochemical processing of organic-rich ices in the presolar cold molecular cloud or the outermost reaches of the early protosolar disk, are abundant in both the Bells and Tagish Lake chondrites and are noteworthy for having particularly high enrichments in 2H and 15N [3,4].

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

    Energy Technology Data Exchange (ETDEWEB)

    Glassley, W., LLNL

    1998-02-03

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

  14. 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; hide

    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.

  15. In Situ Techniques for Mineralogy and Geochemistry of Small Bodies

    Science.gov (United States)

    Blacksberg, J.; Rossman, G. R.; Webster, C. R.

    2012-12-01

    In situ exploration of planetary surfaces employs multiple techniques that, when used together, yield important information about their formation histories and evolution. Combined geochemistry and mineralogy measurements reveal the phases present, their composition, morphology, and isotope ratios of constituents. Small and primitive bodies often present a special case where little to no compositional information has been obtained from ground-based or remote measurements. For example, Trojan asteroids and other D-type objects as well as Phobos and Deimos exhibit relatively featureless reflectance spectra as obtained by remote measurements. Yet samples of primitive material in the meteorite collection (e.g. Allende) reveal a fine grained structure with many phases and a wealth of chemical information. On-surface measurements are therefore a necessary component for understanding the origins of these solar system bodies. We will present measurement techniques that could provide microscopic mineralogy and isotope geochemistry. We will discuss instrumentation and measurements relevant to small body exploration - focusing more specifically on our recent results from the techniques of microscopic time-resolved Raman spectroscopy, Laser Induced Breakdown Spectroscopy (LIBS), and Tunable Laser Spectroscopy (TLS). The research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). This work was performed in part at the California Institute of Technology for the Keck Institute for Space Studies, which is funded by the W. M. Keck Foundation.

  16. Mineralogical composition changes of postagrogenic soils under different plant communities.

    Science.gov (United States)

    Churilin, Nikita; Chizhikova, Natalia; Varlamov, Evgheni; Churilina, Alexandra

    2017-04-01

    Plant communities play the leading role in transformation of soil. The need of studying former arable lands increases due to large number of abandoned lands in Russia. It is necessary to study mineralogical composition of soils involved into natural processes to understand the trends of their development after agricultural activities in the past. The aim of the study is to identify changes in mineralogical composition of soils under the influence of different plant communities. Soils were sampled in the south of Arkhangelsk region, Ustyansky district, near Akichkin Pochinok village. Soils are formed on clay moraine of Moscow glaciation. Soil profiles were dug on interfluve. We selected 4 plant communities on different stages of succession: upland meadow with domination of sod grasses (Phleum pratense, Agrostis tenuis), 16-year-old birch forest where dominants are herbaceous plants such as Poa sp., Chamerion angustiflium, Agrostis tenuis, 16-year-old spruce forest with no herbaceous vegetation and 70-year-old bilberry spruce forest with domination of Vaccinium myrtillus and Vaccinium vitis-idaea. To separate soil fractions <1 micron, 1-5 micron and 5-10 micron samples were rubbed into a thick paste and sedimented. Oriented preparations of fractions were examined by XRD method. The results show that podzol processes lead to significant changes of mineral content. We noticed a clear differentiation of studied soils both in the content of fraction and composition of minerals. Mineralogical composition and major mineral phases correlation of profiles under 70 years and 16 years of spruce forests are different. Mineralogical content in upper part of profile under the young spruce is more differentiated than in old spruce forest: the amount of quartz and kaolinite increases in upper horizon, although in this case the overall pattern of profile formation of clay material during podzolization remains unchanged. There is more substantial desilting under the birch forest

  17. Mineral Supertrumps: A New Card Game to Assist Learning of Mineralogy

    Science.gov (United States)

    Spandler, Carl

    2016-01-01

    Mineralogy is an essential component of Earth Science education, yet many students struggle to obtain adequate comprehension and knowledge of mineralogy during tertiary (postsecondary) degree programs. The use of educational games can be an effective strategy for science teaching as games provide an active learning environment that enhances…

  18. Successful Curriculum Development and Evaluation of Group Work in an Introductory Mineralogy Laboratory

    Science.gov (United States)

    Dohaney, Jacqueline; Brogt, Erik; Kennedy, Ben

    2012-01-01

    Mineralogy is a core topic for tertiary geoscience programs worldwide. We report on the use of laboratory group work as an effective and integral part of a new introductory mineralogy curriculum at the University of British Columbia. The new laboratory curriculum was developed by incorporating student feedback with evidence-based pedagogies. These…

  19. Quantitative assessments of mantle flow models against seismic observations: Influence of uncertainties in mineralogical parameters

    Science.gov (United States)

    Schuberth, Bernhard S. A.

    2017-04-01

    synthetic traveltime data can then be compared - on statistical grounds - to the traveltime variations observed on Earth. Here, we now investigate the influence of uncertainties in the various input parameters that enter our modelling. This is especially important for the material properties at high pressure and high temperature entering the mineralogical models. In particular, this concerns uncertainties that arise from relating measurements in the laboratory to Earth properties on a global scale. As one example, we will address the question on the influence of anelasticity on the variance of global synthetic traveltime residuals. Owing to the differences in seismic frequency content between laboratory measurements (MHz to GHz) and the Earth (mHz to Hz), the seismic velocities given in the mineralogical models need to be adjusted; that is, corrected for dispersion due to anelastic effects. This correction will increase the sensitivity of the seismic velocities to temperature variations. The magnitude of this increase depends on absolute temperature, frequency, the frequency dependence of attenuation and the activation enthalpy of the dissipative process. Especially the latter two are poorly known for mantle minerals and our results indicate that variations in activation enthalpy potentially produce the largest differences in temperature sensitivity with respect to the purely elastic case. We will present new wave propagation simulations and corresponding statistical analyses of traveltime measurements for different synthetic seismic models spanning the possible range of anelastic velocity conversions (while being based on the same mantle circulation model).

  20. 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

  1. 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

  2. Exploring the Mineralogy of the Moon with M3

    Science.gov (United States)

    Pieters, C. M.; Boardman, J.; Buratti, B.; Clark, R.; Green, R.; Head, J. W. III; McCord, T. B.; Mustard, J.; Runyon, C.; Staid, M.

    2006-01-01

    From the initial era or lunar exploration, we have learned that many processes active on the early Moon are common to most terrestrial planets, including the record of early and late impact bombardment. Since most major geologic activity ceased on the Moon approx. 3 Gy ago, the Moon's surface provides a record of the earliest era of terrestrial planet evolution. 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 Moon Mineralogy Mapper (M3, or "m-cube") is a state-of-the-art imaging spectrometer that will fly on Chandrayaan-1, the Indian Space Research Organization (ISRO) mission to be launched late 2007 to early 2008. M3 is one of several foreign instruments chosen by ISRO to be flown on Chandrayaan-1 to complement the strong ISRO payload package. M3 was selected through a peer-review process as part of NASA s Discovery Program. It is under the oversight of PI Carle Pieters at Brown University and is being built by an experienced team at the Jet Propulsion Laboratory. Data analysis and calibration are carried out by a highly qualified and knowledgeable Science Team. To characterize diagnostic properties of lunar minerals, M3 acquires high spectral resolution reflectance data from 700 to 3000 nm (optional to 430 nm). M3 operates as a pushbroom spectrometer with a slit oriented orthogonal to the S/C orbital motion. Measurements are obtained simultaneously for 640 cross track spatial elements and 261 spectral elements

  3. Mineralogical analysis of the Oppia quadrangle of asteroid (4) Vesta: Evidence for occurrence of moderate-reflectance hydrated minerals

    Science.gov (United States)

    Tosi, F.; Frigeri, A.; Combe, J.-Ph.; Zambon, F.; De Sanctis, M. C.; Ammannito, E.; Longobardo, A.; Hoffmann, M.; Nathues, A.; Garry, W. B.; Blewett, D. T.; Pieters, C. M.; Palomba, E.; Stephan, K.; McFadden, L. A.; McSween, H. Y.; Russell, C. T.; Raymond, C. A.

    2015-10-01

    Quadrangle Av-10 'Oppia' is one of five quadrangles that cover the equatorial region of asteroid (4) Vesta. This quadrangle is notable for the broad, spectrally distinct ejecta that extend south of the Oppia crater. These ejecta exhibit the steepest ('reddest') visible spectral slope observed across the asteroid and have distinct color properties as seen in multispectral composite images. Compared to previous works that focused on the composition and nature of unusual ('orange') ejecta found on Vesta, here we take into account a broader area that includes several features of interest, with an emphasis on mineralogy as inferred from data obtained by Dawn's Visible InfraRed mapping spectrometer (VIR). Our analysis shows that the older northern and northeastern part of Av-10 is dominated by howardite-like material, while the younger southwestern part, including Oppia and its ejecta blanket, has a markedly eucritic mineralogy. The association of the mineralogical information with the geologic and topographic contexts allows for the establishment of relationships between the age of the main formations observed in this quadrangle and their composition. A major point of interest in the Oppia quadrangle is the spectral signature of hydrous material seen at the local scale. This material can be mapped by using high-resolution VIR data, combined with multispectral image products from the Dawn Framing Camera (FC) so as to enable a clear correlation with specific geologic features. Hydrated mineral phases studied previously on Vesta generally correlate with low-albedo material delivered by carbonaceous asteroids. However, our analysis shows that the strongest OH signature in Av-10 is found in a unit west of Oppia, previously mapped as 'light mantle material' and showing moderate reflectance and a red visible slope. With the available data we cannot yet assess the presence of water in this material. However, we offer a possible explanation for its origin.

  4. Mineralogical Analysis of the Oppia Quadrangle of Asteroid (4) Vesta: Evidence for Occurrence of Moderate-Reflectance Hydrated Minerals

    Science.gov (United States)

    Tosi, F.; Frigeri, A.; Combe, J.-Ph.; Zambon, F.; De Sanctis, M. C.; Ammannito, E.; Longobardo, A.; Hoffmann, M.; Nathues, A.; Garry, W. B.; hide

    2015-01-01

    Quadrangle Av-10 'Oppia' is one of five quadrangles that cover the equatorial region of asteroid (4) Vesta. This quadrangle is notable for the broad, spectrally distinct ejecta that extend south of the Oppia crater. These ejecta exhibit the steepest ('reddest') visible spectral slope observed across the asteroid and have distinct color properties as seen in multispectral composite images. Compared to previous works that focused on the composition and nature of unusual ('orange') ejecta found on Vesta, here we take into account a broader area that includes several features of interest, with an emphasis on mineralogy as inferred from data obtained by Dawn's Visible InfraRed mapping spectrometer (VIR). Our analysis shows that the older northern and northeastern part of Av-10 is dominated by howardite-like material, while the younger southwestern part, including Oppia and its ejecta blanket, has a markedly eucritic mineralogy. The association of the mineralogical information with the geologic and topographic contexts allows for the establishment of relationships between the age of the main formations observed in this quadrangle and their composition. A major point of interest in the Oppia quadrangle is the spectral signature of hydrous material seen at the local scale. This material can be mapped by using high-resolution VIR data, combined with multispectral image products from the Dawn Framing Camera (FC) so as to enable a clear correlation with specific geologic features. Hydrated mineral phases studied previously on Vesta generally correlate with low-albedo material delivered by carbonaceous asteroids. However, our analysis shows that the strongest OH signature in Av-10 is found in a unit west of Oppia, previously mapped as 'light mantle material' and showing moderate reflectance and a red visible slope. With the available data we cannot yet assess the presence of water in this material. However, we offer a possible explanation for its origin.

  5. 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

  6. Raman spectroscopic analysis of real samples: Brazilian bauxite mineralogy.

    Science.gov (United States)

    Faulstich, Fabiano Richard Leite; Castro, Harlem V; de Oliveira, Luiz Fernando Cappa; Neumann, Reiner

    2011-10-01

    In this investigation, Raman spectroscopy with 1064 and 632.8 nm excitation was used to investigate real mineral samples of bauxite ore from mines of Northern Brazil, together with Raman mapping and X-rays diffraction. The obtained results show clearly that the use of microRaman spectroscopy is a powerful tool for the identification of all the minerals usually found in bauxites: gibbsite, kaolinite, goethite, hematite, anatase and quartz. Bulk samples can also be analysed, and FT-Raman is more adequate due to better signal-to-noise ratio and representativity, although not efficient for kaolinite. The identification of fingerprinting vibrations for all the minerals allows the acquisition of Raman-based chemical maps, potentially powerful tools for process mineralogy applied to bauxite ores. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Mineralogy affects geoavailability, bioaccessibility and bioavailability of zinc.

    Science.gov (United States)

    Molina, Ramon M; Schaider, Laurel A; Donaghey, Thomas C; Shine, James P; Brain, Joseph D

    2013-11-01

    We correlated mineralogical and particle characteristics of Zn-containing particles with Zn geoavailability, bioaccessibility, and bioavailability following gavage and intranasal (IN) administration in rats. We compared samples of Zn/Pb mine waste and five pulverized pure-phase Zn minerals ( hydrozincite > hemimorphite > zincite ≈ smithsonite > sphalerite. We found significant correlations among geoavailability, bioaccessibility and bioavailability. In particular, Zn bioavailability post-gavage and post-IN was significantly correlated with bioaccessibility in simulated phagolysosomal fluid and gastric fluid. These data indicate that solid phase speciation influences biological uptake of Zn and that in vitro tests can be used to predict Zn bioavailability in exposure assessment and effective remediation design. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Mineralogical effects on the detectability of the postperovskite boundary

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-02

    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.

  9. Dust from Zambian smelters: mineralogy and contaminant bioaccessibility.

    Science.gov (United States)

    Ettler, Vojtěch; Vítková, Martina; Mihaljevič, Martin; Šebek, Ondřej; Klementová, Mariana; Veselovský, František; Vybíral, Pavel; Kříbek, Bohdan

    2014-10-01

    Metal smelting is often responsible for local contamination of environmental compartments. Dust materials escaping from the smelting facilities not only settle in the soil, but can also have direct effects on populations living close to these operations (by ingestion or inhalation). In this particular study, we investigate dusts from Cu-Co metal smelters in the Zambian Copperbelt, using a combination of mineralogical techniques (XRD, SEM/EDS, and TEM/EDS), in order to understand the solid speciation of the contaminants, as well as their bioaccessibility using in vitro tests in simulated gastric and lung fluids to assess the exposure risk for humans. The leaching of metals was mainly dependent on the contaminant mineralogy. Based on our results, a potential risk can be recognized, particularly from ingestion of the dust, with bioaccessible fractions ranging from 21 to 89% of the total contaminant concentrations. In contrast, relatively low bioaccessible fractions were observed for simulated lung fluid extracts, with values ranging from 0.01% (Pb) up to 16.5% (Co) of total contaminant concentrations. Daily intakes via oral exposure, calculated for an adult (70 kg, ingestion rate 50 mg dust per day), slightly exceeded the tolerable daily intake limits for Co (1.66× for fly ash and 1.19× for slag dust) and occasionally also for Pb (1.49×, fly ash) and As (1.64×, electrostatic precipitator dust). Cobalt has been suggested as the most important pollutant, and the direct pathways of the population's exposures to dust particles in the industrial parts of the Zambian Copperbelt should be further studied in interdisciplinary investigations.

  10. Mineralogical effects on the detectability of the postperovskite boundary

    Science.gov (United States)

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

    2016-03-01

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

  11. Diversity of Mineralogy and Occurrences of Phyllosilicates on Mars

    Science.gov (United States)

    Clark, R. N.; Swayze, G. A.; Murchie, S. L.; Mustard, J. F.; Milliken, R. E.; Ehlmann, B. L.; McKeown, N. K.; Calvin, W. M.; Wray, J. J.; Bishop, J. L.

    2008-12-01

    Minerals and their occurrences tell us about the chemistry, pressure,and temperatures of past environments, and the possible conditions for past habitability. To date, a fair number of phyllosilicates and other minerals have been detected on Mars (e.g., Poulet et al., Nature v438,p623, 2005; Mustard et al., Nature, v454, p309, 2008; Bishop et al., Science, V321, p830, 2008, and references therein). Minerals and amorphous materials detected and mapped over large areas include kaolinite/halloysite, montmorillonite, Fe/Mg-smectite, nontronite, saponite, chlorite, opal/hydrated glass, illite, muscovite, magnesite, prehnite, olivine, high- and low-calcium pyroxene, hematite, jarosite, alunite, kieserite, gypsum, coquimbite or ferricopiapite, possible szomolnokite and others yet to be identified. Phyllosilicate minerals are generally seen associated with Noachian outcrops and are thought to result from aqueous alteration, perhaps over sustained periods. Poly- and mono-hydrated Mg-sulphates appear to have been formed after the phyllosilicates. The patterns and occurrences of minerals so far mapped do not appear to show classic hydrothermal systems as have been observed on Earth (e.g., Yellowstone, Wyoming, and Cuprite, Nevada). Prehnite, previously identified on Mars as scapolite, a low-temperature phyllosilicate commonly found in mafic volcanics on Earth, appears widespread on Mars, often in association with Fe/Mg-smectite or chlorite. Phyllosilicates are observed in local outcrops, but occur regionally, generally indicating the effects of a common alteration process during the Noachian epoch. The discovery of mineralogies indicating both acidic and alkaline environments using CRISM and OMEGA data show that conditions were locally diverse. If the environments for the regional phyllosilicate deposits are found to be hostile to past habitability, perhaps studying the smaller mineralogically diverse areas may prove more fruitful. This talk will review the minerals and their

  12. Exploring the mineralogy of the Moon with M3

    Science.gov (United States)

    Pieters, C. M.

    From the initial era or lunar exploration we have learned that many processes active on the early Moon are common to most terrestrial planets including the record of early and late impact bombardment Since most major geologic activity ceased on the Moon sim 3 Gy ago the Moon s surface provides a record of the earliest era of terrestrial planet evolution 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 Moon Mineralogy Mapper M3 or m-cube is a state-of-the-art imaging spectrometer that will fly on Chandrayaan-1 the Indian Space Research Organization ISRO mission to be launched late 2007 to early 2008 M3 is one of several foreign instruments chosen by ISRO to be flown on Chandrayaan-1 to complement the strong ISRO payload package M3 was selected through a peer-review process as part of NASA s Discovery Program It is under the oversight of PI Carl e Pieters at Brown University and is being built by an experienced team at the Jet Propulsion Laboratory Data analysis and calibration are

  13. The Moon Mineralogy Mapper (M3) imaging spectrometerfor lunar science: Instrument description, calibration, on‐orbit measurements, science data calibration and on‐orbit validation

    Science.gov (United States)

    C. Pieters,; P. Mouroulis,; M. Eastwood,; J. Boardman,; Green, R.O.; Glavich, T.; Isaacson, P.; Annadurai, M.; Besse, S.; Cate, D.; Chatterjee, A.; Clark, R.; Barr, D.; Cheek, L.; Combe, J.; Dhingra, D.; Essandoh, V.; Geier, S.; Goswami, J.N.; Green, R.; Haemmerle, V.; Head, J.; Hovland, L.; Hyman, S.; Klima, R.; Koch, T.; Kramer, G.; Kumar, A.S.K.; Lee, K.; Lundeen, S.; Malaret, E.; McCord, T.; McLaughlin, S.; Mustard, J.; Nettles, J.; Petro, N.; Plourde, K.; Racho, C.; Rodriguez, J.; Runyon, C.; Sellar, G.; Smith, C.; Sobel, H.; Staid, M.; Sunshine, J.; Taylor, L.; Thaisen, K.; Tompkins, S.; Tseng, H.; Vane, G.; Varanasi, P.; White, M.; Wilson, D.

    2011-01-01

    The NASA Discovery Moon Mineralogy Mapper imaging spectrometer was selected to pursue a wide range of science objectives requiring measurement of composition at fine spatial scales over the full lunar surface. To pursue these objectives, a broad spectral range imaging spectrometer with high uniformity and high signal-to-noise ratio capable of measuring compositionally diagnostic spectral absorption features from a wide variety of known and possible lunar materials was required. For this purpose the Moon Mineralogy Mapper imaging spectrometer was designed and developed that measures the spectral range from 430 to 3000 nm with 10 nm spectral sampling through a 24 degree field of view with 0.7 milliradian spatial sampling. The instrument has a signal-to-noise ratio of greater than 400 for the specified equatorial reference radiance and greater than 100 for the polar reference radiance. The spectral cross-track uniformity is >90% and spectral instantaneous field-of-view uniformity is >90%. The Moon Mineralogy Mapper was launched on Chandrayaan-1 on the 22nd of October. On the 18th of November 2008 the Moon Mineralogy Mapper was turned on and collected a first light data set within 24 h. During this early checkout period and throughout the mission the spacecraft thermal environment and orbital parameters varied more than expected and placed operational and data quality constraints on the measurements. On the 29th of August 2009, spacecraft communication was lost. Over the course of the flight mission 1542 downlinked data sets were acquired that provide coverage of more than 95% of the lunar surface. An end-to-end science data calibration system was developed and all measurements have been passed through this system and delivered to the Planetary Data System (PDS.NASA.GOV). An extensive effort has been undertaken by the science team to validate the Moon Mineralogy Mapper science measurements in the context of the mission objectives. A focused spectral, radiometric

  14. The Moon Mineralogy Mapper (M3) imaging spectrometer for lunar science: Instrument description, calibration, on-orbit measurements, science data calibration and on-orbit validation

    Science.gov (United States)

    Green, R.O.; Pieters, C.; Mouroulis, P.; Eastwood, M.; Boardman, J.; Glavich, T.; Isaacson, P.; Annadurai, M.; Besse, S.; Barr, D.; Buratti, B.; Cate, D.; Chatterjee, A.; Clark, R.; Cheek, L.; Combe, J.; Dhingra, D.; Essandoh, V.; Geier, S.; Goswami, J.N.; Green, R.; Haemmerle, V.; Head, J.; Hovland, L.; Hyman, S.; Klima, R.; Koch, T.; Kramer, G.; Kumar, A.S.K.; Lee, Kenneth; Lundeen, S.; Malaret, E.; McCord, T.; McLaughlin, S.; Mustard, J.; Nettles, J.; Petro, N.; Plourde, K.; Racho, C.; Rodriquez, J.; Runyon, C.; Sellar, G.; Smith, C.; Sobel, H.; Staid, M.; Sunshine, J.; Taylor, L.; Thaisen, K.; Tompkins, S.; Tseng, H.; Vane, G.; Varanasi, P.; White, M.; Wilson, D.

    2011-01-01

    The NASA Discovery Moon Mineralogy Mapper imaging spectrometer was selected to pursue a wide range of science objectives requiring measurement of composition at fine spatial scales over the full lunar surface. To pursue these objectives, a broad spectral range imaging spectrometer with high uniformity and high signal-to-noise ratio capable of measuring compositionally diagnostic spectral absorption features from a wide variety of known and possible lunar materials was required. For this purpose the Moon Mineralogy Mapper imaging spectrometer was designed and developed that measures the spectral range from 430 to 3000 nm with 10 nm spectral sampling through a 24 degree field of view with 0.7 milliradian spatial sampling. The instrument has a signal-to-noise ratio of greater than 400 for the specified equatorial reference radiance and greater than 100 for the polar reference radiance. The spectral cross-track uniformity is >90% and spectral instantaneous field-of-view uniformity is >90%. The Moon Mineralogy Mapper was launched on Chandrayaan-1 on the 22nd of October. On the 18th of November 2008 the Moon Mineralogy Mapper was turned on and collected a first light data set within 24 h. During this early checkout period and throughout the mission the spacecraft thermal environment and orbital parameters varied more than expected and placed operational and data quality constraints on the measurements. On the 29th of August 2009, spacecraft communication was lost. Over the course of the flight mission 1542 downlinked data sets were acquired that provide coverage of more than 95% of the lunar surface. An end-to-end science data calibration system was developed and all measurements have been passed through this system and delivered to the Planetary Data System (PDS.NASA.GOV). An extensive effort has been undertaken by the science team to validate the Moon Mineralogy Mapper science measurements in the context of the mission objectives. A focused spectral, radiometric

  15. 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

  16. Mineralogic mapping of the Av-9 Numisia quadrangle of Vesta

    Science.gov (United States)

    Frigeri, A.; De Sanctis, M. C.; Ammannito, E.; Buczkowski, D.; Combe, J. P.; Tosi, F.; Zambon, F.; Rocchini, D.; Jaumann, R.; Raymond, C. A.; Russell, C. T.

    2015-10-01

    In this manuscript we present the mineralogic mapping of the Av-9 Numisia quadrangle of Vesta using the most up-to-date data from the NASA-Dawn mission. This quadrangle is located in Vesta's equatorial zone (22° south to 22° north, 218° to 288° east, in Claudia coordinate system) and takes its name from the impact crater Numisia. The main feature, which dominates the quadrangle, is the Vestalia Terra plateau, a topographic high about 10 km above the surrounding areas. To the south, this region fades into the Rheasilvia basin, while to the north it is bounded by the steep scarp of Postumia basin. The Visible and Infrared mapping spectrometer (VIR) onboard NASA/Dawn provided the main data source for this work, at an unprecedented level of spatial and spectral resolution. In particular we are using spectral parameters to synthesize characteristics of the whole spectra into a single value. Pyroxene-related spectral parameters allow for the detection of lower crust or mantle material (diogenites) and upper crust material (eucrites) in the study area. The combined analysis of albedo from the Framing Camera, the geologic map and the spectroscopic data offer an interesting opportunity to understand better the surface features of this region of Vesta, and their evolution. Numisia, Cornelia, Fabia, Teia and Drusilla are the main craters in the study area, rich in bright and dark material outcrops, pitted terrains and OH-rich materials. Using the spectral parameters we demonstrate that the internal composition of Vestalia Terra is mainly diogenite-rich howardite, as shown by materials excavated by Cornelia and Fabia, and the composition of the slope north of Vestalia Terra. This agrees with the strong positive Bouguer Anomaly observed in the area, indicating a higher density of these features in relation to the surrounding areas. Besides the recently published works based on gravimetric modeling and geologic interpretation, the mineralogic mapping presented herein gives

  17. A Spectroscopic and Mineralogical Study of Multiple Asteroid Systems

    Science.gov (United States)

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

    2013-10-01

    There are currently ~200 identified multiple asteroid systems (MASs). These systems display a large diversity in heliocentric distance, size/mass ratio, system angular momentum, mutual orbital parameters, and taxonomic class. These characteristics are simplified under the nomenclature of Descamps and Marchis (2008), which divides MASs into four types: Type-1 - large asteroids with small satellites; Type-2 - similar size double asteroids; Type-3 - small asynchronous systems; and Type-4 - contact-binary asteroids. The large MAS diversity suggests multiple formation mechanisms are required to understand their origins. There are currently three broad formation scenarios: 1) ejecta from impacts; 2) catastrophic disruption followed by rotational fission; and 3) tidal disruption. The taxonomic class and mineralogy of the MASs coupled with the average density and system angular momentum provide a potential means to discriminate between proposed formation mechanisms. We present visible and near-infrared (NIR) spectra spanning 0.45 - 2.45 μm for 23 Main Belt MASs. The data were primarily obtained using the Southern Astrophysical Research Telescope (SOAR) Goodman High Throughput Spectrograph (August 2011 - July 2012) for the visible data and the InfraRed Telescope Facility (IRTF) SpeX Spectrograph (August 2008 - May 2013) for the IR data. Our data were supplemented using previously published data when necessary. The asteroids' Bus-DeMeo taxonomic classes are determined using the MIT SMASS online classification routines. Our sample includes 3 C-types, 1 X-type, 1 K-type, 1 L-type, 4 V-types, 10 S-types, 2 Sq- or Q-types, and 1 ambiguous classification. We calculate the 1- and 2-μm band centers, depths, and areas to determine the pyroxene mineralogy (molar Fs and Wo) of the surfaces using empirically derived equations. The NIR band analysis allows us to determine the S-type subclasses, S(I) - S(VII), which roughly tracks olivine-pyroxene chemistry. A comparison of the orbital

  18. Ancient mortars from Cape Verde: mineralogical and physical characterization

    Science.gov (United States)

    Rocha, Fernando; Costa, Cristiana; Velosa, Ana; Quintela, Ana; Terroso, Denise; Marques, Vera

    2014-05-01

    Times and locations of different building constructions means different knowledge, habits, different construction methods and materials. The study and safeguarding of the architectural heritage takes nowadays a progressive importance as a vehicle for transmission of cultures and history of nations. The coatings are of great importance in the durability of a building due to the protective role of the masonry. The compatibility between the materials with which they are executed (masonry, mortar and grout settlement) promotes the proper functioning of the wall and a consequent increase in durability. Therefore, it becomes important to study and characterize the mortar coating of buildings to know its characteristics and to use compatible materials in the rehabilitation and maintenance of buildings. This study aims to characterize the chemical, physical, mechanical and mineralogical mortar samples collected in buildings in three islands of Cape Verde, for the conservation, rehabilitation and preservation of them. The collected samples belong to buildings constructed in the end of XIX century and in the beginning of XX century. In order to characterize the mortar samples some tests was made, such as X-Ray Diffraction, X- Ray Fluorescence, acid attack and mechanical strength. The samples were divided into three groups depending on origin; so we have a first group collected on the island of Santiago, the second on the island of Saint Vincent and the third on the island of Santo Antao. The samples are all carbonated, but Santiago samples have a lower carbonates content. In terms of insoluble residue (from the acid attack) it was concluded that the samples have similar value ranging from 9 to 26%. The compressive strength of the mortars have a range between 1.36 and 4.55 MPa, which is related to the presence of more binder in samples with higher resistance. The chemical and mineralogical analyzes showed that these consist of lime mortars (binder), natural pozzolan and

  19. Compositional diversity and geologic insights of the Aristarchus crater from Moon Mineralogy Mapper data

    Science.gov (United States)

    Mustard, J.F.; Pieters, C.M.; Isaacson, P.J.; Head, J.W.; Besse, S.; Clark, R.N.; Klima, R.L.; Petro, N.E.; Staid, M.I.; Sunshine, J.M.; Runyon, C.J.; Tompkins, S.

    2011-01-01

    The Moon Mineralogy Mapper (M3) acquired high spatial and spectral resolution data of the Aristarchus Plateau with 140 m/pixel in 85 spectral bands from 0.43 to 3.0 m. The data were collected as radiance and converted to reflectance using the observational constraints and a solar spectrum scaled to the Moon-Sun distance. Summary spectral parameters for the area of mafic silicate 1 and 2 m bands were calculated from the M3 data and used to map the distribution of key units that were then analyzed in detail with the spectral data. This analysis focuses on five key compositional units in the region. (1) The central peaks are shown to be strongly enriched in feldspar and are likely from the upper plagioclase-rich crust of the Moon. (2) The impact melt is compositionally diverse with clear signatures of feldspathic crust, olivine, and glass. (3) The crater walls and ejecta show a high degree of spatial heterogeneity and evidence for massive breccia blocks. (4) Olivine, strongly concentrated on the rim, wall, and exterior of the southeastern quadrant of the crater, is commonly associated the impact melt. (5) There are at least two types of glass deposits observed: pyroclastic glass and impact glass. Copyright 2011 by the American Geophysical Union.

  20. Diverse mineralogical and oxygen isotopic signatures recorded in CV3 carbonaceous chondrites

    Science.gov (United States)

    Ishida, Hatsumi; Nakamura, Tomoki; Miura, Hitoshi; Kakazu, Yuki

    2012-08-01

    We describe the petrography and mineralogy of six CV3 carbonaceous chondrites. LAP02206, LAP02228, LAP04843, and GRA06101 are classified as oxidized Allende-like chondrites (CV3oxA). RBT04143 and QUE97186 are classified as members of the reduced subtype (CV3red). Chondrules in the CV3oxA chondrites show extensive Fe-Mg zoning. Fe-rich olivine in the rims of the CV3oxA chondrules are 16O-poor relative to Mg-rich olivine in the cores, suggesting that in addition to Fe and Mg, oxygen was exchanged between chondrules and matrix during weak thermal metamorphism. The CV3red chondrites appear to have formed through various processes. QUE97186 shows chondrule flattening with a preferred orientation, which is interpreted to have resulted from shock impact at a pressure of ˜20 GPa. The post-shock residual heat (˜1000 °C) is likely to be responsible for the restricted Fe/Mg ratios of matrix olivine. Based on the degree of Fe-Mg homogenization of matrix olivines, we estimate the spatial scale of the shock-heated region to be ˜1 m. RBT04143 is a breccia containing many clasts of two types of lithologies: reduced-type material and very weakly altered material.

  1. Weathering trends and parent material characteristics of polygenetic oxisols from Minas Gerais, Brazil: I. Mineralogy

    NARCIS (Netherlands)

    Muggler, C.C.; Buurman, P.; Doesburg, van J.D.J.

    2007-01-01

    In geologically stable areas in the tropics, climatic changes and geomorphic cycles give origin to polygenetic soils. Polygenesis involves new soil formation phases taking place on preweathered materials from previous phases, resulting in soils with rather similar chemical and mineralogical

  2. 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...

  3. 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,...

  4. Definitive Mineralogy of Rocky and Icy Planets and Planetesimals Using Powder X-Ray Diffraction

    Science.gov (United States)

    Blake, D. F.; Sarrazin, P.

    2017-02-01

    X-ray diffraction is a definitive technique for mineral identification, quantification, and composition. Definitive mineralogical analysis can identify modern and ancient habitable environments and provide context for other measurements.

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

    Science.gov (United States)

    Ostrooumov, M.

    2016-08-01

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

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    Based on a statistical model first applied for prediction of compressive strength up to 28 d from the microstructure of Portland cement, potential compressive strength of clinker has been predicted from its mineralogy. The prediction model was evaluated by partial least squares regression....... The mineralogy was described by patterns from X-ray diffraction analysis in the 20-regions 29.88-30.70 degrees and 32.90-34.10 degrees (using CuK alpha-radiation). It has been shown that prediction of potential compressive strength of clinker up to 28 d from the observed variation in the mineralogy gave...... a significant variation of the strength at both 1 and 28 d. Sensitivity analysis based on simulation, optimisation and prediction made it possible to study the influence of the mineralogy on the strength in more detail....

  7. Carbonate mineralogy and faunal relationship in tropical shallow water marine sediments: Cape Comorin, India

    Digital Repository Service at National Institute of Oceanography (India)

    Hashimi, N.H.; Nair, R.R.; Kidwai, R.M.; Rao, V.P.

    The carbonate mineralogy of Recent sediments from the western and eastern continental shelves around Cape Comorin off the southern tip of India was determined by X-ray diffraction analyses. The results show that in the sediments where benthic...

  8. 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...

  9. Thermal Alteration of CI and CM Chondrites: Mineralogical Changes and Metamorphic Temperatures

    Science.gov (United States)

    King, A. J.; Schofield, P. F.; Russell, S. S.

    2015-07-01

    Modal mineralogy, H2O abundances and spectral features are used to constrain the origin of thermally altered CI and CM chondrites. Heterogeneous heating was probably caused by impact shocks and affected the surfaces of many C-type asteroids.

  10. MSL MARS CHEMISTRY AND MINERALOGY 4 RDR V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The CheMin instrument determines the mineralogy and elemental composition of powdered samples through the combined application of X-ray diffraction (XRD, producing...

  11. MSL MARS CHEMISTRY AND MINERALOGY 5 RDR V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The CheMin instrument determines the mineralogy and elemental composition of powdered samples through the combined application of X-ray diffraction (XRD, producing...

  12. Mineralogical and geochemical characters of surface sediments from the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.

    Mineralogy and geochemistry of three types of surface sediments including their intermixtures, from 31 stations, in the ferromanganese nodule belt of the central Indian basin have been studied. Abundant illite, kaolinite and chlorite in terrigenous...

  13. 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

    two spectra taken at base and summit of Olympus Mons provides the atmospheric spectrum. To quickly assess the mineralogy of a large region, CRISM multispectral summary products [5] are applied to OMEGA datasets. Hydrated mineral deposits are located on the basis of the absorption feature centered at ~1.9um. This feature is the result of a combination of v2 bend and v3 (asymmetrical) stretch mode overtones. Noise reduction is performed by applying a principal component transform to the OMEGA data. Principal components which are dominated by noise are manually selected and discarded, after which the data are transformed back to the wavelength domain. Using this approach, a large degree of system noise can be effectively eliminated without significantly affecting signal quality [6]. Results The methods described have led to positive identification of large deposits of hydrated mineralogy in Tyrrhena Terra. Whilst several deposits are evidently associated with cratering processes (e.g. [7]), one major deposit in particular draws attention (figure 1). In this deposit, the light-colored hydrated minerals are generally associated with very rough morphology. In addition, they seem to be located underneath a dark, crater-saturated unit. Given the limited quality of local OMEGA-derived spectra, it is impossible to unambiguously determine the exact mineralogy of the deposit. The hydrated signature is correlated with high night-time temperatures as observed in THEMIS IRnight observations (figure 2). This indicates the hydrated material is present as a solid bedrock mass (e.g. mudstone) instead of a loose concretion. The deposit is situated in a topographic low, bounded by a channel-rich unit in the north and a sharp unit contact in the south. Discussion The sharp unit contact south of the hydrated deposit coincides with a sharp contrast in topographic elevation. It strikes parallel to the contours of Isidis Planitia, a trend which is continued on larger scale. Given the strike

  14. Mini-review: The Morphology, Mineralogy and Microbiology of Accumulated Iron Corrosion Products

    Science.gov (United States)

    2014-03-11

    RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) 11-03-2014 Journal Article Mini-review: the morphology, mineralogy and microbiology of...d Mini-review: the morphology, mineralogy and microbiology of accumulated iron corrosion products Brenda J. Littlea*, Tammie L. Gerkeb and Jason S...Leea aNaval Research Laboratory, Stennis Space Center, MS, USA; bDepartment of Geology and Environmental Earth Science, Miami University, Middletown

  15. Mineralogical and Geochemical Compositions of Modern Bivalve Shells from The Mediterranean Coast Of Egypt

    OpenAIRE

    Holail, Hanafy [حنفي محمود هليل; Tony, R.

    1993-01-01

    The stable isotopic (8 ^C and 8^O) and elemental (Sr and Mg) compositions are presented for marine mollusc Carditacea and Solenacea shells collected off the Mediterranean coast of Egypt. Based on shell microstructures and mineralogy, the bivalve shells are preserved in their original mineralogy and chemistry. The Sr and Mg concentrations of the bivalve shells have mean values of 1960 ppm and 226 ppm; respectively. The stable isotopic composition generally show high values of 818O and 8'3C....

  16. A mineralogical approach of the interactions between bitumen, clay and water in hot mix asphalt (HMA)

    OpenAIRE

    CHEN, Chi-Wei; Gaudefroy, Vincent; Duc, Myriam; Descantes, Yannick; Hammoum, Ferhat; Magnan, Jean Pierre

    2015-01-01

    Clay fines are known to reduce the water resistance of bitumen-aggregates binding and cause stripping in Asphalt Concrete (AC) mixtures. To address this phenomenon, a better understanding of the mineralogical composition of aggregates is needed as well as an assessment of the bitumen-clay-water interactions. This paper contributes to reach this goal from a mineralogical perspective. The most common clays in natural aggregates, kaolinite, illite and montmorillonite, were used to prepare thin c...

  17. 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.

  18. Analisa Struktur dan Mineralogi Batuan dari Sungai Aranio Kabupaten Banjar

    Directory of Open Access Journals (Sweden)

    Sudarningsih Sudarningsih

    2017-03-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui komposisi mineral dan struktur secara mikro dari permukaan batuan yang terdapat di Sungai Aranio, Kabupaten Banjar. Penelitian dilakukan dengan melakukan uji mineralogi dengan alat x-ray difractometer(XRD dan foto dengan alat scanning electron microscope(SEM terhadap empat sampel batuan yang telah diambil dari Sungai Aranio. Berdasarkan penelitian diperoleh hasil bahwa pada sampel 1A komposisi mineralnya adalah magnesiohornblende 27 %, albite, calcian 30 %, kuarsa 17 %, Phillipsite-K 14 % dan muscovit (mika 12 %. Pada sampel 1B mineralnya adalah magnesiohornblende 14 %, albite, calcian 29 %, kuarsa 21 %, Phillipsite-K 15 %, muscovit (mika 12 % dan chlorite-serpentine 13 %. Sampel 2A memiliki komposisi mineral yaitu magnesiohornblende 20 %, albite, calcian 13 %, kuarsa 28 %, muscovit (mika 8 % dan chlorite-serpentine 31 %, sedangkan pada sampel 2B terdapat mineral yaitu magnesiohornblende 28 %, kuarsa 42 %, chlorite-serpentine 21 %, muscovit (mika 4 % dan amfibol 5 %. Hasil pada foto SEM memperlihatkan struktur batuan telah menjadi struktur yang mengalami laminasi dengan dua sampel kenampakan kristal mineralnya masih terlihat dan dua sampel sudah berubah dan banyak terdapat clay atau tanah dan strukturnya adalah struktur foliasi. Dapat disimpulkan bahwa batuan yang berasal dari Sungai Aranio, Kabupaten Banjar telah mengalami pemalihan yang berasal dari batuan beku yang keras.

  19. Chemical, Mineralogical, and Physical Properties of Martian Dust and Soil

    Science.gov (United States)

    Ming, D. W.; Morris, R. V.

    2017-01-01

    Global and regional dust storms on Mars have been observed from Earth-based telescopes, Mars orbiters, and surface rovers and landers. Dust storms can be global and regional. Dust is material that is suspended into the atmosphere by winds and has a particle size of 1-3 micrometer. Planetary scientist refer to loose unconsolidated materials at the surface as "soil." The term ''soil'' is used here to denote any loose, unconsolidated material that can be distinguished from rocks, bedrock, or strongly cohesive sediments. No implication for the presence or absence of organic materials or living matter is intended. Soil contains local and regional materials mixed with the globally distributed dust by aeolian processes. Loose, unconsolidated surface materials (dust and soil) may pose challenges for human exploration on Mars. Dust will no doubt adhere to spacesuits, vehicles, habitats, and other surface systems. What will be the impacts on human activity? The objective of this paper is to review the chemical, mineralogical, and physical properties of the martian dust and soil.

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

    Science.gov (United States)

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

    2011-01-01

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

  1. Mineralogy of a perudic Andosol in central Java, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Van Ranst, Eric; Utami, S. R.; Verdoodt, A.; Qafoku, Nikolla

    2008-02-15

    We studied the mineralogy of a perudic Andosol developed on the Dieng Tephra Sequence in central Java, Indonesia. The objective was to confirm the presence and determine the origin and stability of 2:1 and interlayered 2:1 phyllosilicates in well-drained Andosols. This was and still is a debated topic in the literature. Total elemental and selective dissolution, as well as microscopic and X-ray diffraction analyses, were performed on the soil samples collected from this site. These analyses confirmed that andic properties were present in the soil samples. The allophane content determined by selective dissolution was 3-4% in the A horizons, and increased to 12-18% in the deeper subsoil horizons. In addition, the clay fraction contained dioctahedral smectite, hydroxy-Al-interlayered 2:1 minerals (HIS), Al-chlorite, kaolinite, pyrophyllite, mica, cristobalite and some gibbsite. The silt and sand fractions were rich in plagioclase and pyroxene. The 2:1 minerals (smectite and pyrophyllite), as well as chlorite and kaolinite were of hydrothermal origin and were incorporated in the tephra during volcanic eruption. Besides desilication during dissolution of unstable minerals, Al interlayering of 2:1 layer silicates was most likely the most prominent pedogenic process. Although hydroxy-Al polymeric interlayers would normally stabilize the 2:1 clay phases, the strong weakening, and even disappearance of the characteristic XRD peaks, indicated instability of these minerals in the upper A horizons due to the perudic and intensive leaching conditions.

  2. 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.

  3. Geochemical and mineralogical evidence that Rodinian assembly was unique.

    Science.gov (United States)

    Liu, Chao; Knoll, Andrew H; Hazen, Robert M

    2017-12-05

    The mineralogy and geochemistry associated with Rodinian assembly (~1.3-0.9 Ga) are significantly different from those of other supercontinents. Compared to other supercontinents, relatively more Nb-bearing minerals, Y-bearing minerals, and zircons formed during Rodinian assembly, with corresponding enrichments of Nb, Y, and Zr concentrations in igneous rocks. By contrast, minerals bearing many other elements (e.g., Ni, Co, Au, Se, and platinum group elements) are significantly less abundant, without corresponding depletion of Ni and Co concentrations in igneous rocks. Here we suggest that the Nb, Y, and Zr enrichments in igneous rocks and relatively more occurrences of corresponding Nb-bearing minerals, Y-bearing minerals, and zircons result from significant non-arc magmatism during the mid-Proterozoic, while fewer occurrences of many other minerals suggest enhanced erosion of Rodinian volcanic arcs and orogens. The prolonged, extrovert assembly of Rodinia from thickened mid-Proterozoic continental crust via two-sided subduction can account for both the prevalence of non-arc magmatism and the enhanced erosion.

  4. [Mineralogy and colosation of oil-green jadeite jade].

    Science.gov (United States)

    Yin, Ke; Tian, Jian; Ma, Yu-bo; Wu, Yu; Wang, Yang

    2014-12-01

    Mineralogy and coloration of oil-green jadeite jade were investigated using X-Ray diffraction (XRD), Fourier transform infrared absorption spectroscopy (FTIR) and scanning electron microscopy (SEM). XRD results show that "flesh" of oil-green jadeite jade is mainly composed of relatively pure jadeite, whereas the "skin" of which is dominated by jadeite, chlorite and chrysotile. The mineral constituents revealed by FTIR are fairly consistent with XRD. Three typical adsorption peaks of ~2956, ~2919 and ~2850 cm(-1) related to organic matters occurred in both "flesh" and "skin" of oil-green jadeite jade. Jadeite in "flesh" exhibits an obvious columnar growth and has a better crystallinity than that of "skin". However, jadeite in "skin" is richer in magnesium than that of "flesh", suggesting an intense water-rock reaction of jadeite in "skin". Chrysotile just occurs in "skin" of oil-green jadeite jade, and it presents a curved crystal plane. Flaky chlorite was detected in both cracks of "flesh" and "skin", which might be the main cause of coloration of oil-green jadeite jade. Chlorite, formed in the reducing water-rock reaction, would adsorb or wrap a certain amount of organic matters, resulting in the occurrence of the characteristic adsorptions of oil-green jadeite jade.

  5. Mineralogy of the Pahrump Hills Region, Gale Crater, Mars

    Science.gov (United States)

    Rampe, E. B.; Ming, D. W.; Vaniman, D. T.; Blake, D. F.; Chipera, S. J.; Morris, R. V.; Bish, D. L.; Cavanagh, P. D.; Achilles, C. N.; Bristow, T. F.; hide

    2015-01-01

    The Pahrump Hills region of Gale crater is a approximately 12 millimeter thick section of sedimentary rocks in the Murray formation, interpreted as the basal geological unit of Mount Sharp. The Mars Science Laboratory, Curiosity, arrived at the Pahrump Hills in September, 2014, and performed a detailed six-month investigation of the sedimentary structures, geochemistry, and mineralogy of the area. During the campaign, Curiosity drilled and delivered three rock samples to its internal instruments, including the CheMin XRD/XRF. The three targets, Confidence Hills, Mojave 2, and Telegraph Peak, contain variable amounts of plagioclase, pyroxene, iron oxides, jarosite, phyllosilicates, and X-ray amorphous material. Hematite was predicted at the base of Mount Sharp from orbital visible/near-IR spectroscopy, and CheMin confirmed this detection. The presence of jarosite throughout Pahrump Hills suggests the sediments experienced acid-sulfate alteration, either in-situ or within the source region of the sediments. This acidic leaching environment is in stark contrast to the environment preserved within the Sheepbed mudstone on the plains of Gale crater. The minerals within Sheepbed, including Fe-saponite, indicate these sediments were deposited in a shallow lake with circumneutral pH that may have been habitable.

