Ferritin iron minerals are chelator targets, antioxidants, and coated, dietary iron.

PubMed

Theil, Elizabeth C

2010-08-01

Cellular ferritin is central for iron balance during transfusions therapies; serum ferritin is a small fraction of body ferritin, albeit a convenient reporter. Iron overload induces extra ferritin protein synthesis but the protein is overfilled with the extra iron that damages ferritin, with conversion to toxic hemosiderin. Three new approaches that manipulate ferritin to address excess iron, hemosiderin, and associated oxidative damage in Cooley's Anemia and other iron overload conditions are faster removal of ferritin iron with chelators guided to ferritin gated pores by peptides; more ferritin protein synthesis using ferritin mRNA activators, by metal complexes that target mRNA 3D structures; and determining if endocytotic absorption of iron from legumes, which is mostly ferritin, is regulated during iron overload to prevent excess iron entry while providing protein. More of a focus on ferritin features, including protein cage structure, iron mineral, regulatable mRNA, and specific gut absorption properties, will achieve the three novel experimental goals for managing iron homeostasis with transfusion therapies.

Remote sensing of ferric iron minerals as guides for gold exploration

NASA Technical Reports Server (NTRS)

Taranik, Dan L.; Kruse, Fred A.; Goetz, Alexander F. H.; Atkinson, William W.

1991-01-01

The relationship between the surficial iron mineralogy and economic mineralization is investigated, using data from an airborne imaging spectrometer (the 63-channel Geophysical and Environmental Research Imaging Spectrometer) to map the distribution of iron minerals in the Cripple Creek mining district in Colorado. The airborne image data were coregistered with the field map data for the distribution of iron oxides in the district, in a geographic information computer system, in order to compare their information content. It is shown that the remote imagery was able to uniquely identify the mineral hematite, a mixture of goethite/jarosite, and a mixture of hematite/goethite.

Reduction of iron-bearing lunar minerals for the production of oxygen

NASA Technical Reports Server (NTRS)

Massieon, Charles; Cutler, Andrew; Shadman, Farhang

1992-01-01

The kinetics and mechanism of the reduction of simulants of the iron-bearing lunar minerals olivine ((Fe,Mg)2SiO4), pyroxene ((Fe,Mg,Ca)SiO3), and ilmenite (FeTiO3) are investigated, extending previous work with ilmenite. Fayalite is reduced by H2 at 1070 K to 1480 K. A layer of mixed silica glass and iron forms around an unreacted core. Reaction kinetics are influenced by permeation of hydrogen through this layer and a reaction step involving dissociated hydrogen. Reaction mechanisms are independent of Mg content. Augite, hypersthene, and hedenbergite are reduced in H2 at the same temperatures. The products are iron metal and lower iron silicates mixed throughout the mineral. Activation energy rises with calcium content. Ilmenite and fayalite are reduced with carbon deposited on partially reduced minerals via the CO disproportionation reaction. Reduction with carbon is rapid, showing the carbothermal reduction of lunar minerals is possible.

Derepression of the Azotobacter vinelandii siderophore system, using iron-containing minerals to limit iron repletion.

PubMed Central

Page, W J; Huyer, M

1984-01-01

Azotobacter vinelandii solubilized iron from certain minerals using only dihydroxybenzoic acid, which appeared to be produced constitutively. Solubilization of iron from other minerals required dihydroxybenzoic acid and the siderophore N,N'-bis-(2,3- dihydroxybenzoyl )-L-lysine ( azotochelin ) or these chelators plus the yellow-green fluorescent siderophore azotobactin . In addition to this sequential production of siderophores, cells also demonstrated partial to hyperproduction relative to the iron-limited control. The iron sources which caused partial derepression of the siderophores caused derepression of all the high-molecular-weight iron-repressible outer membrane proteins except a 77,000-molecular-weight protein, which appeared to be coordinated with azotobactin production. Increased siderophore production correlated with increased production of outer membrane proteins with molecular weights of 93,000, 85,000, and 77,000, but an 81,000-molecular-weight iron-repressible protein appeared at a constant level despite the degree of derepression. When iron was readily available, it appeared to complex with a 60,000-molecular-weight protein believed to form a surface layer on the A. vinelandii cell. Images PMID:6233258

Influence of iron redox cycling on organo-mineral associations in arctic tundra soils

NASA Astrophysics Data System (ADS)

Herndon, E.; AlBashaireh, A.; Duroe, K.; Singer, D. M.