  6. Time-resolved Raman spectroscopy for in situ planetary mineralogy.

    Science.gov (United States)

    Blacksberg, Jordana; Rossman, George R; Gleckler, Anthony

    2010-09-10

    Planetary mineralogy can be revealed through a variety of remote sensing and in situ investigations that precede any plans for eventual sample return. We briefly review those techniques and focus on the capabilities for on-surface in situ examination of Mars, Venus, the Moon, asteroids, and other bodies. Over the past decade, Raman spectroscopy has continued to develop as a prime candidate for the next generation of in situ planetary instruments, as it provides definitive structural and compositional information of minerals in their natural geological context. Traditional continuous-wave Raman spectroscopy using a green laser suffers from fluorescence interference, which can be large (sometimes saturating the detector), particularly in altered minerals, which are of the greatest geophysical interest. Taking advantage of the fact that fluorescence occurs at a later time than the instantaneous Raman signal, we have developed a time-resolved Raman spectrometer that uses a streak camera and pulsed miniature microchip laser to provide picosecond time resolution. Our ability to observe the complete time evolution of Raman and fluorescence spectra in minerals makes this technique ideal for exploration of diverse planetary environments, some of which are expected to contain strong, if not overwhelming, fluorescence signatures. We discuss performance capability and present time-resolved pulsed Raman spectra collected from several highly fluorescent and Mars-relevant minerals. In particular, we have found that conventional Raman spectra from fine grained clays, sulfates, and phosphates exhibited large fluorescent signatures, but high quality spectra could be obtained using our time-resolved approach.

  7. Iron Mineralogy and Uranium-Binding Environment in the ...

    Science.gov (United States)

    Wetlands mitigate the migration of groundwater contaminants through a series of biogeochemical gradients that enhance multiple contaminant-binding processes. The hypothesis of this study was that wetland plant roots contribute organic carbon and release O2 within the rhizosphere (plant-impact soil zone) that promote the formation of Fe(III)-(oxyhydr)oxides. In turn, these Fe(III)-(oxyhydr)oxides stabilize organic matter that together contribute to contaminant immobilization. Mineralogy and U binding environments of the rhizosphere were evaluated in samples collected from contaminated and non-contaminated areas of a wetland on the Savannah River Site in South Carolina. Based on Mössbauer spectroscopy, rhizosphere soil was greatly enriched with nanogoethite, ferrihydrite-like nanoparticulates, and hematite, with negligible Fe(II) present. X-ray computed tomography and various microscopy techniques showed that root plaques were tens-of-microns thick and consisted of highly oriented Fe-nanoparticles, suggesting that the roots were involved in creating the biogeochemical conditions conducive to the nanoparticle formation. XAS showed that a majority of the U in the bulk wetland soil was in the +6 oxidation state and was not well correlated spatially to Fe concentrations. SEM/EDS confirm that U was enriched on root plaques, where it was always found in association with P. Together these findings support our hypothesis and suggest that plants can alter mineralo

  8. 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.

  9. Lacrimal sac dacryoliths (86 samples): chemical and mineralogic analyses.

    Science.gov (United States)

    Komínek, Pavel; Doškářová, Sárka; Svagera, Zdeněk; Lach, Karel; Cervenka, Stanislav; Zeleník, Karol; Matoušek, Petr

    2014-03-01

    Because dacryoliths occur at low frequency, few studies have focused on their composition. We aimed to present findings from morphological, chemical, and mineralogic analysis of 86 dacryoliths. We studied 86 dacryoliths obtained during 832 dacryocystorhinostomies (DCR) performed for postsaccal obstruction. We examined the samples with atomic infrared spectrometry (80 samples), amino acid analysis (17 samples), scanning electron microscopy, and an electron microprobe with an energy dispersive detector (seven samples). Dacryoliths were found in 86/832 DCRs (10.3 %), mostly in patients with primary acquired nasolacrimal duct obstruction. All the dacryoliths were soft, composed of organic material, including proteins and mucoproteins, with approximately 20 % amino acid content. There were no "hard" dacryoliths composed of calcium phosphate. The stones were composed of lobes and lobules built on an amorphous core material with small cavities, probably as a result of various chemical processes that produced a gaseous product. The most frequent elements found in inorganic inclusions were silicon, magnesium, sulfur, potassium, calcium, sodium, and chlorine. Also, some particles had high contents of bismuth, titanium, iron, and organic fibers. The fibers found in the core of dacryoliths suggested a potential origin from cotton swabs used in cosmetics. Dacryoliths are composed almost exclusively of organic material, including proteins and mucoproteins, with approximately 20 % amino acid content.

  10. 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.

  11. Chemistry and Mineralogy of Outcrops at Meridiani Planum

    Science.gov (United States)

    Clark, B. C.; Morris, R. V.; McLennan, S. M.; Gellert, R.; Jolliff, B.; Knoll, A. H.; Squyres, S. W.; Lowenstein, T. K.; Ming, D. W.; Tosca, N. J.; hide

    2005-01-01

    Analyses of outcrops created by the impact craters Endurance, Fram and Eagle reveal the broad lateral continuity of chemical sediments at the Meridiani Planum exploration site on Mars. Approximately ten mineralogical components are implied in these salt-rich silicic sediments, from measurements by instruments on the Opportunity rover. Compositional trends in an apparently intact vertical stratigraphic sequence at the Karatepe West ingress point at Endurance crater are consistent with non-uniform deposition or with subsequent migration of mobile salt components, dominated by sulfates of magnesium. Striking variations in Cl and enrichments of Br, combined with diversity in sulfate species, provide further evidence of episodes during which temperatures, pH, and water to rock ratios underwent significant change. To first order, the sedimentary sequence examined to date is consistent with a uniform reference composition, modified by movement of major sulfates upward and of minor chlorides downward. This reference composition has similarities to martian soils, supplemented by sulfate anion and the alteration products of mafic igneous minerals. Lesser cementation in lower stratigraphic units is reflected in decreased energies for grinding with the Rock Abrasion Tool. Survival of soluble salts in exposed outcrop is most easily explained by absence of episodes of liquid H2O in this region since the time of crater formation.

  12. The bulk composition, mineralogy and internal structure of Mars

    Science.gov (United States)

    Longhi, John; Knittle, Elise; Holloway, John R.; Waenke, Heinrich

    1992-01-01

    A bulk composition for Mars is derived to a pressure-dependent mineralogy. The density distribution of the present model is compared with density distributions derived from the global gravity field. It is argued that the uppermost Martian mantle is likely to be dominated by olivine and orthopyroxene, as is the earth's upper mantle, although the Martian mantle has a lower MgO/(MgO + FeO) ratio (0.74 vs 0.89). The olivine-peridotite layer extends to a depth of 900 to 1100 km where the transition to silicate spinel begins. Calculations of the high-pressure liquidus and solidus temperatures indicate that for the case of a molten core the minimum temperature at the core-mantle boundary is about 2000 K, whereas for the case of a solid core the maximum temperature is about 1800 K. Summation of the masses in the various layers of Mars yields a value of 0.353 for the dimensionless moment of inertia, which is intermediate between the generally accepted value of 0.365 and the value of 0.345 predicated on a nonaxisymmetric distribution of mass about the Tharsis plateau.

  13. CLAY MINERALOGY INFLUENCE ON THE PHYSICAL AND CHEMICAL PROPERTIES OF VERTISOLS FROM ROMANIA

    Directory of Open Access Journals (Sweden)

    Victoria Mocanu

    2008-10-01

    Full Text Available The mineralogical investigation of the 33 profiles of vertisol from Romania indicated that there are two principal geographical zones with vertisols (West and South which present some quantitative mineralogical differences at the colloidal level. In spite of the fact that in all investigated profiles, the quantitative mineralogical composition of the clay fraction (below 2μ was the same, (smectite, illite and kaolinite the vertisols from the western zone show a higher content of smectite (montmorillonite and a lower content of illite in comparison with vertisols from southern zone. The correlations between some physical indices of soil and smectite quantity indicated that an increase of soil smectite content determines an increase of bulk density and compaction degree, concomitantly with a decrease of total porosity and air porosity. The established relationships between some chemical indices and mineralogical parameters indicated that cation exchange properties and reaction of these soils appear more closely related to the quality (mineralogical composition than to the quantity of clay fraction. The empirical relationships established between physical and chemical indices of vertisols and mineralogical parameters suggest that in some cases, considered favorable, the clay mineral information could allow some predictions on the physical and chemical properties, in spite of the fact that such of predictions have a limited value from quantitative point of view.

  14. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Investigation of Copper Contamination and Corrosion Scale Mineralogy in Aging Drink Water Distributions Systems

    Science.gov (United States)

    2006-03-01

    steel spatula from the pipe sections, finely ground using a synthetic ruby or agate mortar and pestle, and passed through a 200-mesh sieve...sample. The majority of the sampling locations were points of 71 frequent water usage such as bathroom sinks, kitchen sinks, an actively...could be reached for sampling. These buildings provided no other accessible location, such as a bathroom or kitchen , for pipe sampling. A basement

  16. Practical Implications from Observed Lead Pipe Scale Mineralogy in a Blended Phosphate Treated System - slides

    Science.gov (United States)

    Many water utilities in the United States rely on the addition of phosphate-based corrosion inhibitors to optimize their corrosion control and comply with requirements of the Lead and Copper Rule. Orthophosphate is used on the theory of forming low solubility Pb(II)-orthophosphat...

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

    Science.gov (United States)

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

    2017-01-01

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

  18. 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

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

    Science.gov (United States)

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

    2017-01-01

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

  20. Ancient Lunar Volcanism: Distribution and Mineralogy of Cryptomaria

    Science.gov (United States)

    Whitten, J.; Head, J. W., III

    2014-12-01

    Ancient volcanic deposits on terrestrial planetary bodies preserve the earliest record of planetary evolution, revealing important information about both the interior evolution and the surface modification history of planetary bodies. On the Moon, ancient volcanic deposits are referred to as cryptomaria and are basalt deposits that have been obscured by impact basin ejecta. As a result, cryptomaria appear as smooth high-albedo plains. This physical appearance can easily be confused with other formations such as the Cayley Plains, hypothesized to have formed from the ponding of impact basin ejecta into topographic lows. The difficulty in differentiating between cryptomaria and the Cayley Plains has led to the development of several recognition criteria. A high concentration of dark-halo impact craters (DHCs), a mafic enhancement in regolith, and an intermediate albedo are all different criteria used to positively identify cryptomaria. DHCs are small impact craters ancient impact basins (e.g., Schiller-Zucchius). Including cryptomaria, the total surface area of the Moon covered by mare basalts has increased by ~2%. After identification, M3 spectra collected from DHCs were modeled using the Modified Gaussian Model and indicate that the cryptomaria are basalts and have the same mineralogy as exposed maria in the same study region. Crater counts conducted on the largest cryptomaria produce minimum model age estimates between 3.8 and 4.0 Ga. This, combined with the close association between cryptomaria and exposed maria, suggests that the dated cryptomaria formed just prior to this period of time and imply that the process controlling the distribution of mare basalts was in place near this time in lunar history.

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

    Directory of Open Access Journals (Sweden)

    Livia Arantes Camargo

    2014-06-01

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

  2. Mineralogy of iron microbial mats from loihi seamount.

    Science.gov (United States)

    Toner, Brandy M; Berquó, Thelma S; Michel, F Marc; Sorensen, Jeffry V; Templeton, Alexis S; Edwards, Katrina J

    2012-01-01

    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 (CSD) 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 two-line ferrihydrite (Fh), except for the Pohaku site. The short-range ordered natural Fh (Fh(SRO)) phases were stable at 4°C in the presence of oxygen for at least 1 year and during 400°C treatment. The observed stability of the Fh(SRO) is consistent with magnetic observations that point to non-interacting nanoparticles. PDF analyses of total scattering data provide further evidence for Fh(SRO) particles with a poorly ordered silica coating. The presence of coated particles explains the small CSD 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 Fe deposits may be examined, with the ultimate goal of improved interpretation of past biogeochemical conditions and diagenetic processes.

  3. 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.

  4. Mineralogy and mineral chemistry of rare-metal pegmatites at Abu Rusheid granitic gneisses, South Eastern Desert, Egypt

    National Research Council Canada - National Science Library

    Mohamed Fahmy Raslan; Mohamed A. Ali

    2011-01-01

    .... Correspondingly, mineralogical and geochemical investigation of pegmatites pockets scattered within Abu Rusheid granitic gneisses revealed the presence of Hf-zircon, ferrocolumbite and uranyl silicate minerals...

  5. Chemical and mineralogical proxies of erosion episodes in the dried lake sediments (Amik Lake, Southern Turkey): paleoenvironmental implications

    Science.gov (United States)

    El Ouahabi, Meriam; Hubert-Ferrari, Aurélia; Lebeau, Héléne; Fagel, Nathalie; Vander Auwera, Jacquelinec; Karabacak, Volkan; Schmidt, Sabine

    2016-04-01

    The Amik Basin in the Eastern Mediterranean region has been continuously occupied since 6000-7000 BC. The landscape has sustained with highly variable anthropic pressure culminating during the Late Roman Period when the Antioch city reached its golden age. The basin also sustained a high seismic activity (M≥7) as it is a releasing step-over along the Dead Sea Fault. The study focuses on the sedimentary record of the Amik Lake occupying the central part of the Basin. Our objective is to constrain major paleo-environmental changes in the area over the last 4000 years and to unravel possible human impacts on the sedimentation. A diverse array of complementary methods was applied on the 6 m long record. High resolution of mineralogical (XRD) and geochemical (XRF) analyses were performed. Quantitative mineralogical phases of sediments by the Rietveld method were computed using Topaz software. The age of the record is constrained combining radionuclide and radiocarbon dating, and checked using the correlation between the earthquake history and rapidly deposited layer identified. A high sedimentation rate of 0.12 cm/yr was inferred at the coring site. The 4000 years old record shows that significant fluctuations of the lake level and the riverine system inflow into the Amik Lake occurred. The Late Bronze lowstand leaded to punctual dryings of the lake at the end of the Bronze/Iron transition marked by the collapse of the Hittite Empire and during the Dark ages. At that time, the riverine was carrying a large terrigenous input linked to strong soil erosion related to deforestation, exploitation of mineral resources and the beginning of upland cultivation. During the Roman Period and in the later periods, upland soils were partly depleted and the riverine system completely transformed by channelization that leaded to a mashification of the Amik Basin. Chemical and mineralogical composition of sediments is quite diversified reflecting the significant geological variation

  6. Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars.

    Science.gov (United States)

    Ruecker, A; Schröder, C; Byrne, J; Weigold, P; Behrens, S; Kappler, A

    2016-07-01

    Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties that make these lakes potential analogues for past conditions on Mars. In our study, we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (Lake Orr and from 5.4 to 6.3 in Lake Whurr sediments. Lake Whurr sediments were dominated by orange and red sediment zones in which the main Fe minerals were identified as hematite, goethite, and tentatively jarosite and pyrite. Lake Orr was dominated by brownish and blackish sediments where the main Fe minerals were goethite and another paramagnetic Fe(III)-phase that could not be identified. Furthermore, a likely secondary Fe(II)-phase was observed in Lake Orr sediments. The mineralogy of these two salt lakes in the sampling area is strongly influenced by events such as flooding, evaporation, and desiccation, processes that explain at least to some extent the observed differences between Lake Orr and Lake Whurr. The iron mineralogy of Lake Whurr sediments and the high salinity make this lake a suitable analogue for Meridiani Planum on Mars, and in particular the tentative identification of pyrite in Lake Whurr sediments has implications for the interpretation of the Fe mineralogy of Meridiani Planum sediments. Western Australia-Salt lakes-Jarosite-Hematite-Pyrite-Mars analogue. Astrobiology 16, 525-538.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lance Prothro

    2005-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Robert Pooler

    2017-01-01

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

  9. 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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Mapping soil magnetic susceptibility and mineralogy in Ukraine

    Science.gov (United States)

    Menshov, Oleksandr; Pereira, Paulo; Kruglov, Oleksandr; Sukhorada, Anatoliy

    2017-04-01

    Soil suatainable planning is fundamental for agricultural areas. Soil mapping and modeling are increasingly used in agricultural areas in the entire world (Brevik et al., 2016). They are beneficial to land managers, to reduce soil degradation, increase soil productivity and their restoration. Magnetic susceptibility (MS) methods are low cost and accurate for the developing maps of agricultural areas.. The objective of this work is to identify the minerals responsible for MS increase in soils from the two study areas in Poltava and Kharkiv region. The thermomagnetic analyses were conducted using the KLY-4 with an oven apparatus. The hysteresis parameters were measured with the Rotating Magnetometer at the Geophysical Centre Dourbes, Belgium. The results showed that all of samples from Kharkiv area and the majortity of the samples collected in Poltava area represent the pseudo single domain (PSD) zone particles in Day plot. According to Hanesch et al. (2006), the transformation of goethite, ferrihydrite or hematite to a stronger ferrimagnetic phase like magnetite or maghemite is common in strongly magnetic soils with high values of organic carbon content. In our case of thermomagnetic study, the first peak on the heating curve near 260 ˚C indicates the presence of ferrihydrite which gradually transforms into maghemite (Jordanova et al., 2013). A further decrease in the MS identified on the heating curve may be related to the transformation of the maghemite to hematite. A second MS peak on the heating curve near 530 ˚C and the ultimate loss of magnetic susceptibility near 580 ˚C were caused by the reduction of hematite to magnetite. The shape of the thermomagnetic curves suggests the presence of single domain (SD) particles at room temperature and their transformation to a superparamagnetic (SP) state under heating. Magnetic mineralogical analyses suggest the presence of highly magnetic minerals like magnetite and maghemite as well as slightly magnetic goethite

  11. Mineralogical constraints on seismic heterogeneities in the mid-mantle

    Science.gov (United States)

    Sanchez-Valle, C.; Bolfan-Casanova, N.; Merkel, S.

    2013-12-01

    Seismic observations show extensive evidence for negative shear wave anomalies of 2 to 6% in the shallow to middle parts of the lower mantle ( 800 to 1850 km depths) in the vicinity of subduction zones [e.g., 1-4]. Although the origin of these anomalies is still under debate, shear softening related to the stishovite (rutile structure) to post-stishovite (CaCl2 structure) in subducted MORB may be a plausible explanation for these features [5], suggesting the presence of unmixed slab remnants in the mid-lower mantle. The broad range of depths over which the heterogeneities span may be related to compositional effects on the phase transition pressure [5,6]. To better deciphering the observed seismic heterogeneities in terms of mineralogy and chemistry, a more detailed evaluation of the seismic properties of deformed stishovite due to mantle flow is required. In this contribution, we present and discuss recent investigations of the effect of texture development on the shear wave velocities of Al-bearing stishovite containing 5wt% of Al2O3, a plausible composition for subducted slabs. Experiments were conducted using synchrotron radial x-ray diffraction and a panoramic diamond anvil cell as deformation apparatus at pressures above 50 GPa. Upon compression, changes in the texture and the strength on Al-Stishovite are observed across the stishovite to post-stishovite transition that strongly modify the mechanical properties of the sample at lower mantle pressures. The results from the deformation experiments were combined with available elasticity data for similar samples [5] to model the effect of texture on the shear wave anisotropy of stishovite at lower mantle conditions. The implications of these mineral physics results for the interpretation of seismic heterogeneities in the mid-mantle and the link with chemical heterogeneities derived for unmixing in the mantle will be discussed. [1] Stunff et al., (1995); [2]Kaneshima and Helffrich (1999); [3] Vinnik et al

  12. Geology and mineralogy of ore at the hidden Engteri Au-Ag deposit, the Magadan Region

    Science.gov (United States)

    Obushkov, A. V.; Struzhkov, S. F.; Natalenko, M. V.; Ryzhov, O. B.; Kryazhev, S. G.; Radchenko, Yu. I.

    2010-12-01

    The Engteri is a new hidden Au-Ag deposit in the Russian segment of the Pacific ore belt. The discovery of this deposit merits special attention, because it involves repeated attempts to reappraise a lowprospective ore occurrence, which were crowned with success as a result of fulfillment of large-scale drilling project. The average Au grade is 18.6 gpt. The deposit is classified as the gold geochemical type of Au-Ag deposits. The major ore mineral is pyrite, which amounts to no less than 95% of the total ore minerals. The native phases comprise electrum and to a lesser extent native gold of low fineness (730). The homogenization temperature of fluid inclusions is 125-255°C with a distinct maximum at 145-150°C. Despite blind localization of some orebodies, the Engteri deposits bears evidence for a deep erosion level: (1) small vertical range of economic mineralization (50-100 m); (2) predominant occurrence of massive sugarlike quartz with a low sulfide content; (3) prevalence of massive and brecciated textures above rhythmically banded textures; and (4) lack of low-temperature propylites. The southern part of the ore field distinguished by occurrence of rhythmically banded, framework-tabular, and brecciated texture has the best prospect for revealing new orebodies. The Engteri deposit allowed us to outline the following prospecting guides and methods of prospecting for hidden Au-Ag deposits: (1) these deposits are regularly arranged in ore clusters between heavy concentrate anomalies of cinnabar and gold-silver or silver-base-metal occurrences (method of missed link); (2) findings of fragments of ore mineral assemblages with sporadically high Au and Ag contents in barren calcite-quartz veins (method of indicators); (3) linear zones of ankeritization in the fields of low- and mediumtemperature propylites (mapping of metasomatic rocks); and (4) pyrite-quartz veinlets with rhythmically banded pockets (mineralogical mapping of halos of stringer

  13. Enriched Iron(III)-Reducing Bacterial Communities are Shaped by Carbon Substrate and Iron Oxide Mineralogy.

    Science.gov (United States)

    Lentini, Christopher J; Wankel, Scott D; Hansel, Colleen M

    2012-01-01

    Iron (Fe) oxides exist in a spectrum of structures in the environment, with ferrihydrite widely considered the most bioavailable phase. Yet, ferrihydrite is unstable and rapidly transforms to more crystalline Fe(III) oxides (e.g., goethite, hematite), which are poorly reduced by model dissimilatory Fe(III)-reducing microorganisms. This begs the question, what processes and microbial groups are responsible for reduction of crystalline Fe(III) oxides within sedimentary environments? Further, how do changes in Fe mineralogy shape oxide-hosted microbial populations? To address these questions, we conducted a large-scale cultivation effort using various Fe(III) oxides (ferrihydrite, goethite, hematite) and carbon substrates (glucose, lactate, acetate) along a dilution gradient to enrich for microbial populations capable of reducing Fe oxides spanning a wide range of crystallinities and reduction potentials. While carbon source was the most important variable shaping community composition within Fe(III)-reducing enrichments, both Fe oxide type and sediment dilution also had a substantial influence. For instance, with acetate as the carbon source, only ferrihydrite enrichments displayed a significant amount of Fe(III) reduction and the well-known dissimilatory metal reducer Geobacter sp. was the dominant organism enriched. In contrast, when glucose and lactate were provided, all three Fe oxides were reduced and reduction coincided with the presence of fermentative (e.g., Enterobacter spp.) and sulfate-reducing bacteria (e.g., Desulfovibrio spp.). Thus, changes in Fe oxide structure and resource availability may shift Fe(III)-reducing communities between dominantly metal-respiring to fermenting and/or sulfate-reducing organisms which are capable of reducing more recalcitrant Fe phases. These findings highlight the need for further targeted investigations into the composition and activity of speciation-directed metal-reducing populations within natural environments.

  14. Alkaline igneous rocks of Magnet Cove, Arkansas: Mineralogy and geochemistry of syenites

    Science.gov (United States)

    Flohr, M.J.K.; Ross, M.

    1990-01-01

    Syenites from the Magnet Cove alkaline igneous complex form a diverse mineralogical and geochemical suite. Compositional zoning in primary and late-stage minerals indicates complex, multi-stage crystallization and replacement histories. Residual magmatic fluids, rich in F, Cl, CO2 and H2O, reacted with primary minerals to form complex intergrowths of minerals such as rinkite, fluorite, V-bearing magnetite, F-bearing garnet and aegirine. Abundant sodalite and natrolite formed in pegmatitic segregations within nepheline syenite where Cl- and Na-rich fluids were trapped. During autometasomatism compatible elements such as Mn, Ti, V and Zr were redistributed on a local scale and concentrated in late-stage minerals. Early crystallization of apatite and perovskite controlled the compatible behavior of P and Ti, respectively. The formation of melanite garnet also affected the behaviour of Ti, as well as Zr, Hf and the heavy rare-earth elements. Pseudoleucite syenite and garnet-nepheline syenite differentiated along separate trends, but the two groups are related to the same parental magma by early fractionation of leucite, the presumed precursor of intergrowths of K-feldspar and nepheline. The Diamond Jo nepheline syenite group defines a different differentiation trend. Sphene-nepheline syenite, alkali syenite and several miscellaneous nepheline syenites do not consistently plot with the other syenite groups or each other on element and oxide variation diagrams, indicating that they were derived from still other parental syenite magmas. Mineral assemblages indicate that relatively high f{hook};O2, at or above the fayalite-magnetite-quartz buffer, prevailed throughout the crystallization history of the syenites. ?? 1990.

  15. Mineralogy and skarnification processes at the Avan Cu-Fe Skarn, northeast of Kharvana, NW Iran

    Directory of Open Access Journals (Sweden)

    Mir Ali Asghar Mokhtari

    2017-02-01

    Full Text Available Introduction The Avan Cu-Fe skarn is located at the southern margin of Qaradagh batholith, about 60 km north of Tabriz. The Skarn-type metasomatic alteration is the result of Qaradagh batholith intrusion into the Upper Cretaceous impure carbonates. The studied area belongs to the Central Iranian structural zone. In regional scale, the studied area is a part of the Zangezour mineralization zone in the Lesser Caucasus. Several studies (Karimzadeh Somarin and Moayed, 2002; Calagari and Hosseinzadeh, 2005; Mokhtari, 2008; Baghban Asgharinezhad, 2012; Mokhtari, 2012 including master’s theses and research programs have been done on some skarns in the Azarbaijan area considering their petrologic and mineralization aspects. However, before this study, the Avan skarn aureole has not been studied in detail. In this paper, various geological aspects of the Avan skarn including mineralogy, bi-metasomatic alteration, metasomatism and mineralization during the progressive and retrograde stages of the skarnification processes have been studied in detail. Research Method This research consists of field and laboratory studies. Field studies include preparation of the geological map, identifying the relationship between the intrusion and the skarn aureole, identifying the relationship between different parts of the skarn zone and also collecting samples for laboratory studies. Laboratory studies include petrography, mineralography and microprobe studies. Cameca SX100 Microprobe belonging to Geological Survey of the Czech Republic was used in order to determine the chemical composition of the calc-silicate minerals such as pyroxene and garnet in garnet skarn and pyroxene- garnet skarn sub-zones. Discussion and conclusion Qaradagh batholith is composed of discrete acid to mafic phases including gabbro, diorite, quartz diorite, quartz monzonite, quartz monzodiorite, tonalite, granodiorite, monzogranite and granite porphyry which is dominated by granodiorite

  16. Mineralogy of an active eolian sediment from the Namib dune, Gale crater, Mars

    Science.gov (United States)

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

    2017-11-01

    The Mars Science Laboratory rover, Curiosity, is using a comprehensive scientific payload to explore rocks and soils in Gale crater, Mars. Recent investigations of the Bagnold Dune Field provided the first in situ assessment of an active dune on Mars. The Chemistry and Mineralogy (CheMin) X-ray diffraction instrument on Curiosity performed quantitative mineralogical analyses of the geologic history of the dune material and offers an important opportunity for ground truth of orbital observations. CheMin's analysis of the mineralogy and phase chemistry of modern and ancient Gale crater dune fields, together with other measurements by Curiosity's science payload, provides new insights into present and past eolian processes on Mars.

  17. A composite mineralogical map of Ganges Chasma and surroundings, Valles Marineris, Mars

    Science.gov (United States)

    Cull-Hearth, Selby; Clark, M. Caroline

    2017-08-01

    Ganges Chasma is a mineralogically diverse canyon in the far-eastern portion of the Valles Marineris system. It exposes bedrock outcrops of olivine, large dune fields enriched in olivine, a central Interior Layered Deposit with monohydrated sulfates, and Fe/Mg-phyllosilicates on the plateaus surrounding the canyon and in the canyon walls. The co-existence of hydrated minerals with unaltered olivine makes this an excellent location to study the timing of aqueous processes in this region. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and the High-Resolution Imaging Science Experiment (HiRISE), synthesizing them with previous data sets to produce a composite mineralogical map of Ganges Chasma. We then produce a timeline of mineralogic deposition for the Ganges area, relating it to regional geologic events.

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

    Directory of Open Access Journals (Sweden)

    R. G. Iblaminov

    2016-09-01

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

  19. A diverse Eocene fish scale assemblage from Seymour Island, Antarctica

    Czech Academy of Sciences Publication Activity Database

    Přikryl, Tomáš; Vodrážka, R.

    2012-01-01

    Roč. 34, č. 4 (2012), s. 895-908 ISSN 1280-9659 Institutional research plan: CEZ:AV0Z30130516 Institutional support: RVO:67985831 Keywords : Teleostei * scales * lepidology * Eocene * La Meseta Formation Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.927, year: 2012

  20. Mineralogy of Interplanetary Dust Particles from the Comet Giacobini-Zinner Dust Stream Collections

    Science.gov (United States)

    Nakamura-Messenger, K.; Messenger, S.; Westphal, A. J.; Palma, R. L.

    2015-01-01

    The Draconoid meteor shower, originating from comet 21P/Giacobini-Zinner, is a low-velocity Earth-crossing dust stream that had a peak anticipated flux on Oct. 8, 2012. In response to this prediction, NASA performed dedicated stratospheric dust collections to target interplanetary dust particles (IDPs) from this comet stream on Oct 15-17, 2012 [3]. Twelve dust particles from this targeted collection were allocated to our coordinated analysis team for studies of noble gas (Univ. Minnesota, Minnesota State Univ.), SXRF and Fe-XANES (SSL Berkeley) and mineralogy/isotopes (JSC). Here we report a mineralogical study of 3 IDPs from the Draconoid collection..

  1. Mineralogy and Elemental Composition of Wind Drift Soil at Rocknest, Gale Crater

    Science.gov (United States)

    Blake, D. F.; Bish, D. L.; Morris, R. V.; Downs, R. T.; Trieman, A. H.; Morrison, S. M.; Chipera, S. J.; Ming, D. W.; Yen, A. S.; Vaniman, D. T.; hide

    2013-01-01

    The Mars Science Laboratory rover Curiosity has been exploring Mars since August 5, 2012, conducting engineering and first-time activities with its mobility system, arm, sample acquisition and processing system (SA/SPaH-CHIMRA) and science instruments. Curiosity spent 54 sols at a location named "Rocknest," collecting and processing five scoops of loose, unconsolidated materials ("soil") acquired from an aeolian bedform (Fig. 1). The Chemistry and Mineralogy (CheMin) instrument analyzed portions of scoops 3, 4, and 5, to obtain the first quantitative mineralogical analysis of Mars soil, and to provide context for Sample Analysis at Mars (SAM) measurements of volatiles, isotopes and possible organic materials.

  2. 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

  3. Mineralogy and thermal properties of clay from Slatina (Ub, Serbia)

    Science.gov (United States)

    Milosevic, Maja; Logar, Mihovil; Kaludjerovic, Lazar; Jelic, Ivana

    2017-04-01

    The "Slatina" deposit, Ub, Serbia was opened in 1965 and represents one of few deposits exploited by "Kopovi" a.d., Ub, company. Deposit is composed of clay layers belonging to Neogene sediments that are widespread transgressive over granitoid rocks of Cer mountain and Paleozoic and Mesozoic sediments. Clay is mostly of illite-montmorillonite-kaolinite type and they are generally used as ceramic materials while some of the layers are used as fire-resistant materials. In this study we present mineralogical and thermal characterization of two samples to determine their application as industrial materials. Chemical and mineral composition was determined using inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD) on powder and oriented samples, infrared spectroscopy (IR) and granulometry. Cationic exchange capacity (CEC) and specific surface area (SSA) was determined using spectrophotometry and methylene blue (MB). Thermal properties where determined by gravimetry (120, 350, 600 and 1000 oC) and differential thermal analysis (DTA). Quantitative mineral composition obtained by Rietveld refinement of combined chemical and XRD data shows that the sample 1(SC) is mainly smectite-illite (45%) and kaolinite (14%) clay with 19% of quartz, 10% feldspars and 7% of limonite, while sample 2(SV) is smectite-illite (43%) and kaolinite (11%) clay with 10% of quartz, 15% feldspars and 7% of limonite. Both samples have low content of impurities (carbonate minerals). Medium grain size (μm) goes from 1.02 (SSA = 104 m2/g) for sample 1(SC) to 0.71 (SSA = 117 m2/g) for sample 2(SV) while their CEC is 12.7 and 14.9 mmol/100g for 1(SC) and 2(SV) respectively. IR spectra of the samples shows larger amount of smectite clays with quartz and carbonate minerals for both samples which is in accordance with XRD data. DTA data shows couple of events that are endothermic. First one (100-200 oC) is associated with loss of moisture and constitutive water, second

  4. Comparative Mineralogy, Microstructure and Compositional Trends in the Sub-Micron Size Fractions of Mare and Highland Lunar Soils

    Science.gov (United States)

    Thompson, M. S.; Christoffersen, R.; Noble, S. K.; Keller, L. P.

    2012-01-01

    The morphology, mineralogy, chemical composition and optical properties of lunar soils show distinct correlations as a function of grain size and origin [1,2,3]. In the mineralogy type, microstructure and major element compositions of grains in this important size range in lunar soils.

  5. 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.

  6. Mineralogical and spectral analysis of Vesta's Gegania and Lucaria quadrangles and comparative analysis of their key features

    Science.gov (United States)

    Longobardo, Andrea; Palomba, Ernesto; De Sanctis, Maria Cristina; Zinzi, Angelo; Scully, Jennifer E. C.; Capaccioni, Fabrizio; Tosi, Federico; Zambon, Francesca; Ammannito, Eleonora; Combe, Jean-Philippe; Raymond, Carol A.; Russell, Cristopher T.

    2015-10-01

    This work is aimed at developing and interpreting infrared albedo, pyroxene and OH band depths, and pyroxene band center maps of Vesta's Gegania and Lucaria quadrangles, obtained from data provided by the Visible and InfraRed (VIR) mapper spectrometer on board NASA's Dawn spacecraft. The Gegania and Lucaria quadrangles span latitudes from 22°S to 22°N and longitudes from 0°E to 144°E. The mineralogical and spectral maps identify two large-scale units on this area of Vesta, which extend eastwards and westward of about 60°E, respectively. The two regions are not associated to large-scale geological units, which have a latitudinal distribution rather than longitudinal, but are defined by different contents of carbonaceous chondrites (CC): the eastern region, poor in CCs, is brighter and OH-depleted, whereas the western one, rich in CCs, is darker and OH-enriched. A detailed analysis of the small-scale units in these quadrangles is also performed. Almost all the units show the typical correspondence between high albedo, deep pyroxene bands, short band centers and absence of OH and vice versa. Only a few exceptions occur, such as the ejecta from the Aelia crater, where dark and bright materials are intimately mixed. The most characteristic features of these quadrangles are the equatorial troughs and the Lucaria tholus. The equatorial troughs consist of graben, i.e. a depression limited by two conjugate faults. The graben do not present their own spectral signatures, but spectral parameters similar to their surroundings, in agreement to their structural origin. This is observed also in graben outside the Gegania and Lucaria quadrangles. However, it is possible to observe other structural features, such as tectonic grooves, characterized by a changing composition and hence an albedo variation. This result is confirmed not only by mineralogical maps of Vesta, but also by analyzing the VIRTIS-Rosetta observations of Lutetia. The albedo change is instead a typical

  7. Rock Geochemistry and Mineralogy from Fault Zones and Polymetallic Fault Veins of the Central Front Range, Colorado

    Science.gov (United States)

    Caine, Jonathan S.; Bove, Dana J.

    2010-01-01

    During the 2004 to 2008 field seasons, approximately 200 hand samples of fault and polymetallic vein-related rocks were collected for geochemical and mineralogical analyses. The samples were collected by the U.S. Geological Survey as part of the Evolution of Brittle Structures Task under the Central Colorado Assessment Project (CCAP) of the Mineral Resources Program (http://minerals.cr.usgs.gov/projects/colorado_assessment/index.html). The purpose of this work has been to characterize the relation between epithermal, polymetallic mineral deposits, paleostress, and the geological structures that hosted fluid flow and localization of the deposits. The data in this report will be used to document and better understand the processes that control epithermal mineral-deposit formation by attempting to relate the geochemistry of the primary structures that hosted hydrothermal fluid flow to their heat and fluid sources. This includes processes from the scale of the structures themselves to the far field scale, inclusive of the intrusive bodies that have been thought to be the sources for the hydrothermal fluid flow. The data presented in this report are part of a larger assessment effort on public lands. The larger study area spans the region of the southern Rocky Mountains in Colorado from the Wyoming to New Mexico borders and from the eastern boundary of the Front Range to approximately the longitude of Vail and Leadville, Colorado. Although the study area has had an extensive history of geological mapping, the mapping has resulted in a number of hypotheses that are still in their infancy of being tested. For example, the proximity of polymetallic veins to intrusive bodies has been thought to reflect a genetic relation between the two features; however, this idea has not been well tested with geochemical indicators. Recent knowledge regarding the coupled nature of stress, strain, fluid flow, and geochemistry warrant new investigations and approaches to test a variety of

  8. Correlation of soil organic carbon and nutrients (NPK) to soil mineralogy, texture, aggregation, and land use pattern.

    Science.gov (United States)

    Adhikari, Gopi; Bhattacharyya, Krishna G

    2015-11-01

    This work investigates the correlations existing among soil organic carbon (C), nitrogen (N), phosphorous (P), potassium (K), and physicochemical properties like clay mineralogy, textural components, soil aggregation, and land use pattern. Seven different locations were chosen in the tropical rainforest climate region of Assam, India, for the work. The soil texture classifications were clay, sandy clay loam, and sandy loam with mixed clay mineralogy consisting of tectosilicates and phylosilicates. Two distinct compositions of total Fe/Al oxides≥11.5 and mineralogy suggested that the mineral, chlorite, favored retention of higher SOC content in a particular site. Under similar climatic and mineralogical conditions, both natural and anthropogenic soil disturbances destabilized SOC protection through SOM mineralization and soil aggregate destabilization as indicated by SOC protective capacity studies. Urbanization resulting in soil compaction contributed to enhanced SOC level through increased contact between the occluded organic carbon and the soil mineralogical constituents.

  9. Mineralogical Processes in the Lower Mantle and their Implications for Seismic Heterogeneities

    Science.gov (United States)

    Shim, S.; Catalli, K.; Grocholski, B.

    2009-12-01

    It has been proposed that the large-scale lateral variations in seismic velocities detected at the lower mantle may be related to compositional changes. Yet the source and origin of the heterogeneities are unknown. Some major changes in mantle phases have been recently discovered, such as the charge disproportionation reaction of iron in mantle silicates, spin transitions of iron in mantle silicates and oxides, and the perovskite-to-postperovskite phase transition. These processes may profoundly alter the properties of the lowermost mantle. However, implications of these mineralogical changes to the lower-mantle heterogeneities are not well established. We have conducted systematic experimental investigations on the effects of Fe2+, Fe3+, and Al on the density, compressibility, and phase relations of Mg-silicates (perovskite and postperovskite) in the laser-heated diamond-anvil cell. The most important advance in our large dataset is in the use of the same pressure scale and quasi-hydrostatic pressure medium for all the subsets, which makes the dataset internally consistent therefore enables us to extract compositional effects accurately. Fe2+ in perovskite appears to be in mixed spin state in the lower mantle and its spin state does not impact the density and compressibility of perovskite. However, Fe3+ in the octahedral sites of perovskite undergoes a gradual spin transition, resulting in an increase in the compressibility of perovskite at the mid mantle when Al is absent. When Al is present in perovskite, Fe3+ undergoes a relatively sharp high-spin to low-spin transition, resulting in a volume collapse at the mid lower mantle. This difference in compressional behavior between Fe2+ and Fe3+ in perovskite makes Fe3+ thermodynamically stable in the lowermost mantle, supporting the occurrence of the charge disproportionation reaction and gravitationally stabilizing Al-rich mantle heterogeneities (such as basaltic materials). We also found that the depth of the

  10. Size, surface texture, chemical composition and mineralogy interrelations in ferromanganese nodules of central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Banakar, V.K.; Pattan, J.N.; Jauhari, P.

    Fiftyseven ferromanganese nodules, classified into 3 size class (4,4-6 and 6-8 cm diam.), from the siliceous sediments of central Indian Ocean were analysed for transition metals and representative sample from each size class for mineralogy. Smaller...

  11. 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|info:eu-repo/dai/nl/292012217

    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,

  12. Mineralogical Approaches to Sourcing Pipes and Figurines from the Eastern Woodlands, U.S.A.

    Science.gov (United States)

    Wisseman, S.U.; Moore, D.M.; Hughes, R.E.; Hynes, M.R.; Emerson, T.E.

    2002-01-01

    Provenance studies of stone artifacts often rely heavily upon chemical techniques such as neutron activation analysis. However, stone specimens with very similar chemical composition can have different mineralogies (distinctive crystalline structures as well as variations within the same mineral) that are not revealed by multielemental techniques. Because mineralogical techniques are often cheap and usually nondestructive, beginning with mineralogy allows the researcher to gain valuable information and then to be selective about how many samples are submitted for expensive and somewhat destructive chemical analysis, thus conserving both valuable samples and funds. Our University of Illinois team of archaeologists and geologists employs Portable Infrared Mineral Analyzer (PIMA) spectroscopy, X-ray diffraction (XRD), and Sequential acid dissolution/XRD/Inductively coupled plasma (SAD-XRD-ICP) analyses. Two case studies of Hopewellian pipes and Mississippian figurines illustrate this mineralogical approach. The results for both studies identify sources relatively close to the sites where the artifacts were recovered: Sterling, Illinois (rather than Ohio) for the (Hopewell) pipes and Missouri (rather than Arkansas or Oklahoma) for the Cahokia figurines. ?? 2002 Wiley Periodicals, Inc.

  13. Polyacrylamide effects on aggregate and structure stability of soils with different clay mineralogy

    Science.gov (United States)

    Adding anionic polyacrylamide (PAM) to soils stabilizes existing aggregates and improves bonding between and aggregation of soil particles. However, the dependence of PAM efficacy as an aggregate stabilizing agent with soils having different clay mineralogy has not been studied. Sixteen soil samples...

  14. Exploring Visuospatial Thinking in Learning about Mineralogy: Spatial Orientation Ability and Spatial Visualization Ability

    Science.gov (United States)

    Ozdemir, Gokhan

    2010-01-01

    This mixed-method research attempted to clarify the role of visuospatial abilities in learning about mineralogy. Various sources of data--including quantitative pre- and postmeasures of spatial visualization and spatial orientation tests and achievement scores on six measures and qualitative unstructured observations, interviews, and field trip…

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

    Science.gov (United States)

    Vaniman, D. T.; Bristow, T. F.; Bish, D. L.; Ming, D. W.; Blake, D. F.; Morris, R. V.; Rampe, E. B.; Chipera, S. J.; Treiman, A. H.; Morrison, S. M.; hide

    2014-01-01

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

  16. Ground Truth Mineralogy vs. Orbital Observations at the Bagnold Dune Field

    Science.gov (United States)

    Achilles, C. N.; Downs, R. T.; Ming, D. W.; Rampe, E. B.; Morris, R. V.; Treiman, A. H.; Morrison, S. M.; Blake, D. F.; Vaniman, D. T.; Bristow, T. F.

    2017-01-01

    The Mars Science Laboratory (MSL) rover, Curiosity, is analyzing rock and sediments in Gale crater to provide in situ sedimentological, geochemical, and mineralogical assessments of the crater's geologic history. Curiosity's recent traverse through an active, basaltic eolian deposit, informally named the Bagnold Dunes, provided the opportunity for a multi-instrument investigation of the dune field.

  17. Soil aggregate stability as affected by clay mineralogy and polyacrylamide addition

    Science.gov (United States)

    The addition of polyacrylamide (PAM) to soil leads to stabilization of existing aggregates and improved bonding between, and aggregation of adjacent soil particles However, the dependence of PAM efficacy as an aggregate stabilizing agent on soil-clay mineralogy has not been studied. Sixteen soil sam...

  18. Overview of the mineralogy of the Biwabik Iron Formation, Mesabi Iron Range, northern Minnesota.

    Science.gov (United States)

    McSwiggen, Peter L; Morey, G B

    2008-10-01

    The mineralogy of the Biwabik Iron Formation changes dramatically from west to east as the formation nears the basal contact of the Duluth Complex. This reflects a contact metamorphism that took place with the emplacement of the igneous Duluth Complex at temperatures as high as 1200 degrees C. However, the mineralogy of the Biwabik Iron Formation also varies vertically through the stratigraphy of the unit. This variability in both the vertical and horizontal dimensions makes it difficult to predict exact horizons where specific minerals will occur. The iron-formation has been subdivided into four broad stratigraphic units (lower cherty, lower slaty, upper cherty, and upper slaty) and into four lateral mineralogical zones (1-4). Zone 1, the westernmost zone, is characterized by quartz, magnetite, hematite, carbonates, talc, chamosite, greenalite, minnesotaite, and stilpnomelane. The silicate mineralogy in Zone 2 of the Biwabik Iron Formation changes very little. However, the minerals begin to change dramatically in Zone 3. Most significantly, Zone 3 is characterized by the appearance of grunerite in both a tabular form and a fibrous form. In Zone 4, the original silicate minerals have completely reacted, and a new suite of minerals occupies the iron-formation. These include grunerite, hornblende, hedenbergite, ferrohypersthene (ferrosilite), and fayalite.

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

    Directory of Open Access Journals (Sweden)

    Behnam Keshavarzi

    2016-12-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  1. 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, < 125 μm soil fractions were mineralogically characterized by optical microscopy. We will be presenting results on the optical measurements, also showing the relationship between single scattering albedo (SSA) at three different wavelengths, and chemical as well as mineralogical content and interdependencies of the entrained dust samples. Examples showing the relationships between the single scattering albedos of airborne dusts, and iron (Fe) in hematite, goethite, and clay minerals (montmorillonite, illite, palygorskite), will be discussed. Our goal is to establish a database of the optical, mineralogical, and chemical properties of dust samples collected at multiple global dust sources. These data can be for applications in climate modeling, remote sensing, visibility, health (medical geology), ocean fertilization, and damage to equipment.

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

    Science.gov (United States)

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

    2015-01-01

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

  3. Thermal, mineralogical and chemical studies of the mortars used in the cathedral of Pamplona (Spain)

    OpenAIRE

    Alvarez, J.I. (José Ignacio); Navarro-Blasco, I. (Íñigo); Garcia, P.J.

    2000-01-01

    Different ancient mortar samples of Pamplona cathedral have been analysed to characterize their binder and aggregate fractions. A complete characterization has been carried out including chemical (complete macrochemical analysis, analysis of the soluble fraction in hot HCl (1:5) and of the insoluble residue, trace elements and soluble salts, using traditional chemical procedures, ion chromatography and spectrophotometry techniques), mineralogical (structural characterization, granulometric st...

  4. 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.

  5. 2001 Mars Odyssey: Geologic Questions for Global Geochemical and Mineralogical Mapping

    Science.gov (United States)

    Saunders, R. S.; Meyer, M. A.

    2001-01-01

    2001 Mars Odyssey has three experiments. GRS will map the surface elemental composition. MARIE will characterize the Mars radiation environment for risk to humans. THEMIS will map the mineralogy and morphology with a camera and thermal IR imaging. Additional information is contained in the original extended abstract.

  6. 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...

  7. Mineralogy and geochemistry of banded iron formation and iron ...

    Indian Academy of Sciences (India)

    magnetite to martite and replacing quartz with hydrous iron oxides. In the second stage of super- gene processes, deep burial upgrades the hydrous iron oxides to microplaty hematite (figure 16). The hard laminated ores are found in close association with BHJ. Small and large-scale faults and folds similar to those in BIF ...

  8. 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. PA01.31. Perception of ayurvedic mineral raw drugs in the eye mineralogy

    Science.gov (United States)

    Priya, Madhulika; Sharma, Govinda; Ganti, Basavaraj

    2012-01-01

    Purpose: Each mineral is unique in this universe in its perception. Minerals are defined as naturally occurring, inorganic substances with a definite chemical composition and a regular internal crystalline structure (Gribble 1988). The identity of these depends on their physical, chemical or optical properties. Mineralogy a branch of science has its existence since 17th century. Being a part of Ayurvedic pharmaceutics, Rasashastra deals with a number of minerals categorized under Maharasa, Uparasa etc. These are identified on the basis of grahya lakshana mentioned in the books of Rasashastra documented from 8th century itself. Thus, it is evident that the science of mineralogy as it is practiced presently has its origin almost 1300 years back. 1. To find the features of minerals in the books of Rasashastra and to compare them with the properties of minerals as per Mineralogy. 2. To prove that the knowledge of identifying a mineral based on certain feature existed in India before development of mineralogy. Method: A literary research was undertaken to list out the grahya lakshanas of Rasadravyas mentioned in the literatures of Rasasashtra. An attempt was made to compare them with the equivalent properties of minerals. Only such literatures of Rasashastra which had their existence before 17th century were preferred for present study. Result: The grahya lakshanas mentioned in classical books of Rasasashtra were found to be very much comparable with the physical properties of minerals. Conclusion: This literary research justifies that the ancient scholars of Rasasashtra were able to identify the minerals based on their physical properties many centuries before the mineralogy had its existence.

  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. Coupled X-ray computed tomography and grey level co-occurrence matrices as a method for quantification of mineralogy and texture in 3D

    Science.gov (United States)

    Jardine, M. A.; Miller, J. A.; Becker, M.

    2018-02-01

    Texture is one of the most basic descriptors used in the geological sciences. The value derived from textural characterisation extends into engineering applications associated with mining, mineral processing and metal extraction where quantitative textural information is required for models predicting the response of the ore through a particular process. This study extends the well-known 2D grey level co-occurrence matrices methodology into 3D as a method for image analysis of 3D x-ray computed tomography grey scale volumes of drill core. Subsequent interrogation of the information embedded within the grey level occurrence matrices (GLCM) indicates they are sensitive to changes in mineralogy and texture of samples derived from a magmatic nickel sulfide ore. The position of the peaks in the GLCM is an indication of the relative density (specific gravity, SG) of the minerals and when interpreted using a working knowledge of the mineralogy of the ore presented a means to determine the relative abundance of the sulfide minerals (SG > 4), dense silicate minerals (SG > 3), and lighter silicate minerals (SG texture in 3D.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  13. Synthesis, Properties and Mineralogy of Important Inorganic Materials

    CERN Document Server

    Warner, Terence E

    2010-01-01

    Intended as a textbook for courses involving preparative solid-state chemistry, this book offers clear and detailed descriptions on how to prepare a selection of inorganic materials that exhibit important optical, magnetic and electrical properties, on a laboratory scale. The text covers a wide range of preparative methods and can be read as separate, independent chapters or as a unified coherent body of work. Discussions of various chemical systems reveal how the properties of a material can often be influenced by modifications to the preparative procedure, and vice versa. References to miner

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

    Science.gov (United States)

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

    2015-02-01

    We aim to provide a taxonomic and compositional characterization of Multiple Asteroid Systems (MASs) located in the main belt (MB) using visible (0.45-0.85 μm) and near-infrared (0.7-2.5 μm) spectral data of 42 MB MASs. The compositional and 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. (Marchis et al. [2012]. Icarus 221, 1130-1161) to estimate the porosity of the systems. The macroporosities are used to evaluate the primary MAS formation hypotheses. Our spectral survey consists of visible and near-infrared spectral data. The visible observing campaign includes 25 MASs obtained using the Southern Astrophysical Research (SOAR) telescope with the Goodman High Throughput Spectrometer. The infrared observing campaign includes 34 MASs obtained using the NASA Infrared Telescope Facility (IRTF) with the SpeX spectragraph. For completeness, both visible and NIR data sets are supplemented with publicly available data, and the data sets are combined where possible. The MASs are classified using the Bus-DeMeo taxonomic system. In order to determine mineralogy and meteorite analog, we perform a NIR spectral band parameter analysis using a new analysis routine, the Spectral Analysis Routine for Asteroids (SARA). The SARA routine determines band centers, areas, and depths by utilizing the diagnostic absorption features near 1- and 2-μm due to Fe2+ crystal field transitions in olivine + pyroxene and pyroxene, respectively. The band parameter analysis provides the Gaffey subtype for the S-complex MASs; the relative abundance olivine-to-pyroxene ratio; and olivine and pyroxene modal abundances for S-complex and V-type MASs. This mineralogical information is then applied to determine meteorite analogs. Through applying calibration studies, we are able to determine the H, L, and LL meteorite analogs for 15 MASs with ordinary chondrite-like (OC) mineralogies. We observe an

  15. Synthesis, Properties and Mineralogy of Important Inorganic Materials

    DEFF Research Database (Denmark)

    Warner, Terence Edwin

    , ferroelectric, thermoelectric, luminescent, photochromic and magnetic materials; are technologically important classes of material, that are represented by numerous inorganic phases. Yet how many of us are aware of their precise chemical compositions, and have sufficient knowledge to actually make them......The synthesis of high quality material is an essential step in the process of obtaining meaningful information about the material’s properties, and therefore, is an important link between physics and chemistry. Semiconductors; superconductors; solid-electrolytes; glasses; pigments; dielectric......? This book attempts to address this problem by offering the reader clear and detailed descriptions on how to prepare a selection of fifteen inorganic materials that exhibit important optical, magnetic, electrical and thermal properties; on a laboratory scale. The materials and chemical syntheses have been...

  16. 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.

  17. Mineralogical Changes in a Predominantly Fluviolacustrine Succession at Gale Crater, Mars

    Science.gov (United States)

    Rampe, E. B.; Ming, D. W.; Grotzinger. J. P.; Bristow, T. F.; Blake, D. F.; Vaniman, D. T.; Chipera, S. J.; Gellert, R.; Morris, R. V.; Morrison, S. M.

    2017-01-01

    The Mars Science Laboratory Curiosity rover landed in Gale crater in August 2012 to investigate the strata of lower Aeolis Mons (i.e., Mount Sharp) and characterize their depositional and diagenetic environments. Visible/short-wave infrared spectra from orbit of these strata show variations in phyllosilicate, sulfate, and Fe-oxide minerals, suggesting these units record environmental changes that occurred during the early Hesperian. Curiosity has traversed over 15 km and has climbed through Approx. 200 m of stratigraphic section, made up of predominantly fluviolacustrine (i.e., the Bradbury group and the Murray formation) and aeolian (i.e., the Stimson formation) units. Multiple geochemical and mineralogical instruments are onboard Curiosity to study these ancient rocks, including the Chemistry and Mineralogy (CheMin) instrument, which is an X-ray diffractometer (XRD) and X-ray fluorescence spectrometer, and the Alpha Particle X-ray Spectrometer (APXS).

  18. 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.

  19. Incorporating Environmental and Sustainability Issues into the Curriculum in a Mineralogy Class

    Science.gov (United States)

    Cook, G. W.

    2013-12-01

    A traditional curriculum in mineralogy addresses classic subject matter such as crystal chemistry, crystallography, systematic mineralogy and optical mineralogy. This is entirely reasonable and appropriate, as these time-honored aspects of mineralogy are fundamental to students' understanding of Earth Materials; they are also important building blocks for an understanding of other geologic disciplines such as petrology, structural geology, and sedimentology. Due to the impressive breadth and amount of subject material that is covered in most mineralogy courses, time constraints do not allow instructors to branch out into more contemporary subjects. In our increasingly technologically-advanced (and crowded) modern society, issues pertaining to the environment and sustainability are at the forefront of scientific thought. In many introductory physical geoscience courses these issues are addressed and incorporated into the curriculum, thereby giving students valuable scientific background in modern environmental issues. However, in upper division classes (such as mineralogy) there is little time or motivation for instructors to add new content or to connect the course content with current environmental or societal concerns, even though there may be significant and meaningful opportunities to do so throughout the quarter or semester. Consequently, many students' understanding of environmental issues remains at an introductory or cursory level. In my mineralogy class at the University of California San Diego (UCSD), I teach a traditional curriculum with a modern approach that uses dynamic lectures, makes use of multimedia, and also utilizes current best teaching practices. As a department, we have recently made an increased effort to educate our students about environmental issues. Accordingly, I have integrated environmental and sustainability topics (when they are pertinent) into the curriculum as a regular component of the course. These topics typically relate to how

  20. 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.; hide

    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.

  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.; hide

    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. 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.

  3. Petrophysical properties, mineralogy, fractures, and flow tests in 25 deep boreholes at Yucca Mountain, Nevada

    Science.gov (United States)

    Nelson, Philip H.; Kibler, Joyce E.

    2014-01-01

    As part of a site investigation for the disposal of radioactive waste, numerous boreholes were drilled into a sequence of Miocene pyroclastic flows and related deposits at Yucca Mountain, Nevada. This report contains displays of data from 25 boreholes drilled during 1979–1984, relatively early in the site investigation program. Geophysical logs and hydrological tests were conducted in the boreholes; core and cuttings analyses yielded data on mineralogy, fractures, and physical properties; and geologic descriptions provided lithology boundaries and the degree of welding of the rock units. Porosity and water content were computed from the geophysical logs, and porosity results were combined with mineralogy from x-ray diffraction to provide whole-rock volume fractions. These data were composited on plates and used by project personnel during the 1990s. Improvements in scanning and computer technology now make it possible to publish these displays.

  4. 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

  5. Lack of cross-shelf transport of sediments on the western margin of India: Evidence from clay mineralogy

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaswamy, V.; Nair, R.R.

    transported long distances along the shelf, cross-shelf transport appears to be minimal. Confirmatory evidence of qualitative differences in outer and inner shelf clays is provided by sediment trap clay mineralogy on the outer shelf. Clay bound pollutant...

  6. Bulk Mineralogy of the Northeast Syrtis and Jezero Crater Regions of Mars Derived Through Thermal Infrared Spectral Analyses

    Science.gov (United States)

    Salvatore, M. R.; Goudge, T. A.; Bramble, M. S.; Edwards, C. S.; Bandfield, J. L.; Amador, E. S.; Mustard, J. F.; Christensen, P. R.

    2017-10-01

    We derive quantitative estimates of bulk mineralogy throughout the Jezero crater, Jezero watershed, and NE Syrtis regions of Mars using TIR data. Results suggest the dominance of basaltic compositions and are compared to prior VNIR investigations.

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

    NARCIS (Netherlands)

    Hensen, B.J.

    1967-01-01

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

  8. Potential effects of ocean acidification on Alaskan corals based on calcium carbonate mineralogy composition analysis (NCEI Accession 0157223)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains potential effects of ocean acidification on Alaskan corals based on calcium carbonate mineralogy composition analysis. Effects of...

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

    Directory of Open Access Journals (Sweden)

    Perkov E.S.

    2013-09-01

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

  10. 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...

  11. Influence of aggregate mineralogical composition on water resistance of aggregate–bitumen adhesion

    OpenAIRE

    Zhang, Jizhe; Apeagyei, Alex K.; Airey, Gordon D.; Grenfell, James R.A.

    2015-01-01

    The effects of aggregate mineralogical composition on moistures sensitivity of aggregate–bitumen bonds were investigated using four aggregate types (two limestone and two granite)and two bitumen grades (40/60 penand70/100pen). Moisture sensitivity (or water resistance) of the aggregate–bitumen bonds were characterized using retained strength obtained from three different tensile tests (peel, PATTI and pull-off). The results showed significant differences in the amount of moisture absorbed ...

  12. Assessment of bioavailability of iron delivered to marine phytoplankton in different mineralogical forms

    Science.gov (United States)

    Ammar, Rawaa; Delmelle, Pierre; Journet, Emilie

    2017-04-01

    Iron (Fe) is an essential element in cellular biochemical processes and its availability in the surface ocean limits phytoplankton-mediated fixation of C, i.e. the biological pump. In vast regions of the open ocean, atmospheric deposition of Fe-bearing continental dust and volcanic ash to the surface ocean acts as an important source of bioavailable Fe to phytoplankton. The capacity of dust and ash to alleviate Fe limitation is usually discussed in terms of Fe solubility, which has been shown to be controlled by speciation/mineralogy. However, little information exists on the relationship between Fe bioavailability and Fe speciation/mineralogy in dust and ash. In this study, Fe-bearing materials of known mineralogy, including three volcanic ash samples from different eruptions (Eyjafjallajökull 2010, Chaitén 2008 and Tungurahua 2012), two continental dust specimens (Douz and Banizoumbou) and three Fe-bearing minerals (illite/smectite, ferrihydrite, and goethite) were added to Fe-stressed cultures of Dunaliella tertiolecta, a marine algae commonly found in high-nutrient, low chlorophyll waters. Photosynthetic activity, chlorophyll content and cell population growth were measured at regular intervals during 168 h after Fe addition. Our results indicate that all the tested Fe-bearing materials induced a similar biological response; and were able to alleviate Fe stress in D. tertiolecta within 2 h from the beginning of the experiment and to induce cell growth up to 168 h. This unexpected finding contrasts with the traditional view that Fe speciation/mineralogy in dust and ash plays a key role in governing Fe bioavailability to phytoplankton. Supplementary measurements on the fractional solubility of Fe in dust and ash will be presented.

  13. Mineralogical Study of Zard Koh and Kulli Koh Iron Ore Deposits of Pakistan

    Directory of Open Access Journals (Sweden)

    SULTAN AHMED KHOSO

    2017-10-01

    Full Text Available Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction, XRF (X-Ray Fluorescence, SEM (Scanning Electron Microscope attached with EDS (Energy Dispersive Spectroscope and SM (Stereomicroscope techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques.

  14. 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.; hide

    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.

  15. 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.; hide

    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.

  16. Effect of Aggregate Mineralogy and Concrete Microstructure on Thermal Expansion and Strength Properties of Concrete

    Directory of Open Access Journals (Sweden)

    Jinwoo An

    2017-12-01

    Full Text Available Aggregate type and mineralogy are critical factors that influence the engineering properties of concrete. Temperature variations result in internal volume changes could potentially cause a network of micro-cracks leading to a reduction in the concrete’s compressive strength. The study specifically studied the effect of the type and mineralogy of fine and coarse aggregates in the normal strength concrete properties. As performance measures, the coefficient of thermal expansion (CTE and compressive strength were tested with concrete specimens containing different types of fine aggregates (manufactured and natural sands and coarse aggregates (dolomite and granite. Petrographic examinations were then performed to determine the mineralogical characteristics of the aggregate and to examine the aggregate and concrete microstructure. The test results indicate the concrete CTE increases with the silicon (Si volume content in the aggregate. For the concrete specimens with higher CTE, the micro-crack density in the interfacial transition zone (ITZ tended to be higher. The width of ITZ in one of the concrete specimens with a high CTE displayed the widest core ITZ (approx. 11 µm while the concrete specimens with a low CTE showed the narrowest core ITZ (approx. 3.5 µm. This was attributed to early-age thermal cracking. Specimens with higher CTE are more susceptible to thermal stress.

  17. Gypsum-carbonate speleothems from Cueva de las Espadas (Naica mine, Mexico: mineralogy and palaeohydrogeological implications

    Directory of Open Access Journals (Sweden)

    Martínez-Frías Jesús

    2012-07-01

    Full Text Available Some of the most outstanding hypogenic gypsum speleothems worldwide have been recently discovered in the Naica mines. The Cueva de las Espadas (Swords Cave, which lies at 120 m depth, hosts a rare type of speleothem called “espada” (“sword”. This study contributes to the understanding of the mineralogical composition of these singular speleothems, by means of their examination using micro-Raman spectroscopy, FT-IR spectroscopy and EDX microprobe. Our data revealed a complex mineralogy comprising a high-purity selenite core covered by several layers of calcite, aragonite and gypsum. Solid inclusions of polymetallic oxides (Mn-Pb-Zn and graphite were also detected. The position of the water table during the genesis of the “espada” speleothems (over the past 60 kyr was deduced from their mineralogy. Water level fluctuations at around -120 m depth led to environmental changes within the Cueva de las Espadas. The selenite core and gypsum layers were precipitated under biphasic (water-rock conditions when the cave was submerged under hydrothermal water. The aragonite precipitation required triphasic (air-water-rock conditions and occurred when the water table intercepted the cave, allowing the CO2 exchange necessary for carbonate precipitation. Solid inclusions were trapped in an aerobic environment when the gypsum-aragonite boundary condition occurred. A thin calcite layer was precipitated under vadose conditions after the water table definitively moved out of the cave.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-15

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

  19. Magnetic properties and opaque mineralogy of rocks from selected seafloor hydrothermal sites at oceanic ridges

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, A.L. (Univ. of Miami, FL (United States) NOAA, Miami, FL (United States)); Harrison, C.G.A. (Univ. of Miami, FL (United States)); Rona, P.A. (NOAA, Miami, FL (United States)); Haggerty, S.E. (Univ. of Massachusetts, Amherst (United States))

    1990-08-10

    Magnetic properties (natural remanent magnetization, susceptibility, Curie point temperature, saturation isothermal remanent magnetization, and Koeenigsberger ratio) and opaque mineralogy were determined for basalts, diabases, gabbros, peridotites, and serpentinites collected by dredging and submersible from the rift valley at five hydrothermal sites (the Snake Pit hydrothermal field, the Tag hydrothermal field on the Mid-Atlantic Ridge, and the Sea Cliff hydrothermal field on the northern Gorda Ridge). Evidence for unequivocal magnetic mineral modification by hydrothermal action is present only in a small percentage of extrusive basalts but is pervasive in diabases, gabbros, and ultramafic rocks. The studies reveal distinct correlations between magnetization intensity, thermomagnetic behavior, and magnetic mineralogy, grain size, style, and intensity of alteration and rock type. Layer 2A basalts are the source of median valley magnetic anomalies. The magnetic source may shift from the surface to deeper horizons with progressive seafloor aging and enhanced deuteric oxidation in layer 2B dikes and layer 3 gabbros and the formation of magnetite in derpentinized peridotites. This shift is influenced by fluctuations in the Curie isotherm related to the duration of active magma chambers and convective hydrothermal cells. The magnetic and mineralogic properties of oceanic rocks determined show the effects of a wide range of alteration processes that are variously related to depth in oceanic lithosphere, magmatic cooling history, and hydrothermal circulation.

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

    Science.gov (United States)

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

    2015-09-01

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

  1. 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.

  2. Impact of pulp and paper mill effluents and solid wastes on soil mineralogical and physicochemical properties.

    Science.gov (United States)

    Adhikari, Gopi; Bhattacharyya, Krishna G

    2015-03-01

    The present study was carried out to evaluate the impact of the effluents and the solid wastes generated by a giant pulp and paper mill in the northeastern part of India on soil mineralogy of the area. The impacts were monitored by analysis of soil samples from seven sites located in the potential impact zone and a control site where any kind of effluent discharge or solid waste dumping was absent. The soil belonged to medium texture type (sandy clay loam, sandy loam, loamy sand, and silt loam), and the soil aggregate analysis indicated higher levels of organic carbon, pH, electrical conductivity, effective cation exchange capacity, and mean weight diameter at sites receiving effluents and solid wastes from the pulp and paper mill. Depletion in soil silica level and in feldspar and quartz contents and rise in iron and calcium contents at the sites receiving effluents from the pulp and paper mill indicated significant influence on soil mineralogy. The soil contained a mixture of minerals consisting of tectosilicates (with silicate frameworks as in quartz or feldspar), phylosilicates (layered clays like kaolinite, smectite, chlorite, illite, etc.), and carbonates. Absence of pure clay minerals indicated a state of heterogeneous intermediate soil clay transformation. The significance of the mixed mineralogy in relation to the disposal of effluents and dumping of solid wastes is discussed in details.

  3. 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.

  4. Reconstructing the Holocene depositional environments along the northern coast of Sfax (Tunisia): Mineralogical and sedimentological approaches

    Science.gov (United States)

    Lamourou, Ali; Touir, Jamel; Fagel, Nathalie

    2017-05-01

    A sedimentological and mineralogical study of sedimentary cores allowed reconstructing the evolution of depositional environments along the Northern coast of Sfax (Tunisia). The aim of this research work is to identify the factors controlling the sedimentation from the Holocene to the Present time. Three 30-m sediment cores collected by drilling at 30 m water depth were analyzed for their color, magnetic susceptibility signal, grain size by laser diffraction, organic matter content by loss of ignition, carbonate content by calcimetry and mineralogy by X-ray diffraction on bulk powder and clay sediments characterized by a low magnetic susceptibility signal were replaced by fine bioclastic-rich clayey sediments. The analysis of vertical succession of depositional facies revealed a fluvial depositional environment (coastal plain) basically marked by fluvial channels and inundation plains at the bottom of all cores. However, core-top sediments recorded a littoral marine environment with sand depositions rich in gastropods, lamellibranches and algæ. Depositional facies, sedimentological and mineralogical parameters were consistent with a transition from a fluviatile depositional environment with some emersion phases marked by the gypsum precipitation, to a marine littoral environment. Such evolution was accompanied with a relative sea-level rise which flooded the fluvial system at the coastal plain during the Holocene, in agreement with sea-level fluctuations in southeast Tunisia during the Holocene.

  5. Training Students to Analyze Spatial and Temporal Heterogeneities in Reservoir and Seal Petrology, Mineralogy, and Geochemistry: Implications for CO{sub 2} Sequestration Prediction, Simulation, and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, Brenda

    2013-09-30

    The objective of this project was to expose and train multiple students in geological tools that are essential to reservoir characterization and geologic sequestration including but not limited to advanced petrological methods, mineralogical methods, and geochemical methods; core analysis, and geophysical well-log interpretation. These efforts have included training of multiple students through geologically based curriculum and research using advanced petrological, mineralogical, and geochemical methods. In whole, over the last 3+ years, this award has supported 5,828 hours of student research, supporting the work of several graduate and undergraduate students. They have all received training directly related to ongoing CO{sub 2} sequestration demonstrations. The students have all conducted original scientific research on topics related to understanding the importance of lithological, textural, and compositional variability in formations that are being targeted as CO{sub 2} sequestration reservoirs and seals. This research was linked to the Mount Simon Sandstone reservoir and overlying Eau Claire Formation seal in the Illinois Basin- a system where over one million tons of CO{sub 2} are actively being injected with the first large-scale demonstration of anthropogenic CO{sub 2} storage in the U.S. Student projects focused specifically on 1) reservoir porosity characterization and evaluation, 2) petrographic, mineralogical, and geochemical evidence of fluid-related diagenesis in the caprock, 3) textural changes in reservoir samples exposed to experimental CO{sub 2} + brine conditions, 4) controls on spatial heterogeneity in composition and texture in both the reservoir and seal, 5) the implications of small-scale fractures within the reservoir, and 6) petrographic and stable isotope analyses of carbonates in the seal to understand the burial history of the system. The student-led research associated with this project provided real-time and hands-on experience with a

  6. Mineralogy, geochemistry, genesis, and industrial application of silica in Arefi area, south of Mashhad

    Directory of Open Access Journals (Sweden)

    Mohammad Hassan Karimpour

    2014-10-01

    Full Text Available Introduction Arefi quartz-bearing conglomerate (Middle Jurassic is situated within Binalud structural zone. The unit is trending NW-SE located 25 km south of Mashhad. More than 97% of the pebbles are quartz as mono-crystalline, poly-crystalline, and minor fragments of chert, quartzite, and mica schist. Less that 3% of the remaining minerals are feldspar, mica, chlorite, hornblende, tourmaline, zircon, sphene, and opaque minerals. The cement is mainly silica. Hashemi (Hashemi, 2004 suggested this unit is orthoquartzitic polymictic conglomerate. In this study, we carried out detailed mineralogical studies, geochemical analyses for SiO2 and troublesome elements, determination of quartz pebbles source using geological observations and fluid inclusion microthermometry, and industrial application studies with new insight for porcelain and ceramic factories as the nearest silica-rich reserve to Mashhad. Material and methods 1. Preparing geologic map in 1:10000 scale in the Arefi area. 2. Petrographic study of 65 samples from the quartz-bearing conglomerate unit. 3. Major elements such as SiO2, TFeO, TiO2, and CaO were analyzed at the Maghsoud Porcelain Factories Group, using a Philips PW1480 X-ray spectrometer. 4. Ore dressing analyses in Danesh Faravaran Engineering Company. 5. Fluid-inclusion studies in 4 samples doubly-polished wafers of quartz crystals were studied using standard techniques (Roedder, 1984 and Linkam THM 600 heating-freezing stage (from –190 to 600ºC mounted on a Olympus TH4–200 microscope stage at Ferdowsi University of Mashhad, Iran. Salinities and density of fluid inclusions were calculated using the Microsoft Excel spreadsheet HOKIEFLINCS-H2O-NACL (Steele-MacInnis et al., 2012; Lecumberri-Sanchez et al., 2012 Results and Discussion Fluid Inclusion studies of both mono- and poly- crystalline quartz revealed that the inclusions consist of three phases (LVS with NaCl crystals. Homogenization temperature is between 484 and more

  7. 'Cool-spring' carbonate deposystems, Eastern Alps: controls on formation and mineralogy.

    Science.gov (United States)

    Sanders, D.; Wertl, W.

    2009-04-01

    With respect to their latitudinal and altitudinal range, 'cool'-spring associated limestones (SAL) are among the most widespread carbonate deposits on Earth. Aside of a review by Ford & Pedley (1996), however, no larger-scale perspective on controls over SAL deposition exists. Because of a common presence of SAL in the Eastern Alps, and because of a large range in altitude, geological substrates, and climate, the Alps are well-suited to better understand the formation of limestone-depositing spring. Our results indicate that presence and distribution of Eastern-Alpine SAL are mainly determined by rock substrate and tectonic structure, resulting in suited water chemistry, whereas 'climate' (mean annual temperature and precipitation, duration of snow cover) is of subsidiary influence only. The question for the relation of SAL to environment was approached by parameterized inspection of all available, printed geological maps of the Eastern Alps (status 2008; total number of maps inspected: 168); data extracted from maps for a total of 290 SAL deposits were entered into a database. The geological parameter set was compared with long-term records of temperature, precipitation, and snow cover. In addition, many SAL deposits fossil and active were inspected in the field. Selected active SAL deposits were investigated, since 2004, by diverse physico-chemical and biological methods. In the Eastern Alps, SAL are most common on substrata rich in marls (flysch) or fine-grained calcite (glacial lodgement till), and on substrata bearing sulfate evaporites (e. g. Triassic evaporites) and/or base metal sulfides in presence of carbonate minerals (e. g. calcareous phyllites of 'Bündnerschiefer' type). By combining high solubility (yielding Ca) with sulfate reduction (yielding bicarbonate), sulfate evaporites favour high-Ca/high-bicarbonate spring waters capable of limestone deposition. Oxidation of sulfide ores, present in (sub)economic deposits and/or as disseminated pyrite

  8. Geochemistry and mineralogy of the carbonates of the Creede mining district, Colorado

    Science.gov (United States)

    Wetlaufer, Pamela Heald

    1977-01-01

    This paper describes the results of a study of the carbonate gangue in the silver-base metal ore deposit of the Creede mining district, located in Tertiary volcanic rocks of the central San Juan Mountains, southwestern Colorado. Two carbonate stages can be distinguished and defined on the basis of mineral association, compositional range and position in the sequence of ore deposition. Electron microprobe analyses show that the early pre-ore carbonate stage is comprised of rhodochrosite with a compositional range of 68 to 93 mole percent MnCO3, 7 to 32 mole percent FeCO3, 2 to 15 mole percent CaCO3, and 0.5 to 4 mole percent MgCO3. The later intra-ore carbonate stage is made up of siderite-manganosiderite with a broad range of iron content (33 to 94 mole percent FeCO3; 6 to 67 mole percent MnCO3; 1 to 13 mole percent CaCO3; and 1 to 10 mole percent MgCO3). Both carbonate stages are spatially restricted within the vein system, the rhodochrosite limited to the southern third and the siderite limited to the northern two-thirds. The two stages have not been found at the same sample locality. The two stages of carbonate define two of the five main depositional stages in the history of the Creede hydrothermal system and thereby document broad scale variations within the depositing, and continually evolving fluids. However, the complexity of the textural and mineralogical variations within each carbonate stage limits their usefulness in unraveling the finer details of the character of the ore fluids. The frequently massive rhodochroslte has undergone several periods of leaching and regrowth which, except at one locality, cannot be resolved by compositional, textural or color variations. Although some compositionally zoned siderite rhombs have been documented, the siderite, too, has had a complicated history of leaching and regrowth. The zoning indicates (i) an early low-calcium siderite + hematite growth followed by (2) relatively high-calcium siderite depositlon (without

  9. 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

  10. Impact of water quality change on corrosion scales in full and partially replaced lead service lines

    Science.gov (United States)

    BackgroundChanges in water qualities have been associated with an increase in lead release from full and partial lead service lines (LSLs), such as the cases of Washington D.C. or more recently of Flint (Mi). Water qualities affect the mineralogy of the scales. Furthermore, follo...

  11. A DFN-based High Performance Computing Approach to the Simulation of Radionuclide Transport in Mineralogically Heterogeneous Fractured Rocks

    Science.gov (United States)

    Gylling, B.; Trinchero, P.; Molinero, J.; Deissmann, G.; Svensson, U.; Ebrahimi, H.; Hammond, G. E.; Bosbach, D.; Puigdomenech, I.

    2016-12-01

    Geological repositories for nuclear waste are based multi-barrier concepts using engineered and natural barriers. In fractured crystalline rocks, the efficiency of the host rock as transport barrier is related to the processes: advection along fractures, diffusion into the rock matrix and retention onto the available sorption sites. Anomalous matrix penetration profiles were observed in experiments (i.e. REPRO carried out by Posiva at the ONKALO underground facility in Finland and the Long Term Sorption Diffusion Experiment, LTDE-SD, carried out by SKB at the Äspö Hard Rock Laboratory in Sweden). The textural and mineralogical heterogeneity of the rock matrix was offered as plausible explanation for these anomalous penetration profiles. The heterogeneous structure of the rock matrix was characterised at the grain-scale using a micron-scale Discrete Fracture Network (DFN), which is then represented onto a micron-scale structured grid. Matrix fracture free volumes are identified as reactive biotite-bearing grains whereas the rest of the matrix domain constitutes the inter-granular regions. The reactive transport problem mimics the ingress of cesium along a single transmissive fracture. Part of the injected mass diffuses into the matrix where it might eventually sorb onto the surface of reactive grains. The reactive transport calculations are carried out using iDP (interface between DarcyTools and PFLOTRAN). The generation of the DFN is done by DarcyTools, which also takes care of solving the groundwater flow problem. Computed Darcy velocities are extracted and used as input for PFLOTRAN. All the simulation runs are carried out on the supercomputer JUQUEEN at the Jülich Supercomputing Centre. The results are compared with those derived with an alternative model, where biotite abundance is averaged over the whole matrix volume. The analysis of the cesium breakthrough computed at the fracture outlet shows that the averaged model provides later first-arrival time

  12. Quantitative mineralogy of the Yukon River system: Changes with reach and season, and determining sediment provenance

    Science.gov (United States)

    Eberl, D.D.

    2004-01-01

    The mineralogy of Yukon River basin sediment has been studied by quantitative X-ray diffraction. Bed, beach, bar, and suspended sediments were analyzed using the RockJock computer program. The bed sediments were collected from the main stem and from selected tributaries during a single trip down river, from Whitehorse to the Yukon River delta, during the summer of 2001. Beach and bar sediments were collected from the confluence region of the Tanana and Yukon Rivers during the summer of 2003. Suspended sediments were collected at three stations on the Yukon River and from a single station on the Tanana River at various times during the summers of 2001 through 2003, with the most complete set of samples collected during the summer of 2002. Changes in mineralogy of Yukon River bed sediments are related to sediment dilution or concentration effects from tributary sediment and to chemical weathering during transport. Carbonate minerals compose about 2 wt% of the bed sediments near Whitehorse, but increase to 14 wt% with the entry of the White River tributary above Dawson. Thereafter, the proportion of carbonate minerals decreases downstream to values of about 1 to 7 wt% near the mouth of the Yukon River. Quartz and feldspar contents of bed sediments vary greatly with the introduction of Pelly River and White River sediments, but thereafter either increase irregularly (quartz from 20 to about 50 wt%) or remain relatively constant (feldspar at about 35 wt%) with distance downstream. Clay mineral content increases irregularly downstream from about 15 to about 30 wt%. The chief clay mineral is chlorite, followed by illite + smectite; there is little to no kaolinite. The total organic carbon content of the bed sediments remains relatively constant with distance for the main stem (generally 1 to 2 wt%, with one exception), but fluctuates for the tributaries (1 to 6 wt%). The mineralogies of the suspended sediments and sediment flow data were used to calculate the amount of

  13. Geology and mineralogy of the Auki Crater, Tyrrhena Terra, Mars: A possible post impact-induced hydrothermal system

    Science.gov (United States)

    Carrozzo, F. G.; Di Achille, G.; Salese, F.; Altieri, F.; Bellucci, G.

    2017-01-01

    A variety of hydrothermal environments have been documented in terrestrial impact structures. Due to both past water interactions and meteoritic bombardment on the surface of Mars, several authors have predicted various scenarios that include the formation of hydrothermal systems. Geological and mineralogical evidence of past hydrothermal activity have only recently been found on Mars. Here, we present a geological and mineralogical study of the Auki Crater using the spectral and visible imagery data acquired by the CRISM (Compact Reconnaissance Imaging Spectrometer for Mars), CTX (Context Camera) and HiRISE (High Resolution Imaging Science Experiment) instruments on board the NASA MRO mission. The Auki Crater is a complex crater that is ∼38 km in diameter located in Tyrrhena Terra (96.8°E and 15.7°S) and shows a correlation between its mineralogy and morphology. The presence of minerals, such as smectite, silica, zeolite, serpentine, carbonate and chlorite, associated with morphological structures, such as mounds, polygonal terrains, fractures and veins, suggests that the Auki Crater may have hosted a post impact-induced hydrothermal system. Although the distribution of hydrated minerals in and around the central uplift and the stratigraphic relationships of some morphological units could also be explained by the excavation and exhumation of carbonate-rich bedrock units as a consequence of crater formation, we favor the hypothesis of impact-induced hydrothermal circulation within fractures and subsequent mineral deposition. The hydrothermal system could have been active for a relatively long period of time after the impact, thus producing a potential transient habitable environment. It must be a spectrally neutral component to emphasize the spectral features; It is an average of spectra taken in the same column of the numerator spectra to correct the residual instrument artifacts and reduce detector noise that changes from column to column; It must be taken in

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

    Science.gov (United States)

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

    2015-12-01

    A more than 250 year-old mine dump was studied to document the products of long-term arsenopyrite oxidation under natural conditions in a coarse-grained mine waste dump and to evaluate the environmental hazards associated with this material. Using complementary mineralogical and chemical approaches (SEM/EDS/WDS, XRD, micro-Raman spectroscopy, pore water analysis, chemical extraction techniques and thermodynamic PHREEQC-2 modeling), we documented the mineralogical/geochemical characteristics of the dumped arsenopyrite-rich material and environmental stability of the newly formed secondary minerals. A distinct mineralogical zonation was found (listed based on the distance from the decomposed arsenopyrite): scorodite (locally associated with native sulfur pseudomorphs) plus amorphous ferric arsenate (AFA/pitticite), kaňkite, As-bearing ferric (hydr)oxides and jarosite. Ferric arsenates and ferric (hydr)oxides were found to dissolve and again precipitate from downward migrating As-rich solutions cementing rock fragments. Acidic pore water (pH3.8) has elevated concentrations of As with an average value of about 2.9 mg L(-1). Aqueous As is highly correlated with pH (R2=0.97, 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. A Process Mineralogy Approach to Gravity Concentration of Tantalum Bearing Minerals

    Directory of Open Access Journals (Sweden)

    Yousef Ghorbani

    2017-10-01

    Full Text Available The historic Penouta mine in northwest Spain is the focus of efforts to extract tantalum from tin mining waste. This paper describes the characterisation of the tantalum mineralogy of waste material from the deposit. Characterisation was realised using quantitative mineralogy and geochemistry. This paper further identifies other phases of interest and investigates the potential for extraction using gravity separation techniques. The gravity concentrate obtained through these tests was analysed using quantitative mineralogy and electron probe microanalysis. Following characterisation of the sample material to identify the key Ta-bearing mineral phases and assess liberation, a series of gravity separation trials were conducted using Heavy Liquid Separation (HLS, Mozley table, Knelson concentrator separation and shaking table. The laboratory shaking table used to conduct a rougher test and a rougher/cleaner test to simulate a spiral-table circuit using the Penouta material. Mass balance calculations were carried out to calculate the contained metal content of the feed material and concentrate products in order to assess recovery rates for Ta, Sn and Nb across a range of grains sizes. Ta was found to be present predominantly in the solid-solution columbite-group mineral, along with minor Ta present as microlite and as impurities within cassiterite. It was found that over 70% of the Ta is contained within the −125 μm fraction, with the Ta-bearing minerals tantalite and microlite being closely associated with quartz. Mozley table separation resulted in recoveries of 89% Ta and 85% Nb for the −125 μm fraction. The Knelson Concentrator trial was carried out on the −625 μm size fraction, thereby eliminating low grade material found in the coarsest fractions. Size analysis of the recovery rate for each product, shows that the Knelson concentrator is most efficient for recovery of −125 μm particles.

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

    Directory of Open Access Journals (Sweden)

    D.A. Mousa

    2014-03-01

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

  17. Recirculation of biomass ashes onto forest soils: Ash composition, mineralogy and leaching properties

    DEFF Research Database (Denmark)

    Maresca, Alberto; Hyks, J.; Astrup, Thomas Fruergaard

    2017-01-01

    In Denmark, increasing amounts of wood ashes are generated from biomass combustion for energy production. The utilisation of ashes on top of forest soil for liming purposes has been proposed asan alternative to landfilling. Danish wood ash samples were collected and characterised with respect...... to chemical composition, mineralogy and leaching properties (batch leaching at L/S 2 and 10L/kg, and pH-dependent leaching at 10L/kg). Large variations in the ash liming properties were observed (ANC7.5: 1.8-6.4meqH+/g), indicating that similar soil application dosages may result in different liming effects...

  18. The mineralogy and trace element constituents of suspended stream sediments of the Linggi River Basin, Malaysia

    Science.gov (United States)

    Nather Khan, I. S. A.

    The mineralogy and trace element concentrations of suspended stream sediments were determined at selected stations in the Linggi River Basin, Malaysia, while conducting an intensive study on water quality and a biological assessment of water pollution in the basin. The minerals that were identified from the X-ray patterns of the suspended stream sediments are kaolinite, mica, feldspar and quartz. Kaolinite was the most abundant mineral, followed by mica. By considering mean concentrations of various trace elements, aluminum and manganese were the most abundant elements. Higher concentrations of copper and zinc at some stations were due to pollutants from the nearby Senawang Industrial Estate.

  19. Mineralogy, early marine diagenesis, and the chemistry of shallow-water carbonate sediments

    Science.gov (United States)

    Higgins, J. A.; Blättler, C. L.; Lundstrom, E. A.; Santiago-Ramos, D. P.; Akhtar, A. A.; Crüger Ahm, A.-S.; Bialik, O.; Holmden, C.; Bradbury, H.; Murray, S. T.; Swart, P. K.

    2018-01-01

    Shallow-water carbonate sediments constitute the bulk of sedimentary carbonates in the geologic record and are widely used archives of Earth's chemical and climatic history. One of the main limitations in interpreting the geochemistry of ancient carbonate sediments is the potential for post-depositional diagenetic alteration. In this study, we use paired measurements of calcium (44Ca/40Ca or δ44Ca) and magnesium (26Mg/24Mg or δ26Mg) isotope ratios in sedimentary carbonates and associated pore-fluids as a tool to understand the mineralogical and diagenetic history of Neogene shallow-water carbonate sediments from the Bahamas and southwest Australia. We find that the Ca and Mg isotopic composition of bulk carbonate sediments at these sites exhibits systematic stratigraphic variability that is related to both mineralogy and early marine diagenesis. The observed variability in bulk sediment Ca isotopes is best explained by changes in the extent and style of early marine diagenesis from one where the composition of the diagenetic carbonate mineral is determined by the chemistry of the fluid (fluid-buffered) to one where the composition of the diagenetic carbonate mineral is determined by the chemistry of the precursor sediment (sediment-buffered). Our results indicate that this process, together with variations in carbonate mineralogy (aragonite, calcite, and dolomite), plays a fundamental and underappreciated role in determining the regional and global stratigraphic expressions of geochemical tracers (δ13C, δ18O, major, minor, and trace elements) in shallow-water carbonate sediments in the geologic record. Our results also provide evidence that a large shallow-water carbonate sink that is enriched in 44Ca can explain the mismatch between the δ44/40Ca value of rivers and deep-sea carbonate sediments and call into question the hypothesis that the δ44/40Ca value of seawater depends on the mineralogy of primary carbonate precipitations (e.g. 'aragonite seas' and

  20. 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

  1. Mineralogy of agricultural soil of selected regions of South Western Karnataka, Peninsular India.

    Science.gov (United States)

    Smitha, P G; Byrappa, K; Ranganathaiah, C

    2015-07-01

    Agricultural soils of selected regions of Southwestern Karnataka, Peninsular India, were subjected to systematic mineralogical characterization along with the study of soil physical properties. Physical properties such as soil texture and micro porosity were studied using particle size analyses and positron annihilation lifetime analysis (PALS) technique, respectively. The latter was used to analyze micro porosity of agricultural soil. Both major and minor minerals were identified and confirmed by some analytical techniques like thin section study, powder X-ray diffraction, X-ray fluorescence spectroscopy and Fourier transform infrared spectroscopy.

  2. Ultra-Compact Imaging Spectrometer (UCIS) for In-Situ Planetary Mineralogy: Laboratory and Field Calibration

    Science.gov (United States)

    Van Gorp, Byron; Mouroulis, Pantazis; Green, Robert O.; Rodriguez, Jose I.; Blaney, Diana; Wilson, Daniel W.; Sellar, R. Glenn; Richardson, Brandon S.

    2012-01-01

    The Ultra-Compact Imaging Spectrometer (UCIS) is a miniature telescope and spectrometer system intended for mapping terrain mineralogy over distances from 1.5 m to infinity with spatial sampling of 1.35 mrad over a 33 deg field, and spectral sampling of 10 nm in the 600-2500 nm range. The core of the system has been designed for operation in a Martian environment, but can also be used in a terrestrial environment when placed inside a vacuum vessel. We report the laboratory and field calibration data that include spatial and spectral calibration, and demonstrate the use of the system.

  3. Regolith Evolved Gas Analyzer (REGA): An Instrument to Characterize the Martian Soil Mineralogy and Atmosphere Composition

    Science.gov (United States)

    Hoffman, John H.; McKay, David S.; Ming, Douglas; Allen, Carlton C.; Hedgecock, Jud; Nienaber, Terry

    2000-01-01

    This abstract describes an instrument and experiment to be proposed for a future Mars surface mission to conduct basic research on environmental characterization. The Regolith Evolved Gas Analyzer (REGA) experiment is designed to provide information on Mars surface material properties in preparation for human missions of exploration. The goals of the investigation are: 1) Define and determine surface mineralogy of soil and dust and their effects on humans and machines; and 2) Conduct in-situ investigations aimed at identifying possible evidence of past or present life on Mars.

  4. Global mineralogical and aqueous mars history derived from OMEGA/Mars Express data.

    Science.gov (United States)

    Bibring, Jean-Pierre; Langevin, Yves; Mustard, John F; Poulet, François; Arvidson, Raymond; Gendrin, Aline; Gondet, Brigitte; Mangold, Nicolas; Pinet, P; Forget, F; Berthé, Michel; Bibring, Jean-Pierre; Gendrin, Aline; Gomez, Cécile; Gondet, Brigitte; Jouglet, Denis; Poulet, François; Soufflot, Alain; Vincendon, Mathieu; Combes, Michel; Drossart, Pierre; Encrenaz, Thérèse; Fouchet, Thierry; Merchiorri, Riccardo; Belluci, Giancarlo; Altieri, Francesca; Formisano, Vittorio; Capaccioni, Fabricio; Cerroni, Pricilla; Coradini, Angioletta; Fonti, Sergio; Korablev, Oleg; Kottsov, Volodia; Ignatiev, Nikolai; Moroz, Vassili; Titov, Dimitri; Zasova, Ludmilla; Loiseau, Damien; Mangold, Nicolas; Pinet, Patrick; Douté, Sylvain; Schmitt, Bernard; Sotin, Christophe; Hauber, Ernst; Hoffmann, Harald; Jaumann, Ralf; Keller, Uwe; Arvidson, Ray; Mustard, John F; Duxbury, Tom; Forget, François; Neukum, G

    2006-04-21

    Global mineralogical mapping of Mars by the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activité (OMEGA) instrument on the European Space Agency's Mars Express spacecraft provides new information on Mars' geological and climatic history. Phyllosilicates formed by aqueous alteration very early in the planet's history (the "phyllocian" era) are found in the oldest terrains; sulfates were formed in a second era (the "theiikian" era) in an acidic environment. Beginning about 3.5 billion years ago, the last era (the "siderikian") is dominated by the formation of anhydrous ferric oxides in a slow superficial weathering, without liquid water playing a major role across the planet.

  5. Geochemistry and mineralogy of old concentration tailings (Dal’negorsky ore district, Primorsky Krai, Russia)

    Science.gov (United States)

    Tarasenko, I. A.; Zinkov, A. V.; Ovodova, E. V.; Petukhov, V. I.; Solyanik, I. V.

    2017-10-01

    The paper gives the granulometric characteristics of the old tailings of the Krasnorechenskaya concentration mill (Primorsky Krai, Russia) and discusses their mineralogical-geochemical features. The original ore and newly formed mineral associations belonging to certain subzones are characterized by the concrete formation conditions and occupy a definite position in space thus forming a mineral zoning. The resources of main elements concentrated in the tailing dumps have been calculated. The KCM tailing dumps are shown to be the promising objects for the repeated extraction of mineral raw material and, at the same time, the sources of environment pollution with toxic elements.

  6. A mineralogical characterization of biogenic calcium carbonates precipitated by heterotrophic bacteria isolated from cryophilic polar regions.

    Science.gov (United States)

    Ronholm, J; Schumann, D; Sapers, H M; Izawa, M; Applin, D; Berg, B; Mann, P; Vali, H; Flemming, R L; Cloutis, E A; Whyte, L G

    2014-11-01

    Precipitation of calcium carbonate (CaCO3(s) ) can be driven by microbial activity. Here, a systematic approach is used to identify the morphological and mineralogical characteristics of CaCO3(s) precipitated during the heterotrophic growth of micro-organisms isolated from polar environments. Focus was placed on establishing mineralogical features that are common in bioliths formed during heterotrophic activity, while in parallel identifying features that are specific to bioliths precipitated by certain microbial phylotypes. Twenty microbial isolates that precipitated macroscopic CaCO3(s) when grown on B4 media supplemented with calcium acetate or calcium citrate were identified. A multimethod approach, including scanning electron microscopy, high-resolution transmission electron microscopy, and micro-X-ray diffraction (μ-XRD), was used to characterize CaCO3(s) precipitates. Scanning and transmission electron microscopy showed that complete CaCO3(s) crystal encrustation of Arthrobacter sp. cells was common, while encrustation of Rhodococcus sp. cells did not occur. Several euhedral and anhedral mineral formations including disphenoid-like epitaxial plates, rhomboid-like aggregates with epitaxial rhombs, and spherulite aggregates were observed. While phylotype could not be linked to specific mineral formations, isolates tended to precipitate either euhedral or anhedral minerals, but not both. Three anhydrous CaCO3(s) polymorphs (calcite, aragonite, and vaterite) were identified by μ-XRD, and calcite and aragonite were also identified based on TEM lattice-fringe d value measurements. The presence of certain polymorphs was not indicative of biogenic origin, although several mineralogical features such as crystal-encrusted bacterial cells, or casts of bacterial cells embedded in mesocrystals are an indication of biogenic origin. In addition, some features such as the formation of vaterite and bacterial entombment appear to be linked to certain phylotypes. Identifying

  7. Raman study of the role of pressure and temperature on potential Martian mineralogy

    Science.gov (United States)

    Motamedi, R.; Davies, G.

    2011-10-01

    Water is potentially the key to understanding the geological and biological evolution of Mars. Here, we analyses the structure of selected hydrated minerals such as phyllosilicates, hydrated sulphates, carbonates and mafic minerals with Raman spectroscopy in a Mars atmospheric simulation chamber (MASC) between +40 and -40°C and a dominantly CO2 atmosphere between 0.1-30 mbar. Temperature is shown to have a significant influence on Raman spectra emphasizing that quantitative analysis of mineralogy under ambient P-T conditions is needed prior to the use of the Raman techniques on planetary bodies.