2016-12-01

Geochemical interactions between soil organic matter and minerals influence decomposition in many environments but remain poorly understood in arctic tundra systems. In tundra soils that are periodically to persistently saturated, the accumulation of iron oxyhydroxides and organo-iron precipitates at redox interfaces may inhibit decomposition by binding organic molecules and protecting them from microbial degradation. Here, we couple synchrotron-source spectroscopic techniques with chemical sequential extractions and physical density fractionations to evaluate the spatial distribution and speciation of Fe-bearing phases and associated organic matter in organic and mineral horizons of the seasonally thawed active layer in tundra soils from northern Alaska. Mineral-associated organic matter comprised 63 ± 9% of soil organic carbon stored in the active layer of ice wedge polygons. Ferrous iron produced in anoxic mineral horizons diffused upwards and precipitated as poorly-crystalline oxyhydroxides and organic-bound Fe(III) in the organic horizons. Ferrihydrite and goethite were present as coatings on mineral grains and plant debris and in aggregates with clays and particulate organic matter. Organic matter released through acid-dissolution of iron oxides may represent a small pool of readily-degradable organic molecules temporarily stabilized by sorption to iron oxyhydroxide surfaces, while larger quantities of particulate organic carbon and humic-like substances may be physically protected from decomposition by Fe-oxide coatings and aggregation. We conclude that formation of poorly-crystalline and crystalline iron oxides at redox interfaces contributes to mineral protection of organic matter through sorption, aggregation, and co-precipitation reactions. Further study of organo-mineral associations is necessary to determine the net impact of mineral-stabilization on carbon storage in rapidly warming arctic ecosystems.

Conductive iron oxide minerals accelerate syntrophic cooperation in methanogenic benzoate degradation.

PubMed

Zhuang, Li; Tang, Jia; Wang, Yueqiang; Hu, Min; Zhou, Shungui

2015-08-15

Recent studies have suggested that conductive iron oxide minerals can facilitate syntrophic metabolism of the methanogenic degradation of organic matter, such as ethanol, propionate and butyrate, in natural and engineered microbial ecosystems. This enhanced syntrophy involves direct interspecies electron transfer (DIET) powered by microorganisms exchanging metabolic electrons through electrically conductive minerals. Here, we evaluated the possibility that conductive iron oxides (hematite and magnetite) can stimulate the methanogenic degradation of benzoate, which is a common intermediate in the anaerobic metabolism of aromatic compounds. The results showed that 89-94% of the electrons released from benzoate oxidation were recovered in CH4 production, and acetate was identified as the only carbon-bearing intermediate during benzoate degradation. Compared with the iron-free controls, the rates of methanogenic benzoate degradation were enhanced by 25% and 53% in the presence of hematite and magnetite, respectively. This stimulatory effect probably resulted from DIET-mediated methanogenesis in which electrons transfer between syntrophic partners via conductive iron minerals. Phylogenetic analyses revealed that Bacillaceae, Peptococcaceae, and Methanobacterium are potentially involved in the functioning of syntrophic DIET. Considering the ubiquitous presence of iron minerals within soils and sediments, the findings of this study will increase the current understanding of the natural biological attenuation of aromatic hydrocarbons in anaerobic environments. Copyright © 2015 Elsevier B.V. All rights reserved.

The role of FeS(aq) molecular clusters in microbial redox cycling and iron mineralization.

NASA Astrophysics Data System (ADS)

Druschel, G.; Oduro, H.; Sperling, J.; Johnson, C.

2008-12-01

Iron sulfide molecular clusters, FeS(aq), are a group of polynuclear Fe-S complexes varying in size between a few and a few hundred molecules that occur in many environments and are critical parts of cycling between soluble iron and iron sulfide minerals. These clusters react uniquely with voltammetric Au-amalgam electrodes, and the signal for these molecules has now been observed in many terrestrial and marine aquatic settings. FeS(aq) clusters form when aqueous sulfide and iron(II) interact, but the source of those ions can come from abiotic or microbial sulfate and iron reduction or from the abiotic non-oxidative dissolution of iron sulfide minerals. Formation of iron sulfide minerals, principally mackinawite as the first solid nanocrystalline phase in many settings, is necessarily preceeded by formation and evolution of these molecular clusters as mineralization proceeds, and the clusters have been suggested to additionally be part of the pyritization process (Rickard and Luther, 1997; Luther and Rickard, 2005). In several systems, we have also observed FeS(aq) clusters to be the link between Fe-S mineral dissolution and oxidation of iron and sulfide, with important implications for changes to the overall oxidation pathway. Microorganisms can clearly be involved in the formation of FeS(aq) through iron and sulfate reduction, but it is not clear to date if organisms can utilize these clusters either as metabolic components or as anabolic 'building blocks' for enzyme production. Cycling of iron in the Fe-S system linked to FeS(aq) would clearly be a critical part of understanding iron isotope dynamics preserved in iron sulfide minerals. We will review ongoing work towards understanding the role of FeS(aq) in iron cycling and isotope fractionation as well as the measurement and characterization of this key class of iron complexes using environmental voltammetry.