  8. Mineralogía y microestructura de la pizarra de techar: comportamiento termooptico y fisibilidad

    OpenAIRE

    García-Guinea, J.; Lombardero, M.; Roberts, B.; Taboada, J.; Peto, A.

    1998-01-01

    La exfoliación de las pizarras depende fundamentalmente de su mineralogía y microestructura, especialmente de la fuerte orientación de los filosilicatos. Esta propiedad permite hendir o abrir las pizarras de techar en láminas muy grandes, delgadas y planas. Se han analizado varias pizarras de techar con diferentes calidades comerciales, correspondientes a diferentes grados de físibilidad, por radioluminiscencia (RL), termoluminiscencia espectral (TL3D), difracción de rayos X (DRX), microscopí...

  9. Mineralogical Mapping of the Banded Iron Formations using Fourier Transform Infra-Red (FTIR) Spectroscopy and micro-Raman Spectroscopy

    Science.gov (United States)

    McKeeby, B. E.; Schoonen, M. A.; Glotch, T. D.; Ohmoto, H.

    2013-12-01

    Banded Iron Formations (BIFs) consist of thin alternating layers of iron-poor silica and iron-bearing phylosilicates, iron oxides, and carbonates and/or sulfides. BIFs are common in the Precambrian. Although BIFs have been the subject of numerous studies, the mechanism and environments of formation remains poorly understood. It has been hotly debated whether BIFs formed by microbes in Fe2+-rich oceans under a reducing atmosphere, or by reactions between locally discharged submarine hydrothermal fluids and O2-rich deep ocean water. The debates have continued mostly because of the lack of detailed studies on the paragenesis of minerals in BIFs to determine which minerals are primary precipitates, and which are diagenetic and metamorphic products. The purpose of this study is to explore the applications of FTIR spectroscopy and micro-Raman spectroscopy in micro-scale paragenetic studies of BIF samples. FTIR and Raman are vibrational spectroscopy techniques that provide insight into the chemical bonding within a compound. With these techniques it is possible to resolve the iron oxide, carbonate, and clay mineralogy within BIFs, which is difficult with techniques that rely on elemental analysis, such as TEM-EDAX. Samples used in this study are thin sections of the 2.7 Ga BIFs from Temagami in the Abitibi green stone belt, Ontario, Canada. FTIR analyses were conducted using a Nicolet iN10MX Micro-Imaging FTIR Spectrometer. This instrument is capable of collecting hyperspectral infrared images with a pixel size of 25 microns covering the range from 7000 to 715 cm-1. In addition, we collected point spectra measuring 50X50 microns over a spectral range from 4000 to 400 cm-1. These point spectra were used to distinguish among different iron minerals in the thin sections. Using the hyperspectral data, we created composite false color Images to show mineral variation across the samples. The spectra were modeled using a digital spectral library. After modeling and examination

  10. Insights Into the Mineralogic Diversity of Lower Mount Sharp Units from Mars Science Laboratory Mastcam Multispectral Observations

    Science.gov (United States)

    Wellington, D. F.; Bell, J. F., III; Johnson, J. R.; Kinch, K. M.; Rice, M. S.; Hardgrove, C. J.; Godber, A.

    2015-12-01

    The Mars Science Laboratory Curiosity Rover has been exploring the environment of Gale Crater since it landed in August 2012. By September 2014 the rover had reached the basal units of the Mt. Sharp (Aeolis Mons) stratigraphy. The ongoing scientific investigation of these strata includes multispectral imaging acquired by the Mast Cameras (Mastcams), Bayer-patterned CCD cameras each equipped with a rotating filter wheel whose filter band centers span twelve unique wavelengths in the visible to near-infrared. This wavelength range (445-1013 nm) covers the locations of many broad spectral absorptions exhibited by a variety of iron-bearing minerals, including both primary igneous minerals such as pyroxenes and olivines as well as minerals such as oxides and sulfates that can form via water-rock interactions. Mastcam spectra acquired to date over the traverse have shown a great variety of spectra in outcrops, float rocks, drill tailings, and other material imaged by the camera. Comparisons with the results of other instruments, such as ChemCam or in the case of drill samples, CheMin, aid in the interpretation of spectral features. Recent results from the Mastcam multispectral investigation have shown that since reaching the Murray Formation at the base of Mt. Sharp, the spectral diversity observed by Mastcam has increased, including the appearance of distinct absorption features not previously observed in the mission. Much of this new diversity is seen to be variable over small spatial scales within an outcrop, sometimes in association with light-toned veins, suggesting alteration by fluids percolating through fractures in the rock. Follow-up analyses by other instruments further constrain the mineralogy that gives rise to these spectral features. The results are consistent with the interpretation that the alteration environment has shifted from that observed in Yellowknife Bay and the surrounding plains.

  11. Report on hydro-mechanical and chemical-mineralogical analyses of the bentonite buffer in Canister Retrieval Test

    Energy Technology Data Exchange (ETDEWEB)

    Dueck, Ann; Johannesson, Lars-Erik; Kristensson, Ola; Olsson, Siv [Clay Technology AB (Sweden)

    2011-12-15

    The effect of five years of exposure to repository-like conditions on compacted Wyoming bentonite was determined by comparing the hydraulic, mechanical, and mineralogical properties of samples from the bentonite buffer of the Canister Retrieval Test (CRT) with those of reference material. The CRT, located at the Swedish Aspo Hard Rock Laboratory (HRL), was a full-scale field experiment simulating conditions relevant for the Swedish KBS-3 concept for disposal of high-level radioactive waste in crystalline host rock. The compacted bentonite, surrounding a copper canister equipped with heaters, had been subjected to heating at temperatures up to 95 deg C and hydration by natural Na-Ca-Cl type groundwater for almost five years at the time of retrieval. Under the thermal and hydration gradients that prevailed during the test, sulfate in the bentonite was redistributed and accumulated as anhydrite close to the canister. The major change in the exchangeable cation pool was a loss in Mg in the outer parts of the blocks, suggesting replacement of Mg mainly by Ca along with the hydration with groundwater. Close to the copper canister, small amounts of Cu were incorporated in the bentonite. A reduction of strain at failure was observed in the innermost part of the bentonite buffer, but no influence was seen on the shear strength. No change of the swelling pressure was observed, while a modest decrease in hydraulic conductivity was found for the samples with the highest densities. No coupling was found between these changes in the hydro-mechanical properties and the montmorillonite . the X-ray diffraction characteristics, the cation exchange properties, and the average crystal chemistry of the Na-converted < 1 {mu}m fractions provided no evidence of any chemical/structural changes in the montmorillonite after the 5-year hydrothermal test.

  12. Micromorphology, mineralogy, and genesis of soils and fracture fills and the Pajarito Plateau, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Davenport, D.W. [Texas Tech Univ., Lubbock, TX (United States)

    1993-12-01

    The town of Los Alamos, and the Los Alamos National Laboratory (LANL), are located on the Pajarito Plateau in north-central New Mexico. Environmental concerns have recently focused attention on the numerous fractures in the Bandelier Tuff, the series of volcanic rock units that make up most of the plateau. These fractures have come into question as possible conduits for transport of contaminants downward through the tuff. This, study arose out of a need to evaluate the potential for contaminant transport in the fractures. Because the fractures are typically filled, or partially filled, with soil-like material, and appear to be physically continuous with the soils on the surface of the Pajarito Plateau, it was decided to approach the question of the fractures from a soil genesis and morphology standpoint. Specifically, it was believed that soil characterization techniques, including soil micromorphological and mineralogical analyses, could provide information about the dominant processes (past and present) acting in the soils and fractures. The specific objectives of this research were to investigate: (1) the physical, mineralogical and chemical nature of fracture-filling materials in the Bandelier Tuff, as well as associated surface soils; (2) the relationships among fracture-fills, tuff bedrock, and surface soils of the Pajarito Plateau; (3) the processes responsible for the development of the fracture-fills; and (4) the likely sequence of events leading to the present morphology of the soils and fracture-fills.

  13. Recycling of construction and demolition waste materials: a chemical-mineralogical appraisal.

    Science.gov (United States)

    Bianchini, G; Marrocchino, E; Tassinari, R; Vaccaro, C

    2005-01-01

    Building activity is currently demanding remarkable amounts of inert materials (such as gravel and sand) that are usually provided by alluvial sediments. The EU directives and Italian Legislation are encouraging the re-use of construction and demolition waste provided by continuous urban redevelopment. The re-utilisation of building waste is a relatively new issue for Italy: unfortunately the employment of recycled inert materials is still limited to general bulk and drainage fills, while a more complete re-evaluation is generally hampered by the lack of suitable recycling plants. In this paper, chemical-mineralogical characterization of recycled inert materials was carried out after preliminary crushing and grain-size sorting. XRF and XRD analysis of the different grain-size classes allowed us to recognise particular granulometric classes that can be re-utilised as first-order material in the building activity. Specifically, the presented chemical-mineralogical appraisal indicates that the recycled grain-size fraction 0.6-0.125 mm could be directly re-employed in the preparation of new mortar and concrete, while finer fractions could be considered as components for industrial processing in the preparation of cements and bricks/tiles.

  14. The stratigraphy and history of Mars' northern lowlands through mineralogy of impact craters: A comprehensive survey

    Science.gov (United States)

    Pan, Lu; Ehlmann, Bethany L.; Carter, John; Ernst, Carolyn M.

    2017-09-01

    The basin-filling materials of the northern lowlands, which cover approximately one third of Mars' surface, record the long-term evolution of Mars' geology and climate. The buried stratigraphy was inferred through analyses of impact crater mineralogy, detected using data acquired by the Compact Reconnaissance Imaging Spectrometer for Mars. Examining 1045 impact craters across the northern lowlands, we find widespread olivine and pyroxene and diverse hydrated/hydroxylated minerals, including Fe/Mg smectite, chlorite, prehnite, and hydrated silica. The distribution of mafic minerals is consistent with infilling volcanic materials across the entire lowlands ( 1-4 × 107 km3), indicating a significant volume of volatile release by volcanic outgassing. Hydrated/hydroxylated minerals are detected more frequently in large craters, consistent with the scenario that the hydrated minerals are being excavated from deep basement rocks, beneath 1-2 km thick mafic lava flows or volcaniclastic materials. The prevalences of different types of hydrated minerals are similar to statistics from the southern highlands. No evidence of concentrated salt deposits has been found, which would indicate a long-lived global ocean. We also find significant geographical variations of local mineralogy and stratigraphy in different basins (geological provinces), independent of dust cover. For example, many hydrated and mafic minerals are newly discovered within the polar Scandia region (>60°N), and Chryse Planitia has more mafic mineral detections than other basins, possibly due to a previously unrecognized volcanic source.

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

    Science.gov (United States)

    Alawneh, Firas; Bala'awi, Fadi

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

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

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Jazi

    2010-11-01

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

  17. The Private Lives of Minerals: Social Network Analysis Applied to Mineralogy and Petrology

    Science.gov (United States)

    Hazen, R. M.; Morrison, S. M.; Fox, P. A.; Golden, J. J.; Downs, R. T.; Eleish, A.; Prabhu, A.; Li, C.; Liu, C.

    2016-12-01

    Comprehensive databases of mineral species (rruff.info/ima) and their geographic localities and co-existing mineral assemblages (mindat.org) reveal patterns of mineral association and distribution that mimic social networks, as commonly applied to such varied topics as social media interactions, the spread of disease, terrorism networks, and research collaborations. Applying social network analysis (SNA) to common assemblages of rock-forming igneous and regional metamorphic mineral species, we find patterns of cohesion, segregation, density, and cliques that are similar to those of human social networks. These patterns highlight classic trends in lithologic evolution and are illustrated with sociograms, in which mineral species are the "nodes" and co-existing species form "links." Filters based on chemistry, age, structural group, and other parameters highlight visually both familiar and new aspects of mineralogy and petrology. We quantify sociograms with SNA metrics, including connectivity (based on the frequency of co-occurrence of mineral pairs), homophily (the extent to which co-existing mineral species share compositional and other characteristics), network closure (based on the degree of network interconnectivity), and segmentation (as revealed by isolated "cliques" of mineral species). Exploitation of large and growing mineral data resources with SNA offers promising avenues for discovering previously hidden trends in mineral diversity-distribution systematics, as well as providing new pedagogical approaches to teaching mineralogy and petrology.

  18. Tracing of aerosol sources in an urban environment using chemical, Sr isotope, and mineralogical characterization.

    Science.gov (United States)

    Duarte, Regina M B O; Matos, João T V; Paula, Andreia S; Lopes, Sónia P; Ribeiro, Sara; Santos, José Francisco; Patinha, Carla; da Silva, Eduardo Ferreira; Soares, Rosário; Duarte, Armando C

    2017-04-01

    In the framework of two national research projects (ORGANOSOL and CN-linkAIR), fine particulate matter (PM 2.5 ) was sampled for 17 months at an urban location in the Western European Coast. The PM 2.5 samples were analyzed for organic carbon (OC), water-soluble organic carbon (WSOC), elemental carbon (EC), major water-soluble inorganic ions, mineralogical, and for the first time in this region, strontium isotope ( 87 Sr/ 86 Sr) composition. Organic matter dominates the identifiable urban PM 2.5 mass, followed by secondary inorganic aerosols. The acquired data resulted also in a seasonal overview of the carbonaceous and inorganic aerosol composition, with an important contribution from primary biomass burning and secondary formation processes in colder and warmer periods, respectively. The fossil-related primary EC seems to be continually present throughout the sampling period. The 87 Sr/ 86 Sr ratios were measured on both the labile and residual PM 2.5 fractions as well as on the bulk PM 2.5 samples. Regardless of the air mass origin, the residual fractions are more radiogenic (representative of a natural crustal dust source) than the labile fractions, whose 87 Sr/ 86 Sr ratios are comparable to that of seawater. The 87 Sr/ 86 Sr ratios and the mineralogical composition data further suggest that sea salt and mineral dust are important primary natural sources of fine aerosols throughout the sampling period.

  19. Mineralogy of mine waste at the Vermont Asbestos Group mine, Belvidere Mountain, Vermont

    Science.gov (United States)

    Levitan, D.M.; Hammarstrom, J.M.; Gunter, M.E.; Seal, R.R.; Chou, I.-Ming; Piatak, N.M.

    2009-01-01

    Samples from the surfaces of waste piles at the Vermont Asbestos Group mine in northern Vermont were studied to determine their mineralogy, particularly the presence and morphology of amphiboles. Analyses included powder X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and Raman spectroscopy. Minerals identified by XRD were serpentine-group minerals, magnetite, chlorite, quartz, olivine, pyroxene, and brucite; locally, mica and carbonates were also present. Raman spectroscopy distinguished antigorite and chrysotile, which could not be differentiated using XRD. Long-count, short-range XRD scans of the (110) amphibole peak showed trace amounts of amphibole in most samples. Examination of amphiboles in tailings by optical microscopy, SEM, and EPMA revealed non-fibrous amphiboles compositionally classified as edenite, magnesiohornblende, magnesiokatophorite, and pargasite. No fibrous amphibole was found in the tailings, although fibrous tremolite was identified in a sample of host rock. Knowledge of the mineralogy at the site may lead to better understanding of potential implications for human health and aid in designing a remediation plan.

  20. Study of chemical-mineralogical properties of modified soils with polymers addition

    Directory of Open Access Journals (Sweden)

    Patricio Jonny

    2016-01-01

    Full Text Available On highways, the soil is considered a supported material and compound pavements layers. For this, they must have such characteristics that confer stability and mechanical resistance to traffic internal forces during the pavement life. When soils do not have required characteristics by the project can be used stabilization techniques that make the natural soil adequately to roads requirement. Based on this assumption, this study aimed to evaluate the efficacy of polymer association in soil stabilization for use in roads pavements. Were evaluated chemical and mineralogical properties on two (2 different soils with sample of pure soil and with the addition of the polymer association. Based on the obtained results, polymer association changes was observed on X-ray fluorescent spectrometry (XRF; X-ray diffraction (XRD; scanning electron microscopy (SEM and Methylene blue. In general, the polymeric association studied in this research was effective in chemical and mineralogical analyzes for use on stabilized soils, making this technique efficient for use in layers of road pavements.

  1. 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'. © 2016 The Author(s).

  2. Ultrastructure, chemistry and mineralogy of the growing shell of the European abalone Haliotis tuberculata.

    Science.gov (United States)

    Auzoux-Bordenave, Stéphanie; Badou, Aïcha; Gaume, Béatrice; Berland, Sophie; Helléouet, Marie-Noëlle; Milet, Christian; Huchette, Sylvain

    2010-09-01

    An integrated study of shell formation was initiated covering the entire life cycle of the marine gastropod Haliotis tuberculata. Shell microstructure, chemistry and mineralogy were investigated by polarized microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and infra-red (IR) spectroscopy. SEM images of trochophore and veliger larvae showed the different stages of shell growth from the initial shell field to the late calcified protoconch. Cross-sections revealed the microstructural arrangement of biominerals, showing the progressive mineralization of the organic protoconch prior to metamorphosis. To gain more information on mineralogical composition, EDX analyses and IR spectroscopy were performed along the development stages. The results demonstrated that early protoconch was mostly composed of amorphous calcium carbonate, while veliger stages showed a gradually crystallization under the form of aragonite. Post-metamorphic shell contained two distinct parts, the original protoconch supporting the new juvenile shell characterized by a marked sculptural pattern. The shells from post-larval and juvenile abalones were essentially made of aragonite. Copyright 2010 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-01

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

  5. Maps showing mineralogical data for nonmagnetic heavy-mineral concentrates in the Talkeetna Quadrangle, Alaska

    Science.gov (United States)

    Tripp, R.B.; Karlson, R.C.; Curtin, G.C.

    1978-01-01

    Reconnaissance geochemical and mineralogical sampling was done in the Talkeetna Quadrangle during 1975 and 1976 as part of the Alaska Mineral Resource Assessment Program (AMRAP). These maps show the distribution of gold, scheelite, chalcopyrite, arsenopyrite, galena, fluorite, cinnabar, and malachite in the nonmagnetic fraction of heavy-mineral concentrates. Heavy-mineral concentrate samples were collected at 812 sites from active stream channels. The heavy-mineral concentrates were obtained by panning stream sediment in the field to remove most of the light minerals. The panned samples were then sieved through a 20-mesh (0.8 mm) sieve in the laboratory, and the minus-20-mesh fraction was further separated with bromoform (specific gravity, 2.86) to remove any remaining light-mineral grains. Magnetite and other strongly magnetic heavy minerals were removed from the heavy-mineral fraction by use of a hand magnet. The remaining sample was passed through a Frantz Isodynamic Separator and a nonmagnetic fraction was examined for its mineralogical content with the aid of a binocular microscope and an x-ray diffractometer. The nonmagnetic concentrates primarily contain phyllite fragments, muscovite, sphene, zircon, apatite, tourmaline, rutile, and anatase. Most ore and ore-related minerals also occur in this fraction.

  6. Nebula Models of Non-Equilibrium Mineralogy: Wark-Lovering Rims

    Science.gov (United States)

    Cuzzi, J. N.; Petaev, M.; Krot, A. N.

    2005-01-01

    Introduction: The meteorite record contains several examples of minerals that would not persist if allowed to come to equilibrium with a cooling gas of solar composition. This includes all minerals in CAIs and AOAs. Their survival is generally ascribed to physical removal of the object from the gas (isolation into a large parent object, or ejection by a stellar wind), but could also result from outward radial diffusion into cooler regions, which we discuss here. Accretion of CAIs into planetesimals has also been relied on to preserve them against loss into the sun. However, this suggestion faces several objections. Simple outward diffusion in turbulence has recently been modeled in some detail, and can preserve CAIs against loss into the sun [2]. Naturally, outward radial diffusion in turbulence is slower than immediate ejection by a stellar wind, which occurs on an orbital timescale. Here we ask whether these different transport mechanisms can be distinguished by nonequilibrium mineralogy, which provides a sort of clock. Our application here is to one aspect of CAI mineralogy - the Wark-Lovering rims (WLR); even more specifically, to alteration of one layer in the WLR sequence from melilite (Mel) to anorthite (An).

  7. 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.

  8. The effects of carbon dioxide on the mineralogical and geochemical alterations of phyllosilicate minerals

    Science.gov (United States)

    Wang, Sookyun; Park, Eundoo; Lee, Minhee

    2014-05-01

    This study aims to identify the geochemical and mineralogical effects of carbon dioxide stored in geological formations on subsurface environments in deep rock formations. A series of autoclave experiments were conducted to simulate the interactions in the scCO2-groundwater-phyllosilicate minerals reaction systems using a high pressure and high temperature cells at 50C and 100 bar. Kaolinite and montmorillonite were used as geological materials reactive in CO2-rich acidic environments, and groundwater sampled from a 800-depth well were applied as aqueous solutions. The dissolution characteristics of phyllosilicate minerals and their geochemical and mineralogical alternations after 30-days reactions were quantitatively examined by XRD, XRF, ICP-OES and SEM/EDX investigation. Throughout experimental processes, it was observed that the acidic environments induced by the dissolution of CO2 resulted in the changes in pH and cation concentration in the aqueous phase, and, thereby, the mineral phase changes in composition and interlayer spacing. The experimental results clearly showed an enhanced dissolution of kaolinite and montmorillonite with the presence of CO2. They also suggested that geochemical processes such as dissolution/precipitation and cation exchange played major roles in physical and chemical changes in pore structure and groundwater in relevant formations and aquifers.

  9. 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.

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

    Science.gov (United States)

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

    2017-01-01

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

  11. 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.

  12. Mineralogical variation of skarn ore from the Tellerhäuser deposit, Pöhla, Germany

    Science.gov (United States)

    Simons, Bethany; Andersen, Jens Christian; Rollinson, Gavyn; Armstrong, Robin; Dolgopolova, Alla; Seltmann, Reimar; Stanley, Chris; Roscher, Marco

    2017-04-01

    The polymetallic Zn-Fe-Sn-Cu-In skarns at Pöhla Tellerhäuser in the western Erzgebirge represent some of the largest unexploited occurrences of Sn and In in Europe. The skarns developed in schists and gneisses at the margin of the Schwarzenberg Gneiss cupola and the Eibenstock granites. The flat-lying skarn layers display extreme mineralogical variability with alternating units of pyroxene, sphalerite, magnetite, amphibole and calc-silicate skarns with hanging wall schist and feeder stockwork. The polymetallic skarn ores represent a complex challenge for mineral processing, with fine-grained, locked target minerals and partitioning of target metals into silicates (e.g. Sn in malayaite). Optical microscopy, QEMSCAN® and electron-probe microanalysis have been used to determine the mineralogical variability of the skarn types with the aim to determine the deportment of the target metals to guide mineral processing test work. The composition of the skarns is extremely variable reflecting the complex mineralogy and indicating substantial variability associated with replacement reactions through the protolith(s). Cassiterite (SnO2) is the dominant Sn-bearing mineral in all the skarn types. However, the skarns also carry malayaite (CaSnO[SiO4], up to 0.03 vol%), which locally dominates over cassiterite. Cassiterite is intergrown with Fe-amphibole, grossular garnet, fluorite and magnetite. The cassiterite is unaltered, but some grains have rare iron oxide rims and inclusions. Malayaite shows a similar association to cassiterite and is intergrown as clusters of grains with silicate gangue, particularly Fe amphibole and grossular garnet and remains unaltered with no inclusions. Zinc is exclusively hosted in sphalerite and varies from 0.02 wt.% in the hanging wall schist to 36.5 wt.% in the sphalerite skarn. The high Zn values are accompanied by high values of Cd (locally in excess of 1000 ppm) and In (up to 180 ppm). Sphalerite grains are locally up to 4 mm, subhedral

  13. Multi-scale Modeling of Plasticity in Tantalum.

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hojun [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Battaile, Corbett Chandler. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Carroll, Jay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Buchheit, Thomas E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boyce, Brad [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Weinberger, Christopher [Drexel Univ., Philadelphia, PA (United States)

    2015-12-01

    In this report, we present a multi-scale computational model to simulate plastic deformation of tantalum and validating experiments. In atomistic/ dislocation level, dislocation kink- pair theory is used to formulate temperature and strain rate dependent constitutive equations. The kink-pair theory is calibrated to available data from single crystal experiments to produce accurate and convenient constitutive laws. The model is then implemented into a BCC crystal plasticity finite element method (CP-FEM) model to predict temperature and strain rate dependent yield stresses of single and polycrystalline tantalum and compared with existing experimental data from the literature. Furthermore, classical continuum constitutive models describing temperature and strain rate dependent flow behaviors are fit to the yield stresses obtained from the CP-FEM polycrystal predictions. The model is then used to conduct hydro- dynamic simulations of Taylor cylinder impact test and compared with experiments. In order to validate the proposed tantalum CP-FEM model with experiments, we introduce a method for quantitative comparison of CP-FEM models with various experimental techniques. To mitigate the effects of unknown subsurface microstructure, tantalum tensile specimens with a pseudo-two-dimensional grain structure and grain sizes on the order of millimeters are used. A technique combining an electron back scatter diffraction (EBSD) and high resolution digital image correlation (HR-DIC) is used to measure the texture and sub-grain strain fields upon uniaxial tensile loading at various applied strains. Deformed specimens are also analyzed with optical profilometry measurements to obtain out-of- plane strain fields. These high resolution measurements are directly compared with large-scale CP-FEM predictions. This computational method directly links fundamental dislocation physics to plastic deformations in the grain-scale and to the engineering-scale applications. Furthermore, direct

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

    Science.gov (United States)

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

    2011-01-01

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

  15. Nucleation and thickening of shear bands in nano-scale twin/matrix lamellae of a Cu-Al alloy processed by dynamic plastic deformation

    DEFF Research Database (Denmark)

    Hong, C.S.; Tao, N.R.; Huang, Xiaoxu

    2010-01-01

    to be a two-stage process, namely a nucleation stage resulting in a narrow band composed of nano-sized (sub)grains intersecting the T/M lamellae, followed by a thickening stage of the narrow band into adjacent T/M lamellae regions. The nucleation stage occurred within a narrow region of an almost constant......Microstructural evolution associated with the shear banding in nano-scale twin/matrix (T/M) lamellae of a Cu–Al alloy processed by means of dynamic plastic deformation was investigated using transmission electron microscopy (TEM) and high-resolution TEM. The development of a shear band was found...... strain gradients accommodated by high density of dislocations. Increasing shear strains leads to thickening of shear bands at the expense of the adjoining T/M lamellae, which is composed of thickening of the core region by transforming the TRLs into the core region with DDS and NGS, analogous to steps (2...

  16. Geology, mineralogy and ore fluid characteristics of the Masjed Daghi gold bearing veins system, NW Iran

    Directory of Open Access Journals (Sweden)

    Susan Ebrahimi

    2017-11-01

    Full Text Available Introduction The Masjed- Daghi gold deposit lies in an area of widespread Cenozoic volcanic and plutonic rocks at the intersection of the Alborz- Azarbaijan and Urumieh- Dokhtar belts. The area was covered by a detailed exploration program, including geological maps at 1:1,000 scales (~8 km², several hundred meters of trenches and systematic sampling for Au, Ag, Pb, Zn, Cu, As, Hg analysis, and 16 diamond drill holes at a total of 1200 meters (Mohammadi et al, 2005. The vein type gold deposit in Masjed- Daghi is closely associated with a porphyry type Cu-Au deposit. Our study focuses on the gold bearing veins system in an attempt to understand the characteristics of ore fluids and mechanisms of ore formation, and to develop exploration criteria for Masjed Daghi and similar occurrences in Alborz and other Cenozoic magmatic assemblages in Iran. Materials and methods Various rock types, alteration assemblages and mineral parageneses were characterized by transmitting and reflected light microscopy, X-ray diffraction (XRD and electron microprobe analysis. Microprobe analyses were performed using a JEOL 8600 Superprobe electron microprobe at Saskatchewan University. Operating conditions were an accelerating voltage of 15 kV and a beam current of 50 nA. Representative samples from drill holes were selected for fluid inclusion studies. Fluid inclusion data were obtained using a fluid Inc. adapted USGS gas flow heating and freezing system at the Department of Geological Science at the University of Saskatchewan, Canada. To investigate the source of ore fluids, representative sulfidic samples from drill holes were selected for sulfur isotope studies. Isotopic analyses were performed using a Thermo Finnigan DeltaPlus at the G.G. Hatch Stable Isotope Laboratories, University of Ottawa. The standard error of analyses is less than ±0.1 per mil. Results Auriferous quartz veins in Masjed- Daghi are associated with porphyry style mineralization. Various

  17. Investigation on type and origin of iron mineralization at Mesgar occurrence, south of Zanjan, using petrological, mineralogical and geochemical data

    Directory of Open Access Journals (Sweden)

    Mohammad Ebrahimi

    2015-04-01

    Full Text Available Introduction Mesgar iron occurrence is located in northwestern part of the Central Iran, 115 km south of Zanjan. Although there is a sequence of volcanic-pyroclastic rocks accompanied by iron mineralization, no detailed works had been conducted in the area. The present paper provides an overview of the geological framework, the mineralization characteristics, and the results of geochemical study of the Mesgar iron occurrence with an application to the ore genesis. Identification of these characteristics can be used as a model for exploration of this type of iron mineralization in the Central Iran and elsewhere. Materials and methods Detailed field work has been carried out at different scales in the Mesgar area. About 16 polished thin and thin sections from host rocks and mineralized and altered zones were studied by conventional petrographic and mineralogic methods at the Department of Geology, University of Zanjan. In addition, a total of 3 samples from least-altered volcanic host rocks and 2 samples from ore zones from the Mesgar occurrence were analyzed by ICP-MS and ICP-OES for whole-rock major and trace elements and REE compositions at the Zarazma Laboratories, Tehran, Iran. Results and Discussion Based on field observation, rock units exposed in the Mesgar area consist of Miocene sedimentary rocks and volcanic-pyroclastic units (Rādfar et al., 2005. The pyroclastic units consist of volcanic breccia and agglomerate. They lie concordantly on the Miocene sedimentary units, and are in turn concordantly overlain by andesitic basalt lavas. The lavas show porphyritic texture consisting of plagioclase (up to 3 mm in size and pyroxene phenocrysts set in a fine-grained to glassy groundmass. Seriate, cumulophyric, glomeroporphyritic and trachytic textures are also observed. Iron mineralization occurs as vein and lens-shaped bodies within and along the contacts of pyroclastic (footwall and andesitic basalt lavas (hanging wall. The veins reach up to

  18. Geochemical and mineralogical constraints on the distribution and enrichment of the rare earth elements during pedogenesis and tropical weathering

    Science.gov (United States)

    Hardy, Liam; Smith, Martin; Moles, Norman; Marsellos, Antonios

    2015-04-01

    ? These results will then be applied in targeted, environmentally focused exploration projects, and perhaps enhance techniques used industrially for the extraction of HREEs, for less environmentally damaging production in sensitive areas (with current research sites within national parks in Italy and Portugal; and in areas where it is believed more attention should be paid to environmental preservation, including Central Turkey and Southern China). It is hypothesised that: HREE content in tropical laterite formations is due primarily to the source rock's mineralogy, although it's distribution is a result of slower genesis and leaching as opposed to more common biogenetic pedogenesis. It is suggested this distribution initially forms banded horizontal enrichment zones according to protolith, but eventual separation of heavy and light REEs is controlled by clay-surface (the protolith's weathering style), solvent type, fluctuation and availability. It may be found, as in Fe-Ni laterite resources globally (Herrington, Boni, Skarpelis, & Large, 2007) (Eliopoulos, 2000), that high initial bedrock concentrations of REEs are not necessarily required if prolonged weathering continues to concentrate these elements/minerals over longer periods (although this has been found inversely in certain Turkish bauxites (Karadag˘, Peli, Ary, & Ayhan, 2008)). Regardless of eventual concentrations, identifying the argillic phase and the time scales required for clay REE hosting clay formation may broaden the European search for supergene enrichments to REE hosting marine shales, mineral sands and other sedimentary formations that have been long-term- weathered without major displacement.

  19. Visible and Near-IR Reflectance Spectra of Smectite Acquired Under Dry Conditions for Interpretation of Martian Surface Mineralogy

    Science.gov (United States)

    Morris, Richard V.; Achilles, Cherie N; Archer, Paul D.; Graff, Trevor G.; Agresti, David G.; Ming, Douglas W; Golden, Dadi C.; Mertzman, Stanley A.

    2011-01-01

    Visible and near-IR (VNIR) spectra from the MEx OMEGA and the MRO CRISM hyper-spectral imaging instruments have spectral features associated with the H2O molecule and M OH functional groups (M = Mg, Fe, Al, and Si). Mineralogical assignments of martian spectral features are made on the basis of laboratory VNIR spectra, which were often acquired under ambient (humid) conditions. Smectites like nontronite, saponite, and montmorillionite have interlayer H2O that is exchangeable with their environment, and we have acquired smectite reflectance spectra under dry environmental conditions for interpretation of martian surface mineralogy. We also obtained chemical, Moessbauer (MB), powder X-ray diffraction (XRD), and thermogravimetric (TG) data to understand variations in spectral properties. VNIR spectra were recorded in humid lab air at 25-35C, in a dynamic dry N2 atmosphere (50-150 ppmv H2O) after exposing the smectite samples (5 nontronites, 3 montmorillionites, and 1 saponite) to that atmosphere for up to approximately l000 hr each at 25-35C, approximately 105C, and approximately 215C, and after re-exposure to humid lab air. Heating at 105C and 215C for approximately 1000 hr is taken as a surrogate for geologic time scales at lower temperatures. Upon exposure to dry N2, the position and intensity of spectral features associated with M-OH were relatively insensitive to the dry environment, and the spectral features associated with H2O (e.g., approximately 1.90 micrometers) decreased in intensity and are sometimes not detectable by the end of the 215C heating step. The position and intensity of H2O spectral features recovered upon re-exposure to lab air. XRD data show interlayer collapse for the nontronites and Namontmorillionites, with the interlayer remaining collapsed for the latter after re-exposure to lab air. The interlayer did not collapse for the saponite and Ca-montmorillionite. TG data show that the concentration of H2O derived from structural OH was invariant

  20. Evaporite caprock integrity: an experimental study of reactive mineralogy and pore-scale heterogeneity during brine-CO2 exposure.

    Science.gov (United States)

    Smith, Megan M; Sholokhova, Yelena; Hao, Yue; Carroll, Susan A

    2013-01-02

    We present characterization and geochemical data from a core-flooding experiment on a sample from the Three Fingers evaporite unit forming the lower extent of caprock at the Weyburn-Midale reservoir, Canada. This low-permeability sample was characterized in detail using X-ray computed microtomography before and after exposure to CO(2)-acidified brine, allowing mineral phase and voidspace distributions to be quantified in three dimensions. Solution chemistry indicated that CO(2)-acidified brine preferentially dissolved dolomite until saturation was attained, while anhydrite remained unreactive. Dolomite dissolution contributed to increases in bulk permeability through the formation of a localized channel, guided by microfractures as well as porosity and reactive phase distributions aligned with depositional bedding. An indirect effect of carbonate mineral reactivity with CO(2)-acidified solution is voidspace generation through physical transport of anhydrite freed from the rock matrix following dissolution of dolomite. The development of high permeability fast pathways in this experiment highlights the role of carbonate content and potential fracture orientations in evaporite caprock formations considered for both geologic carbon sequestration and CO(2)-enhanced oil recovery operations.

  1. High-resolution mineralogical and rock magnetic study of ferromagnetic phases in metabasites from Oscar II Land, Western Spitsbergen—towards reliable model linking mineralogical and palaeomagnetic data

    Science.gov (United States)

    Burzyński, Mariusz; Michalski, Krzysztof; Nejbert, Krzysztof; Domańska-Siuda, Justyna; Manby, Geoffrey

    2017-07-01

    Typical 'whole rock' rock magnetic analyses are limited to the identification of the magnetic properties of the mixture of all ferromagnetic minerals within the samples. In this contribution standard 'whole rock' rock magnetic studies of two types of metabasites (metadolerites and metavolcanics) from the metamorphic Proterozoic-Lower Palaeozoic complex of Oscar II Land (Western Spitsbergen) are followed by separation of Fe-containing fractions and conducting magnetic analyses on Fe-containing separates. The main aim here is to determine if any ferromagnetic carriers of a palaeomagnetic signal preceding the Caledonian metamorphism persisted in the metabasites. A comprehensive set of applied methods has allowed for the precise identification of the ferromagnetic carriers and have revealed their textural context in the investigated rocks. The results of mineralogical and rock magnetic analyses of separates confirmed a dominance of low coercivity magnetite/maghemite and pyrrhotite in the metadolerites while in the metavolcanics the existence of magnetite/maghemite and hematite was highlighted. Our investigations support the hypothesis that Caledonian metamorphic remineralization has completely replaced the primary magmatic - Proterozoic/Lower Palaeozoic ferromagnetic minerals in the metadolerites. In the case of the metavolcanics, however, the existence of the ferromagnetic pre-Caledonian relicts cannot be excluded. Furthermore, this approach provided a unique opportunity for conducting rock magnetic experiments on natural mono-ferromagnetic fractions. The described methodologies and results of this study form a new approach that can be applied in further palaeomagnetic and petrographic studies of metamorphosed rock complexes of Svalbard.

  2. Technical note: Mineralogical, chemical, morphological, and optical interrelationships of mineral dust re-suspensions

    Directory of Open Access Journals (Sweden)

    J. P. Engelbrecht

    2016-08-01

    Full Text Available This paper promotes an understanding of the mineralogical, chemical, and physical interrelationships of re-suspended mineral dusts collected as grab samples from global dust sources. Surface soils were collected from arid regions, including the southwestern USA, Mali, Chad, Morocco, Canary Islands, Cabo Verde, Djibouti, Afghanistan, Iraq, Kuwait, Qatar, UAE, Serbia, China, Namibia, Botswana, Australia, and Chile. The  <  38 µm sieved fraction of each sample was re-suspended in a chamber, from which the airborne mineral dust could be extracted, sampled, and analyzed. Instruments integrated into the entrainment facility included two PM10 and two PM2.5 filter samplers, a beta attenuation gauge for the continuous measurement of PM10 and PM2.5 particulate mass fractions, an aerodynamic particle size analyzer, and a three-wavelength (405, 532, 781 nm photoacoustic instrument with integrating reciprocal nephelometer for monitoring absorption and scattering coefficients during the dust re-suspension process. Filter sampling media included Teflon® membrane and quartz fiber filters for chemical analysis and Nuclepore® filters for individual particle analysis by scanning electron microscopy (SEM. The  <  38 µm sieved fractions were also analyzed by X-ray diffraction for their mineral content while the  >  75,  <  125 µm soil fractions were mineralogically assessed by optical microscopy. Presented here are results of the optical measurements, showing the interdependency of single-scattering albedos (SSA at three different wavelengths and mineralogical content of the entrained dust samples. To explain the elevated concentrations of iron (Fe and Fe ∕ Al ratios in the soil re-suspensions, we propose that dust particles are to a large extent composed of nano-sized particles of micas, clays, metal oxides, and ions of potassium (K+, calcium (Ca2+, and sodium (Na+ evenly dispersed as a colloid or adsorbed in amorphous

  3. Mineralogy of the North Polar Sands of Mars from MGS/TES Observations

    Science.gov (United States)

    Bell, James F.; Horgan, B. N. H.; Noe Dobrea, E. Z.

    2009-09-01

    The north polar region of Mars has had a complex geologic history, part of which has involved aqueous processes. A major surface unit in this region is a large (4.7 million km2), low albedo area of sand dunes/sheets (the north polar erg) spanning the circumpolar plains. We are investigating the mineralogy and geologic history of the erg using a variety of data sets, including mid-IR spectra from MGS/TES and near-IR spectra from MEx/OMEGA. The southernmost extent of this deposit extends into Acidalia Planitia, where it is the type locality for the TES "ST2" global compositional endmember. We are using TES and OMEGA data to identify the primary (mafic) mineralogy of these sand deposits, and to explore the processes and relationships between these primary minerals and previously-identified secondary alteration products in the region like polyhydrated sulfates. Our TES data subset, chosen from generally warm (> 250K), high-quality spectra taken through relatively clear atmospheric conditions, consists of several thousand emissivity spectra at latitudes above 70N. We are performing atmospheric corrections and deriving estimated mineral abundances for these spectra using a previously-developed iterative linear matrix inversion spectral unmixing method (Noe Dobrea et al., 2006: doi:10.1029/2005JE002431) and laboratory-derived mineral endmembers from the TES library. Using 68 spectrally-unique endmembers, we compute best-fit abundances for all possible endmember combinations and estimate average abundances for each mineral. Minerals not detected above a minimum detection threshold are discarded, which then allows us to converge on the most statistically accurate representation of the likely mineral assemblage. Initial results of modeling average polar erg spectra reveals an "expected" mafic assemblage (olivine, pyroxene, feldspar) plus a silica-bearing amorphous phase. "Unexpected" phases identified include Mg-, Al-, and Fe-bearing sulfates and iron oxides. Our results

  4. Effects of thermal treatment on mineralogy and heavy metal behavior in iron oxide stabilized air pollution control residues

    DEFF Research Database (Denmark)

    Sørensen, Mette Abildgaard; Bender-Koch, C.; Starckpoole, M. M.

    2000-01-01

    Stabilization of air pollution control residues by coprecipitation with ferrous iron and subsequent thermal treatment (at 600 and 900 °C) has been examined as a means to reduce heavy metal leaching and to improve product stability. Changes in mineralogy and metal binding were analyzed using various...

  5. Original Mineralogy and Recognition of Upper Boundary of the Sarvak Formation Based on Geochemistry and Isotope Studies

    DEFF Research Database (Denmark)

    Asgari, M; Tahmasebi Poor, A; Barari, Amin

    2014-01-01

    elements and carbon and oxygen isotope values and bivariate plot of them indicate that aragonite was the original carbonate mineralogy of the Sarvak Formation. Variations of Sr/Ca and delta O-18 values versus Mn also illustrate that they were affected by nonmarine diagenesis in a nearly closed system...

  6. Matrix mineralogy of the Lance CO3 carbonaceous chondrite - A transmission electron microscope study

    Science.gov (United States)

    Keller, Lindsay P.; Buseck, Peter R.

    1990-01-01

    Results are presented on electron microprobe analyses of three CO chondrites, all of which are falls: Lance, Kainsaz, and Warrenton. The TEM mineralogy results of Lance chondrite show that Fe-rich matrix olivines have been altered to Fe-bearing serpentine and Fe(3+) oxide; matrix metal was also altered to produce Fe(3+) oxides, leaving the residual metal enriched in Ni. Olivine grains in Lance's matrix contain channels along their 100-line and 001-line directions; the formation and convergence of such channels resulted in a grain-size reduction of the olivine. A study of Kainsaz and Warrenton showed that these meteorites do not contain phyllosilicates in their matrices, although both contain Fe(3+) oxide between olivine grains. It is suggested that, prior to its alteration, Lance probably resembled Kainsaz, an unaltered CO3 chondrite.

  7. Infrared detection of the mineralogical aspects that influence the processing of calcined kaolin

    Science.gov (United States)

    Groenheide, Stefan; Guatame-Garcia, Adriana; Buxton, Mike; van der Werff, Harald

    2017-04-01

    Calcined kaolin is an industrial minerals product used in the production of paper, paint, rubber and other specialty applications. It is produced from kaolinite through a series of refinement steps and final calcination at temperatures of above 900°C, with the aim of generating a whiter and more abrasive material. The raw kaolin ore is a mixture of clay minerals, quartz and feldspars, where kaolinite is the main constituent. The optimal kaolin ores to feed the processing plant should ideally have high kaolinite abundance, be free in Fe-bearing mineralogy (to avoid influence in the colour of the product), and the kaolinite itself should be of high crystallinity (to ensure the correct abrasiveness after calcination). This work presents a case study from the kaolin deposits in the St. Austell Granite (South-West England), which are known for their high quality and world-class size. In this area, the kaolin is of primary-hydrothermal origin, with mineral associations that are related to the genetic history. The eventual depletion of the high-quality reserves is bringing now the attention to the lower grade zones, where the amount of impurities increases. As a consequence, it is critical to developing strategies that ensure the supply of high-quality ore to the processing plant. For this, it is necessary to acquire a thorough knowledge of the ore, including relative abundance of the minerals and their textural relationships. Hyperspectral images in the visible-near infrared (VNIR) and short-wave infrared (SWIR) ranges were collected from drill cores and run-off-mine (ROM) samples, obtained from one of the kaolin pits in the St. Austell area, where the kaolin quality is known to be lower than in the rest of the deposit. A series of mineral maps were generated to assess the distribution, texture and abundance of the Fe-bearing mineralogy and the other kaolin-associated minerals, as well as the variations in the crystallinity of kaolinite. The mineral maps enabled the

  8. Chemical composition of two mineralogically contrasting Arctic bivalves' shells and their relationships to environmental variables.

    Science.gov (United States)

    Iglikowska, A; Bełdowski, J; Chełchowski, M; Chierici, M; Kędra, M; Przytarska, J; Sowa, A; Kukliński, P

    2017-01-30

    The main goal of this study was to determine the concentrations of trace elements in the mineralogically contrasting shells of two Arctic bivalves: Chlamys islandica and Ciliatocardium ciliatum. Aragonite shells seem to be more susceptible to the binding of metal ions, which is most likely a result of their crystal lattice structure. We suggest that less biologically controlled aragonite mineralization tends to incorporate more metal impurities into the crystal lattice in waters with a lower pH, where metal ions are more available. Higher concentrations of impurities may further increase the lattice distortion causing lower crystal lattice stability and higher susceptibility to dissolution. Calcitic shells seem to be less prone to bind metal ions than aragonite shells most likely because under strict biological control, the uptake of ions from ambient seawater is more selective; thus, the final crystal lattice is less contaminated by other metals and is more resistant to dissolution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.; hide

    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.

  15. Mineralogy and Oxygen Isotope Compositions of Two C-Rich Hydrated Interplanetary Dust Particles

    Science.gov (United States)

    Snead, C. J.; McKeegan, K. D.; Messenger, S.; Nakamura-Messenger, K.

    2012-01-01

    Oxygen isotopic compositions of chondrites reflect mixing between a O-16-rich reservoir and a O-17,O-18-rich reservoir produced via mass-independent fractionation. The composition of the O-16-rich reservoir is reasonably well constrained, but material representing the O-17,O-18-rich end-member is rare. Self-shielding models predict that cometary water, presumed to represent this reservoir, should be enriched in O-17 and O-18 18O by > 200%. Hydrated interplanetary dust particles (IDPs) rich in carbonaceous matter may be derived from comets; such particles likely contain the products of reaction between O-16-poor water and anhydrous silicates that formed in the inner solar system. Here we present mineralogy and oxygen isotope compositions of two C-rich hydrated IDPs, L2083E47 and L2071E35.

  16. Mineralogy. Discovery of bridgmanite, the most abundant mineral in Earth, in a shocked meteorite.

    Science.gov (United States)

    Tschauner, Oliver; Ma, Chi; Beckett, John R; Prescher, Clemens; Prakapenka, Vitali B; Rossman, George R

    2014-11-28

    Meteorites exposed to high pressures and temperatures during impact-induced shock often contain minerals whose occurrence and stability normally confine them to the deeper portions of Earth's mantle. One exception has been MgSiO3 in the perovskite structure, which is the most abundant solid phase in Earth. Here we report the discovery of this important phase as a mineral in the Tenham L6 chondrite and approved by the International Mineralogical Association (specimen IMA 2014-017). MgSiO3-perovskite is now called bridgmanite. The associated phase assemblage constrains peak shock conditions to ~ 24 gigapascals and 2300 kelvin. The discovery concludes a half century of efforts to find, identify, and characterize a natural specimen of this important mineral. Copyright © 2014, American Association for the Advancement of Science.

  17. Mineralogical, Microstructural and Thermal Characterization of Coal Fly Ash Produced from Kazakhstani Power Plants

    Science.gov (United States)

    Tauanov, Z.; Abylgazina, L.; Spitas, C.; Itskos, G.; Inglezakis, V.

    2017-09-01

    Coal fly ash (CFA) is a waste by-product of coal combustion. Kazakhstan has vast coal deposits and is major consumer of coal and hence produces huge amounts of CFA annually. The government aims to recycle and effectively utilize this waste by-product. Thus, a detailed study of the physical and chemical properties of material is required as the data available in literature is either outdated or not applicable for recently produced CFA samples. The full mineralogical, microstructural and thermal characterization of three types of coal fly ash (CFA) produced in two large Kazakhstani power plants is reported in this work. The properties of CFAs were compared between samples as well as with published values.

  18. 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.

  19. 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.

  20. The Mineralogy, Chemistry, and Physics of Tropical Soils With Variable Charge Clays

    Science.gov (United States)

    Cassel, D. K.; Nielsen, D. R.

    This book is the culmination of an effort started in 1974 when the senior author started assembling information for a tropical soils course that he taught while on sabbatical leave at North Carolina State University. The literature cited throughout the book was current when the book went to press.Soil systems contain mineral and organic materials that have constant or permanent surface charges, such as montmorillonite, or constant surface potentials, usually referred to as variable charge materials. Most soil systems contain some of both kinds. In the tropics, most of the minerals with permanent charge have been severely weathered. Consequently, the surface charge of the remaining material results from adsorption of potential determining ions. This book treats the mineralogy, chemistry, and physics of the variable charge minerals and soil organic matter.

  1. Results and Implications of Mineralogical Models for Chemical Sediments at Meridiani Planum

    Science.gov (United States)

    Clark, B. C.; McLennan, S. M.; Morris, R. V.; Gellert, R.; Jolliff, B.; Knoll, A.; Lowenstein, T. K.; Ming, D. W.; Tosca, N. J.; Christensen, P. R.

    2005-01-01

    The Mars Exploration Rover (MER) "Opportunity" has explored chemically-enriched sedimentary outcrops at Meridiani Planum, Mars. In its first year, three different crater sites - Eagle, Fram and Endurance - have been explored. Nineteen high-interest outcrop rocks were investigated by first grinding a hole to reach the interior (using the Rock Abrasion Tool, RAT), and then conducting APXS (alpha particle x-ray spectrometry) analysis, MB (M ssbauer) analysis, and close up imaging (MI, microscopic imager). Sixteen elements and four Fe-bearing minerals were assayed to good accuracy in each sample, producing 380 compositional data points. The Miniature Thermal Emission Spectrometer (Mini- TES) obtained spectra on outcrop materials which provide direct indication of several mineral classes. Preliminary reports on Eagle crater and three RAT samples have been published. Chemical trends and a derived mineralogical model for all RAT d outcrop samples to date has been developed.

  2. Effect of humic acid on the uranium(VI) sorption onto phyllite and its mineralogical constituents

    Energy Technology Data Exchange (ETDEWEB)

    Schmeide, K.; Jander, R.; Heise, K.H.; Bernhard, G. [Forschungszentrum Rossendorf e.V. (FZR) (Germany). Inst. fuer Radiochemie

    1999-06-01

    The effect of humic acid (HA) on the uranium(VI) sorption onto phyllite and onto its individual main mineralogical constituents, muscovite, albite, and quartz was studied in air-equilibrated batch experiments in the pH range of 3.5 to 9.5. The uranyl(VI) and HA concentration was 1 x 10{sup -6}M and 5 mg/L, respectively. The ionic strength was held constant at 0.1 M (NaClO{sub 4} solution). A size fraction of 63 to 200 {mu}m of the solids was used, the mass loading was 12.5 g/L, and the experimental volume was 40 mL. (orig.)

  3. Mineralogical aspects of terrestrial weathering effects in chondrites from Allan Hills, Antarctica

    Science.gov (United States)

    Gooding, J. L.

    1982-01-01

    The work reported here represents a first attempt at comparing the mineralogical aspects of weathering effects in selected Antarctic chondrites with those present in a petrologically similar chondrite which was weathered in the Arizona desert. The methods of analysis employed include X-ray diffractometry, differential thermal analysis, and reflectance spectrophotometry. It is found that the dominant weathering products in the rocks are complex, multiple-phase, hydrous ferric oxides which formed by alteration of Ni-Fe metal and sulfide particles under the influence of liquid water. The Fe-oxide weathering products may comprise approximately 15-20 wt % of the most intensely weathered samples although the same samples contain not more than 5% goethite as the only well-crystallized hydrous ferric oxide.

  4. 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.

  5. 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. © 2013.

  6. Geochemistry, mineralogy, solid-phase fractionation and oral bioaccessibility of lead in urban soils of Lisbon.

    Science.gov (United States)

    Reis, A P; Patinha, C; Wragg, J; Dias, A C; Cave, M; Sousa, A J; Costa, C; Cachada, A; Ferreira da Silva, E; Rocha, F; Duarte, A

    2014-10-01

    An urban survey of Lisbon, the largest city in Portugal, was carried out to investigate its environmental burden, emphasizing metallic elements and their public health impacts. This paper examines the geochemistry of lead (Pb) and its influence on human health data. A total of 51 soil samples were collected from urban recreational areas used by children to play outdoors. The semi-quantitative analysis of Pb was carried out by inductively coupled plasma mass spectrometry after an acid digestion. X-ray diffraction was used to characterize the soil mineralogy. The solid-phase distribution of Pb in the urban soils was investigated on a subset of 7 soils, out of a total of 51 samples, using a non-specific sequential extraction method coupled with chemometric analysis. Oral bioaccessibility measurements were obtained using the Unified BARGE Method developed by the Bioaccessibility Research Group of Europe. The objectives of the study are as follows: (1) investigation of Pb solid-phase distribution; (2) interpretation of Pb oral bioaccessibility measurements; (3) integration of metal geochemistry with human health data; and (4) understanding the influence of geochemistry and mineralogy on oral bioaccessibility. The results show that the bioaccessible fraction of Pb is lower when major metal fractions are associated with less soluble soil phases such as Fe oxyhydroxides, and more increased when the metal is in the highly soluble carbonate phase. However, there is some evidence that the proportion of carbonates in the soil environment is also a key control over the oral bioaccessibility of Pb, irrespective of its solid-phase fractionation.

  7. Reviving legacy clay mineralogy data and metadata through the IEDA-CCNY Data Internship Program

    Science.gov (United States)

    Palumbo, R. V.; Randel, C.; Ismail, A.; Block, K. A.; Cai, Y.; Carter, M.; Hemming, S. R.; Lehnert, K.

    2016-12-01

    Reconstruction of past climate and ocean circulation using ocean sediment cores relies on the use of multiple climate proxies measured on well-studied cores. Preserving all the information collected on a sediment core is crucial for the success of future studies using these unique and important samples. Clay mineralogy is a powerful tool to study weathering processes and sedimentary provenance. In his pioneering dissertation, Pierre Biscaye (1964, Yale University) established the X-Ray Diffraction (XRD) method for quantitative clay mineralogy analyses in ocean sediments and presented data for 500 core-top samples throughout the Atlantic Ocean and its neighboring seas. Unfortunately, the data only exists in analog format, which has discouraged scientists from reusing the data, apart from replication of the published maps. Archiving and preserving this dataset and making it publicly available in a digital format, linked with the metadata from the core repository will allow the scientific community to use these data to generate new findings. Under the supervision of Sidney Hemming and members of the Interdisciplinary Earth Data Alliance (IEDA) team, IEDA-CCNY interns digitized the data and metadata from Biscaye's dissertation and linked them with additional sample metadata using IGSN (International Geo-Sample Number). After compilation and proper documentation of the dataset, it was published in the EarthChem Library where the dataset will be openly accessible, and citable with a persistent DOI (Digital Object Identifier). During this internship, the students read peer-reviewed articles, interacted with active scientists in the field and acquired knowledge about XRD methods and the data generated, as well as its applications. They also learned about existing and emerging best practices in data publication and preservation. Data rescue projects are a fun and interactive way for students to become engaged in the field.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Petrography and mineralogy of the ungrouped type 3 carbonaceous chondrite Dar al Gani 978

    Science.gov (United States)

    Zhang, Ai-Cheng; Yurimoto, Hisayoshi

    2013-09-01

    Dar al Gani (DaG) 978 is an ungrouped type 3 carbonaceous chondrite. In this study, we report the petrography and mineralogy of Ca,Al-rich inclusions (CAI), amoeboid olivine aggregates (AOAs), chondrules, mineral fragments, and the matrix in DaG 978. Twenty-seven CAIs were found: 13 spinel-diopside-rich inclusions, 2 anorthite-rich inclusions, 11 spinel-troilite-rich inclusions, and 1 spinel-melilite-rich inclusion. Most CAIs have a layered texture that indicates a condensation origin and are most similar to those in R chondrites. Compound chondrules represent a high proportion (approximately 8%) of chondrules in DaG 978, which indicates a local dusty chondrule-forming region and multiple heating events. Most spinel and olivine in DaG 978 are highly Fe-rich, which corresponds to a petrologic type of >3.5 and a maximum metamorphic temperature of approximately 850-950 K. This conclusion is also supported by other observations in DaG 978: the presence of coarse inclusions of silicate and phosphate in Fe-Ni metal, restricted Ni-Co distributions in kamacite and taenite, and low S concentrations in the matrix. Mineralogic records of iron-alkali-halogen metasomatism, such as platy and porous olivine, magnetite, hedenbergite, nepheline, Na-rich in CAIs, and chlorapatite, are present, but relatively limited, in DaG 978. The fine-grained, intergrowth texture of spinel-troilite-rich inclusions was probably formed by reaction between pre-existing Al-rich silicates and shock-induced, high-temperature S-rich gas on the surface of the parent body of DaG 978. A shock-induced vein is present in the matrix of DaG 978, which indicates that the parent body of DaG 978 at least experienced a shock event with a shock stage up to S3.

  13. 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 (<20 ??m), complex mixture of kaolinite, halloysite, goethite, and possibly gibbsite and lepidocrocite. The mineral 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.

  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. Use of mineralogical analysis in geotechnical assessment of rock strata for coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Colin R.; Nunt-jaruwong, Sorawit; Swanson, Jeni [School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052 (Australia)

    2005-10-17

    The fundamental geotechnical properties of sedimentary rocks from the coal-bearing Sydney Basin of New South Wales, Australia, including density, porosity, water absorption and moisture content, as well as compressive strength, have been related to the mineralogy of the materials as determined by quantitative X-ray diffraction of powdered rock samples and processing by the Rietveld-based Siroquant technique. The results show, for example, that the overall proportions of clay minerals in the rocks, as well as the types of clay minerals present, affect properties such as water absorption and moisture content. The presence of clay minerals also adds to the dry strength of silica-cemented quartz sandstones; however, the strength of finer-grained mudrocks is inversely related to the total percentage of clay minerals. Correlations have been established between the deterioration or slaking behaviour of mudrocks in water and their clay mineral content, based on either simple immersion tests or on more sophisticated slake durability index determinations. These relationships may be of significance in understanding the longer-term behaviour of rock strata when exposed in different types of mining operations. The propensity of different rocks to ignite methane in underground mines by frictional effects has also been shown to depend on the mineralogy of the rock materials, whether determined by point counting of thin sections or by Rietveld-based XRD analysis. Abundant quartz, feldspar, and rock fragments in sandstones, for example, increase the likelihood of frictional ignitions, whereas clay minerals and (especially) carbonates in the rock reduce the frictional ignition potential. Pyrite in the rocks, if present, also increases the ignition risk; pyrite undergoes exothermic oxidation at high temperatures whereas other minerals respond by simple heating due to rock-on-rock or pick-on-rock friction processes. (author)

  16. Reconstruction of the palaeoenvironment using biomarkers and clay mineralogy in loess deposits of northern Iran

    Directory of Open Access Journals (Sweden)

    A. Shahriari

    2016-10-01

    Full Text Available Introduction: Knowledge about palaeoenviroment and palaeovegetation provides information about how vegetation reacts on climate fluctuations in the past, what will help understanding current and future developments caused by e.g. climate change. Northern Iranian Loess-Plateau forms a strongly dissected landscape with steeply sloping loess hills. This loess record reflects numerous cycles of climate change and landscape evolution for the Middle to Late Quaternary period. therefore, this study was done for reconstruction of palaeoenvironment (climate and vegetation in loess-palaeosol sequences in northern Iran. Therefore, this study aims at a preliminary reconstruction of palaeovegetation and palaeoenvironment, in loess-palaeosol sequences along a cliomosequnce in Northern Iran. Materials and Methods: Two loess-palaeosol sequences (Agh Band and Nowdeh sections were chosen in Golestan province, in northern Iran and step-wise profiles were prepared. Agh Band section is located in the western most part of the Northern Iranian loess plateau and has about 50 m thickness of loess deposits. Nowdeh loess-palaeosol sequence is located about 20 km southeast of Gonbad-e Kavus, in the vicinity of the Nowdeh River. Soil sampling was done in several field campaigns in spring 2012. More than 30cm of the surface deposits were removed in order to reach for undisturbed loess and palaeosols and one mixed sample was taken from each horizonA comparison of palaeosols with modern soils formed under known Holocene climatic conditions, which are derived from substrates with similar granulometric and mineralogical composition are suited for reconstructing past climate and environment. Hence, six modern soil profiles were prepared along the climosequnce and the vegetation cover changed from grassland in the dry area to dense shrub land and forest in the moist part of the ecological gradient. For reconstruction of palaeoenvironment (climate and vegetation some basic physico

  17. 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

  18. Bulk mineralogy of the NE Syrtis and Jezero crater regions of Mars derived through thermal infrared spectral analyses

    Science.gov (United States)

    Salvatore, M. R.; Goudge, T. A.; Bramble, M. S.; Edwards, C. S.; Bandfield, J. L.; Amador, E. S.; Mustard, J. F.; Christensen, P. R.

    2018-02-01

    We investigated the area to the northwest of the Isidis impact basin (hereby referred to as "NW Isidis") using thermal infrared emission datasets to characterize and quantify bulk surface mineralogy throughout this region. This area is home to Jezero crater and the watershed associated with its two deltaic deposits in addition to NE Syrtis and the strong and diverse visible/near-infrared spectral signatures observed in well-exposed stratigraphic sections. The spectral signatures throughout this region show a diversity of primary and secondary surface mineralogies, including olivine, pyroxene, smectite clays, sulfates, and carbonates. While previous thermal infrared investigations have sought to characterize individual mineral groups within this region, none have systematically assessed bulk surface mineralogy and related these observations to visible/near-infrared studies. We utilize an iterative spectral unmixing method to statistically evaluate our linear thermal infrared spectral unmixing models to derive surface mineralogy. All relevant primary and secondary phases identified in visible/near-infrared studies are included in the unmixing models and their modeled spectral contributions are discussed in detail. While the stratigraphy and compositional diversity observed in visible/near-infrared spectra are much better exposed and more diverse than most other regions of Mars, our thermal infrared analyses suggest the dominance of basaltic compositions with less observed variability in the amount and diversity of alteration phases. These results help to constrain the mineralogical context of these previously reported visible/near-infrared spectral identifications. The results are also discussed in the context of future in situ investigations, as the NW Isidis region has long been promoted as a region of paleoenvironmental interest on Mars.

  19. 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.

  20. Comparison of the mineralogical effects of an experimental forest fire on a goethite/ferrihydrite soil with a topsoil that contains hematite, maghemite and goethite

    DEFF Research Database (Denmark)

    Nørnberg, Per; Vendelboe, Anders Lindblad; Gunnlaugsson, Haraldur Pall

    2009-01-01

    as the result of high temperature as found after forest fires. However, a body of evidence argues against these sites having been exposed to fire. In an attempt to get closer to an explanation of this Fe mineralogy, an experimental forest fire was produced. The results showed a clear mineralogical zonation down...... is in contrast to the natural sites. The conclusion from this work is that the mineralogy of these sites is not consistent with exposure to forest fire, but may instead result from long-term transformation in a reducing environment, possibly involving microbiology....

  1. 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

  2. Mineralogy of an ancient lacustrine mudstone succession from the Murray formation, Gale crater, Mars

    Science.gov (United States)

    Rampe, E. B.; Ming, D. W.; Blake, D. F.; Bristow, T. F.; Chipera, S. J.; Grotzinger, J. P.; Morris, R. V.; Morrison, S. M.; Vaniman, D. T.; Yen, A. S.; Achilles, C. N.; Craig, P. I.; Des Marais, D. J.; Downs, R. T.; Farmer, J. D.; Fendrich, K. V.; Gellert, R.; Hazen, R. M.; Kah, L. C.; Morookian, J. M.; Peretyazhko, T. S.; Sarrazin, P.; Treiman, A. H.; Berger, J. A.; Eigenbrode, J.; Fairén, A. G.; Forni, O.; Gupta, S.; Hurowitz, J. A.; Lanza, N. L.; Schmidt, M. E.; Siebach, K.; Sutter, B.; Thompson, L. M.

    2017-08-01

    The Mars Science Laboratory Curiosity rover has been traversing strata at the base of Aeolis Mons (informally known as Mount Sharp) since September 2014. The Murray formation makes up the lowest exposed strata of the Mount Sharp group and is composed primarily of finely laminated lacustrine mudstone intercalated with rare crossbedded sandstone that is prodeltaic or fluvial in origin. We report on the first three drilled samples from the Murray formation, measured in the Pahrump Hills section. Rietveld refinements and FULLPAT full pattern fitting analyses of X-ray diffraction patterns measured by the MSL CheMin instrument provide mineral abundances, refined unit-cell parameters for major phases giving crystal chemistry, and abundances of X-ray amorphous materials. Our results from the samples measured at the Pahrump Hills and previously published results on the Buckskin sample measured from the Marias Pass section stratigraphically above Pahrump Hills show stratigraphic variations in the mineralogy; phyllosilicates, hematite, jarosite, and pyroxene are most abundant at the base of the Pahrump Hills, and crystalline and amorphous silica and magnetite become prevalent higher in the succession. Some trace element abundances measured by APXS also show stratigraphic trends; Zn and Ni are highly enriched with respect to average Mars crust at the base of the Pahrump Hills (by 7.7 and 3.7 times, respectively), and gradually decrease in abundance in stratigraphically higher regions near Marias Pass, where they are depleted with respect to average Mars crust (by more than an order of magnitude in some targets). The Mn stratigraphic trend is analogous to Zn and Ni, however, Mn abundances are close to those of average Mars crust at the base of Pahrump Hills, rather than being enriched, and Mn becomes increasingly depleted moving upsection. Minerals at the base of the Pahrump Hills, in particular jarosite and hematite, as well as enrichments in Zn, Ni, and Mn, are products of

  3. "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

  4. Clay Mineralogy Studies of Soils Located on Different Geomorphic Surfaces in Jabalbarez-Jiroft Area

    Directory of Open Access Journals (Sweden)

    naser boroumand

    2017-02-01

    Full Text Available Introduction: Soil and geomorphology are closely related to each other. That is why considering geomorphic concepts in soil genesis and classification studies may cause a better understanding of soil genesis processes. Paleosols with argillic horizons were investigated on stable pediment surfaces in Jiroft area, central Iran, by Sanjari et al. (2011. They found that secondary gypsum and calcium carbonate were accumulated in mantled pediments, but moving down the slope toward lowlands, salts more soluble than gypsum have been accumulated. Clay mineralogy in soil researches helps to better studying soil genesis and development. A quantitative and qualitative study of clay minerals together with their structural composition provides valuable data on the absorption, fixation, and desorption of different cations in soils. Smectite, chlorite, illite, vermiculite, kaolinite, palygorskite, and sepiolite were reported as dominant clay minerals found in arid and semi-arid areas. The objectives of the present study are to evaluate the clay mineralogy of Jabalbarez-Jiroft soils on different geomorphic surfaces. Materials and Methods: The study area was located in Jabalbarez, 200 Km south Kerman, Central Iran. Fig. 1 showed the exact location of study area. Soil temperature and moisture regimes of the area were thermic and aridic, respectively. Hill, rock pediment, mantled pediment and piedmont alluvial plain landforms were identified, using aerial photo interpretation, topography and geological map observation, in addition to detailed field works. Air-dried soil samples were crushed and passed through a 2-mm sieve. Routine physicochemical analyses wereperformed on the samples. Undisturbed soil samples from the Bt horizon of pedons 4, 5 and 6 were chosen for micromorphology investigations. Beside, eight samples including A and C2 horizons of pedon 1, A and Bt horizon of pedon 3, Bt and Bw horizons of pedon 4, and Bt and C horizon of pedon 5 were selected for

  5. Mineralogy and environmental geochemistry of historical iron slag, Hopewell Furnace National Historic Site, Pennsylvania, USA

    Science.gov (United States)

    Piatak, Nadine; Seal, Robert

    2012-01-01

    The Hopewell Furnace National Historic Site in southeastern Pennsylvania, which features an Fe smelter that was operational in the 18th and 19th centuries, is dominated by three slag piles. Pile 1 slag, from the Hopewell Furnace, and pile 2 slag, likely from the nearby Cornwall Furnace, were both produced in cold-blast charcoal-fired smelters. In contrast, pile 3 slag was produced in an anthracite furnace. Ore samples from the nearby Jones and Hopewell mines that fed the smelter are mainly magnetite-rich with some sulfides (pyrite, chalcopyrite, sphalerite) and accessory silicates (quartz, garnet, feldspar, and clay minerals). Slag piles 1 and 2 are similar mineralogically containing predominantly skeletal and dendritic aluminian diopside and augite, skeletal forsteritic olivine, glass, rounded blebs of metallic Fe, and exotic quartz. Olivine is a major phase in all samples from pile 2, whereas it occurs in only a few samples from pile 1. Samples of the glass, euhedral spinel, metallic Fe, alabandite–oldhamite solid solution, as well as a sparse Ti carbonitride phase. The bulk chemistry of the slag is dominated by Al2O3 (8.5–16.2 wt.%), CaO (8.2–26.2 wt.%), MgO (4.2–24.7 wt.%), and SiO2 (36.4–59.8 wt.%), constituting between 81% and 97% of the mass of the samples. Piles 1 and 2 are chemically similar; pile 1 slag overall contains the highest Fe2O3, K2O and MnO, and the lowest MgO concentrations. Pile 3 slag is high in Al2O3, CaO and S, and low in Fe2O3, K2O and SiO2 compared to the other piles. In general, piles 1 and 2 are chemically similar to each other, whereas pile 3 is distinct – a conclusion that reflects their mineralogy. The similarities and differences among piles in terms of mineralogy and major element chemistry result from the different smelting conditions under which the slag formed and include the fuel source, the composition of the ore and flux, the type of blast (cold versus hot), which affects the furnace temperature, and other

  6. Geology, Mineralogy and Geochemistry of the Mount Deans Pegmatite Field, Eastern Yilgarn Craton/Australia

    Science.gov (United States)

    Dittrich, Thomas; Seifert, Thomas; Schulz, Bernhard

    2014-05-01

    Lithium-Cesium-Tantal (LCT) pegmatites are an important source for the rare metals Li, Cs and Ta, commodities that are now consumed in a rapidly increasing amount in high technology applications. Despite that LCT pegmatites are characteristic features for the Archaean geology of Western Australia, only the Greenbushes, Cattlin Creek and Wodgina deposits are currently exploited for Li and Ta. Therefore, Western Australia still possesses a great potential for the identification of additional resources for Li, Ta and possibly also Cs. The present study presents an overview of the geology, mineralogy and geochemistry of the Mount Deans pegmatite field, located c. 13 km S of Norseman, in the Eastern Goldfields Terrane of the Yilgarn Craton. The Mount Deans pegmatite field is Meso- to Neo-Archaean in age and hosted in the N-S trending Dundas Hill greenstone belt. The pegmatite field covers an area of 6 km in N-S and 4 km in E-W extension and comprises several dozens of individual pegmatite sheets and lenses. Structurally the pegmatite bodies are subdivided into two distinct types. Type I occurs predominantly in the southern part, is gently dipping (5-10°) to various directions and has variable thicknesses (3-25 m). Type II occurs in the northern part of the pegmatite field, dips steeply (50-90°) with a general N-S striking and has only a limited thickness (10 cm to 5 m). A clear distinction can also be made through their internal structure and mineralogy. Type I pegmatites exhibit a distinct structural and mineralogical zoning, whereas type II pegmatites are unzoned. Also albite, zinnwaldite, lepidolite and quartz form the bulk of the pegmatite; lepidolite is considerably more common in type II. Based on its peraluminous and strongly calc-alkaline character, as well as its enrichment in rare elements (i.e., Li, Rb, Cs, Ta, Nb, F), the pegmatites at Mount Deans are interpreted as LCT-pegmatites. However, despite the occurrence of rare element minerals like cassiterite

  7. Concepts of scale and scaling

    Science.gov (United States)

    Jianguo Wu; Harbin Li

    2006-01-01

    The relationship between pattern and process is of great interest in all natural and social sciences, and scale is an integral part of this relationship. It is now well documented that biophysical and socioeconomic patterns and processes operate on a wide range of spatial and temporal scales. In particular, the scale multiplicity and scale dependence of pattern,...

  8. Determination of lead 210 in scales from industrial processes

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Lígia S.; Moreira, Rubens M.; Kastner, Geraldo F.; Barbosa, João B.S., E-mail: ligsfaria@gmail.com, E-mail: rubens@cdtn.br, E-mail: gfk@cdtn.br, E-mail: jbsb@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-11-01

    Industrial processes such as oil and gas extraction and groundwater exploitation are examples of installations that can accumulate naturally occurring radioactive materials (NORM) during the extraction and production. Lead-210 deposits in the production can be formed by the same mechanisms that occur in the environment through the support of Radon-222, (where {sup 210}Pb is produced at {sup 222}Rn decay) or without support, as {sup 210}Pb. The objective of this work is to evaluate the mineralogical characteristics and determine the activity of lead-210 in the scales using the X-Ray Diffraction and Gamma Spectrometry techniques. Were analyzed fifteen samples, four scales from oil industry, ten scales from groundwater conductors and one for groundwater supply pipe. The highest activity found in the oil scale and groundwater conductors scale was 0.30 ± 0.06 Bq g{sup -1} and 3.80 ± 0.20 Bq g{sup -1}, respectively. (author)

  9. 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

  10. Assessing the mineralogy and hydration of rocky cores of satellites: insights from experiments and thermodynamics

    Science.gov (United States)

    Reynard, B.; Neri, A.; Sotin, C.

    2016-12-01

    Icy satellites and similar objects likely form from a mixture of hydrated rocky material, such as the CI chondrites, and various amounts of ices. Mass-balance estimates show that hydrous silicates such as serpentine, and brucite, the simple Mg-Fe hydroxide, dominate fully hydrated mineralogy. The inferred iron content of these minerals is, however, very dependent on assumptions of iron redox state, and whether it forms sulfides or segregates into a metal core. From the determination of the moment of inertia inferred from gravity measurements at Jupiter and Saturn by the Galileo and Cassini spacecraft, Ganymede and Europa would have a differentiated iron-rich core whereas Titan and Enceladus would not. Whatever the case, iron content is generally significantly higher than that of the terrestrial ultrabasic rocks used as analogs in modeling of hydrated satellite cores. Thus, we investigated the phase relations of iron-rich ultrabasic systems based on chondritic composition by combining thermodynamic modeling and preliminary high-pressure experiments. Our starting composition model is that of CI carbonaceous chondrites. Stable mineral assemblages are calculated with the PerpleX package (Connolly, 1990), assuming excess water, and various amounts of iron in the silicate phase through varying the amount of iron sulfide (troilite) or iron oxide (magnetite). Results show stable hydrated minerals are serpentine, chlorite, brucite, Na-phlogopite and in extreme cases, talc in the 1.5-5 GPa range relevant to bodies larger than about 1000 km in radius. Dehydration temperatures are extremely sensitive to the iron content, hence on the chosen amount of iron bearing phase (troilite or magnetite), and to a lower extent on average CI composition. An experimental approach was developed to simulate hydrous alteration of CI-like material. A mixture of synthetic silicates, troilite, and organic compounds, to which excess water is added, is used. Mineralogy and composition is checked

  11. 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

  12. Occurrence and Mineralogical Characteristics of Tremolite Asbestos Occurred in Boryeong area, Chungnam, South Korea

    Science.gov (United States)

    Yoon, K.; Hwang, J.; Oh, J.; Lee, H.

    2009-12-01

    Abandoned tremolite mines, which had been exploited for several decades since 1930, are distributed in Boryeong, Chungnam. It is known that tremolite asbestos is approximately 100 times more harmful than chrysotile asbestos. Recently, it become a regional social problem because lung disease (mesothelioma and lung cancer) suspect patients are largely found among the residents of the mining area. Therefore, Korean government making every endeavor to remove asbestos risk in the area. However, there is insufficiency geological and mineralogical studies for tremolite asbestos. In the present study, the occurrence and mineralogical characteristics of tremolite asbestos were studied using polarization microscope, XRD, XRF, EPMA, SEM and TEM. Mica-schist of precambrian metasedimentary rock, which is widely distributed in the area, is the host rock of tremolite deposits. The rocks are largely disturbed by faults and folds, and shows sudden changes in strike and slope of strata. Tremolite ore bodies, which show relatively light colored, mainly occur as stratiform or veinlet and some occurs in brecciated rock fragments. Tremolite is a major asbestos mineral, and chrysotile, talc, mica, chlorite and quartz occurs as associated minerals. Considerable amount of ore containing pure tremolite is found, and ores having mineral assemblages of tremolite+talc, tremolite+quartz and chrysotile+talc also occurs. From optical microscope observations, most tremolites are asbestos from that meets to the criterion (length > 5 μm, diameter 3:1) defined by the international organization (WHO, ILO), but non-asbestos form tremolites are also included. Most asbestos form tremolites have the size range of 1.0-2.0 μm width and 5-10 μm length. The length can be shorten with crushing experiments, but the width remains unchanged. Non-asbestos form hardly change to asbestos form by mechanical crushing. From comprehensive studies for geological occurrence and mineral assemblage, it is considered that

  13. Microbial sulfidogenesis in ferrihydrite-rich environments: Effects on iron mineralogy and arsenic mobility

    Science.gov (United States)

    Burton, Edward D.; Johnston, Scott G.; Bush, Richard T.

    2011-06-01

    Microbial sulfidogenesis plays a potentially important role in Fe and As biogeochemistry within wetland soils, sediments and aquifers. This study investigates the specific effects of microbial sulfidogenesis on Fe mineralogy and associated As mobility in mildly acidic (pH 6) and mildly basic (pH 8) advective-flow environments. A series of experiments were conducted using advective-flow columns, with an initial solid-phase comprising As(III)-bearing ferrihydrite-coated quartz sand. Columns for each pH treatment were inoculated with the sulfate-reducing bacteria Desulfovibrio vulgaris, and were compared to additional abiotic control columns. Over a period of 28 days, microbial sulfidogenesis (as coupled to the incomplete oxidation of lactate) caused major changes in Fe mineralogy, including replacement of ferrihydrite by mackinawite and magnetite at the in-flow end of the inoculated columns. At pH 8, the Fe 2+ produced by electron transfer between sulfide and ferrihydrite was mainly retained near its zone of formation. In contrast, at pH 6, much of the produced Fe 2+ was transported with advecting groundwater, facilitating the downstream Fe 2+-catalyzed transformation of ferrihydrite to goethite. At both pH 6 and pH 8, the sulfide-driven reductive dissolution of ferrihydrite and its replacement by mackinawite at the in-flow end of the inoculated columns resulted in substantial mobilization of As into the pore-water. At pH 8, this caused the downstream As concentrations within the inoculated columns to be greater than the corresponding abiotic column. However, the opposite occurred under pH 6 conditions, with the Fe 2+-catalyzed transformation of ferrihydrite to goethite in the inoculated columns causing a decrease in downstream As concentrations compared to the abiotic column. Although thermodynamically favorable at intermediate times and depth intervals within the inoculated columns, solid As sulfide phases were undetectable by As XANES spectroscopy. Our findings

  14. Classification, mineralogical and geochemical variations in pegmatites of the Cape Cross-Uis pegmatite belt, Namibia

    Science.gov (United States)

    Fuchsloch, Warrick C.; Nex, Paul A. M.; Kinnaird, Judith A.

    2018-01-01

    The Pan African aged Damara Orogen in Namibia is host to the Cape Cross-Uis pegmatite belt, one of several NE-trending pegmatite belts which host Li, Nb, Ta and Sn mineralisation. Field mapping and structural analysis of thirty seven pegmatite bodies has shown that the pegmatites intrude along crustal weaknesses such as fold axes and bedding planes, predominantly following the approximate NE orientated regional structural fabric. The lack of deformation together with cross-cutting relationships mapped, suggest that pegmatites were emplaced during post-tectonic extension that resulted from end-orogeny crustal relaxation. Based on mineralogy, geochemistry and ore mineralogy, three groups of pegmatites are distinguished within the Cape Cross-Uis belt. (1) The most common are the unzoned Nb-Ta-Sn type with mineralised alteration areas in the form of greisenised and albitised zones that occur sporadically in the pegmatites in various morphologies. (2) The garnet-tourmaline, crudely zoned pegmatites are slightly less common. They are granite-hosted and differ from other pegmatite types in terms of their low Rb, Sr, Nb, Ta, Sn, Cs (lithium-bearing pegmatites are rare but the most complex. They are subdivided into two groups: The Li-Nb-Ta-Sn spodumene-bearing pegmatites of the Karlowa swarm and the Li-Nb-Ta-Sn-Be petalite-bearing pegmatites of the Strathmore swarm. They are highly fractionated with typical values of Nb (206 ppm), Ta (185 ppm) and Sn (10,016 ppm). There is no spatial distribution or regional zonation of the pegmatites type relative to granite outcrops within the belt. Contrasting geochemical fractionation patterns and the lower concentrations of REE in pegmatites than in granites suggests that pegmatites resulted from varying degrees of partial melting of a muscovite-ilmenite-bearing source. The Sn, Nb and Ta in pegmatites is likely to have originated from this source rather than from assimilation of metasedimentary host rocks as clear fractionation trends

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

    Directory of Open Access Journals (Sweden)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-01

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

  17. Internal Structure and Mineralogy of Differentiated Asteroids Assuming Chondritic Bulk Composition: The Case of Vesta

    Science.gov (United States)

    Toplis, M. J.; Mizzon, H.; Forni, O.; Monnereau, M.; Prettyman, T. H.; McSween, H. Y.; McCoy, T. J.; Mittlefehldt, D. W.; DeSanctis, M. C.; Raymond, C. A.; hide

    2012-01-01

    Bulk composition (including oxygen content) is a primary control on the internal structure and mineralogy of differentiated asteroids. For example, oxidation state will affect core size, as well as Mg# and pyroxene content of the silicate mantle. The Howardite-Eucrite-Diogenite class of meteorites (HED) provide an interesting test-case of this idea, in particular in light of results of the Dawn mission which provide information on the size, density and differentiation state of Vesta, the parent body of the HED's. In this work we explore plausible bulk compositions of Vesta and use mass-balance and geochemical modelling to predict possible internal structures and crust/mantle compositions and mineralogies. Models are constrained to be consistent with known HED samples, but the approach has the potential to extend predictions to thermodynamically plausible rock types that are not necessarily present in the HED collection. Nine chondritic bulk compositions are considered (CI, CV, CO, CM, H, L, LL, EH, EL). For each, relative proportions and densities of the core, mantle, and crust are quantified. Considering that the basaltic crust has the composition of the primitive eucrite Juvinas and assuming that this crust is in thermodynamic equilibrium with the residual mantle, it is possible to calculate how much iron is in metallic form (in the core) and how much in oxidized form (in the mantle and crust) for a given bulk composition. Of the nine bulk compositions tested, solutions corresponding to CI and LL groups predicted a negative metal fraction and were not considered further. Solutions for enstatite chondrites imply significant oxidation relative to the starting materials and these solutions too are considered unlikely. For the remaining bulk compositions, the relative proportion of crust to bulk silicate is typically in the range 15 to 20% corresponding to crustal thicknesses of 15 to 20 km for a porosity-free Vesta-sized body. The mantle is predicted to be largely

  18. 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

  19. Mineralogy and environmental stability of slags from the Tsumeb smelter, Namibia

    Energy Technology Data Exchange (ETDEWEB)

    Ettler, Vojtech [Institute of Geochemistry, Mineralogy and Mineral Resources, Charles University, Albertov 6, 128 43 Prague 2 (Czech Republic)], E-mail: ettler@natur.cuni.cz; Johan, Zdenek [Bureau des Recherches Geologiques et Minieres (BRGM), av. Claude Guillemin, 45060 Orleans, cedex 2 (France); Kribek, Bohdan [Czech Geological Survey, Geologicka 6, 152 00 Prague 5 (Czech Republic); Sebek, Ondrej [Laboratories of the Geological Institutes, Charles University, Albertov 6, 128 43 Prague 2 (Czech Republic); Mihaljevic, Martin [Institute of Geochemistry, Mineralogy and Mineral Resources, Charles University, Albertov 6, 128 43 Prague 2 (Czech Republic)

    2009-01-15

    Three types of smelting slags originating from historically different smelting technologies in the Tsumeb area (Namibia) were studied: (i) slags from processing of carbonate/oxide ore in a Cu-Pb smelter (1907-1948), (ii) slags from Cu and Pb smelting of sulphide ores (1963-1970) and (iii) granulated Cu smelting slags (1980-2000). Bulk chemical analyses of slags were combined with detailed mineralogical investigation using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM/EDS) and electron microprobe (EPMA). The slags are significantly enriched in metals and metalloids: Pb (0.97-18.4 wt.%), Cu (0.49-12.2 wt.%), Zn (2.82-12.09 wt.%), Cd (12-6940 mg/kg), As (930-75,870 mg/kg) and Sb (67-2175 mg/kg). Slags from the oldest technology are composed of primary Ca- and Pb-bearing feldspars, spinels, complex Cu-Fe and Cu-Cr oxides, delafossite-mcconnellite phases and Ca-Pb arsenates. The presence of arsenates indicates that these slags underwent long-term alteration. More recent slags are composed of high-temperature phases: Ca-Fe alumosilicates (olivine, melilite), Pb- and Zn-rich glass, spinel oxides and small sulphide/metallic inclusions embedded in glass. XRD and SEM/EDS were used to study secondary alteration products developed on the surface of slags exposed for decades to weathering on the dumps. Highly soluble complex Cu-Pb-(Ca) arsenates (bayldonite, lammerite, olivenite, lavendulan) associated with litharge and hydrocerussite were detected. To determine the mineralogical and geochemical parameters governing the release of inorganic contaminants from slags, two standardized short-term batch leaching tests (European norm EN 12457 and USEPA TCLP), coupled with speciation-solubility modelling using PHREEQC-2 were performed. Arsenic in the leachate exceeded the EU regulatory limit for hazardous waste materials (2.5 mg/L). The toxicity limits defined by USEPA for the TCLP test were exceeded for Cd, Pb and As. The PHREEQC-2 calculation predicted that

  20. Geochemical,Petrological and Mineralogical Investigation of Nickeliferous Laterite Goynukbelen, Turkey.

    Science.gov (United States)

    Kabiru, Mohammed; Kumral, Mustafa; Kocaturk, Huseyin; Gumus, Lokman; Kaya, Mustafa

    2017-04-01

    The obduction and tectonically emplacement of ophiolite during late Cretaceous in the Goynukbelen terrane has acted as a potential source for the enrichment of nickeliferous laterite. These ultramafic rocks are highly susceptible to intense chemical and mechanical weathering which are very unstable at surface environment. The lithologies of the rock unit consist of Dunite and peridotite which are unstable and metamorphosed serpentinite and lizardite which are stable ore forming minerals. The laterite is formed as a result of weathering of the above rock types with interplaying role of climate and topography. The terrane provides the ingredients for the association of laterites. The geochemical, petrological and mineralogical associations of low grade laterite samples that are related to nickeliferous mineralization, the lithological profile of the area were studied looking at the different possible areas of enrichment of such a deposit. Weathering of olivine rich ultramafic rocks result in the breakdown of Magnesium and Silica which are replaced in the lattice with Nickel and Iron are precipitate as ferric hydroxide which form oxide deposit. Nickel bearing mineralogy, hydrous magnesium silicate, smectite, Violarite which is a supergene sulfide mineral that indicate weathering and oxidation of primary pentladite, ullmannite which replaces awaruite in it mineral form, Nickeline,Trevorite, Rammelsbergite and gerdoffite also seen. Petrographic indication shows that serpentinization benefic the Nickeliferous ore forming process as they provide adequate texture and porosity for water channel that facilitate the hydrolysis which breakdown silica, increasing the instability of the rock while paving a way for the formation of lizardite which is an ore forming mineral. From the geochemical analyses the Nickel concentration ranges from 1000-4000PPM. Nickeliferous laterite indicates a supergene enrichment which is favour by the ultramafic parent rock, climate and topography

  1. Mineralogy and Geochemistry of Neogene Terrestrial Sediments from North- East of Malatya (Eastern Turkey)

    Science.gov (United States)

    Akkoca, Dicle Bal; Tatar, Cihan

    2017-04-01

    This study focuses on the Neogene alluvial fan deposits at the North- East of Malatya (Eastern Turkey). These alluvial fan sediments are largely the products of stream deposition during Upper Miocene - Pliocene. Previous sedimentary studies suggest that most of the alluvial input into the basin was from the the north, northeast, and east. Paleozoic-Mesozoic Metamorphics, the Oligocene - marine sediments, the Miocene Yamadaǧ Volcanics, and Neogene alluvial and intercalated lacustrine rocks comprise the main lithologic units in the area. Alluvial sediments are ocur in successive mudstone, sandstone and conglomerates. Macroscobic determinations show that clastics in the alluviums are derived from Yamadaǧ Volcanics which are at the north, northeast, and east of the alluviums. Previous petrographic studies show that these volcanics are composed of basaltic andesite to dacite in composition with typical calc-alkaline character. The aim of this study is to interpret the mineralogical and geochemical characteristics of source area of these alluviums. Samples were collected from these alluvial fan alluviums, and X - ray powder diffraction (XRD), ICP-AES, ICP-MS were performed on these samples, Samples consist of clay minerals, calcite, feldspar, quartz and dolomite. Clay minerals were smectite, illite, mixed layer smectite-illite,and palygorskite, with Ca-smectite being the dominant clay phase. Smectite was derived from the transformation of volcanic glass and volcanic rock fragments. These samples are convenient with Fe shales and shales. The ratios of Zr/TiO2, Th/Sc, Zr/Sc, Y/Ni-Cr/V, Al/(Al+Fe+Mn) show dominance of neutral-basic volcanism in the area. Chondrite-normalized REE diagram show the presence of REE-bearing accessory minerals resulted in a positive LREE anomaly with respect to chondrite. Eu/Eu* values are between 0.77 and 1.53, (average 1.17). The absence of Eu anomalies shows that our samples are generally neutral-basic in composition. Key Words: Mineralogy

  2. Unique Mineralogy of Triassic Diamondiferous Hypabyssal Kimberlite Postdated Siberian Flood Basalt (sfb) Province

    Science.gov (United States)

    Sobolev, N. V.; Sobolev, A. V.; Tomilenko, A. A.; Schertl, H. P.; Neuser, R. D.; Timina, T. Y.; Karmanov, N. S.; Batanova, V. G.; Logvinova, A. M.; Kuzmin, D.

    2014-12-01

    The Siberian flood basalt (SFB) province is the largest terrestrial province with the estimated volume of igneous rocks up to 5 million cubic km. The majority of SFB erupted over less than one million years at 251 Ma. The main epochs of kimberlites emplacement took place in Devonian (344-364 Ma) producing principal diamond mines including Udachnaya mine and in Triassic (about 240 Ma) with only one, Malokuonapskaya kimberlite pipe with near-commercial diamond grade. This indicates the availability of complete lithospheric cross section. It contains flood basalt and peridotite xenoliths. We report here preliminary data on mineralogy of this hypabyssal kimberlite containing fresh olivine. Homogeneous cores of zoned olivine with Fo 78.5-93 are different in compositional range from those of Udachnaya olivines (Fo 85-94). Outer rims composition are also different (Fo 85-86 and 89-90 respectively). Concentration of Ni, Mn, Co, Ca, Cr, Al, Ti, P, Na and Zn were measured by EPMA using an innovative method which has been developed based on earlier publication (Sobolev et al., Science, 2007, 316: 412-417). It made possible to obtain external precision down to 10 ppm (2SD) and detection limit down to 2 ppm. High resolution compositional maps of olivine zoning for all mentioned elements are produced. "Hot cathode" CL microscope was applied for study of luminescent minerals including calcite, apatite and baryte. Twenty percent of representative olivine samples are characterized by low Fo 78.5-85 and NiO from 600 to 2300 ppm. Clear zoning in concentration of some trace elements, P in particular, is detected in the cores of studied olivines. Ba-phlogopite containing BaO from less than 1 up to 14.5 wt.% is another specific feature of Malokuonapskaya kimberlite, which is different from any kimberlites and especially from Udachnaya with highest BaO - 4.85 wt.% of its phlogopite. Chromediopsides contain 1.3 - 5.2 wt.% FeO, 0.6 - 2.0 wt.% Cr2O3 and 0.45 - 2.0 wt.% Na2O. Pyropes

  3. 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

  4. Magma dynamics during the 2007 Stromboli eruption (Aeolian Islands, Italy): Mineralogical, geochemical and isotopic data

    Science.gov (United States)

    Landi, P.; Corsaro, R. A.; Francalanci, L.; Civetta, L.; Miraglia, L.; Pompilio, M.; Tesoro, R.

    2009-05-01

    After the 6 month-long effusive event of 2002-2003, a new lava effusion occurred at Stromboli between 27 February and 2 April 2007. Despite the different durations, approximately the same volume of magma was emitted in both eruptions, in the order of 10 7 m 3. A paroxysmal eruption occurred at the summit craters in both the 2002-2003 and 2007 episodes, during which a significant amount of low porphyritic (LP), volatile-rich magma was erupted. In both cases, the paroxysm did not interrupt the lava emission. Here, we present compositional data, including texture, mineralogy, chemistry and Sr and Nd isotope ratios of bulk-rock, groundmass and separated minerals of lavas erupted in 2007, together with chemistry and Sr and Nd isotope composition of the pumices emitted during the 15 March paroxysm. As a whole, the lavas have the same texture and chemistry that characterize the highly porphyritic (HP) products usually erupted at Stromboli during normal Strombolian activity and effusive events. Compared to the previous HP products, the 2007 lavas show minor but systematic mineralogical and isotopic variations which are consistent with a modest increase of the magma supply rate of the volcano. Compositional variations during the entire duration of the event are very modest. Glass chemistry changes in lavas erupted in the second half of March can be explained by the minor mixing between the volatile-rich LP magma rising through the shallow magmatic system during the 15 March paroxysm and the degassed residing HP magma. A first conclusion of this study is that there is no compositional evidence supporting major changes in the magma dynamics of the volcano accompanying the effusive activity, as also suggested for the 2002-2003 event. The activity of Stromboli is controlled by a steady state feeding system in which refilling, mixing, degassing and crystallization at shallow level continuously operate, with modest oscillations in the magma supply rate. Switching between normal

  5. Mineralogical investigations of the interaction between iron corrosion products and bentonite from the NF-PRO Experiments (Phase 2)

    Energy Technology Data Exchange (ETDEWEB)

    Milodowski, A.E.; Cave, M.R.; Kemp, S.J.; Taylor, B.H.; Green, K.A.; Williams, C.L.; Shaw, R.A.; Gowing, C.J.B.; Eatherington, N.D. (British Geological Survey (United Kingdom))

    2009-01-15

    present from the original MX-80 bentonite but part of this will also probably be secondary magnetite formed as a corrosion product of the steel. Nevertheless, sequential chemical extraction analyses also suggest that a large proportion of the iron (11-38%) may be present within the silicate/clay mineral lattice. The implication of this would be that there has been significant conversion of the original montmorillonite to an Fe-rich clay mineral within these alteration haloes. Although XRD does not detect very much change in clay mineralogy, and suggests that the smectite in the altered bentonite is dioctahedral, it is likely that the subsampling for XRD analysis was on too coarse a scale to be able to resolve the alteration within these very narrow reaction zones around the corroded wires. The alteration observed around the corroded steel wires in experiments NFC4, NFC7 and NFC13 is more complex than that in NFC1 or earlier experiments studied in Phase 1 or previously by Smart et al. 2006. The reacted bentonite from these experiments exhibited the formation of a Mg-Fe-rich clay mineral or aluminosilicate alteration product. This was formed within the Fe-enriched alteration halo but appears to have formed relatively early and was subsequently partially overprinted or replaced by more Fe-rich aluminosilicate. EDXA microchemical mapping did suggest some slight Mg enhancement in the reacted bentonite from NFC1 but no discrete Mg-rich phase was detected. Whilst Mg may potentially have been derived from the 'Allard' reference water used in experiment NFC4, in the case of NFC7 and NFC13 it could only have been derived from the breakdown of the bentonite itself since the porefluid only contained NaCl in these two experiments. XRD observations indicated a slight increase in d002/d003 peak ratio, which could possibly be accounted for by a small amount of substitution of Fe into the octahedral layers of the smectite. This is not supported by exchangeable cation analyses

  6. Raman spectroscopy, an innovative tool to explore the mineralogy and provenance of dust (1-5 µm): Dome B ice core, East Antarctica

    Science.gov (United States)

    Ileana Paleari, Chiara; Andò, Sergio; Delmonte, Barbara; Maggi, Valter; Garzanti, Eduardo

    2017-04-01

    The polar ice sheets are invaluable archives preserving information about past climate changes and atmosphere composition. Deep ice cores from Greenland and Antarctica provide records of several climate-dependent proxies allowing climate reconstructions at different time scales, among which greenhouse gases, atmospheric aerosol and aeolian dust. In this project, the mineralogy of dust preserved in the Dome B (77°05'S, 94°55'E, 3650 m a.s.l.) ice core was investigated using Raman spectroscopy. The thermal drilled ice core, made during the 1987-1988 Austral season by the 33rd Soviet Antarctic Expedition, covers the last 30 kyr. The record thus encompasses the last glacial period, the Last Glacial Maximum (LGM), the deglaciation and the beginning of the Holocene. Four Dome B ice core samples from the LGM were selected, and the mineralogical fingerprint of dust particles was investigated. Dust in central Antarctic ice cores is clay to finest silt, the volume-size distribution of particles showing modal values around 2-2.6 µm at the Dome B site. Detrital minerals of such a fine grain-size range are exceedingly difficult to determine one by one, a task that to the best of our knowledge has never been accomplished so far. In order to meet this challenge, we have developed a new protocol for the preparation and analysis of particles between 1 and 5 µm in diameter, in a clean room at the EuroCold Lab and at the Laboratory for Provenance Studies of Milano-Bicocca University. Three slides were prepared for each sample, and 962 particles were studied overall. In total, 41 different minerals were recognized, including species derived from granitoid, metamorphic or siliciclastic rocks (e.g., quartz, feldspars and phyllosilicates), from volcanic source rocks (e.g., sanidine, anorthite, pyroxenes, zeolites) associated with biogenic marine aragonite and iron oxides probably derived from erosion of soil profiles. Our observations indicate southern South America as the most

  7. The Effect of Land Use Change on Soil Type and Clay Mineralogy in Safashahr Area, Fars Province

    Directory of Open Access Journals (Sweden)

    R. Karimi

    2015-06-01

    Full Text Available Nowadays, changing the rangelands to agriculture and garden is common. To investigate the impact of land use change on the soils type and clay mineralogy, four land uses including rangeland with poor vegetation, agricultural land, new and old apple orchards were selected in Safashahr area, Fars province. In each land use, three soil profiles were excavated and described and one profile was considered as representative. After required physical and chemical analyses, they were classified according to Soil Taxonomy (ST and the World Reference Base for Soil Resources (WRB. Selected surface and subsurface samples were also collected for clay mineralogy studies. Results showed that changing land use did not have significant effect on soil type and clay minerals and all soils consist of mica, chlorite, smectite, kaolinite and mixed layer minerals. Results demonstrated that ST is more efficient compared to WRB to classify the studied soils.