Effects of iron-containing minerals on hydrothermal reactions of ketones

NASA Astrophysics Data System (ADS)

Yang, Ziming; Gould, Ian R.; Williams, Lynda B.; Hartnett, Hilairy E.; Shock, Everett L.

2018-02-01

Hydrothermal organic transformations occurring in geochemical processes are influenced by the surrounding environments including rocks and minerals. This work is focused on the effects of five common minerals on reactions of a model ketone substrate, dibenzylketone (DBK), in an experimental hydrothermal system. Ketones play a central role in many hydrothermal organic functional group transformations, such as those converting hydrocarbons to oxygenated compounds; however, how these minerals control the hydrothermal chemistry of ketones is poorly understood. Under the hydrothermal conditions of 300 °C and 70 MPa for up to 168 h, we observed that, while quartz (SiO2) and corundum (Al2O3) had no detectable effect on the hydrothermal reactions of DBK, iron-containing minerals, such as hematite (Fe2O3), magnetite (Fe3O4), and troilite (synthetic FeS), accelerated the reaction of DBK by up to an order of magnitude. We observed that fragmentation products, such as toluene and bibenzyl, dominated in the presence of hematite or magnetite, while use of troilite gave primarily the reduction products, e.g., 1, 3-diphenyl-propane and 1, 3-diphenyl-2-propanol. The roles of the three iron minerals in these transformations were further explored by (1) control experiments with various mineral surface areas, (2) measuring H2 in hydrothermal solutions, and (3) determining hydrogen balance among the organic products. These results suggest the reactions catalyzed by iron oxides (hematite and magnetite) are promoted mainly by the mineral surfaces, whereas the sulfide mineral (troilite) facilitated the reduction of ketone in the reaction solution. Therefore, this work not only provides a useful chemical approach to study and uncover complicated hydrothermal organic-mineral interactions, but also fosters a mechanistic understanding of ketone reactions in the deep carbon cycle.

Biogenic iron mineralization at Iron Mountain, CA with implications for detection with the Mars Curiosity rover

USGS Publications Warehouse

Williams, Amy J.; Sumner, Dawn Y.; Alpers, Charles N.; Campbell, Kate M.; Nordstrom, D. Kirk

2014-01-01

(Introduction) Microbe-mineral interactions and biosignature preservation in oxidized sulfidic ore bodies (gossans) are prime candidates for astrobiological study. Such oxidized iron systems have been proposed as analogs for some Martian environments. Recent studies identified microbial fossils preserved as mineral-coated filaments. This study documents microbially-mediated mineral biosignatures in hydrous ferric oxide (HFO) and ferric oxyhydroxysulfates (FOHS) in three environments at Iron Mountain, CA. We investigated microbial community preservation via HFO and FOHS precipitation and the formation of filamentous mineral biosignatures. These environments included 1) actively precipitating (1000's yrs), naturally weathered HFO from in situ gossan, and 3) remobilized iron deposits, which contained lithified clastics and zones of HFO precipitate. We used published biogenicity criteria as guidelines to characterize the biogenicity of mineral filaments. These criteria included A) an actively precipitating environment where microbes are known to be coated in minerals, B) presence of extant microbial communities with carbon signatures, C) structures observable as a part of the host rock, and D) biological morphology, including cellular lumina, multiple member population, numerous taxa, variable and 3-D preservation, biological size ranges, uniform diameter, and evidence of flexibility. This study explores the relevance and detection of these biosignatures to possible Martian biosignatures. Similar filamentous biosignatures are resolvable by the Mars Hand Lens Imager (MAHLI) onboard the Mars Science Laboratory (MSL) rover, Curiosity, and may be identifiable as biogenic if present on Mars.

Influence of iron redox cycling on organo-mineral associations in Arctic tundra soil

DOE PAGES

Herndon, Elizabeth; Oak Ridge National Lab.; AlBashaireh, Amineh; ...

2017-03-25

Arctic tundra stores large quantities of soil organic matter under varying redox conditions. As the climate warms, these carbon reservoirs are susceptible to increased rates of decomposition and release to the atmosphere as the greenhouse gases carbon dioxide (CO 2) and methane (CH 4). Geochemical interactions between soil organic matter and minerals influence decomposition in many environments but remain poorly understood in Arctic tundra systems and are not considered in decomposition models. The accumulation of iron (Fe) oxyhydroxides and organo- iron precipitates at redox interfaces may be particularly important for carbon cycling given that ferric iron [Fe(III)] species can enhancemore » decomposition by serving as terminal electron acceptors in anoxic soils or inhibit microbial decomposition by binding organic molecules. Here in this paper, we examine chemical properties of solid-phase Fe and organic matter in organic and mineral horizons within the seasonally thawed active layer of Arctic tundra on the North Slope of Alaska. Spectroscopic techniques, including micro-X-ray fluorescence ( XRF) mapping, micro-X-ray absorption near-edge structure ( XANES) spectroscopy, and Fourier transform infrared spectroscopy (FTIR), were coupled with chemical sequential extractions and physical density fractionations to evaluate the spatial distribution and speciation of Fe-bearing phases and associated organic matter in soils. Organic horizons were enriched in poorly crystalline and crystalline iron oxides, and approximately 60% of total Fe stored in organic horizons was calculated to derive from upward translocation from anoxic mineral horizons. Ferrihydrite and goethite were present as coatings on mineral grains and plant debris, and in aggregates with clays and particulate organic matter. Minor amounts of ferrous iron [Fe(II)] were present in iron sulfides (i.e., pyrite and greigite) in mineral horizon soils and iron phosphates (vivianite) in organic horizons

Influence of iron redox cycling on organo-mineral associations in Arctic tundra soil

NASA Astrophysics Data System (ADS)

Herndon, Elizabeth; AlBashaireh, Amineh; Singer, David; Roy Chowdhury, Taniya; Gu, Baohua; Graham, David

2017-06-01

Arctic tundra stores large quantities of soil organic matter under varying redox conditions. As the climate warms, these carbon reservoirs are susceptible to increased rates of decomposition and release to the atmosphere as the greenhouse gases carbon dioxide (CO2) and methane (CH4). Geochemical interactions between soil organic matter and minerals influence decomposition in many environments but remain poorly understood in Arctic tundra systems and are not considered in decomposition models. The accumulation of iron (Fe) oxyhydroxides and organo-iron precipitates at redox interfaces may be particularly important for carbon cycling given that ferric iron [Fe(III)] species can enhance decomposition by serving as terminal electron acceptors in anoxic soils or inhibit microbial decomposition by binding organic molecules. Here, we examine chemical properties of solid-phase Fe and organic matter in organic and mineral horizons within the seasonally thawed active layer of Arctic tundra on the North Slope of Alaska. Spectroscopic techniques, including micro-X-ray fluorescence (μXRF) mapping, micro-X-ray absorption near-edge structure (μXANES) spectroscopy, and Fourier transform infrared spectroscopy (FTIR), were coupled with chemical sequential extractions and physical density fractionations to evaluate the spatial distribution and speciation of Fe-bearing phases and associated organic matter in soils. Organic horizons were enriched in poorly crystalline and crystalline iron oxides, and approximately 60% of total Fe stored in organic horizons was calculated to derive from upward translocation from anoxic mineral horizons. Ferrihydrite and goethite were present as coatings on mineral grains and plant debris, and in aggregates with clays and particulate organic matter. Minor amounts of ferrous iron [Fe(II)] were present in iron sulfides (i.e., pyrite and greigite) in mineral horizon soils and iron phosphates (vivianite) in organic horizons. Concentrations of organic

Influence of iron redox cycling on organo-mineral associations in Arctic tundra soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herndon, Elizabeth; Oak Ridge National Lab.; AlBashaireh, Amineh