  8. Coordinated mineralogical and isotopic analyses of a cosmic symplectite discovered in a comet 81P/Wild 2 sample

    Science.gov (United States)

    Nguyen, Ann N.; Berger, Eve L.; Nakamura-Messenger, Keiko; Messenger, Scott; Keller, Lindsay P.

    2017-09-01

    We have discovered in a Stardust mission terminal particle a unique mineralogical assemblage of symplectically intergrown pentlandite ((Fe,Ni)9S8) and nanocrystalline maghemite (γ-Fe2O3). Mineralogically similar cosmic symplectites (COS) have only been found in the primitive carbonaceous chondrite Acfer 094 and are believed to have formed by aqueous alteration. The O and S isotopic compositions of the Wild 2 COS are indistinguishable from terrestrial values. The metal and sulfide precursors were thus oxidized by an isotopically equilibrated aqueous reservoir either inside the snow line, in the Wild 2 comet, or in a larger Kuiper Belt object. Close association of the Stardust COS with a Kool mineral assemblage (kosmochloric Ca-rich pyroxene, FeO-rich olivine, and albite) that likely originated in the solar nebula suggests the COS precursors also had a nebular origin and were transported from the inner solar system to the comet-forming region after they were altered.

  9. Mineralogical-chemical characteristics and feasibility studies of utilizing waste materials that accompany coal at the Bogdanka mine

    Energy Technology Data Exchange (ETDEWEB)

    Gazda, L.; Oleszczynski, B.; Pollo, I.

    1988-11-01

    Technological waste material from the coal preparation plant at the Bogdanka mine (Lublin-Chelm Mine Group) was mineralogically and chemically investigated and assessed as to its usefulness as a valuable, kaolinite type raw material for the cement, ceramic and foundry industries. The LW rock and sludges from the Bogdanka mine were investigated. Their mineralogical composition is given. Feasibility studies of utilization of these materials were conducted at the Lublin Polytechnical in the years 1982-1987 and it was found that they can replace 10% of marl, clay and cement rock. They can also be added (12-13%) to moulding sands and replace 10-30% of kaolin clays. They can also serve as raw material for production of building ceramics. With proper preparation they can improve the domestic raw material supply and reduce imports. Investigations revealed that coal residues in them can be removed by sintering. Higher temperatures are required for firing. 16 refs.

  10. Depth profiles of 230Th excess, transition metals and mineralogy of ferromanganese crusts of the Central Indian Ocean basin and implications for palaeoceanographic influence on crust genesis

    Digital Repository Service at National Institute of Oceanography (India)

    Banakar, V.K.; Borole, D.V.

    6 M HCl leachates of the depth samples using a Perkin Elmer@ 5000 atomic absorption spec- trometer (AAS). (Standard error lo; preci- sion within ? 6% ) . Mineralogical studies were carried out on depth samples using a Philips@ X...

  11. Synchrotron characterization of nanograined UO2sub> grain growth

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Kun [Argonne National Lab. (ANL), Argonne, IL (United States); Miao, Yinbin [Argonne National Lab. (ANL), Argonne, IL (United States); Yun, Di [Argonne National Lab. (ANL), Argonne, IL (United States); Jamison, Laura M. [Argonne National Lab. (ANL), Argonne, IL (United States); Lian, Jie [Rensselaer Polytechnic Inst., Troy, NY (United States); Yao, Tiankei [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2015-09-30

    This activity is supported by the US Nuclear Energy Advanced Modeling and Simulation (NEAMS) Fuels Product Line (FPL) and aims at providing experimental data for the validation of the mesoscale simulation code MARMOT. MARMOT is a mesoscale multiphysics code that predicts the coevolution of microstructure and properties within reactor fuel during its lifetime in the reactor. It is an important component of the Moose-Bison-Marmot (MBM) code suite that has been developed by Idaho National Laboratory (INL) to enable next generation fuel performance modeling capability as part of the NEAMS Program FPL. In order to ensure the accuracy of the microstructure based materials models being developed within the MARMOT code, extensive validation efforts must be carried out. In this report, we summarize our preliminary synchrotron radiation experiments at APS to determine the grain size of nanograin UO2. The methodology and experimental setup developed in this experiment can directly apply to the proposed in-situ grain growth measurements. The investigation of the grain growth kinetics was conducted based on isothermal annealing and grain growth characterization as functions of duration and temperature. The kinetic parameters such as activation energy for grain growth for UO2 with different stoichiometry are obtained and compared with molecular dynamics (MD) simulations.

  12. Impact of chemical oxidation and water acidification on the mineralogical and physico-chemical properties of the Tournemire argillaceous formation; Role de l'oxydation chimique et de l'acidification des eaux sur les proprietes mineralogiques et physico-chimiques de la formation argileuse de Tournemire

    Energy Technology Data Exchange (ETDEWEB)

    Charpentier, D

    2001-11-01

    The French Institute for Protection and Nuclear Safety (IPSN) has selected a site near Tournemire (France) for research programmes on deep geological waste disposal in clay-rich rock formation. A railway tunnel was built about 100 years ago through the thick indurated Toarcian argillite of the Tournemire Massif and two galleries were constructed five years ago. They are used to study the evolution of rock mineralogical composition, texture, water content and water-rock interactions in the excavated disturbed zone. Multi-scale and multi-technique investigations were carried out on the evolution of physical and mineralogical rock properties. Experiments and numerical modelling were used to predict changes due to water-rock interactions and subsequent rock mineralogy and water chemistry modifications. The argillite consists of detrital clay-rich layers and carbonate layers. Pyrites are always present in significant amounts (2 to 2.5 %). The rock presents very low porosity and very low water content (around 3 %). Leaching experiments show that the interstitial water is Na and SO{sub 4}-rich and Cl-poor. The tunnel and galleries digging induces fracture formation. In the altered samples, the clay particles show a better orientation in the stratification plan, which increases the porosity. The oxidation effect yields to mineralogical transformation on the surfaces of the argillite: oxidation of pyrite, dissolution of calcite, dissolution of illite layers in interstratified I/S and formation of gypsum, Fe-oxi/hydroxides, celestite and jarosite. During cycles of hydration/dehydration, condensation water interacts with the argillite and quickly becomes Ca and SO{sub 4}-rich. The local dissolution of clay particles leads to an increase of the chloride and potassium water content. These phenomena are important for the consideration of the underground work stability, especially the evolution of the water-rock equilibria during the re-hydration of the excavated disturbed zones

  13. The effect of mineralogy, texture and mechanical properties of anti-skid and asphalt aggregates on urban dust

    OpenAIRE

    Räisänen, M.; Kupiainen, K.; Tervahattu, H.

    2003-01-01

    In northern latitudes mineral dust is formed when cars use studded tyres and roads are sanded to obtain more traction on the icy surfaces. Anti-skid and asphalt aggregates with different textural, mineralogical and mechanical properties were tested with an indoor road simulator fitted with studded and friction tyres. The particle size distribution and proportions of dust from pavement and anti-skid aggregate were analyzed using SEM-EDX. The wear on the road pavement...

  14. Mineralogy and mineral chemistry of rare-metal pegmatites at Abu Rusheid granitic gneisses, South Eastern desert, Egypt:

    OpenAIRE

    Mohamed Fahmy Raslan; ALI, MOHAMED A.

    2011-01-01

    The Abu Rushied area, situated in the South Eastern Desert of Egypt is a distinctive occurrence of economically important rare-metal mineralization where the host rocks are represented by granitic gneisses. Correspondingly, mineralogical and geochemical investigation of pegmatites pockets scattered within Abu Rusheid granitic gneisses revealed the presence of Hf-zircon, ferrocolumbite and uranyl silicate minerals (uranophane and kasolite). Electronmicroprobe analyses revealed the presence of ...

  15. Mineralogical and experimental study of serpentine minerals and ultramafic rocks with application to carbon capture and storage by mineralisation

    OpenAIRE

    Lacinska, Alicja M.

    2016-01-01

    The type of feedstock and host rock utilised in ex situ and in situ Carbon Capture and Storage by Mineralisation (CCSM) is an important aspect of these technologies, and detailed appraisal of candidate mineral/rock performance in the presence of CO2 may greatly improve CCSM efficiency. Here, a detailed mineralogical and geochemical investigation of serpentine minerals and ultramafic rocks under laboratory-controlled experiments simulating ex situ and in situ process conditions is presented. ...

  16. Geochemistry and mineralogy of arsenic in mine wastes and stream sediments in a historic metal mining area in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Rieuwerts, J.S., E-mail: jrieuwerts@plymouth.ac.uk [School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA (United Kingdom); Mighanetara, K.; Braungardt, C.B. [School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA (United Kingdom); Rollinson, G.K. [Camborne School of Mines, CEMPS, University of Exeter, Tremough Campus, Penryn, Cornwall TR10 9EZ (United Kingdom); Pirrie, D. [Helford Geoscience LLP, Menallack Farm, Treverva, Penryn, Cornwall TR10 9BP (United Kingdom); Azizi, F. [School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA (United Kingdom)

    2014-02-01

    Mining generates large amounts of waste which may contain potentially toxic elements (PTE), which, if released into the wider environment, can cause air, water and soil pollution long after mining operations have ceased. The fate and toxicological impact of PTEs are determined by their partitioning and speciation and in this study, the concentrations and mineralogy of arsenic in mine wastes and stream sediments in a former metal mining area of the UK are investigated. Pseudo-total (aqua-regia extractable) arsenic concentrations in all samples from the mining area exceeded background and guideline values by 1–5 orders of magnitude, with a maximum concentration in mine wastes of 1.8 × 10{sup 5} mg kg{sup −1} As and concentrations in stream sediments of up to 2.5 × 10{sup 4} mg kg{sup −1} As, raising concerns over potential environmental impacts. Mineralogical analysis of the wastes and sediments was undertaken by scanning electron microscopy (SEM) and automated SEM-EDS based quantitative evaluation (QEMSCAN®). The main arsenic mineral in the mine waste was scorodite and this was significantly correlated with pseudo-total As concentrations and significantly inversely correlated with potentially mobile arsenic, as estimated from the sum of exchangeable, reducible and oxidisable arsenic fractions obtained from a sequential extraction procedure; these findings correspond with the low solubility of scorodite in acidic mine wastes. The work presented shows that the study area remains grossly polluted by historical mining and processing and illustrates the value of combining mineralogical data with acid and sequential extractions to increase our understanding of potential environmental threats. - Highlights: • Stream sediments in a former mining area remain polluted with up to 25 g As per kg. • The main arsenic mineral in adjacent mine wastes appears to be scorodite. • Low solubility scorodite was inversely correlated with potentially mobile As. • Combining

  17. Microscopic emission and reflectance thermal infrared spectroscopy: instrumentation for quantitative in situ mineralogy of complex planetary surfaces.

    Science.gov (United States)

    Edwards, C S; Christensen, P R

    2013-04-10

    The diversity of investigations of planetary surfaces, especially Mars, using in situ instrumentation over the last decade is unprecedented in the exploration history of our solar system. The style of instrumentation that landed spacecraft can support is dependent on several parameters, including mass, power consumption, instrument complexity, cost, and desired measurement type (e.g., chemistry, mineralogy, petrology, morphology, etc.), all of which must be evaluated when deciding an appropriate spacecraft payload. We present a laboratory technique for a microscopic emission and reflectance spectrometer for the analysis of martian analog materials as a strong candidate for the next generation of in situ instruments designed to definitively assess sample mineralogy and petrology while preserving geologic context. We discuss the instrument capabilities, signal and noise, and overall system performance. We evaluate the ability of this instrument to quantitatively determine sample mineralogy, including bulk mineral abundances. This capability is greatly enhanced. Whereas the number of mineral components observed from existing emission spectrometers is high (often >5 to 10 depending on the number of accessory and alteration phases present), the number of mineral components at any microscopic measurement spot is low (typically mineralogy and atmospheric data, much in the same manner as the mini-TESs, is of significant additional value and maintains the long history of atmospheric monitoring for Mars. Miniaturization of this instrument has also been demonstrated, as the same microscope objective has been mounted to a flight-spare mini-TES. Further miniaturization of this instrument is straightforward with modern electronics, and the development of this instrument as an arm-mounted device is the end goal.

  18. Geochemistry and mineralogy of vanadium in mine tailings at Berg Aukas, northeastern Namibia

    Science.gov (United States)

    Sracek, O.; Mihaljevič, M.; Kříbek, B.; Majer, V.; Filip, J.; Vaněk, A.; Penížek, V.; Ettler, V.; Mapani, B.

    2014-08-01

    Vanadium-rich mine tailings at Berg Aukas, site with a world-known vanadium mineralization in northeastern Namibia, were investigated using a combination of solid phase and mineralogical analyses, leaching tests and speciation modeling. Principal objective of the study was to determine, if vanadium can be released into the environment. In spite of >30 y of weathering and oxidation of tailings material to a maximum sampling depth of 2.4 m, a large portion of V still remains in the primary mineral descloizite, (Pb, Zn)2(OH)VO4. A part of V was mobilized and adsorbed/co-precipitated with ferric oxyhydroxides. Based on sequential extraction and 57Fe Mössbauer spectroscopy, a large amount of ferric iron is present in insoluble hematite and goethite, where V is effectively bound. Other potential contaminants are Zn, present mostly in the primary mineral willemite, Zn2SiO4, descloizite and also in secondary smithsonite, ZnCO3; and Pb, which was transferred from completely dissolved galena to cerussite, PbCO3 and is also partly present in primary descloizite. Conditions in the mine tailings are alkaline (pH generally >8.2) and oxidizing during dry period, but mobility of V is low due to low solubility of descloizite and secondary crystalline ferric phases such as hematite. In contrast, Zn and especially Pb in secondary carbonates, probably represent more serious environmental and health risks.

  19. Greenhouse conditions induce mineralogical changes and dolomite accumulation in coralline algae on tropical reefs.

    Science.gov (United States)

    Diaz-Pulido, Guillermo; Nash, Merinda C; Anthony, Kenneth R N; Bender, Dorothea; Opdyke, Bradley N; Reyes-Nivia, Catalina; Troitzsch, Ulrike

    2014-01-01

    Human-induced ocean acidification and warming alter seawater carbonate chemistry reducing the calcification of reef-building crustose coralline algae (CCA), which has implications for reef stability. However, due to the presence of multiple carbonate minerals with different solubilities in seawater, the algal mineralogical responses to changes in carbonate chemistry are poorly understood. Here we demonstrate a 200% increase in dolomite concentration in living CCA under greenhouse conditions of high pCO2 (1,225 μatm) and warming (30 °C). Aragonite, in contrast, increases with lower pCO2 (296 μatm) and low temperature (28 °C). Mineral changes in the surface pigmented skeleton are minor and dolomite and aragonite formation largely occurs in the white crust beneath. Dissolution of high-Mg-calcite and particularly the erosive activities of endolithic algae living inside skeletons play key roles in concentrating dolomite in greenhouse treatments. As oceans acidify and warm in the future, the relative abundance of dolomite in CCA will increase.

  20. Lunar and Planetary Science XXXV: Mars: Radar, Gamma Ray Spectrometer, and Cratering Mineralogy

    Science.gov (United States)

    2004-01-01

    The session "Mars: Radar, Gamma Ray Spectrometer, and Cratering Mineralogy" contained the following reports:The Dielectric Properties of Martian Soil Simulant JSC Mars-1 in the Range from 20Hz to 10kHz; Eastern Sahara Geology from Orbital Radar: Potential Analog to Mars On the Dielectric Properties of the Martian-like Surface Sediments; Radar Observations of Recent Mars Landing Sites; Sounding of Subsurface Water Through Conductive Media in Mars Analog Environments Using Transient Electromagnetics and Low Frequency Ground-penetrating Radar; Burial Depth of the Reservoirs of Hydrogen at the Equatorial Latitudes on Mars; Elemental Composition Variations for Large Dusty and Rocky Regions on Mars Using Gamma-Ray Data from the Mars Odyssey Gamma-Ray Spectrometer; The Distribution of Non-Volatile Elements on Mars: Mars Odyssey GRS Results; Using Mars Odyssey GRS Data to Assess Models for the Bulk Composition of Mars; Mars: The Terra Arabia Low Epithermal Neutron Flux Anomaly; The Isidis Basin of Mars: New Results from MOLA, MOC, and THEMIS; Remote Sensing of the Haughton Impact Structure (HIS): A Terrestrial Proof of Concept for Using the Remote Sensing of Martian Craters as a Probe of Subsurface Composition;and Thermal Emission Spectra of Impact Glass and Shocked Deccan Basalt from Lonar Crater, India and Implications for Remote Sensing of Mars.

  1. Organo-mineral Interactions in Ultisols and Andosols with Contrasting Mineralogy

    Science.gov (United States)

    Sparks, D. L.

    2015-12-01

    Organo-mineral associations play an important role in long-term stabilization of soil organic matter. To understand the role of soil minerals and major cations in organo-mineral interactions, we applied STXM-NEXAFS spectroscopy at C, N, Al and Si K-edges, as well as Ca and Fe L-edges, to conduct submicron-level investigations of the associations of C and C forms with Ca, Fe, Al and Si in soil clay fraction of Ultisols and Andosols with contrasting mineralogy. Ultisols were under agricultural use receiving input of limestone and mushroom compost, whereas Andosols were under natural vegetation. The poorly crystalline minerals such as allophane and ferrihydrite were rich in Andosols, while Ultisols were dominated by vermiculite, illite and kaolinite. STXM analysis showed a high spatial correlation between C and Ca in the Utisols. The major Ca forms in agricultural Ultisols were organic Ca. A variety of C forms such as phenols, heterocyclic compounds, carboxylamides were found in Ca-rich "hot spots" in Ultisols. In contrast a relatively uniform distribution of C and C forms on mineral surfaces was observed in Andosols, revolutionizing our view of heterogeneous distribution of OM in natural soil. The C forms associated with minerals were aromatic and carboxyl C. These results demonstrates the importance of Ca containing organic compounds in soil C sequestration in agricultural Ultisols, and highlights the important role of the poorly-crystalline soil minerals in soil organic matter sequestration in Andosols.

  2. Evidence for a changing Martian climate from the mineralogy at Mawrth Vallis

    Science.gov (United States)

    Bishop, Janice L.; Rampe, Elizabeth B.

    2016-08-01

    Layered outcrops in the Mawrth Vallis region of Mars contain the greatest diversity of aqueous alteration products on the planet, and these materials are used to infer past aqueous environments. Orbital investigations indicate Al/Si-rich clay-bearing units overly an Fe/Mg-smectite-rich unit. Many different secondary minerals have been identified in the upper Al/Si-rich clay units, but the presence of poorly crystalline phases has not been previously investigated. Identification of ∼10-30% allophane and imogolite in the clay-bearing units resolves previous mineralogical discrepancies between TES and CRISM of clay-bearing units on Mars. We demonstrate here that the poorly crystalline aluminosilicates allophane and imogolite comprise a significant portion of the uppermost stratum of the Al/Si-clay-rich units. These phases are unique to immature soils derived from volcanic ash in well-drained, mildly acidic environments on Earth, and we hypothesize that the deposits discovered here originate from supervolcanic activity in nearby Arabia Terra. The transition through time from smectite-bearing units to the uppermost allophane/imogolite unit in Mawrth Vallis signifies a change in climate from a warm and wet environment to one where water was sporadic and likely depleted rapidly.

  3. Clay mineralogy of weathering rinds and possible implications concerning the sources of clay minerals in soils.

    Science.gov (United States)

    Colman, Steven M.

    1982-01-01

    Weathering rinds on volcanic clasts in Quaternary deposits in the western US contain only very fine-grained and poorly crystalline clay minerals. Rinds were sampled from soils containing well-developed argillic B horizons in deposits approx 105 yr old or more. The clay-size fraction of the rinds is dominated by allophane and iron hydroxy-oxides, whereas the B horizons contain abundant well-crystallized clay minerals. The contrast between the clay mineralogy of the weathering rinds, in which weathering is isolated from other soil processes, and that of the associated soil matrices suggests a need to reassess assumptions concerning the rates at which clay minerals form and the sources of clay minerals in argillic B horizons. It seems that crystalline clay minerals form more slowly in weathering rinds than is generally assumed for soil environments and that the weathering of primary minerals may not be the dominant source of crystalline clay minerals in Middle to Late Pleistocene soil.-A.P.

  4. Seismic anisotropy of the inner core deduced from geodynamical and mineralogical models

    Science.gov (United States)

    Lincot, A.; Cardin, P.; Merkel, S.

    2012-12-01

    We generate different geodynamical models of formation of the inner core which take into account differential growth and stratification. According to the relative importance of the different processes, the time evolution and the present day inner core show a large variability. Then, we use a visco plastic standart model to compute the lattice prefered orientation generated during the geodynamical deformation process. Considering the presumed stable crystallographic phases of iron at inner core conditions, we define a chosen set of mineralogical elastic models both published and artificially generated. We compute the variation (amplitude and direction) of the P-wave velocity in the inner core. Then, we represent these results as maps/graph of travelling time anomalies which can be easily compared to real seismological data. These comparisons lead us to propose a preferred model of the growth evolution of the inner core. Also, the comparative study of the artificial elastic models allows a better understanding of the impact of the variation of specific crystallographic parameters on the resulting seismic signal and feedback on the different published Ab-Initio elastic models of iron.;

  5. A comparative mineralogical study of Te-rich magmatic-hydrothermal systems in northeastern Greece

    Science.gov (United States)

    Voudouris, P.

    2006-07-01

    Several magmatic-hydrothermal systems in northeastern Greece (western Thrace and Limnos Island) are highly enriched in tellurides which, in addition to native gold and electrum, represent major carriers of precious metals in the ore. Deposition near the porphyry-epithermal transition for several systems is indicated by field relations and by the presence of key minerals (Pb- and Ag-rich tellurides, Bi-sulfosalts and Bi-tellurides/tellurosulfides). Hessite, stützite, sylvanite, petzite, coloradoite, altaite, unnamed Ag-sulfotelluride, native tellurium and electrum are abundant in intermediate sulfidation quartz-carbonate veins together with zincian tetrahedrite-group minerals, chalcopyrite and galena. The presence of hessite, goldfieldite, native gold and enargite or famatinite suggests deposition at a high sulfidation state. The main stage of telluride deposition took place at ˜275 °C at log fTe2 values of -8.5 to -7.1 and log fS2 values of -10.8 to -9.0, based on the Fe-content in sphalerite and the sulfide-telluride mineralogy. The close spatial association of telluride mineralization with intrusive centers of intermediate composition, the base metal enrichment and the trace element signature involving Au, Ag, Te, Bi, Sn and Mo suggest that ore-forming components were introduced at the porphyry-epithermal transition. Potential sources of tellurium are the high-K calc-alkaline (western Thrace) to shoshonitic (Limnos) intrusive rocks.

  6. Low Hesperian PCO2 constrained from in situ mineralogical analysis at Gale Crater, Mars

    Science.gov (United States)

    Bristow, Thomas F.; Haberle, Robert M.; Blake, David F.; Des Marais, David J.; Eigenbrode, Jennifer L.; Fairén, Alberto G.; Grotzinger, John P.; Stack, Kathryn M.; Mischna, Michael A.; Rampe, Elizabeth B.; Siebach, Kirsten L.; Sutter, Brad; Vaniman, David T.; Vasavada, Ashwin R.

    2017-02-01

    Carbon dioxide is an essential atmospheric component in martian climate models that attempt to reconcile a faint young sun with planetwide evidence of liquid water in the Noachian and Early Hesperian. In this study, we use mineral and contextual sedimentary environmental data measured by the Mars Science Laboratory (MSL) Rover Curiosity to estimate the atmospheric partial pressure of CO2 (PCO2) coinciding with a long-lived lake system in Gale Crater at ˜3.5 Ga. A reaction-transport model that simulates mineralogy observed within the Sheepbed member at Yellowknife Bay (YKB), by coupling mineral equilibria with carbonate precipitation kinetics and rates of sedimentation, indicates atmospheric PCO2 levels in the 10s mbar range. At such low PCO2 levels, existing climate models are unable to warm Hesperian Mars anywhere near the freezing point of water, and other gases are required to raise atmospheric pressure to prevent lake waters from being lost to the atmosphere. Thus, either lacustrine features of Gale formed in a cold environment by a mechanism yet to be determined, or the climate models still lack an essential component that would serve to elevate surface temperatures, at least locally, on Hesperian Mars. Our results also impose restrictions on the potential role of atmospheric CO2 in inferred warmer conditions and valley network formation of the late Noachian.

  7. Annama H chondrite—Mineralogy, physical properties, cosmic ray exposure, and parent body history

    Science.gov (United States)

    Kohout, TomáÅ.¡; Haloda, Jakub; Halodová, Patricie; Meier, Matthias M. M.; Maden, Colin; Busemann, Henner; Laubenstein, Matthias; Caffee, Marc. W.; Welten, Kees C.; Hopp, Jens; Trieloff, Mario; Mahajan, Ramakant R.; Naik, Sekhar; Trigo-Rodriguez, Josep M.; Moyano-Cambero, Carles E.; Oshtrakh, Michael I.; Maksimova, Alevtina A.; Chukin, Andrey V.; Semionkin, Vladimir A.; Karabanalov, Maksim S.; Felner, Israel; Petrova, Evgeniya V.; Brusnitsyna, Evgeniia V.; Grokhovsky, Victor I.; Yakovlev, Grigoriy A.; Gritsevich, Maria; Lyytinen, Esko; Moilanen, Jarmo; Kruglikov, Nikolai A.; Ishchenko, Aleksey V.

    2017-08-01

    The fall of the Annama meteorite occurred early morning (local time) on April 19, 2014 on the Kola Peninsula (Russia). Based on mineralogy and physical properties, Annama is a typical H chondrite. It has a high Ar-Ar age of 4.4 Ga. Its cosmic ray exposure history is atypical as it is not part of the large group of H chondrites with a prominent 7-8 Ma peak in the exposure age histograms. Instead, its exposure age is within uncertainty of a smaller peak at 30 ± 4 Ma. The results from short-lived radionuclides are compatible with an atmospheric pre-entry radius of 30-40 cm. However, based on noble gas and cosmogenic radionuclide data, Annama must have been part of a larger body (radius >65 cm) for a large part of its cosmic ray exposure history. The 10Be concentration indicates a recent (3-5 Ma) breakup which may be responsible for the Annama parent body size reduction to 30-35 cm pre-entry radius.

  8. Mineralogical and textural characterization of mortars and plasters from the archaeological site of Barsinia, northern Jordan

    Directory of Open Access Journals (Sweden)

    Mustafa Mohammad AL-Naddaf

    2014-12-01

    Full Text Available Twelve mortar and plaster samples excavated in the archaeological site of Barsinia were mineralogically and petrographically examined by XRay Diffraction (XRD and Stereo and Polarized Light Microscopy, while the total carbonate content was measured using a DietrichFruhling Calcimeter. The physical properties of the samples, such as water uptake under atmospheric pressure and under vacuum, together with density and porosity, were measured. Only twelve samples were available for the purposes of this study: 8 plaster samples and 4 mortar samples. Eleven samples out of the total number of samples were mortars or plasters with lime binder and silica aggregate; calcite and quartz were identified in all of these samples. In most of the samples one or more pozzolanic components were detected; a hydraulic effect therefore exists in practically most of the studied mortars. Excluding the plasters taken from waterbearing constructions such as cisterns, and the mortar sample from the compact floor, the binder content is high; in general, the overall porosity of the studied samples is high. Porosity and petrographic investigation results suggest that the burning temperature of the limestone was low and/or the duration of the combustion was short; such preparation conditions produce a desirable quicklime. Owing to the significant compositional and textural differences between the samples that were reported, there is consequently no suitable general mortar that can be adopted for the restoration of the whole site.

  9. Optical properties and mineralogical composition of different Saharan mineral dust samples: a laboratory study

    Directory of Open Access Journals (Sweden)

    C. Linke

    2006-01-01

    Full Text Available In aerosol chamber experiments optical properties of resuspended mineral dust samples of defined size distributions were measured. Extinction coefficients (bext and mass specific extinction cross sections (σext were determined for Saharan dust samples from different locations. The results for σext were not very sensitive to the type of dust and varied at λ=550 nm between 3.3±0.4 m2 g−1 and 3.7±0.4 m2 g−1. The absorption coefficients (babs and mass specific absorption cross sections (σabs were determined with a novel multi-wavelength photo-acoustic absorption spectrometer (PAS. The single scattering albedo was close to 1 (0.98 to 0.99 at 532 nm and 1064 nm, but significantly lower (0.63 to 0.76 at 266 nm. Additionally the chemical and mineralogical composition of the dust samples were analysed with special regard to the iron oxide phases hematite and goethite. At λ=266 nm the mineral dust sample without any detectable iron oxides showed a significantly higher SSA compared to the sample with a hematite content of 0.6 wt-%.

  10. Thermal conductivity of sedimentary rocks - selected methodological, mineralogical and textural studies

    Energy Technology Data Exchange (ETDEWEB)

    Midttoemme, Kirsti

    1997-12-31

    The thermal conductivity of sedimentary rocks is an important parameter in basin modelling as the main parameter controlling the temperature within a sedimentary basin. This thesis presents measured thermal conductivities, mainly on clay- and mudstone. The measured values are compared with values obtained by using thermal conductivity models. Some new thermal conductivity models are developed based on the measured values. The values obtained are less than most previously published values. In a study of unconsolidated sediments a constant deviation was found between thermal conductivities measured with a needle probe and a divided bas apparatus. Accepted thermal conductivity models based on the geometric mean model fail to predict the thermal conductivity of clay- and mudstone. Despite this, models based on the geometric mean model, where the effect of porosity is taken account of by the geometric mean equation, seem to be the best. Existing models underestimate the textural influence on the thermal conductivity of clay- and mudstone. The grain size was found to influence the thermal conductivity of artificial quartz samples. The clay mineral content seems to be a point of uncertainty in both measuring and modelling thermal conductivity. A good universal thermal conductivity model must include many mineralogical and textural factors. Since this is difficult, different models restricted to specific sediment types and textures are suggested to be the best solution to obtain realistic estimates applicable in basin modelling. 243 refs., 64 figs., 31 tabs.

  11. Mineralogy and heavy metal leachability of magnetic fractions separated from some Chinese coal fly ashes.

    Science.gov (United States)

    Lu, S G; Chen, Y Y; Shan, H D; Bai, S Q

    2009-09-30

    Magnetic fractions (MFs) in fly ashes from eight coal-burning power plants were extracted by magnetic separation procedure. Their mineralogy and potential leachability of heavy metals were analyzed using rock magnetism, X-ray diffraction (XRD), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX) and leaching procedures (toxicity characteristics leaching procedure by the United States Environmental Protection Agency, TCLP, and gastric juice simulation test, GJST). Results show that the MFs in the fly ashes range between 2.2 and 16.3wt%, and are generally composed of magnetite, hematite, quartz and mullite. Thermomagnetic analysis and SEM/EDX indicate that the main magnetic carrier magnetite is substituted with small amounts of impure ions, and its structures are featured by rough, dendritic and granular iron spherules. The MFs are found to be rich in Fe, Mn, Cr, Cu, Cd and Pb. Compared with the non-magnetic fractions (NMFs), the MFs have about 5 times higher iron, and 1.6 times higher Mn, Cr, Cu and Cd concentrations. The TCLP test shows that the TCLP-extractable Cr, Cu, and Pb concentrations in the MFs are higher than those in the NMFs, while the TCLP-extractable Cd concentration in the MFs and NMFs is below the detection limit (Cr>Pb>Cd. The heavy metals of fly ashes have a great potential to be released into the environment under acid environment.

  12. Mineralogy and Microbial Diversity of the Microbialites in the Hypersaline Storr's Lake, the Bahamas.

    Science.gov (United States)

    Paul, Varun G; Wronkiewicz, David J; Mormile, Melanie R; Foster, Jamie S

    2016-04-01

    Microbialites found in the low-light-intensity, hypersaline waters of Storr's Lake (SL), San Salvador Island, the Bahamas, were investigated with respect to their morphology, mineralogy, and microbial diversity. Previously described microbialite morphologies, as well as a newly identified "multi-cuspate" morphology, were observed at various depths. Electron microscopy analysis revealed the presence of angular, blocky, and needle-shaped crystals with mineralized cyanobacterial filaments and remains of exopolymeric substances. X-ray diffraction studies confirmed the presence of both Mg-calcite and aragonite in the plateau-mushroom and pinnacle mound microbialites, whereas only Mg-calcite was identified in the other microbialite morphotypes. A comprehensive molecular analysis using barcoded pyrosequencing of five different microbial mat communities identified at least 12 dominant bacterial phyla. Cyanobacteria were generally low in abundance and ranged from ∼0.01% in the deeper pinnacle mounds to ∼3.2% in the shallow calcareous knobs. Other photosynthetic members included green nonsulfur bacteria of the phylum Chloroflexi and purple sulfur bacteria of the class Gammaproteobacteria. All mat types contained significant amounts of sulfate-reducing and dehalogenating bacteria. The low light intensity reaching the deeper microbialites, the lack of dominant cyanobacteria, and the abundance of sulfate reducers and Chloroflexi collectively suggest that sulfate reduction and anoxygenic photosynthetic processes influence the carbonate biomineralization process in these systems.

  13. The internal microstructure and fibrous mineralogy of fly ash from coal-burning power stations.

    Science.gov (United States)

    Brown, Patrick; Jones, Tim; BéruBé, Kelly

    2011-12-01

    Coal fly ash (CFA) is a significant environmental pollutant that presents a respiratory hazard when airborne. Although previous studies have identified the mineral components of CFA, there is a paucity of information on the structural habits of these minerals. Samples from UK, Polish and Chinese power stations were studied to further our understanding of the factors that affect CFA geochemistry and mineralogy. ICP-MS, FE-SEM/EDX, XRD, and laser diffraction were used to study physicochemical characteristics. Analysis revealed important differences in the elemental compositions and particle size distributions of samples between sites. Microscopy of HF acid-etched CFA revealed the mullite present possesses a fibrous habit; fibres ranged in length between 1 and 10 μm. Respirable particles (<10 μm) were frequently observed to contain fibrous mullite. We propose that the biopersistence of these refractory fibres in the lung environment could be contributing towards chronic lung diseases seen in communities and individuals continually exposed to high levels of CFA. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Lithology and mineralogy recognition from geochemical logging tool data using multivariate statistical analysis.

    Science.gov (United States)

    Konaté, Ahmed Amara; Ma, Huolin; Pan, Heping; Qin, Zhen; Ahmed, Hafizullah Abba; Dembele, N'dji Dit Jacques

    2017-10-01

    The availability of a deep well that penetrates deep into the Ultra High Pressure (UHP) metamorphic rocks is unusual and consequently offers a unique chance to study the metamorphic rocks. One such borehole is located in the southern part of Donghai County in the Sulu UHP metamorphic belt of Eastern China, from the Chinese Continental Scientific Drilling Main hole. This study reports the results obtained from the analysis of oxide log data. A geochemical logging tool provides in situ, gamma ray spectroscopy measurements of major and trace elements in the borehole. Dry weight percent oxide concentration logs obtained for this study were SiO2, K2O, TiO2, H2O, CO2, Na2O, Fe2O3, FeO, CaO, MnO, MgO, P2O5 and Al2O3. Cross plot and Principal Component Analysis methods were applied for lithology characterization and mineralogy description respectively. Cross plot analysis allows lithological variations to be characterized. Principal Component Analysis shows that the oxide logs can be summarized by two components related to the feldspar and hydrous minerals. This study has shown that geochemical logging tool data is accurate and adequate to be tremendously useful in UHP metamorphic rocks analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Ore mineralogy and textural zonation in the world-class epithermal Waihi Vein System, Hauraki Goldfield

    Science.gov (United States)

    Mauk, Jeffrey L.; Skinner, Erin G; Fyfe, Sarah J; Menzies, Andrew H; Lowers, Heather A.; Koenig, Alan E.

    2016-01-01

    The Waihi district in the Hauraki Goldfield of New Zealand contains adularia-sericite epithermal gold-silver veins that have produced more than 7.7 Moz gold. The outermost veins of the district (Martha, Favona, Moonlight, and Cowshed) contain abundant colloform, cherty, and black quartz fill textures, with minor crustiform and massive quartz. The central veins (Amaranth, Trio, and Union) contain predominantly massive and crustiform textures, and these veins are also commonly coarser grained than outermost veins. Pyrite, sphalerite, galena, chalcopyrite, electrum, and acanthite occur in both outermost and central veins; base metal sulfide minerals typically increase in abundance in deeper samples. Antimony-, arsenic-, and selenium-bearing minerals are most abundant in the Favona and Moonlight veins, whereas base metal sulfide minerals are more abundant in the central veins at Correnso. Throughout the Waihi vein system, electrum is by far the most widespread, abundant, and significant gold-bearing mineral, but LA-ICP-MS analyses show that arsenian pyrite also contains some gold. Mineralogical and textural data are consistent with the central veins forming at a deeper structural level, or from hydrothermal fluids with different chemistry, or both.

  16. Constraints on the Mineralogy of Gale Crater Mudstones from MSL SAM Evolved Water

    Science.gov (United States)

    McAdam, A. C.; Sutter, B.; Franz, H. B.; Hogancamp, J. V. (Clark); Knudson, C. A.; Andrejkovicova, S.; Archer, P. D.; Eigenbrode, J. L.; Ming, D. W.; Mahaffy, P. R.

    2017-01-01

    The Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments on the Mars Science Laboratory (MSL) have analysed more than 150 micron fines from 14 sites at Gale Crater. Here we focus on the mudstone samples. Two were drilled from sites John Klein (JK) and Cumberland (CB) in the Sheepbed mudstone. Six were drilled from Murray Formation mudstone: Confidence Hills (CH), Mojave (MJ), Telegraph Peak (TP), Buckskin (BK), Oudam (OU), Marimba (MB). SAM's evolved gas analysis mass spectrometry (EGA-MS) detected H2O, CO2, O2, H2, SO2, H2S, HCl, NO, and other trace gases, including organic fragments. The identity and evolution temperature of evolved gases can support CheMin mineral detection and place constraints on trace volatile-bearing phases or phases difficult to characterize with X-ray diffraction (e.g., amorphous phases). Here we will focus on SAM H2O data and comparisons to SAM-like analyses of key reference materials.

  17. Crossing redox boundaries--aquifer redox history and effects on iron mineralogy and arsenic availability.

    Science.gov (United States)

    Banning, Andre; Rüde, Thomas R; Dölling, Bettina

    2013-11-15

    Cretaceous shallow marine sediments from northwestern Germany exhibit a distinct colour and geochemical boundary in a depth of several decametres, witnessing a terrestrial oxidative paleo redox process which resulted in cement loss and oxidation of Fe(II) phases. Sediment samples were obtained from boreholes drilled in near-coastal and further basinward paleo environments, including both reduced and oxidized redox facies, to characterize As and Fe occurrence in unaltered layers and redistributional consequences of the redox event. Geochemical and mineralogical composition and As fractionation were assessed. Arsenic resides in pyrite in the reduced section with a bulk rock maximum concentration of 39 μg g(-1), calculated Aspyrite is ~0.2 wt.%. Siderite concretions in the fine sands do not function as As sinks, neither does glauconite whose general As/Fe leaching behaviour was characterized. In the zone of redox transition, reduced and oxidized phases coexist and elevated As concentrations (up to 73 μg g(-1)) with high proportions of reactive As were detected. Arsenic behaviour changes from relatively homogeneous Fe sulphide-control in the unaltered sediments to very heterogeneous Fe hydroxide-control above the paleo redox boundary. The studied characteristics determine recent As availability in the subsurface and must be considered during groundwater extraction from this highly important aquifer. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Technical note: Mineralogical, chemical, morphological, and optical interrelationships of mineral dust re-suspensions

    Science.gov (United States)

    Engelbrecht, Johann P.; Moosmüller, Hans; Pincock, Samuel; Jayanty, R. K. M.; Lersch, Traci; Casuccio, Gary

    2016-08-01

    This paper promotes an understanding of the mineralogical, chemical, and physical interrelationships of re-suspended mineral dusts collected as grab samples from global dust sources. Surface soils were collected from arid regions, including the southwestern USA, Mali, Chad, Morocco, Canary Islands, Cabo Verde, Djibouti, Afghanistan, Iraq, Kuwait, Qatar, UAE, Serbia, China, Namibia, Botswana, Australia, and Chile. The ® membrane and quartz fiber filters for chemical analysis and Nuclepore® filters for individual particle analysis by scanning electron microscopy (SEM). The 75, iron (Fe) and Fe / Al ratios in the soil re-suspensions, we propose that dust particles are to a large extent composed of nano-sized particles of micas, clays, metal oxides, and ions of potassium (K+), calcium (Ca2+), and sodium (Na+) evenly dispersed as a colloid or adsorbed in amorphous clay-like material. Also shown are differences in SSA of the kaolinite/hematite/goethite samples from Mali and those from colloidal soils elsewhere. Results from this study can be integrated into a database of mineral dust properties, for applications in climate modeling, remote sensing, visibility, health (medical geology), ocean fertilization, and impact on equipment.

  19. Quantitative Mineralogical Analysis of Mars Analogues Using CHEMIN Data and Rietveld Refinement

    Science.gov (United States)

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

    2004-01-01

    Mineralogical analysis is a critical component of planetary surface exploration. Chemical data alone leave serious gaps in our understanding of the surfaces of planets where complex minerals may form in combination with H, S, and halogens. On such planets (e.g., Mars) a single chemical composition may represent a range of mineral assemblages. For example, Viking chemical analyses of excavated duricrust indicate that Mg and S are correlated and 10% MgSO4 (anhydrous weight) is a likely cementing agent. Pathfinder chemical data support a similar abundance of MgSO4 in the most altered materials. However, there are many possible Mg-sulfates with widely varying hydration states (including dehydrated and 1-, 2-, 3-, 4-, 5-, 6-, and 7-hydrates). In addition, other sulfate minerals such as gypsum (CaSO4 .2H2O) and other salts containing Cl may also exist. X-ray diffraction (XRD) has the ability to decipher mixtures of these phases that would be difficult, if not impossible to unravel using only chemical or spectral data.

  20. Mineralogical, Chemical, and Isotopic Heterogeneity in Zagami: Evidence for a Complex Petrogenesis

    Science.gov (United States)

    Nyquist, L. E.; Misawa, K.; Shih, C-Y.; Niihara, T.; Park, J.

    2013-01-01

    Textural variations in the shergottite Zagami were initially interpreted as evidence that it formed in a heterogeneous lava flow. Variations in initial Sr-87/Sr-86 ratios between a Coarse Grained (CG) and a Fine Grained (FG) lithology and evidence for more extensive fractionation of the Rb/Sr ratio in a Dark Mottled Lithology (DML) are consistent with such an interpretation. More recently, Niihara et al. and Misawa et al. have reported the mineralogy and Sr-isotopic systematics of an Olivine Rich Lithology (ORL) found in association with the coarse-grained DML lithology in the Kanagawa Zagami specimen [6,7]. Here we call this lithology DML(Ka) to maintain a distinction with DML(USNM) as studied. An Ar-Ar study by Park et al. of a late stage K-rich melt enriched in K2O to approx 7% and intruded into ORL yielded an Ar-Ar age of 202+/0 7 Ma. The present work extends the study of Kanagawa Zagami to Nd-isotopes.

  1. Mineralogy, geochemistry and physical properties of fly ash from the Megalopolis lignite fields, Peloponnese, southern Greece

    Energy Technology Data Exchange (ETDEWEB)

    Sakorafa, V.; Michailidis, K.; Burragato, F. [Universita degli Studi di Roma `La Sapienza`, Rome (Italy). Dipt. di Scienze della Terra

    1996-03-01

    Results are given on the mineralogy, morphology, geochemistry and physical characteristics of fly ash from the Megalopolis lignite fields, Peloponnese (S. Greece). The main mineral species present are quartz, anhydride, plagioclase, haematite, gehlenite and calcite. Also present, in minor and trace amounts, are lime, alkali feldspars, bassanite, gypsum, mica and unburnt lignite. Morphologically, fly ash consists of irregularly shaped, oval and spherical particles, of widely varying sizes. Chemically, the fly ash samples examined fall in the pozzolan field in the triangular diagram CaO-SiO{sub 2}-Al{sub 2}O{sub 3}. The trace elements As, Cd, Mo and Se, and Ni, V, and Zn of great and moderate environmental concern respectively, occur in concentrations higher than the respective Clarke values. Ash fusion temperatures vary within the range 1257{degree}C (initial deformation temperature) to 1339{degree}C (flow temperature) on average. Fouling and slagging parameters of the ash are within the preferred ranges of empirical practice. The chemistry of the fly ash reveals properties of concern to the construction industry, to the prediction of lignite-fired boiler performance and to health and environment. 21 refs., 4 figs., 3 tabs.

  2. Fly ash from a Mexican mineral coal I: Mineralogical and chemical characterization.

    Science.gov (United States)

    Medina, Adriana; Gamero, Prócoro; Querol, Xavier; Moreno, Natalia; De León, Beatriz; Almanza, Manuel; Vargas, Gregorio; Izquierdo, María; Font, Oriol

    2010-09-15

    The properties of coal fly ash are strongly dependent on the geological origin and the combustion process of the coal. It is important to characterize regional fly ash in detail to ascertain its potential uses as raw material in the production of high value products. The physicochemical properties of fly ash coming from the "Jose Lopez Portillo" coal-fired power plant, Coahuila, Mexico (MFA), are presented in this work. A detailed study of trace elements, the chemical composition of the amorphous phase, thermal stability and the leaching of contaminant elements under different conditions are included. MFA is composed of mullite, quartz, calcite, magnetite and an amorphous phase. This material contains mainly silica (59.6%), alumina (22.8%) and magnetite (5.6%). Its amorphous phase (78.3%) has a high silica (49.4%) and alumina (14.4%) content. According to its mineralogical and chemical composition, MFA is potentially useful as a raw material for making cement, silica, and alumina, as well as low silica/alumina ratio zeolites. Deleterious elements could be removed during the zeolitization process or with an additional acid treatment. Because of its morphological properties and structural and thermal stability, MFA can be used in thermal isolation and refractory materials and as a support for heterogeneous catalysts. Copyright 2010 Elsevier B.V. All rights reserved.

  3. Friedrich Tamnau (1802–1879 – Mineraloge, Mineralsammler und Mäzen

    Directory of Open Access Journals (Sweden)

    G. Hoppe

    2004-01-01

    Full Text Available Der Berliner Bankier Friedrich Tamnau betätigte sich neben seinem Beruf sein ganzes Leben lang als Mineraloge und mit großem finanziellem Aufwand als Mineralsammler. Seine berühmten Sammlungsbestände stellte er Fachleuten großzügig zur Verfügung. Eine erste große Sammlung verkaufte er 1841 der Berliner Universität. Seine noch größere zweite Sammlungsbeständte er am Lebensende testamentarisch der Berliner Technischen Hochschule. Außerdem gründete er die Tamnau-Stiftung, die der Finanzierung von Auslandsreisen zum Sammeln und Bearbeiten von Mineralen diente. The banker Friedrich Tamnau, Berlin, was active as a mineralogist during his entire life while at the same time conducting his profession. He also a large financial imput into the collection of minerals. He generously offered his famous collection to scinetists for study. He sold his first large collection to the University of Berlin. A the end of his life he presented by testament a second even larger collection to the Technical University of Berlin. In addition he founded the Tamnau-Foundation to support foreign travel to collect and study minerals. doi:10.1002/mmng.20040070104

  4. Río Tinto: A Geochemical and Mineralogical Terrestrial Analogue of Mars

    Directory of Open Access Journals (Sweden)

    Ricardo Amils

    2014-09-01

    Full Text Available The geomicrobiological characterization of the water column and sediments of Río Tinto (Huelva, Southwestern Spain have proven the importance of the iron and the sulfur cycles, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals, but also in maintaining the high level of microbial diversity detected in the basin. It has been proven that the extreme acidic conditions of Río Tinto basin are not the product of 5000 years of mining activity in the area, but the consequence of an active underground bioreactor that obtains its energy from the massive sulfidic minerals existing in the Iberian Pyrite Belt. Two drilling projects, MARTE (Mars Astrobiology Research and Technology Experiment (2003–2006 and IPBSL (Iberian Pyrite Belt Subsurface Life Detection (2011–2015, were developed and carried out to provide evidence of subsurface microbial activity and the potential resources that support these activities. The reduced substrates and the oxidants that drive the system appear to come from the rock matrix. These resources need only groundwater to launch diverse microbial metabolisms. The similarities between the vast sulfate and iron oxide deposits on Mars and the main sulfide bioleaching products found in the Tinto basin have given Río Tinto the status of a geochemical and mineralogical Mars terrestrial analogue.

  5. Potential carcinogenic erionite from Lessini Mounts, NE Italy: Morphological, mineralogical and chemical characterization.

    Science.gov (United States)

    Giordani, Matteo; Mattioli, Michele; Dogan, Meral; Dogan, Ahmet Umran

    2016-01-01

    Exposure of humans to erionite fibers of suitable morphology and dimension has been unambiguously linked to the occurrence of malignant mesothelioma. For this reason, a morphological, morphometrical, mineralogical, and chemical investigation was performed on two representative samples of potential carcinogenic, fibrous erionite from Lessini Mounts, northeastern (NE) Italy, which has not apparently been examined previously. The first sample is erionite-Ca with an extremely fibrous, hair-like and flexible appearance, and growth in intimate association with levyne. The second sample is erionite-Ca with prismatic to acicular crystals and rigid behavior, enriched in K(+) and Ca(2+) extra-framework cations. Although erionite is a nominally Fe-free phase, iron (Fe) was detected in low amounts in all the analyzed crystals. In both the investigated samples, erionite is present as individual fibers of respirable size. Considering that the toxicity and carcinogenic potential of erionite is associated with its size parameters, together with its in vivo durability and high surface area, most of the investigated fibers may also be potentially carcinogenic. The presence of erionite in extensively quarried and largely employed volcanic rocks, suggesting the need for detailed health-based studies in the region.

  6. Mineralization study on Dehbid magnetite deposit, Fars; using mineralogical and geochemical data

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Rajabzadeh

    2011-11-01

    Full Text Available The Dehbid magnetite deposit is located in northeastern part of Fars province, in the southern border of Sanandaj-Sirjan metamorphic zone. The mineralization occurred as veins and lenses along NW-SE faults. The ores are mainly hosted in silicified dolomite of early Mesozoic (Triassic. Mineralogical studies show that the ores are dominated by magnetite and minor hematite with massive texture occurring as cement of angular remnants of silicified host dolomite. According to geochemical data, Fe2O3 content in the mineralized zones show extensive variation between 34 to 75 wt %. The P, Ti, Cr and V contents of the iron ores are remarkably low and Co/Ni, Cr/V and LREE/HREE ratios, positive Eu anomalies, negative Ce anomalies, Eu/Sm = 1, along with field and textural observations of Dehbid ores indicate that the deposit belongs to the class of hydrothermal iron ores. At Dehbid, the magnetite ores are formed as open space fillings. The sparse rhyolites and basalts in the area may be regarded as the origin of iron and heat in the hydrothermal system. A decrease in temperature and likely pressure due to fluid mixing are the major causes of iron oxide deposition.

  7. Maximum availability and mineralogical control of chromium released from AOD slag.

    Science.gov (United States)

    Li, Junguo; Liu, Bao; Zeng, Yanan; Wang, Ziming; Gao, Zhiyuan

    2017-03-01

    AOD (argon oxygen decarburization) slag is the by-product in the stainless steel refining process. Chromium existing in AOD slag can leach out and probably poses a serious threat to the environment. To assess the leaching toxicity of chromium released from AOD slag, the temperature-dependent maximum availability leaching test was performed. To determine the controlling mineralogical phases of chromium released from AOD slag, a Visual MINTEQ simulation was established based on Vminteq30 and the FactSage 7.0 database. The leaching tests indicated that the leaching availability of chromium was slight and mainly consisted of trivalent chromium. Aging of AOD slag under the atmosphere can oxidize trivalent chromium to hexavalent chromium, which could be leached out by rainwater. According to the simulation, the chromium concentration in leachates was controlled by the freely soluble pseudo-binary phases in the pH = 7.0 leaching process and controlled by the Cr2O3 phase in the pH = 4.0 leaching process. Chromium concentrations were underestimated when the controlling phases were determined to be FeCr2O4 and MgCr2O4. Facilitating the generation of the insoluble spinel-like phases during the cooling and disposal process of the molten slag could be an effective approach to decreasing the leaching concentration of chromium and its environmental risk.

  8. Study of mineralogical speciation of arsenic in soils using X ray microfluorescence and scanning electronic microscopy.

    Science.gov (United States)

    Gómez-Parrales, Isidoro; Bellinfante, Nicolás; Tejada, Manuel

    2011-05-15

    In this paper we studied the As content in natural contaminated soils, classified as Dystric Leptosol, Chromic Luvisol, Eutric Cambisol and Mollic Leptosol. In soil samples, sieved (mineralogical speciation was studied by X-ray microfluorescence, XRD with Göbbel mirror and SEM-BEI-EDX. Total As contents ranging from 61.00 to 131.00 mg kg(-1). The results of the sequential extraction showed that As was, mainly, in the residual fraction (52.51-98.76 mg kg(-1)) and in the fraction bound to iron oxyhydroxides (0-36.5 mg kg(-1)). Mapping of As with X-ray microfluorescence show strongly relationship between Fe and As. Iron (III) oxyhydroxides (FeOHs) (lepidocrocite and goethite), scorodite, angelellite, schultenite and dussertite were identified by XRD analysis as most likely mineral phases. The contents of As, Fe, Pb and Ba obtained with EDX-microprobe, confirmed the results of XRD. The results of sequential extraction and X-ray microfluorescence indicate that As is strongly bound to the soils because the identified As-bearing mineral phases are very stable at the pH conditions of studied soils. Consequently, a low mobility of As can be assumed in these soils. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Mineralogical composition of the meteorite El Pozo (Mexico): a Raman, infrared and XRD study.

    Science.gov (United States)

    Ostrooumov, Mikhail; Hernández-Bernal, Maria del Sol

    2011-12-01

    The Raman (RMP), infrared (IR) and XRD analysis have been applied to the examination of mineralogical composition of El Pozo meteorite (an ordinary chondrite L5 type; village Valle of Allende, founded in State of Chihuahua, Mexico: 26°56'N and 105°24'W, 1998). RMP measurements in the range of 100-3500 cm(-1) revealed principal characteristic bands of the major minerals: olivine, two polymorph modifications of pyroxene (OPx and CPx) and plagioclase. Some bands of the minor minerals (hematite and goethite) were also identified. All these minerals were clearly distinguished using IR and XRD techniques. XRD technique has shown the presence of some metallic phases such as kamacite and taenite as well as troilite and chromite. These minerals do not have characteristic Raman spectra because Fe-Ni metals have no active modes for Raman spectroscopy and troilite is a weak Raman scatterer. Raman mapping microspectroscopy was a key part in the investigation of El Pozo meteorite's spatial distribution of the main minerals because these samples are structurally and chemically complex and heterogeneous. The mineral mapping by Raman spectroscopy has provided information for a certain spatial region on which a spatial distribution coexists of the three typical mineral assemblages: olivine; olivine+orthopyroxene; and orthopyroxene. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Low Hesperian PCO2 constrained from in situ mineralogical analysis at Gale Crater, Mars.

    Science.gov (United States)

    Bristow, Thomas F; Haberle, Robert M; Blake, David F; Des Marais, David J; Eigenbrode, Jennifer L; Fairén, Alberto G; Grotzinger, John P; Stack, Kathryn M; Mischna, Michael A; Rampe, Elizabeth B; Siebach, Kirsten L; Sutter, Brad; Vaniman, David T; Vasavada, Ashwin R

    2017-02-28

    Carbon dioxide is an essential atmospheric component in martian climate models that attempt to reconcile a faint young sun with planetwide evidence of liquid water in the Noachian and Early Hesperian. In this study, we use mineral and contextual sedimentary environmental data measured by the Mars Science Laboratory (MSL) Rover Curiosity to estimate the atmospheric partial pressure of CO2 (PCO2) coinciding with a long-lived lake system in Gale Crater at ∼3.5 Ga. A reaction-transport model that simulates mineralogy observed within the Sheepbed member at Yellowknife Bay (YKB), by coupling mineral equilibria with carbonate precipitation kinetics and rates of sedimentation, indicates atmospheric PCO2 levels in the 10s mbar range. At such low PCO2 levels, existing climate models are unable to warm Hesperian Mars anywhere near the freezing point of water, and other gases are required to raise atmospheric pressure to prevent lake waters from being lost to the atmosphere. Thus, either lacustrine features of Gale formed in a cold environment by a mechanism yet to be determined, or the climate models still lack an essential component that would serve to elevate surface temperatures, at least locally, on Hesperian Mars. Our results also impose restrictions on the potential role of atmospheric CO2 in inferred warmer conditions and valley network formation of the late Noachian.

  11. Influence of Basicity on High-Chromium Vanadium-Titanium Magnetite Sinter Properties, Productivity, and Mineralogy

    Science.gov (United States)

    Zhou, Mi; Yang, Songtao; Jiang, Tao; Xue, Xiangxin

    2015-05-01

    The effect of basicity on high-chromium vanadium-titanium magnetite (V-Ti-Cr) sintering was studied via sintering pot tests. The sinter rate, yield, and productivity were calculated before determining sinter strength (TI) and reduction degradation index (RDI). Furthermore, the effect of basicity on V-Ti-Cr sinter mineralogy was clarified using metallographic microscopy, x-ray diffraction, and scanning electron microscopy-energy-dispersive x-ray spectroscopy. The results indicate that increasing basicity quickly increases the sintering rate from 25.4 mm min-1 to 28.9 mm min-1, yield from 75.3% to 87.2%, TI from 55.4% to 64.8%, and productivity from 1.83 t (m2 h)-1 to 1.94 t (m2 h)-1 before experiencing a slight drop. The V-Ti-Cr sinter shows complex mineral composition, with main mineral phases such as magnetite, hematite, silicate (dicalcium silicate, Ca-Fe olivine, glass), calcium and aluminum silico-ferrite (SFCA/SFCAI) and perovskite. Perovskite is notable because it lowers the V-Ti sinter strength and RDI. The well intergrowths between magnetite and SFCA/SFCAI, and the decrease in perovskite and secondary skeletal hematite are the key for improving TI and RDI. Finally, a comprehensive index was calculated, and the optimal V-Ti-Cr sinter basicity also for industrial application was 2.55.

  12. Investigationof Clay Mineralogy, Micromorphology and Evolution of Soils in Bajestan Playa

    Directory of Open Access Journals (Sweden)

    Mohammad Ghasemzadeh Ganjehie

    2017-03-01

    Full Text Available Introduction: Playa is one of the most important landscapes in arid regions which covers about 1% of the world's total land area. Study of playas is important from different points of view especially pedology, sedimentology, mineralogy, environmental geology, groundwater and surface water chemistry. More than 60 playas have been identified in Iran. Considering the fact that playas and surrounding landforms are important archive of landscape evolution and paleoenvironmental variations, it seems that less attention has been paid to them so far. Soils are known as indicators of the landscapes evolution. Previous studies in arid regions of Iran imply different periods of deposition and soil formation in playa and alluvial fans or pediments. Bajestan playa is one of the known playa in northeastern Iran, and the largest clay flat exists in this playa. There is no information on the soils and their evolution in Bajestan playa. The objective of this study were to 1 identify the soils in different landforms along a transect from alluvial fan to clay in Bajestan playa 2 determine the morphological, micromorphological and mineralogical characteristics of these soils 3 determine the periods of soil and landform evolution and 4 comparison of soils evolution of the study area to other arid regions of Iran. Material and Methods: The study area of approximately 20000 hectares is located in southeastern of KhorasanRazavi province. The climate of the study area is hot and dry with mean annual temperature and rainfall of 17.3 °C and 193 mm, respectively. Soil moisture regime is aridic with subdivisions of weak aridic and soil temperature regime is thermic. Firstly, landforms and geomorphic surfaces of the study area were recognized based on Google Earth images interpretations and field observations. Four main landforms were recognized in the study area. The landforms from north to the south of the study area were alluvial fan, intermediate alluvial fan- clay flat

  13. Petrography and Mineralogy of 18 Newly Recovered Ordinary Chondrites in China

    Science.gov (United States)

    Li, S. L.

    2015-05-01

    Petrology and mineralogy of 18 newly recovered ordinary chondrites in China are reported in this paper. Fifteen meteorites were found in Xinjiang, among which 13 meteorites were found in the Lop Nur desert, and the other 2 meteorites were found in Kumtag and Aksai Chin, respectively. Three other meteorites are observed falls in Xining, Fuhe, and Dongyang, respectively. All meteorites are equilibrated ordinary chondrites with 8 H group and 10 L group meteorites. Their petrographic types vary from 4 to 6 in the L group meteorites, with most being type 5, while all H group meteorites are classified as type 5. The features of shock metamorphism of most meteorites are moderate though a few have features of ≥S4 stage. Most Lop Nur meteorites underwent intense weathering with only two of which have weathering degree of W1 and W2. Both Kumtag and Aksai Chin meteorite have a weathering degree of W2. The newly discovered tens of meteorites in the gobi deserts east to the Taklimakan Desert indicate that this region may become an important dense meteorite collection area in Eurasia.

  14. Clay Mineralogy of Soils on Quaternary Sediment in Northeast of Urmia

    Directory of Open Access Journals (Sweden)

    Parisa Farzamnia

    2017-03-01

    Full Text Available Introduction: Minerals are one of the main components of soils which play different roles in the soils. Minerals make up about 50% of the volume of most soils. They provide physical support for plants, and create the water- and air-filled pores that make plant growth possible. Mineral weathering releases plant nutrients which are retained by other minerals through adsorption, cation exchange, and precipitation. Minerals are indicators of the amount of weathering that has taken place, and the presence or absence of particular minerals gives clues to how soils have been formed. The physical and chemical characteristics of soil minerals are important consideration in planning, constructing, and maintaining of buildings, roads, and airports. Clay minerals can be used for understanding of soil formation, optimum management of dry and wet lands and interpretation of paleo environments. Moreover, clay minerals can provide some valuable information such as the origin of sediments, transportation and precipitation of sediments and also some information about intercontinental weathering regimes. Quaternary sediments have occupied most of the agricultural and natural resources of Urima plain and recognition of mineralogical of these soils is essential to optimum and stabile use of these soils. Additionally, caly mineralogical investigation can provide some information about the intensity of weathering processes and climate change in this area. Thus, in this study clay minerals of quaternary sediments in northeast of Urmia and the mechanisms of their formation and also tracing probable climate change in this area were investigated. Materials and Methods: This study was performed in theUrmia plain in west Azerbaijan Province. The study area is located on quaternary sediments and physiographically, this area is a part of a river alluvial plain with the gentle slope toward Urmia Lake. The mean annual precipitation and temperature of this area are 345.37 mm and

  15. Effect of zeolitization on physico-chemico-mineralogical and geotechnical properties of lagoon ash

    Energy Technology Data Exchange (ETDEWEB)

    Kolay, P. K.; Singh, D. N. [Indian Inst. of Technology, Dept. of Civil Engineering, Bombay, (India)

    2001-10-01

    Ash from coal-fired generating stations is commonly disposed of by mixing the ash with water and placing the ash-water slurry in a pond or lagoon. This allows the alkalis present to react with the water, which leads to zeolitization of the ash and changes in its overall properties. A controlled experiment was conducted to simulate such action on Indian ash and zeolitization on the physico-chemico-mineralogical properties were studied. Results of the study showed that alkali activation caused an increase in particle size and a decrease in silica and alumina content of the ash, and increased specific gravity and specific surface area of the ash by about 18 per cent and 11 per cent respectively. Cation capacity of the ash increased two-fold. Formation of NaP1 zeolite was also noted, as well as increase in the void ratio and porosity of the ash, which resulted in significantly increased water absorption capacity and hydraulic conductivity at the optimum moisture content. 39 refs., 4 tabs., 9 figs.

  16. Mineralogical and chemical characterization of iron-, manganese-, and copper-containing synthetic hydroxyapatites.

    Science.gov (United States)

    Sutter, B; Ming, D W; Clearfield, A; Hossner, L R

    2003-01-01

    The National Aeronautics and Space Administration's (NASA) Advanced Life Support (ALS) Program is evaluating the use of Fe-, Mn-, and Cu-containing synthetic hydroxyapatite (SHA) as a slow release fertilizer for crops that might be grown on the International Space Station or at Lunar and Martian outposts. Separate Fe-, Mn-, and Cu-containing SHA materials along with a transition-metal free SHA (pure-SHA) were synthesized using a precipitation method. Chemical and mineralogical analyses determined if and how Fe, Mn, and Cu were incorporated into the SHA structure. X-ray diffraction (XRD), Rietveld refinement, and transmission electron microscopy (TEM) confirmed that SHA materials with the apatite structure were produced. Chemical analyses indicated that the metal containing SHA materials were deficient in Ca relative to pure-SHA. The shift in the infrared PO4-mu 3 vibrations, smaller unit cell parameters, smaller particle size, and greater structural strain for Fe-, Mn-, and Cu-containing SHA compared with pure-SHA suggested that Fe, Mn, and Cu were incorporated into SHA structure. Rietveld analyses revealed that Fe, Mn, and Cu substituted into the Ca2 site of SHA. An Fe-rich phase was detected by TEM analyses and backscattered electron microscopy in the Fe-containing SHA material with the greatest Fe content. The substitution of metals into SHA suggests that metal-SHA materials are potential slow-release sources of micronutrients for plant uptake in addition to Ca and P.

  17. Mineralogical analysis of dust collected from typical recycling line of waste printed circuit boards.

    Science.gov (United States)

    Wang, Fangfang; Zhao, Yuemin; Zhang, Tao; Duan, Chenlong; Wang, Lizhang

    2015-09-01

    As dust is one of the byproducts originating in the mechanical recycling process of waste printed circuit boards such as crushing and separating, from the viewpoints of resource reuse and environmental protection, an effective recycling method to recover valuable materials from this kind of dust is in urgent need. In this paper, detailed mineralogical analysis on the dust collected from a typical recycling line of waste printed circuit boards is investigated by coupling several analytical techniques. The results demonstrate that there are 73.1wt.% organic matters, 4.65wt.% Al, 4.55wt.% Fe, 2.67wt.% Cu and 1.06wt.% Pb in the dust, which reveals the dust is worthy of reuse and harmful to environment. The concentration ratios of Fe, Mn and Zn can reach 12.35, 12.33 and 6.67 respectively by magnetic separation. The yield of dust in each size fraction is nonuniform, while the yield of -0.75mm size fraction is up to 51.15wt.%; as the particle size decreases, the content of liberated metals and magnetic materials increase, and metals are mainly in elemental forms. The F, Cl and Br elements combing to C in the dust would make thermal treatment dangerous to the environment. Based on these results, a flowsheet to recycle the dust is proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Mineralogical and Geochemical Compositions of the No. 5 Coal in Chuancaogedan Mine, Junger Coalfield, China

    Directory of Open Access Journals (Sweden)

    Ning Yang

    2015-11-01

    Full Text Available This paper reports the mineralogy and geochemistry of the Early Permian No. 5 coal from the Chuancaogedan Mine, Junger Coalfield, China, using optical microscopy, scanning electron microscopy (SEM, Low-temperature ashing X-ray diffraction (LTA-XRD in combination with Siroquant software, X-ray fluorescence (XRF, and inductively coupled plasma mass spectrometry (ICP-MS. The minerals in the No. 5 coal from the Chuancaogedan Mine dominantly consist of kaolinite, with minor amounts of quartz, pyrite, magnetite, gypsum, calcite, jarosite and mixed-layer illite/smectite (I/S. The most abundant species within high-temperature plasma-derived coals were SiO2 (averaging 16.90%, Al2O3 (13.87%, TiO2 (0.55% and P2O5 (0.05%. Notable minor and trace elements of the coal include Zr (245.89 mg/kg, Li (78.54 mg/kg, Hg (65.42 mg/kg, Pb (38.95 mg/kg, U (7.85 mg/kg and Se (6.69 mg/kg. The coal has an ultra-low sulfur content (0.40%. Lithium, Ga, Se, Zr and Hf present strongly positive correlation with ash yield, Si and Al, suggesting they are associated with aluminosilicate minerals in the No. 5 coal. Arsenic is only weakly associated with mineral matter and Ge in the No. 5 coals might be of organic and/or sulfide affinity.

  19. Lithological and Mineralogical Characteristics and Forming Conditions of the Jurassic Sediments on the West Siberian Basin

    Directory of Open Access Journals (Sweden)

    R.R. Khaziev

    2017-11-01

    Full Text Available In the present work, lithological and mineralogical features, granulometric composition, as well as reservoir properties of the formation YuV1-1 of the Ety-Purovsky oil field are considered. It is established that the main rock-forming minerals of the reservoir – quartz, potassium feldspar and mica, also fragments of rocks, including carbonate rocks, are also found. Sandstone is diagnosed as carbonate greywack by the examined thin sections. According to the granulometry data, the formation is characterized as fine-grained sandstone with a dominant fraction of grains of 0.1-0.25 mm (47% of the total mass. According to the petrogenetic Passega diagram it was established that the formation was formed under the conditions of the gradation suspension generated in the lower parts of the fast river streams, directly at the bottom, which agrees with the literature data. Moreover, according to design factors (So, Q3, Q1, it is established that the formation is characterized by a poor degree of sorting of the sand material, as well as low roundness of grains and deteriorated reservoir properties, measured in laboratory conditions. It follows from the analysis that the reservoir is characterized by low productivity, and its development requires the use of hydraulic fracturing at an early stage of development.

  20. Source apportionment of the sediments entering dam using lithological and mineralogical studies

    Directory of Open Access Journals (Sweden)

    S. Afshar

    2016-05-01

    Full Text Available The present study was carried out to determine the possible origins of sediments entering Taleghan Dam in northern part of Iran, in order to avoid further sedimentation and helping in extension of the useful life of the proposed dam. This was performed by XRD analysis. To do so, first of all, sediment sampling points were positioned along the Taleghan River. The collected samples, after coding, were transferred to the laboratory for mineralogical testing. Then, the samples were exposed to X-ray diffraction analysis. The experimental results were compared with data from geology, land cover land use and slope maps in order to find the possible primary origins of deposits in the Taleghan Dam. Furthermore, the geological formations and physiographical parameter such as slope were also analyzed to test erodibility of the formations. The results showed that most sediment samples in Taleghan are of sedimentary sandstone, mainly containing the quartz and plagioclase minerals (quartz sandstone and arkose sandstone. The findings also showed that calcite and dolomite were abundant in the collected samples, while aragonite and anthracite were found to a lesser extent in the samples. Accordingly, acidic and alkaline formations, mudstone, and siltstone of Karaj area formations, the gypsum of upper red formation, particularly at places with steep slope with a dominance of rangeland land use type, are main origins of sediments in the Taleghan reservoir. In another hand, the control of sediments at these areas would substantially decrease total sediment yields of the entire basin as in the dam reservoir.

  1. Río tinto: a geochemical and mineralogical terrestrial analogue of Mars.

    Science.gov (United States)

    Amils, Ricardo; Fernández-Remolar, David; The Ipbsl Team

    2014-09-15

    The geomicrobiological characterization of the water column and sediments of Río Tinto (Huelva, Southwestern Spain) have proven the importance of the iron and the sulfur cycles, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals), but also in maintaining the high level of microbial diversity detected in the basin. It has been proven that the extreme acidic conditions of Río Tinto basin are not the product of 5000 years of mining activity in the area, but the consequence of an active underground bioreactor that obtains its energy from the massive sulfidic minerals existing in the Iberian Pyrite Belt. Two drilling projects, MARTE (Mars Astrobiology Research and Technology Experiment) (2003-2006) and IPBSL (Iberian Pyrite Belt Subsurface Life Detection) (2011-2015), were developed and carried out to provide evidence of subsurface microbial activity and the potential resources that support these activities. The reduced substrates and the oxidants that drive the system appear to come from the rock matrix. These resources need only groundwater to launch diverse microbial metabolisms. The similarities between the vast sulfate and iron oxide deposits on Mars and the main sulfide bioleaching products found in the Tinto basin have given Río Tinto the status of a geochemical and mineralogical Mars terrestrial analogue.

  2. An Improved Technique for dry Soil Moisture Release Curves to Determine Soil Mineralogical and Physical Properties

    Science.gov (United States)

    Campbell, G. S.; Campbell, C. S.; Cobos, D. R.

    2008-12-01

    Soil moisture release curves (MRC) or moisture sorption isotherms, which relate the amount of water in soil to its water potential or water activity, have many applications in soil physics and geotechnical engineering including determining soil water flow, specific surface area, swelling potential, and clay mineralogy and activity. Although research showing MRC for various soils dates back more than 50 years, limitations with the measurement technique have made developing MRC time consuming and inaccurate, especially in dry soils. Recently, an instrument was developed to create moisture sorption isotherms for various food and pharmaceutical products. The objective of this research was to investigate its use in soils for obtaining MRC in dry soils simply and accurately. Several different soil types were tested in the instrument from pure sand to bentonite and smectite clays. From the MRC of these soils, we were able to develop good correlations between actual and derived clay activity, surface area, and swelling potential. In addition, we were able to see hysteresis in dry soil water uptake for all soils, including sand. According to our tests, this new instrument will provide a powerful tool to investigate several soil physical properties simply and accurately.

  3. CHEMICAL AND MINERALOGICAL PROPERTIES OF ULTISOLS OF SASAMBA AREA, EAST KALIMANTAN

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    B.H. Prasetyo

    2016-10-01

    Full Text Available Ultisols are a major group of marginal soils extensively found in the upland area of Indonesia. To better understand the potential of the Ultisols developed from claystone and sandstone in the Sasamba Integrated Economical Development Area in East Kalimantan, chemical and mineralogical characteristics of 27 Ultisols pedons consisting of 76 topsoil and 118 subsoil samples were investigated. Besides analysis and interpretation of data, relationships of several soil characteristics were constructed using simple regression. The results indicated that Ultisols showed acid to very acid reaction, had low content of organic matter and low base saturation. Soils generally exhibited net negative charge, and the point of zero charge was reached at pH 3.6. Both potential and available phosphates were low, and there was a trend that amorphous aluminum was responsible for phosphate fixation. The low content of exchangeable potassium in topsoil and subsoil indicated a positive correlation with potential potassium. Clay mineral was composed chiefly of kaolinite, with small amounts of illite, vermiculite, and quartz. The domination of kaolinite and low organic matter content causes the soils to have low cation exchange capacity. Soil management in this area should be focused on building up and maintaining soil fertility, and applying appropriate soil conservation techniques to minimize erosion. To obtain sustained productivity, various soil amendments including the use of farm and/or green manure, liming with agricultural lime, and application of rock phosphate and K fertilizers were highly recommended.

  4. Mineralogical and Geochemical Characteristics of the Early Permian Upper No. 3 Coal from Southwestern Shandong, China

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    Xibo Wang

    2016-06-01

    Full Text Available The Upper No. 3 coal of the Early Permian age is a major workable seam in the southwestern Shandong coalfield, which is located in the eastern part of North China. From Early Jurassic to Neogene, the coalfield was subjected to intensive tectonic processes, leading to a significant rearrangement in depth of coal seams. In this paper, three Upper No. 3 coals occurring at −228, −670 and −938 m in the Luxi, Liangbaosi, and Tangkou mines, respectively, were collected to investigate their mineralogical and geochemical characteristics, with emphasis on modes of occurrence and origin of epigenetic minerals. The three coal seams are similar in vitrinite reflectance, volatile matter yield, and maceral components, suggesting insignificant influence from the tectonic activities on coal rank. Terrigenous minerals (e.g., kaolinite and quartz are comparable in both types and distribution patterns in the three coals. The presence of siderite and pyrite of syngenetic or penecontemporaneous origin indicate they were emplaced during peat accumulation. The distribution of epigenetic minerals (e.g., calcite, ankerite, and dolomite are associated with the underground water activities, which were Ca (Mg, Fe-bearing.

  5. Geochemistry and Mineralogy of Tuff in Zhongliangshan Mine, Chongqing, Southwestern China

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    Jianhua Zou

    2016-05-01

    Full Text Available Coal-bearing strata that host rare metal deposits are currently a hot issue in the field of coal geology. The purpose of this paper is to illustrate the mineralogy, geochemistry, and potential economic significance of rare metals in the late Permian tuff in Zhongliangshan mine, Chongqing, southwestern China. The methods applied in this study are X-ray fluorescence spectrometry (XRF, inductively coupled mass spectrometry (ICP-MS, X-ray diffraction analysis (XRD plus Siroquant, and scanning electron microscopy in conjunction with an energy-dispersive X-ray spectrometry (SEM-EDX. The results indicate that some trace elements including Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Zr, Nb, Cd, Sb, REE, Hf, Ta, Re, Th, and U are enriched in the tuff from Zhongliangshan mine. The minerals in the tuff mainly include kaolinite, illite, pyrite, anatase, calcite, gypsum, quartz, and traces of minerals such as zircon, florencite, jarosite, and barite. The tuff is of mafic volcanic origin with features of alkali basalt. Some minerals including florencite, gypsum, barite and a portion of anatase and zircon have been derived from hydrothermal solutions. It is suggested that Zhongliangshan tuff is a potential polymetallic ore and the recovery of these valuable elements needs to be further investigated.

  6. A Mineralogical Assessment on Residues after Acidic Leaching of Bauxite Residue (Red Mud for Titanium Recovery

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    Gözde Alkan

    2017-10-01

    Full Text Available Due to its alkalinity, red mud produced by the Bayer process may affect both the environment and human health. For this reason, its further utilization instead of disposal is of great importance. Numerous methods have already been studied for hydrometallurgical treatment of red mud, especially for the recovery of various metallic components such as iron, aluminum, titanium or rare earth elements. This study focuses on the extraction of titanium from red mud and in particular the mineralogical changes, induced by leaching. Sulfuric acid, hydrochloric acid and their combination have been utilized as leaching agents with the same leaching parameters. It has been determined that sulfuric acid is the best candidate for the red mud treatment in terms of titanium leaching efficiency at the end of 2 h with a value of 67.3%. Moreover, samples from intermediate times of reaction revealed that leaching of Ti exhibit various reaction rates at different times of reaction depending on acid type. In order to explain differences, X-ray Diffraction (XRD, scanning electron microscope (SEM and QEMSCAN techniques were utilized. Beside titanium oxide (TiO2 with available free surface area, a certain amount of the TiO2 was detected as entrapped in Fe dominating oxide. These associations between Ti and Fe phases were used to explain different leaching reaction rates and a reaction mechanism was proposed to open a process window.

  7. Correlation between the mineralogic and geologic maps of Vesta: spatial analysis and perspectives towards the mapping of Ceres

    Science.gov (United States)

    Frigeri, A.; De Sanctis, M. C.; Ammannito, E.; Yingst, R. A.; Williams, D. A.; Capaccioni, F.; Tosi, F.; Palomba, E.; Zambon, F.; Jaumann, R.; Pieters, C. M.; Raymond, C. A.; Russell, C. T.

    2015-10-01

    Between July 2011 and September 2012, the NASA/Dawn mission has mapped the surface of Vesta with images from the Framing Camera (FC [1]), spectral data from the Visible and Infrared Mapping Spectrometer (VIR [2]), and elemental data from the Gamma Ray and Neutron Detector (GRaND [3]). The successful acquisition of imagery from FC and VIR allowed us to produce global image mosaics reaching 20 meters per pixel and global mineralogic maps at 100 meters per pixel. A global geologic map of Vesta has been recently published [4,5]. Geologic units and structures have been identified and put into their stratigraphic context using FC image-mosaic and the digital terrain model derived from stereo image processing. The VIR spectra have been synthesized into spectral parameters or indicators [6] that have been used to produce quadrangle and global maps showing the mineralogic diversity across Vesta, through the variation of the compositional and the physical state of the pyroxene-rich lithologies, which are typical of Vesta[7]. Herein we present the work done to explore the spatial correlation between the mineralogic and geologic map of Vesta (Figure 1).

  8. Mineralogy of the clay fraction of alfisols in two slope curvatures: IV - spatial correlation with physical properties

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    Livia Arantes Camargo

    2013-04-01

    Full Text Available Although the influence of clay mineralogy on soil physical properties has been widely studied, spatial relationships between these features in Alfisols have rarely been examined. The purpose of this work was to relate the clay minerals and physical properties of an Alfisol of sandstone origin in two slope curvatures. The crystallographic properties such as mean crystallite size (MCS and width at half height (WHH of hematite, goethite, kaolinite and gibbsite; contents of hematite and goethite; aluminium substitution (AS and specific surface area (SSA of hematite and goethite; the goethite/(goethite+hematite and kaolinite/(kaolinite+gibbsite ratios; and the citrate/bicarbonate/dithionite extractable Fe (Fe d were correlated with the soil physical properties through Pearson correlation coefficients and cross-semivariograms. The correlations found between aluminium substitution in goethite and the soil physical properties suggest that the degree of crystallinity of this mineral influences soil properties used as soil quality indicators. Thus, goethite with a high aluminium substitution resulted in large aggregate sizes and a high porosity, and also in a low bulk density and soil penetration resistance. The presence of highly crystalline gibbsite resulted in a high density and micropore content, as well as in smaller aggregates. Interpretation of the cross-semivariogram and classification of landscape compartments in terms of the spatial dependence pattern for the relief-dependent physical and mineralogical properties of the soil proved an effective supplementary method for assessing Pearson correlations between the soil physical and mineralogical properties.

  9. Sustainable rehabilitation of mining waste and acid mine drainage using geochemistry, mine type, mineralogy, texture, ore extraction and climate knowledge.

    Science.gov (United States)

    Anawar, Hossain Md

    2015-08-01

    The oxidative dissolution of sulfidic minerals releases the extremely acidic leachate, sulfate and potentially toxic elements e.g., As, Ag, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Th, U, Zn, etc. from different mine tailings and waste dumps. For the sustainable rehabilitation and disposal of mining waste, the sources and mechanisms of contaminant generation, fate and transport of contaminants should be clearly understood. Therefore, this study has provided a critical review on (1) recent insights in mechanisms of oxidation of sulfidic minerals, (2) environmental contamination by mining waste, and (3) remediation and rehabilitation techniques, and (4) then developed the GEMTEC conceptual model/guide [(bio)-geochemistry-mine type-mineralogy- geological texture-ore extraction process-climatic knowledge)] to provide the new scientific approach and knowledge for remediation of mining wastes and acid mine drainage. This study has suggested the pre-mining geological, geochemical, mineralogical and microtextural characterization of different mineral deposits, and post-mining studies of ore extraction processes, physical, geochemical, mineralogical and microbial reactions, natural attenuation and effect of climate change for sustainable rehabilitation of mining waste. All components of this model should be considered for effective and integrated management of mining waste and acid mine drainage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Geochemical and mineralogical fingerprints of the sediments supply and early diagenetic processes in the Bizerte Lagoon (Tunisia

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    Noureddine Zaaboub

    2016-10-01

    Full Text Available The Bizerte Lagoon (Tunisia functions as a sedimentation environment characterized by receiving allochthonous sediments mainly transported by the Ben Hassine, Rharek and Guenich streams, as well as marine sediments from the Mediterranean Sea. It is subjected to significant environmental changes due to the natural and anthropic influences altering the natural patterns of circulation, extraction and/or deposition of mineralogical materials. The aim of this investigation is to analyze the sediments supply and early diagenetic processes in Bizerte Lagoon. The physicochemical parameter of the sediment pore water, as well as their texture, mineralogical composition (X-Ray diffraction technique - XRD, magnetic susceptibility and their geochemical composition (namely lithogenic and biogenic chemical elements analyzed by ICP-MS were analyzed in 10 sampling stations. The water temperature with an average of 15.2°C was stable in the study area. The sediments were generally characterized by fine granulometry, mainly mud and sandy mud, poorly to very poorly sorted, and constituted by two or more granulometric particle modes. The mineralogical results revealed the presence of phyllosilicates, quartz, pyrite, calcite, anatase and K-feldspar, and other minerals in smaller proportions. The fine sediment and high phyllosilicates and Al contents indicate the presence of weak currents in most part of the studied area. The results of sorting, skewness and kurtosis suggest that the currents are more active in the northern region of the lagoon, near the channel of communication with the Mediterranean Sea. They also evidence a coarser particle contribution of the Ben Hassine stream to the lagoon. The other streams seem to introduce mostly fine-grained sediments in the lagoon. The currents circulation, the water residence time and the biological productivity influence the mineralogical and geochemical characteristics of the bottom sediments. The industrial activity is

  11. Andic soils : mineralogical effect onto organic matter dynamics, organic matter effect onto mineral dynamics, or both?

    Science.gov (United States)

    Basile-Doelsch, Isabelle; Amundson, Ronald; Balesdent, Jérome; Borschneck, Daniel; Bottero, Jean-Yves; Colin, Fabrice; de Junet, Alexis; Doelsch, Emmanuel; Legros, Samuel; Levard, Clément; Masion, Armand; Meunier, Jean-Dominique; Rose, Jérôme

    2014-05-01

    From a strictly mineralogical point of view, weathering of volcanic glass produces secondary phases that are short range ordered alumino-silicates (SRO-AlSi). These are imogolite tubes (2 to 3 nm of diameter) and allophane supposedly spheres (3.5 to 5 nm). Their local structure is composed of a curved gibbsite Al layer and Si tetrahedra in the vacancies (Q0). Proto-imogolites have the same local structure but are roof-shape nanoparticles likely representing the precursors of imogolite and allophanes (Levard et al. 2010). These structures and sizes give to the SRO-AlSi large specific surfaces and high reactivities. In some natural sites, imogolites and allophanes are formed in large quantities. Aging of these phases may lead to the formation of more stable minerals (halloysite, kaolinite and gibbsite) (Torn et al 1997). In natural environments, when the weathering of volcanic glass is associated with the establishment of vegetation, the soils formed are generally andosols. These soils are particularly rich in organic matter (OM), which is explained by the high ability of SRO-AlSi mineral phases to form bonds with organic compounds. In a first order "bulk" approach, it is considered that these bonds strongly stabilize the organic compounds as their mean age can reach more than 10 kyrs in some studied sites (Basile-Doelsch et al. 2005; Torn et al. 1997). However, the structure of the mineral phases present in andosols deserves more attention. Traditionally, the presence in the SRO-AlSi andosols was shown by selective dissolution approaches by oxalate and pyrophosphate. Using spectroscopic methods, mineralogical analysis of SRO-AlSi in andosols samples showed that these mineral phases were neither imogolites nor allophanes as originally supposed, but only less organized structures remained in a state of proto-imogolites (Basile-Doelsch al. 2005 ; Levard et al., 2012). The presence of OM would have an inhibitory effect on the formation of secondary mineral phases, by

  12. Magnesium isotope fractionation in volcanic soils controlled by clay mineralogy and exchangeable Mg

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    Opfergelt, S.; Georg, B.; Burton, K.; Delvaux, B.; Siebert, C.; Guicharnaud, R.; Cabidoche, Y.; Halliday, A.

    2010-12-01

    Continental weathering of calcium-magnesium silicates exerts a strong control on atmospheric CO2 concentrations. Mg stable isotopes are used here as a biogeochemical tracer to quantify the contributions from soil weathering processes and vegetation on the Mg budget and the chemistry of soil solutions exported to the hydrosphere. We report the isotopic budget of Mg in distinct Mg pools (bedrock, vegetation, bulk soils, clay fractions, exchangeable Mg, soil pore waters) in tropical (Guadeloupe, Basse-Terre) and temperate volcanic soils (Iceland, Borgarfjordur catchment). Exchangeable Mg was collected by percolation of ammonium acetate 1N at pH7. Mg isotope ratios were measured by MC-ICP-MS (Nu Plasma HR) with an external reproducibility for DSM3 standard (Galy et al., 2003, JAAS 18, 1352-1356) of ± 0.15 ‰, 2SD, for δ26Mg. We investigated two soil sequences from Guadeloupe, both derived from andesitic ash, with the mineralogical sequence evolving towards Mg-bearing and non Mg-bearing secondary phases, respectively: (1) Andosol - Cambisol - Vertisol with the mineralogical sequence A - All - H,S - S (*), and (2) Andosol - Nitisol - Ferralsol with the sequence A - G,All - H,F - K,G,F. The basaltic soils from Iceland include Histosol and Histic, Gleyic and Brown Andosol with clay fractions mainly constituted of All, H and F. This selection of soils, with contrasting Mg-bearing and non-bearing secondary phases, and contrasting amount of Mg exchangeable (1.2 to 6.6 cmolc.kg-1), allows for a direct assessment of the weathering control on Mg isotope ratios and the Mg budget in both tropical and temperate conditions. In Guadeloupe, bulk soils and clay fractions were isotopically heavier (-0.41 to -0.10 ‰) than the andesite bedrock (-0.47 ‰). Icelandic bulk soils were isotopically similar or lighter (-0.80 to -0.25 ‰) than the parental basalt (-0.31 ‰). In both Guadeloupe and Iceland, soils were isotopically lighter with increasing amount of exchangeable Mg

  13. Sulphide and sulphosalt mineralogy and paragenesis from the Sierra Almagrera veins, Betic Cordillera (SE Spain

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    Martínez Frías, J.

    1991-12-01

    Full Text Available The Sierra Almagrera vein-type mineralization contains base metal sulphides and Pb-Sb- Cu-Ag sulphosalts. The sulphides possess significant proportions of Ag, Sb (galena, Fe (sphalerite and Sb, Zn (chalcopyrite. Ore microscopy and electron microprobe have revealed a mineralogical and textural variation and confirmed the presence of bournonite, boulangerite and anomalous tetrahedrite. The average sulphosalt formulas are bournonite Cu0.98 Pb0. 96 Sb0.98 S3.04, boulangerite Pb4.8Sb3.8S11.34 and anomalous tetrahedrite Ag0.6Cu9.7 Zn3.6 Fe0. 44 Sb3.47 S13- The sequence of mineral deposition indicates the existance of four mineralizing stages and one supergene alteration: 1 Fe-(As; 2 Zn-Cu-Fe; 3 Pb-Sb-Cu-Ag; 4 Cu-Zn-Fe, and 5 carbonates, sulphates and supergene oxides. In broad terms, it is possible to establish the following conclusions: a there exist a mineralogical and textural variation with depth, the Pb-Sb-Cu-Ag stage reaching the maximum development; b a temperature decrease during the formation of sph. 1, linked to the progressive increase in Fe-content of the sphalerite has been detected; c the compositional homogeneity of the bournonite (and the fair lack of As in the tetrahedrite could indicate the existance of a possible tendancy to individually crystallise the Sb and As sulphosalts, according to the trend Bi → Sb → As.La mineralización filoniana de Sierra Almagrera presenta una interesante paragénesis caracterizada por la presencia de sulfuros de metales base y sulfosales de Pb-Sb-Cu-Ag. Se ha identificado una secuencialidad textural y química de las distintas fases minerales, según la cual los sulfuros poseen variaciones significativas de las proporciones de Ag, Sb (galena, Fe (esfalerita, y Sb, Zn (calcopirita, yen la que las sulfosales son fundamentalmente sulfoantimoniuros (bournonita: Cu0.98 Pb0. 96 Sb0.98 S3.04, boulangerita Pb4.8Sb3.8S11.34 y tetraedrita anómala Ag0.6Cu9.7 Zn3.6 Fe0. 44 Sb3.47 S13-. La secuencia de

  14. The effects of metamorphism on iron mineralogy and the iron speciation redox proxy

    Science.gov (United States)

    Slotznick, Sarah P.; Eiler, John M.; Fischer, Woodward W.

    2018-03-01

    As the most abundant transition metal in the Earth's crust, iron is a key player in the planetary redox budget. Observations of iron minerals in the sedimentary record have been used to describe atmospheric and aqueous redox environments over the evolution of our planet; the most common method applied is iron speciation, a geochemical sequential extraction method in which proportions of different iron minerals are compared to calibrations from modern sediments to determine water-column redox state. Less is known about how this proxy records information through post-depositional processes, including diagenesis and metamorphism. To get insight into this, we examined how the iron mineral groups/pools (silicates, oxides, sulfides, etc.) and paleoredox proxy interpretations can be affected by known metamorphic processes. Well-known metamorphic reactions occurring in sub-chlorite to kyanite rocks are able to move iron between different iron pools along a range of proxy vectors, potentially affecting paleoredox results. To quantify the effect strength of these reactions, we examined mineralogical and geochemical data from two classic localities where Silurian-Devonian shales, sandstones, and carbonates deposited in a marine sedimentary basin with oxygenated seawater (based on global and local biological constraints) have been regionally metamorphosed from lower-greenschist facies to granulite facies: Waits River and Gile Mountain Formations, Vermont, USA and the Waterville and Sangerville-Vassalboro Formations, Maine, USA. Plotting iron speciation ratios determined for samples from these localities revealed apparent paleoredox conditions of the depositional water column spanning the entire range from oxic to ferruginous (anoxic) to euxinic (anoxic and sulfidic). Pyrrhotite formation in samples highlighted problems within the proxy as iron pool assignment required assumptions about metamorphic reactions and pyrrhotite's identification depended on the extraction techniques

  15. Palaeomagnetic, rock-magnetic and mineralogical investigations of metadolerites from Western Svalbard : A preliminary report

    Science.gov (United States)

    Michalski, Krzysztof; Nejbert, Krzysztof; Domańska-Siuda, Justyna; Manby, Geoffrey

    2014-05-01

    A group of 42 independently oriented palaeomagnetic samples from 7 sites located in central part of the West Spitsbergen Thrust and Fault Belt has been investigated. The samples were collected from 5 distinct metadolerite sheets intruded into the Proterozoic - Lower Paleozoic metamorphic complex of Western Oscar II Land (Western Svalbard Caledonian Terrane - Harland, 1997 division). All analyzed metadolerite samples were metamorphosed under greenschist facies metamorphism. The metamorphic assemblage consist of hornblende, biotite, actinolite, chlorite, epidote, stilpnomelane, titanite, albite, and quartz. Calcite, associated with pyrrhotite, pyrite chalcopyrite, sphalerite, and covellite, that occurs as irregular intergrowths or thin veins, document high activity of H2O-CO2-rich fluids during metamorphism. Primary magmatic phases represented by clinopyroxene occur rarely, and only in thick metadolerite dykes. Accessory oxides change their mineralogical and chemical composition during metamorphism. In all examined samples primary Ti-magnetite and oxy-exsolved hematite break-down completely into titanite or have been dissolved. The ilmenite are also replaced by titanite, but in metadolerites at contact with host metapelites, slightly altered ilmenite grains with preserved hematite exsolution were documented. Basing on mineralogical observations it should be expected that metamorphic processes have almost completely reset the paleomagnetic data record from the time of dolerite crystallization. This stage can document only rare hematite oxy-exsolution preserved within ilmenite, and presumably small inclusion of magnetite still preserved within unaltered clinopyroxene. The paleomagnetic record of metamorphic stage is probably recorded by pyrrhotite, hematite, goethite, and late Ti-free magnetite that can grow during breakdown of pyrrhotite to pyrite (Ramdohr. 1980). The NRM (Natural Remanent Magnetisation) intensities of the palaeomagnetic samples exceed the minimum 10

  16. The Homestead kimberlite, central Montana, USA: mineralogy, xenocrysts, and upper-mantle xenoliths

    Science.gov (United States)

    Carter Hearn, B.

    2004-09-01

    The Homestead kimberlite was emplaced in lower Cretaceous marine shale and siltstone in the Grassrange area of central Montana. The Grassrange area includes aillikite, alnoite, carbonatite, kimberlite, and monchiquite and is situated within the Archean Wyoming craton. The kimberlite contains 25-30 modal% olivine as xenocrysts and phenocrysts in a matrix of phlogopite, monticellite, diopside, serpentine, chlorite, hydrous Ca-Al-Na silicates, perovskite, and spinel. The rock is kimberlite based on mineralogy, the presence of atoll-textured groundmass spinels, and kimberlitic core-rim zoning of groundmass spinels and groundmass phlogopites. Garnet xenocrysts are mainly Cr-pyropes, of which 2-12% are G10 compositions, crustal almandines are rare and eclogitic garnets are absent. Spinel xenocrysts have MgO and Cr 2O 3 contents ranging into the diamond inclusion field. Mg-ilmenite xenocrysts contain 7-11 wt.% MgO and 0.8-1.9 wt.% Cr 2O 3, with (Fe +3/Fe tot) from 0.17-0.31. Olivine is the only obvious megacryst mineral present. One microdiamond was recovered from caustic fusion of a 45-kg sample. Upper-mantle xenoliths up to 70 cm size are abundant and are some of the largest known garnet peridotite xenoliths in North America. The xenolith suite is dominated by dunites, and harzburgites containing garnet and/or spinel. Granulites are rare and eclogites are absent. Among 153 xenoliths, 7% are lherzolites, 61% are harzburgites, 31% are dunites, and 1% are orthopyroxenites. Three of 30 peridotite xenoliths that were analysed are low-Ca garnet-spinel harzburgites containing G10 garnets. Xenolith textures are mainly coarse granular, and only 5% are porphyroclastic. Xenolith modal mineralogy and mineral compositions indicate ancient major-element depletion as observed in other Wyoming craton xenolith assemblages, followed by younger enrichment events evidenced by tectonized or undeformed veins of orthopyroxenite, clinopyroxenite, websterite, and the presence of phlogopite

  17. The Mineralogical and Chemical Case for Habitability at Yellowknife Bay, Gale Crater, Mars

    Science.gov (United States)

    Blake, David Frederick; Vaniman, David; Grotzinger, John P.; Conrad, Pamela Gales; Ming, Douglas W.; Bish, David L.; Farmer, Jack D.; Bristow, Thomas

    2013-01-01

    Sediments of the Yellowknife Bay formation (Gale crater) include the Sheepbed member, a mudstone cut by light-toned veins. Two drill samples, John Klein and Cumberland, were collected and analyzed by the CheMin XRD/XRF instrument and the Sample Analysis at Mars (SAM) evolved gas and isotopic analysis suite of instruments. Drill cuttings were also analyzed by the Alpha Particle X-ray Spectrometer (APXS) for bulk composition. The CheMin XRD analysis shows that the mudstone contains basaltic minerals (Fe-forsterite, augite, pigeonite, plagioclase), as well as Fe-oxide/hydroxides, Fe-sulfides, amorphous materials, and trioctahedral phyllosilicates. SAM evolved gas analysis of higher-temperature OH matches the CheMin XRD estimate of 20% clay minerals in the mudstone. The light-toned veins contain Ca-sulfates; anhydrite and bassanite are detected by XRD but gypsum is also indicated from Mastcam spectral mapping. These sulfates appear to be almost entirely restricted to late-diagenetic veins. The sulfate content of the mudstone matrix itself is lower than other sediments analyzed on Mars. The presence of phyllosilicates indicates that the activity of water was high during their formation and/or transport and deposition (should they have been detrital). Lack of chlorite places limits on the maximum temperature of alteration (likely <100 C). The presence of Ca-sulfates rather than Mg- or Fe-sulfates suggests that the pore water pH was near-neutral and of relatively low ionic strength (although x-ray amorphous Mg-and Fe- sulfates could be present and undetectable by CheMin). The presence of Fe and S in both reduced and oxidized states represents chemical disequilibria that could have been utilized by chemolithoautotrophic biota, if present. When compared to the nearby Rocknest sand shadow mineralogy or the normative mineralogy of Martian soil, both John Klein and Cumberland exhibit a near-absence of olivine and a surplus of magnetite (7-9% of the crystalline component). The

  18. Mineralogy and microstructure of roofing slate: thermo-optical behaviour and fissility

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    García-Guinea, J.

    1998-09-01

    Full Text Available The mineralogy and microstructure, which affect the slaty cleavage, are linked with the strong preferred orientation of phyllosilicates and this enables the rock to be split into large, thin, flat sheets. Roofing slate samples with different commercial fissilities have been analyzed by radioluminescence (RL, thermoluminescence (3DTL, by X-ray diffraction (XRD, by scanning electron microscopy (SEM using the back-scattered mode (BSEI and by electron microprobe (EMP. They are made up of white micas, chlorite, quartz, detrital feldspars, ilmenite, pyrite, rutile apatite and tourmaline. Texturally, all consist of silt-sized clasts of detrital quartz, feldspars, chlorite-mica stacks, muscovite and ilmenite in a recrystalline, lepidoblastic matrix of white micas and chlorite with quartz lenses, all showing a very strong preferred orientation. The luminescence emission centers are a low broad blue band around the 400 nm spectra positions linked with alkali losses and formation of [AlO4]º defects; a peak at 473 nm interpreted as a the first thermal step (150-300ºC of a non-isothermal dehydroxylation of the slate phyllosilicates; and a 568 nm peak which agrees with Mn2+ point defects in aluminosilicate lattices. The studies on the slaty cleavage could be significant because Spain is the largest producer of roofing slate tiles in the world (87% of world production.

    La exfoliación de las pizarras depende fundamentalmente de su mineralogía y microestructura, especialmente de la fuerte orientación de los filosilicatos. Esta propiedad permite hendir o abrir las pizarras de techar en láminas muy grandes, delgadas y planas. Se han analizado varias pizarras de techar con diferentes calidades comerciales, correspondientes a diferentes grados de físibilidad, por radioluminiscencia (RL, termoluminiscencia espectral (TL3D, difracción de rayos X (DRX, microscopía electrónica de barrido (MEB utilizando el modo backscattered (BSEI

  19. Elemental and Mineralogical Analysis of Tsunami Deposits from Phra Thong Island, Thailand

    Science.gov (United States)

    Pham, D. T.; Gouramanis, C.; Switzer, A.; Rubin, C. M.; Jones, B. G.; Jankaew, K.; Carr, P. F.

    2014-12-01

    Characterizing sediment provenance from the geologic and geomorphic records left by natural disasters may shed light on the sedimentary and hydrodynamic processes happening during such events. In this study, we collected modern sediment samples from onshore, offshore, the 2004 Indian Ocean Tsunami and three palaeotsunamis and a 2007 storm deposit from Phra Thong Island, Thailand. To explore the relationship between the sedimentary deposits, we examined grainsize parameters, mineralogy (from X-Ray Diffraction) and trace element geochemistry (from X-Ray Fluorescence) from each deposit and applied a series of statistical analyses including cluster analysis, principal component analysis and discriminant function analysis. Our results show that the mineral content and grainsize parameters are statistically inadequate to distinguish the provenance of tsunami deposits, but that trace element geochemistry is potentially a good discriminator. In most of our statistical analyses, the trace elements show that the onshore samples are distinguished from the offshore and tsunami sediment samples. Also, the near-shore samples and tsunami deposits are very similar. This reveals that the near-shore marine sediments significantly contributed to the 2004 tsunami deposits. In addition, our analyses show that all four tsunami units statistically differ from each other, and that the storm deposits are similar to the second palaeo-tsunami group. This indicates that sediment sources are diverse and that the tsunami deposits did not come from the same source. Such complexity raises questions about the origin of various sedimentary environments and it also reflects the importance of local context and paleogeography that cannot be ignored in tsunami provenance studies.

  20. A visible and near-infrared photometric correction for Moon Mineralogy Mapper (M3)

    Science.gov (United States)

    Besse, S.; Sunshine, J.; Staid, M.; Boardman, J.; Pieters, C.; Guasqui, P.; Malaret, E.; McLaughlin, S.; Yokota, Y.; Li, J.-Y.

    2013-01-01

    Observations of the Moon obtained by the Moon Mineralogy Mapper (M3) instrument were acquired at various local viewing geometries. To compensate for this, a visible near-infrared photometric correction for the M3 observations of the lunar surface has been derived. Images are corrected to the standard geometry of 30° phase angle with an incidence of 30° and an emission of 0°. The photometric correction is optimized for highland materials but is also a good approximation for mare deposits. The results are compared with ground-based observations of the lunar surface to validate the absolute reflectance of the M3 observations. This photometric model has been used to produce the v1.0 Level 2 delivery of the entire set of M3 data to the Planetary Data System (PDS). The photometric correction uses local topography, in this case derived from an early version of the Lunar Orbiter Laser Altimeter data, to more accurately determine viewing geometry. As desired, this photometric correction removes most of the topography of the M3 measurements. In this paper, two additional improvements of the photometric modeling are discussed: (1) an extrapolated phase function long ward of 2500 nm to avoid possible misinterpretation of spectra in the wavelength region that includes possible OH/H2O absorptions and (2) an empirical correction to remove a residual cross-track gradient in the data that likely is an uncorrected instrumental effect. New files for these two effects have been delivered to PDS and can be applied to the M3 observations.

  1. The Piriá aluminous lateritic profile: mineralogy, geochemistry and parent rock

    Directory of Open Access Journals (Sweden)

    Pabllo Henrique Costa dos Santos

    Full Text Available ABSTRACT: Relatively small aluminous lateritic deposits are abundant in the northeast and northwest parts of the Pará and Maranhão states, respectively. Most of them hosts aluminum phosphate mineralization forming hills and plateaus that stand out in the topography of the undulating plains of this region. The Piriá ridge is one of those topographic features, covered by lateritic iron crusts that have been studied in the 1970s as part of iron ore exploration campaigns and recently for phosphates prospection. This study improves the knowledge about the evolution of the lateritic Piriá deposit and demonstrates its relationship with the most evolved laterites of the Amazon, known as mature laterites, which formed major ore deposits during the Paleogene. Samples of a 17 meter-deep borehole were investigated through mineralogical (X-ray diffraction -XRD, optical and electron microscopy and chemical methods (inductively coupled plasma mass spectrometry - ICP-MS, inductively coupled plasma optical emission spectrometry - ICP-OES and X-ray fluorescence - XRF. The studied lateritic profile comprises a clay bauxitic horizon overlaid by an aluminous iron crust. Upwardly continuous dissolution of kaolinite occurs with the formation of gibbsite, as the result of intensive leaching, resulting in a higher Al2O3 content in the crust. The continuous formation of hematite from goethite resulted from the transition to more arid conditions. Anatase is a newly formed mineral (100-400 nm crystallites, showing a gradual increase, following the increase in TiO2 content, which is high and indicative of a mafic parent rock, confirmed by the Ti × Zr dispersion pattern. Prominent zoning in the lateritic profile is characterized by the mineralization in bauxite and augelite and abrupt chemical transition between the horizons, marked by a decrease in Si and increase in Fe content from the bottom to the top of the profile. These features are compatible and indicative of

  2. Ma_MISS on ExoMars: Mineralogical Characterization of the Martian Subsurface

    Science.gov (United States)

    De Sanctis, Maria Cristina; Altieri, Francesca; Ammannito, Eleonora; Biondi, David; De Angelis, Simone; Meini, Marco; Mondello, Giuseppe; Novi, Samuele; Paolinetti, Riccardo; Soldani, Massimo; Mugnuolo, Raffaele; Pirrotta, Simone; Vago, Jorge L.; Ma_MISS Team

    2017-07-01

    The Ma_MISS (Mars Multispectral Imager for Subsurface Studies) experiment is the visible and near infrared (VNIR) miniaturized spectrometer hosted by the drill system of the ExoMars 2020 rover. Ma_MISS will perform IR spectral reflectance investigations in the 0.4-2.2 μm range to characterize the mineralogy of excavated borehole walls at different depths (between 0 and 2 m). The spectral sampling is about 20 nm, whereas the spatial resolution over the target is 120 μm. Making use of the drill's movement, the instrument slit can scan a ring and build up hyperspectral images of a borehole. The main goal of the Ma_MISS instrument is to study the martian subsurface environment. Access to the martian subsurface is crucial to our ability to constrain the nature, timing, and duration of alteration and sedimentation processes on Mars, as well as habitability conditions. Subsurface deposits likely host and preserve H2O ice and hydrated materials that will contribute to our understanding of the H2O geochemical environment (both in the liquid and in the solid state) at the ExoMars 2020 landing site. The Ma_MISS spectral range and sampling capabilities have been carefully selected to allow the study of minerals and ices in situ before the collection of samples. Ma_MISS will be implemented to accomplish the following scientific objectives: (1) determine the composition of subsurface materials, (2) map the distribution of subsurface H2O and volatiles, (3) characterize important optical and physical properties of materials (e.g., grain size), and (4) produce a stratigraphic column that will inform with regard to subsurface geological processes. The Ma_MISS findings will help to refine essential criteria that will aid in our selection of the most interesting subsurface formations from which to collect samples.

  3. Mineralogy and geochemistry of the No. 6 Coal (Pennsylvanian) in the Junger Coalfield, Ordos Basin, China

    Science.gov (United States)

    Dai, S.; Ren, D.; Chou, C.-L.; Li, S.; Jiang, Y.

    2006-01-01

    This paper discusses the mineralogy and geochemistry of the No. 6 Coal (Pennsylvanian) in the Junger Coalfield, Ordos Basin, China. The results show that the vitrinite reflectance (0.58%) is lowest and the proportions of inertinite and liptinite (37.4% and 7.1%, respectively) in the No. 6 Coal of the Junger Coalfield are highest among all of the Late Paleozoic coals in the Ordos Basin. The No. 6 Coal may be divided vertically into four sections based on their mineral compositions and elemental concentrations. A high boehmite content (mean 6.1%) was identified in the No. 6 Coal. The minerals associated with the boehmite in the coal include goyazite, rutile, zircon, and Pb-bearing minerals (galena, clausthalite, and selenio-galena). The boehmite is derived from weathered and oxidized bauxite in the weathered crust of the underlying Benxi Formation (Pennsylvanian). A high Pb-bearing mineral content of samples ZG6-2 and ZG6-3 is likely of hydrothermal origin. The No. 6 coal is enriched in Ga (44.8 ??g/g), Se (8.2 ??g/g), Sr (423 ??g/g), Zr (234 ??g/g), REEs (193.3 ??g/g), Hg (0.35 ??g/g), Pb (35.7 ??g/ g), and Th (17.8 ??g/g). Gallium and Th in the No. 6 Coal mainly occur in boehmite, and the Pb-bearing selenide and sulfide minerals contribute not only to Se and Pb contents in the coal, but also probably to Hg content. A high Zr content is attributed to the presence of zircon, and Sr is related to goyazite. The REEs in the coal are supplied from the sediment-source region, and the REEs leached from the adjacent partings by groundwater. ?? 2005 Elsevier B.V. All rights reserved.

  4. Geochemical and Mineralogical Changes in Compacted MX-80 Bentonite Submitted to Heat and Water Gradients

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Espina, R.; Villar, M. V.

    2010-05-01

    A 20-cm high column of MX80 bentonite compacted at dry density 1.70 g/cm{sup 3} with an initial water content of 16 percent was submitted to heating and hydration by opposite ends for 496 days (TH test). The temperature at the bottom of the column was set at 140 degree centigrade and on top at 30 degree centigrade, and deionised water was injected on top at a pressure of 0.01 MPa. Upon dismantling water content, dry density, mineralogy, specific surface area, cation exchange capacity, content of exchangeable cations, and concentration of soluble salts and pH of aqueous extracts were determined in different positions along the bentonite column. The pore water composition was modelled with a geochemical software. The test tried to simulate the conditions of an engineered barrier in a deep geological repository for high-level radioactive waste. The water intake and distribution of water content and dry density along the bentonite were conditioned by the thermal gradient. Liquid water did not penetrate into the column beyond the area in which the temperature was higher than 100 degree centigrade. A convection cell was formed above this area, and liquid water loaded with ions evaporated towards cooler bentonite as it reached the area where the temperature was too high. In this area precipitation of mineral phases took place, Advection, interlayer exchange and dissolution/precipitation processes conditioned the composition of the pore water along the column. In most of the column the pore water was Na-SO{sub 4} {sup 2}- type, and changed to Na-Cl near the heater. TH treatment did not cause significant changes in the smectite content or the other mineral phases of the bentonite. (Author) 41 refs.

  5. Mineralogical and chemical characterization of DD3 kaolin from the east of Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Senoussi, H.; Osmani, H.; Courtois, C.; Bourahli, M. H.

    2016-08-01

    The mineralogical and chemical characteristics, based on X-ray diffraction (XRD) and scanning electron microscopy, of a kaolin known as DD3, from eastern Algeria were examined in the present study. The results showed that kaolin DD3 has an alumina content of 39%. The SiO{sub 2}/Al{sub 2}O{sub 3} molar ratio of 2.14 is close to that of a pure halloysite. The hematite concentration is relatively large and the flux oxides ratios remain as acceptable impurities. Microscopic observations showed a predominant tubular halloysite phase, flattened hexagonal platelets corresponding to the presence of kaolinite and its polymorphs (nacrite, dickite), and hydrated alumina. The SiO{sub 2}/Al{sub 2}O{sub 3} molar ratio and tubular DD3 suggest possible uses in technical ceramics and nano technology applications. Analysis by XRD revealed the presence of many phases. Thermal treatment at 450 degree centigrade and chemical treatment with HCl confirmed the presence of halloysite. The inclusion in the clay of organic molecules (dimethylsulfoxide (DMSO), DMF, and diluted glycerol) showed that the DMSO led to expansion of the inter-planar distance. The intercalation by DMSO molecules resulted in a shift of the basal peak from 10 to 11.02 A and partial displacement of the peak from 3.35 to 3.65 A. These two peaks are characteristic of halloysite. The presence of residual nacrite was also confirmed by the shift of the peak observed at 3.35 A. A full analysis of the XRD patterns using the Match software, based on these results, showed that the DD3 clay consists of >60% halloysite. (Author)

  6. Mineralogical, geochemical and radiological characterisation of Selmo Formation in Batman area, Turkey.

    Science.gov (United States)

    Isik, Umit; Damla, Nevzat; Akkoca, Dicle Bal; Cevik, Uğur

    2012-06-01

    This work deals with the mineralogical, geochemical and radiological characterisations of Selmo Formation in Batman neighbourhood. The upper Miocene-Pliocene Selmo Formation is common in the centre of Batman and composed of carbonated sandy claystones and silty-sandy stone lenses. The common whole minerals of the samples are quartz, feldspars, calcite and dolomite. The clay minerals are smectite, illite, chlorite and mixed-layer clay (chlorite-smectite). The geochemical mean values of the samples are 51.7% SiO(2); 12.6% Al(2)O(3); 6.2% Fe(2)O(3); 3.6% MgO; 6.3% CaO; 1.1% Na(2)O; 1.7% K(2)O; 0.8% TiO(2); 0.2% P(2)O(5); 0.1% MnO; and 0.03% Cr(2)O(3). In addition, baseline maps for the concentrations of each radionuclide, the radium equivalent activity and the outdoor gamma dose rate distributions have been plotted for the study area. The mean activity concentrations of (226)Ra, (232)Th, (40)K and (137)Cs were determined to be 32, 24, 210 and 9 Bq kg(-1), respectively. The assessments of the radiological hazard indices, such as radium equivalent activity, absorbed dose rate in air, annual effective dose equivalent, excess lifetime cancer risk, external hazard index and internal hazard index, were calculated and compared with the internationally accepted reference values. This study shows that the concentrations of radioactivities in the measured samples were within the recommended safety limits and did not pose to be any significant source of radiation hazard.

  7. Influence of substrate mineralogy on bacterial mineralization of calcium carbonate: implications for stone conservation.

    Science.gov (United States)

    Rodriguez-Navarro, Carlos; Jroundi, Fadwa; Schiro, Mara; Ruiz-Agudo, Encarnación; González-Muñoz, María Teresa

    2012-06-01

    The influence of mineral substrate composition and structure on bacterial calcium carbonate productivity and polymorph selection was studied. Bacterial calcium carbonate precipitation occurred on calcitic (Iceland spar single crystals, marble, and porous limestone) and silicate (glass coverslips, porous sintered glass, and quartz sandstone) substrates following culturing in liquid medium (M-3P) inoculated with different types of bacteria (Myxococcus xanthus, Brevundimonas diminuta, and a carbonatogenic bacterial community isolated from porous calcarenite stone in a historical building) and direct application of sterile M-3P medium to limestone and sandstone with their own bacterial communities. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD), and 2-dimensional XRD (2D-XRD) analyses revealed that abundant highly oriented calcite crystals formed homoepitaxially on the calcitic substrates, irrespective of the bacterial type. Conversely, scattered spheroidal vaterite entombing bacterial cells formed on the silicate substrates. These results show that carbonate phase selection is not strain specific and that under equal culture conditions, the substrate type is the overruling factor for calcium carbonate polymorph selection. Furthermore, carbonate productivity is strongly dependent on the mineralogy of the substrate. Calcitic substrates offer a higher affinity for bacterial attachment than silicate substrates, thereby fostering bacterial growth and metabolic activity, resulting in higher production of calcium carbonate cement. Bacterial calcite grows coherently over the calcitic substrate and is therefore more chemically and mechanically stable than metastable vaterite, which formed incoherently on the silicate substrates. The implications of these results for technological applications of bacterial carbonatogenesis, including building stone conservation, are discussed.

  8. Mineralogy and metals speciation in Mo rich mineral sludges generated at a metal recycling plant.

    Science.gov (United States)

    Vemic, M; Bordas, F; Guibaud, G; Joussein, E; Labanowski, J; Lens, P N L; van Hullebusch, E D

    2015-04-01

    In France, more than 250 million metric tons of sludges need to be treated each year. These sludges are either dumped on the landfills or reused as secondary resources in order to preserve natural resources. A large portions of these sludges are mineral sludges, originating from metal recycling plants. In order to estimate their metal recovery potential, these mineral sludges were characterized. Four types of mineral sludge samples were collected from a metal recycling plant (3 from the recycling plant storage areas (bulk storage, barrel storage and storage shed) and 1 from the collection basin). The sludges were characterized, wherein the Mo, Ni, Cr, Co, Zn and W content and speciation were quantified. The samples had pH values between 5.9 and 10.3 with organic matter contents varying between 6.3% (storage shed) and 29.5% (bulk storage) (loss on ignition at 500 °C). Based on their leaching properties, the four mineral sludge samples (in the case of Mo) and the bulk storage sludge (in the case of Ni and Zn) were classified as potentially hazardous regarding the EN 12457-1 and EN 12457-2 method. Mineralogical results reveal that both bulk storage and the storage shed give the highest contributions to the metal content of the collection basin sample. Sequential extraction of the collection basin samples indicated that Mo is bound to the oxidizable and residual fraction, while Ni, Cr and Co were bound to the residual fraction, and Zn to the soluble acid fraction, respectively. W tends to be equally distributed among all extracted fractions. A strong correlation existed between Mo and Co, as well as between Ni, Zn and Cr, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Biochar Properties Influencing Greenhouse Gas Emissions in Tropical Soils Differing in Texture and Mineralogy.

    Science.gov (United States)

    Butnan, Somchai; Deenik, Jonathan L; Toomsan, Banyong; Antal, Michael J; Vityakon, Patma

    2016-09-01

    The ability of biochar applications to alter greenhouse gases (GHGs) (CO, CH, and NO) has been attracting research interest. However, inconsistent published results necessitate further exploration of potential influencing factors, including biochar properties, biochar rates, soil textures and mineralogy, and their interactions. Two short-term laboratory incubations were conducted to evaluate the effects of different biochars: a biochar with low ash (2.4%) and high-volatile matter (VM) (35.8%) contents produced under low-temperature (350°C) traditional kiln and a biochar with high ash (3.9%) and low-VM (14.7%) contents produced with a high-temperature (800°C) Flash Carbonization reactor and different biochar rates (0, 2, and 4% w/w) on the GHG emissions in a loamy-sand Ultisol and a silty-clay-loam Oxisol. In the coarse-textured, low-buffer Ultisol, cumulative CO and CH emissions increased with increasing VM content of biochars; however, CO emission sharply decreased at 83 μg VM g soil. In the fine-textured, high-buffer Oxisol, there were significant positive effects of VM content on cumulative CO emission without suppression effects. Regarding cumulative NO emission, there were significant positive effects in the Mn-rich Oxisol. Ash-induced increases in soil pH had negative effects on all studied GHG emissions. Possible mechanisms include the roles biochar VM played as microbial substrates, a source of toxic compounds and complexing agents reducing the toxicity of soil aluminum and manganese, and the role of biochar ash in increasing soil pH affecting GHG emissions in these two contrasting soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  10. The Trouble With Tailings: How Alteration Mineralogy can Hinder Quantitative Phase Analysis of Mineral Waste

    Science.gov (United States)

    Wilson, S. A.; Mills, S. J.; Dipple, G. M.; Raudsepp, M.

    2009-05-01

    Quantitative phase analysis, using the Rietveld method and X-ray powder-diffraction data, has become a standard technique for analysis of mineral waste from mining operations. This method relies upon the availability of well defined crystal structures for all detectable mineral phases in a sample. An even more basic assumption, central to quantitative mineralogy, is that all significant mineral phases can be detected from X-ray diffraction data. This is not always the case, because X-ray amorphous and nanocrystalline mineral phases can develop within geological samples as a result of chemical weathering. The extent of mineral-water interaction to which mine tailings are exposed, during processing and storage, makes these materials particularly susceptible to weathering and alteration. We have used the Rietveld method and X-ray powder-diffraction data to quantify the uptake of atmospheric CO2 into secondary carbonate minerals at two operating mines: the Diavik Diamond Mine, Northwest Territories, Canada, and the Mount Keith Nickel Mine, Western Australia, Australia. At Diavik, nominally anhydrous minerals in kimberlitic mine tailings have been found to contain X-ray amorphous material and hydroxyl groups detectable by Raman spectroscopy. A series of weighed mixtures, prepared to simulate kimberlite mine tailings, has been used to assess the effects of X-ray amorphous material on quantitative phase analysis of Diavik tailings. At Mount Keith, hydrated sulphate minerals and halide minerals develop efflorescent crusts at the surface of the tailings storage facility. Hydrated sulphate minerals in these mine tailings commonly decompose to amorphous substances rather than dehydrating to produce minerals detectable from X-ray powder-diffraction patterns. Nanocrystalline and X-ray amorphous material in mine tailings can affect the accuracy of quantitative determinations of CO2 trapping and abundances of sulphur-bearing minerals associated with redox reactions. Here we

  11. Clay mineralogy of the Boda Claystone Formation (Mecsek Mts., SW Hungary)

    Science.gov (United States)

    Németh, Tibor; Máthé, Zoltán; Pekker, Péter; Dódony, István; Kovács-Kis, Viktória; Sipos, Péter; Cora, Ildikó; Kovács, Ivett

    2016-04-01

    Boda Claystone Formation (BCF) is the host rock of the planned site for high level nuclear waste repository inHungary. Samples representing the dominant rock types of BCF were studied: albitic claystone, claystone with high illite content, and analcime bearing claystone. Clay minerals in these three rock types were characterized by Xray powder diffraction (XRD), transmission electron microscopy (TEM) and thermal analysis (DTA-TG), and the results were discussed from the point of view of the radionuclide sorption properties being studied in the future. Mineral compositions of bulk BCF samples vary in wide ranges. In the albitic sample, besides the dominant illite, few percent of chlorite represents the layer silicates in the clay fraction. Illite is the dominating phase in the illitic sample, with a few percent of chlorite. HRTEM study revealed that the thickness of illite particles rarely reaches 10 layers, usually are of 5-6 TOT layer thick. Illite crystals are generally thicker in the albitic sample than in the illitic one. The significant difference between the clay mineral characterisitics of the analcimous and the other two samples is that the former contains regularly interstratified chlorite/smectite beside the dominant illite. Based on the structural and chemical data two illite type minerals are present in the BCF samples: 1M polytype containing octahedral Fe and Mg besides Al, 2M polytype illite generally is free of Fe andMg. Close association of very thin illite plates and nanosized hematite crystals is typical textural feature for BCF. The goal of this study is to provide solid mineralogical basis for further studies focusing on radionuclide sorption properties.

  12. Carbon saturation in the silt and clay particles in soils with contrasting mineralogy

    Directory of Open Access Journals (Sweden)

    Francisco Matus

    2016-07-01

    Full Text Available The silt and clay particles play a key role as stabilizing agents of soil organic carbon (SOC. Several lines of evidence indicate a theoretical maximum or C saturation in individual particles. In the present study, we hypothesized that a C fraction displaying linear accumulation relative to the SOC is not influenced by C saturation, while a fraction displaying an asymptotic relationship is regarded as saturated (Stewart et al., 2008. The aim of the present study was to compare the amount of C in the silt and clay sized fractions in temperate and subtropical cropping soils across a range of textures with different mineralogy. Twenty-one and 18 soil samples containing 1:1 and 2:1 clay of temperate soil from Chile under monoculture of maize (Zea maiz L. for at least 30 years and 9 subtropical soils from Mexico under maize and bean (Phaseolus vulgaris L. cropping for 9 years having mixed clay were collected at 0-0.1 m. The SOC of 2:1 soils was significantly higher (14±0.5 g kg-1 dry soil than 1:1 soils (10±0.7 g kg-1. However, subtropical soils showed the highest values (59±0.5 g kg-1. A positive (P < 0.01 relationship was observed between the SOC and the C in the silt fraction (R2 0.80-0.97, P < 0.01. In contrast, the clay fraction remained constant or showed asymptotic behavior. We conclude that the silt fraction, unlike clay, showed no evidence of C saturation, while clay accumulates C to a maximum. On average, the 2:1 clay was saturated at 1-2 g C kg-1 and 1:1 at 1 g C kg-1, and subtropical soils at 14 g C kg-1.

  13. Mineralogical and physico-chemical characterization of Mbodiene palygorskite for pharmaceutical applications

    Science.gov (United States)

    Sylla Gueye, Rokhaya; Davy, Catherine A.; Cazaux, Frédéric; Ndiaye, Augustin; Diop, Mouhamadou Bassir; Skoczylas, Frédéric; Wele, Alassane

    2017-11-01

    This contribution provides a wide morphological, mineralogical, chemical and physical characterization of Mbodiene palygorskite (Senegal), to serve as a basis for the formulation of antidiarrheal and cosmetic products. Data are compared with other palygorskite deposits, either in Senegal or on other continents. Qualitative total rock XRD, semi-quantitative XRD of the clay fraction and quantitative X-Ray fluorescence (XRF) show the presence of 72%wt palygorskite (±2%wt), 13%wt montmorillonite (±2%wt), 8%wt dolomite (±2%wt), 5%wt quartz SiO2 (±2%wt) and 2%wt inter-stratified illite/smectite (±2%wt). Coupled SEM + EDX and TEM + EDX confirm the presence of fibrous palygorskite, with greater amounts of Mg than Al, and Fe substitution to Mg and Al, interspersed with dolomite cubes CaMg(CO3)2. The presence of carbonates in Mbodiene palygorskite may limit its use in the Pharmacopoeia, and make its purification necessary. A specific signature of Mbodiene palygorskite, relevant to the palygorskite family, is deduced from both FTIR and TGA analysis. In terms of physico-chemical characterization, Mbodiene palygorskite has usual values when compared to the literature (for its specific surface area, specific gravity, compressibility and Haussner indexes, CEC, loss on ignition, etc.). After grinding (down to a peak grain size of 500 nm), Mbodiene palygorskite is considered a normal clay, extremely highly plastic, with hard consistency owing to the values of its Atterberg plasticity and liquidity limits, with good flowability owing to its compressibility and Haussner indexes. Its physical characteristics are suitable for manufacturing pastes and colloidal suspensions.

  14. Strategies for increasing student knowledge and understanding about conflict minerals in a mineralogy class

    Science.gov (United States)

    Cook, G. W.

    2014-12-01

    Conflict minerals, including their uses and methods of extraction, are associated with significant societal and environmental issues in today's world. Minerals such as columbite-tantalite (also referred to as COLTAN), wolframite, cassiterite and gold are important in electronics manufacturing and have a wide variety of other usages. Mining practices are frequently unsustainable and have significant impacts on the environment; moreover, in many locations, such as the Democratic Republic of the Congo—the epicenter of the conflict mineral trade—major human rights violations are associated with the extraction and production of these minerals. Because conflict minerals represent a relatively new issue, students in geology classes are frequently unfamiliar with the topic and commonly have little understanding of the concerns. In some cases they are completely unaware of the issues. In an introductory mineralogy class at the University of California, San Diego I have introduced a content module into my otherwise traditional curriculum that introduces students to conflict minerals, explains the issues, and delineates the problems our society will face with the continued uses of these natural resources. Most significantly, an assignment has been created and implemented in class that is paired with the content module and is designed to enhance and reinforce student learning. Its goal is to increase awareness of the societal and environmental issues surrounding conflict minerals. Initial results suggest (based on pre and post-tests) that our students have learned significantly from the combination of content, exercise, and assessment and that they are much better informed on the issues of conflict minerals. This model, including the exercise, can be modified and adapted for other introductory classes and learning settings.

  15. Mineralogical and morphological investigation of kidney stones of a Mediterranean region (Basilicata, Italy).

    Science.gov (United States)

    Giannossi, Maria Luigia; Mongelli, Giovanni; Tateo, Fabio; Summa, Vito

    2012-01-01

    Kidney stones are a very frequent finding in southern Italy, but stone analysis is not routinely performed. However, it is an important requirement not only for a successful treatment of this disease, but also for the prophylaxis to prevent any recurrence. We therefore set out to analyze 80 kidney stones collected from Basilicata Region (Southern, Italy). X-ray powder diffraction as well as optical and scanning electron microscopy and petrographic thin section analysis have been applied in order to determine the mineralogical and morphological compositions. The internal structure and the relation between major and minor components have facilitated the classification of the kidney stones according to a detailed scheme. As it is known from other country, calcium oxalate stones were the most frequent (59%) [39% mainly composed of whewellite, CaC₂O₄*H₂O and 29% is mainly made of weddellite, CaC₂O₄*2H₂O]. Uric acid stones were abundant too (18%). Calcium phosphate and cystine stone were less. The results of the observations of kidney stones in thin petrographic sections led to the identification of more cores in the same whewellite kidney stones. In some kidney stones the core is not situated in the central zone, which represents the point of attachment on kidney wall. Basilicata kidney stone prevalence is different from the average prevalence determined in other Mediterranean areas. The comparison showed that calcium oxalate stones seem to be more frequent, and there is a high prevalence of uric acid kidney stones and a lower prevalence of phosphate kidney stones, especially hydroxyapatite. The relative increase frequency of uric acid stones in the northern part of the Region may be due to high-purine diets and softness water consumption.

  16. Mineralogy and noble gas isotopes of micrometeorites collected from Antarctic snow

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    Okazaki, Ryuji; Noguchi, Takaaki; Tsujimoto, Shin-ichi; Tobimatsu, Yu; Nakamura, Tomoki; Ebihara, Mitsuru; Itoh, Shoichi; Nagahara, Hiroko; Tachibana, Shogo; Terada, Kentaro; Yabuta, Hikaru

    2015-06-01

    We have investigated seven micrometeorites (MMs) from Antarctic snow collected in 2003 and 2010 by means of electron microscopy, X-ray diffraction, micro-Raman spectroscopy, transmission electron microscopy (TEM) observation, and noble-gas isotope analysis. Isotopic ratios of He and Ne indicate that the noble gases in these MMs are mostly of solar wind (SW). Based on the release patterns of SW 4He, which should reflect the degree of heating during atmospheric entry, the seven MMs were classified into three types including two least heated, three moderately heated, and two severely heated MMs. The heating degrees are well correlated to their mineralogical features determined by TEM observation. One of the least heated MMs is composed of phyllosilicates, whereas the other consists of anhydrous minerals within which solar flare tracks were observed. The two severely heated MMs show clear evidence of atmospheric heating such as partial melt of the uppermost surface layer in one and abundant patches of dendritic magnetite and Si-rich glass within an olivine grain in the other. It is noteworthy that a moderately heated MM composed of a single crystal of olivine has a 3He/4He ratio of 8.44 × 10-4, which is higher than the SW value of 4.64 × 10-4, but does not show a cosmogenic 21Ne signature such as 20Ne/21Ne/22Ne = 12.83/0.0284/1. The isotopic compositions of He and Ne in this sample cannot be explained by mixing of a galactic cosmic ray (GCR)-produced component and SW gases. The high 3He/4He ratio without cosmogenic 21Ne signature likely indicates the presence of a 3He-enriched component derived from solar energetic particles.

  17. Evaluating a Mineralogical Control on Arsenic and Lead Concentrations in California Gold Mine Tailings

    Science.gov (United States)

    Neptune, C. K.; De Graff, J.

    2012-12-01

    Abandoned gold mining operations in California often host tailings piles, which are a source of various heavy metal contaminants including arsenic (As) and lead (Pb). Based on internal USDA Forest Service studies, it has been determined that some tailings are a concern due to high As and Pb while others are only a concern for high As. The research hypothesis is that this difference reflects a mineralogical control on the presence and concentration of As and Pb. This information would be valuable in the prioritization of mining sites for mitigation, as identifying whether both As and Pb are a concern or only As is key in determining the level of risk posed by the tailings. Ore from two mines (Bright Star and May-Lundy) in the Sierra Nevada provided a preliminary test of this hypothesis. Samples were collected from presumed ore found in proximity to mine adits or milling sites. A biased sampling method, based on the presence of clearly visible concentrations of metal sulfide minerals, served as a selection approach. Prior to lab processing, the samples were evaluated for their proportion of metal sulfide minerals to non-metallic minerals, to establish the range of variability at each mine site. A Gyral grinder was used to reduce samples to particles of less than 149 microns in size. The samples were then analyzed with a Niton XL3t model X-ray fluorescence (XRF) device for a one-minute interval. Based on this initial sampling, it is suggestive that the ratio of Pb/As, in the ore material reflects the concentration ratios within the tailings at the respective mine sites. This method assumes that a whole rock analysis is indicative of the proportion of As to Pb bearing minerals present.

  18. 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.; Haba, M. K.; Harrington, R.; Herzog, G. F.; Keller, L. P.; Locke, D.; Lindsay, F. N.; McCoy, T. J.; Morris, R. V.; Nagao, K.; Nakamura-Messenger, K.; Niles, P. B.; Nyquist, L. E.; Park, J.; Peng, Z. X.; Shih, C.-Y.; Simon, J. I.; Swisher, C. C.; Tappa, M. J.; Turrin, B. D.; Zeigler, R. A.

    2015-10-01

    Three masses of the Chelyabinsk meteorite have been studied with a wide range of analytical techniques to understand the mineralogical variation and thermal history of the Chelyabinsk parent body. The samples exhibit little to no postentry oxidation via Mössbauer and Raman spectroscopy indicating their fresh character, but despite the rapid collection and care of handling some low levels of terrestrial contamination did nonetheless result. Detailed studies show three distinct lithologies, indicative of a genomict breccia. A light-colored lithology is LL5 material that has experienced thermal metamorphism and subsequent shock at levels near S4. The second lithology is a shock-darkened LL5 material in which the darkening is caused by melt and metal-troilite veins along grain boundaries. The third lithology is an impact melt breccia that formed at high temperatures (~1600 °C), and it experienced rapid cooling and degassing of S2 gas. Portions of light and dark lithologies from Chel-101, and the impact melt breccias (Chel-102 and Chel-103) were prepared and analyzed for Rb-Sr, Sm-Nd, and Ar-Ar dating. When combined with results from other studies and chronometers, at least eight impact events (e.g., ~4.53 Ga, ~4.45 Ga, ~3.73 Ga, ~2.81 Ga, ~1.46 Ga, ~852 Ma, ~312 Ma, and ~27 Ma) are clearly identified for Chelyabinsk, indicating a complex history of impacts and heating events. Finally, noble gases yield young cosmic ray exposure ages, near 1 Ma. These young ages, together with the absence of measurable cosmogenic derived Sm and Cr, indicate that Chelyabinsk may have been derived from a recent breakup event on an NEO of LL chondrite composition.

  19. Mineralogy and chemistry of Rumuruti: The first meteorite fall of the new R chondrite group

    Science.gov (United States)

    Schulze, H.; Bischoff, A.; Palme, H.; Spettel, B.; Dreibus, G.; Otto, J.

    1994-03-01

    The Rumuruti meteorite shower fell in Rumuruti, Kenya, on 1934 January 28 at 10:45 p.m. Rumuruti is an olivine-rich chondritic breccia with light-dark structure. Based on the coexistence of highly recrystallized fragments and unequilibrated components, Rumuruti is classified as a type 3-6 chondrite breccia. The most abundant phase of Rumuruti is olivine (mostly Fa(approximately 39) with about 70 vol%. Feldspar (approximately 14 vol%; mainly plagioclase), Ca-pyroxene (5 vol%), pyrrhotite (4.4 vol%), and pentlandite (3.6 vol%) are major constituents. All other phases have abundances below 1 vol%, including low-Ca pyroxene, chrome spinels, phosphates (chlorapatite and whitlockite), chalcopyrite, ilemenite, tridymite, Ni-rich and Ge-containing metals, kamacite, and various particles enriched in noble metals like Pt, Ir, and Au. The chemical composition of Rumuruti is chondritic. The depletion in refractory elements (Sc, REE, etc.) and the comparatively high Mn, Na, and K contents are characteristic of ordinary chondrites and distinguish Rumuruti from carbonaceous chondrites. However, S, Se, and Zn contents in Rumuruti are significantly above the level expected for ordinary chondrites. The oxygen isotope composition of Rumuruti is high in delta O-17 (5.52%) and delta O-18 (5.07%). With Rumuruti, nine meteorites samples exist that are chemically and mineralogically very similar. These meteorites are attributed to at least eight different fall events. It is proposed in this paper to call this group R chondrites (rumurutites) after the first and only fall among these meteorites. The meteorites have a close relationship to ordinary chondrites. However, they are more oxidized than any of the existing groups of ordinary chondrites. Small, but significant differences in chemical composition and in oxygen isotopes between R chondrites and ordinary chondrites exclude formation of R chondrites from ordinary chondrites by oxidation. This implies a separate, independent R chondrite

  20. Mineralogical and particulate morphological characterization of geophagic clayey soils from Botswana

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    Georges-Ivo Ekosse

    2012-12-01

    Full Text Available This study focused on determining the minerals composition and particle morphology of geophagic clayey soils from Botswana in order to infer on how they could influence human health. Six representative geophagic clayey soils from Botswana were mineralogically characterized using X-ray powder diffractometry (XRPD, optical microscopy, and environmental scanning electron microscopy (ESEM. Results of identified mineral phases revealed quartz (SiO2 as the most dominant in all samples constituting close to 70 wt %; followed by goethite (FeO.OH having a mean concentration of 9 wt%, and kaolinite (Al2Si2O5(OH4 with a mean concentration of 8 wt%. Other minerals present were smectite ((Na,Ca(Al,Mg6(Si4O103(OH6-n(H2O, mica (AB2-3(Al,SiSi3O10(F,OH2, feldspar (Na/K(AlSi3O8 and hematite (Fe2O3. The quartz particles were generally coarse; and angular to very angular in morphology. Due to ions present in goethite, kaolinite, and smectite, these minerals impact positively on properties of geophagic clayey soils and could possibly influence human health when consumed. The quartz particles could negatively affect dental enamel as a result of mastication; and cause abrasion of the walls of the gastro-intestinal tract which may lead to rupturing. Although the studied clayey soils could have potential to provide medicinal benefits to the consumer, there is need for beneficiation exercise to be conducted to reduce the coarse angular particles contained in them. It is therefore necessary for constructive efforts to be directed at beneficiating geophagic materials which will render them safe for human consumption.DOI: http://dx.doi.org/10.4314/bcse.v26i3.6

  1. Geology mineralogy, structure and texture of Agh-Otagh base- precious metal mineralization (North Takab

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    Nahid Rahmati

    2017-07-01

    Full Text Available The Agh-Otagh mineralization area in the north of Takab, was formed within the andesistic tuffaceous rocks of the Oligo- Miocene age. Mineralization include polymetallic (Cu-Pb-Zn-Au-Ag quartz veins and silicified zones, which occurred as breccia and vein- veinlets with comb, cockade and disseminated textures. Chalcopyrite, pyrite, galena and sphalerite are common ore minerals. Alteration zones consist of silicification, sericitization, argillitic, propelitic and carbonatization. Cu-Au mineralization is associated with silicification and sericitization. Analytical results of the samples from the ore- bearing quartz veins and the silicified zones indicate that the highest grade for Au is 664 ppb (ave.181 ppb. The highest and the average grades for Ag, Cu, Pb, and Zn are 120 ppm (300 ppm, 1.3 % (0.38 %, 5.5 % (0.06 % and 4.5 % (0.28 %, respectively. The investigations indicate that the Agh-Otagh mineralization was formed in four stages. In the first stage or the pre-mineralization stage, the host rock, as a result of hydrothermal process, underwent brecciation and some quartz veins and siliceous cap were formed. In the second stage or the mineralization stage the sulfide minerals formed within the quartz veins and silicification zones developed at the third stage, some unmineralized quartz, barite and carbonate vein- veinlets crosscut the previous stages. The last stage of mineralization related to supergene processes. Based on geological, mineralogical, alteration, structural and textural evidences, the Agh-Otagh base- precious metal mineralization is similar to the medium sulfidation epithermal deposits.

  2. Mineralogy and crystallochemical characteristics of HEU-type minerals from zeolitic tuff deposits of Serbia

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    Kašić Vladan D.

    2017-01-01

    Full Text Available The results of perennial research of several Serbian zeolitic tuffs enriched with HEU-type minerals are presented in this paper. There are several recognized zeolitic tuff deposits containing HEU-type minerals: Zlatokop, Igroš, Beočin, Toponica, Slanci, but their comparative mineralogical and crystallochemical features have not been studied in detail so far. These zeolitic tuff deposits are spatially and genetically connected to volcanic and pyroclastic rocks of marine and lake environments of Senonian and Eocene, and Neogene age, respectively. As a result of devitrification and diagenesis process of volcanic glass within zeolitic tuffs hypocrys