Arctic tundra stores large quantities of soil organic matter under varying redox conditions. As the climate warms, these carbon reservoirs are susceptible to increased rates of decomposition and release to the atmosphere as the greenhouse gases carbon dioxide (CO 2) and methane (CH 4). Geochemical interactions between soil organic matter and minerals influence decomposition in many environments but remain poorly understood in Arctic tundra systems and are not considered in decomposition models. The accumulation of iron (Fe) oxyhydroxides and organo- iron precipitates at redox interfaces may be particularly important for carbon cycling given that ferric iron [Fe(III)] species can enhancemore » decomposition by serving as terminal electron acceptors in anoxic soils or inhibit microbial decomposition by binding organic molecules. Here in this paper, we examine chemical properties of solid-phase Fe and organic matter in organic and mineral horizons within the seasonally thawed active layer of Arctic tundra on the North Slope of Alaska. Spectroscopic techniques, including micro-X-ray fluorescence ( XRF) mapping, micro-X-ray absorption near-edge structure ( XANES) spectroscopy, and Fourier transform infrared spectroscopy (FTIR), were coupled with chemical sequential extractions and physical density fractionations to evaluate the spatial distribution and speciation of Fe-bearing phases and associated organic matter in soils. Organic horizons were enriched in poorly crystalline and crystalline iron oxides, and approximately 60% of total Fe stored in organic horizons was calculated to derive from upward translocation from anoxic mineral horizons. Ferrihydrite and goethite were present as coatings on mineral grains and plant debris, and in aggregates with clays and particulate organic matter. Minor amounts of ferrous iron [Fe(II)] were present in iron sulfides (i.e., pyrite and greigite) in mineral horizon soils and iron phosphates (vivianite) in organic horizons

Appraisal of iron deposits in southern and western Turkey

USGS Publications Warehouse

Gair, Jacob Eugene; Capan, Ussal Z.

1972-01-01

Between May 20 and June 17, 1969, previously known iron deposits were examined widely at eight separate localities in western Turkey. The object of the examinations was to learn the, nature, geologic setting, and approximate size of each deposit, to review prior estimates of size, and possibly recommend additional exploratory work.. The full extent of each deposit is poorly known at the present time, so recommended additional work entails drilling, digging trenches or pits, geologic mapping or, combinations of these activities. On Qaldagi Mountain an area of about 1 sq km is capped by bredciated chert under which may be a continuous zone of mixed iron oxides and chert fragments. The thickness of the ferruginous zone is poorly known but is as much as 12 meters, in at least one place. The- ferruginous material and chert appear to have formed by the weathering of serpentine, bun this concept needs further testing. Drilling is recommended to determine the grade, thickness, and extent-of the ferruginous zone beneath the cherty cap. Inasmuch as mining by hand sorting is in progress, part of the deposit can be considered to be marginally in the category of iron reserves. The Keceborlu iron deposit consists of earthy to slightly compacted hematite and limonite mixed with small chert fragments. The surface area underlain by ferruginous rock is about 5,000 to 7,500 sq meters. The maximum known thickness of the deposit is about 7 meters. Iron appears to have been concentrated by weathering and oxidation of cherty limestone. The deposit is probably either a remnant of a once more extensive weathered cap, or a sink hole filling. The Keceborlu area warrants a low priority for further exploration, but one drill hole is recommended to test the thickness of the deposit. The iron deposits at Mellec are layered and vein-magnetite replacements of limestone. The six known deposits are discontinuous. No additional. work is recommended. ' The Gilindire Iron deposit consists of irregular

Planktonic Marine Iron-Oxidizers Drive Iron(III) Mineralization Under Low Oxygen Conditions

NASA Astrophysics Data System (ADS)

Luther, G. W., III; Field, E.; Findlay, A.; MacDonald, D. J.; Chan, C. S. Y.; Kato, S.

2016-02-01

Observations of modern microbes have led to several hypotheses on how microbes precipitated the extensive banded iron formations in the geologic record, but we have yet to resolve the exact microbial contributions. An initial hypotheses was that cyanobacteria produced oxygen that oxidized iron(II) abiotically; however, in modern environments such as microbial mats, where Fe(II) and O2 coexist, we commonly find microaerophilic chemolithotrophic iron(II)-oxidizing bacteria producing Fe(III) oxyhydroxides. This suggests that such iron-oxidizers could have inhabited niches in ancient coastal oceans where Fe(II) and O2 coexisted, and therefore contributed to iron deposits, but there is currently little evidence for planktonic marine iron-oxidizers in modern analogs. Here, we demonstrate successful cultivation of planktonic microaerophilic iron-oxidizing Zetaproteobacteria from the Chesapeake Bay during seasonal stratification. Iron-oxidizers were associated with low oxygen concentrations and active iron redox cycling in the oxic-anoxic transition zone (<3 µM O2, <0.2 µM H2S). While cyanobacteria were also detected in this transition zone, oxygen concentrations were too low to support significant rates of abiotic iron oxidation. Instead, cyanobacteria may be providing oxygen for microaerophilic iron(II) oxidation through a symbiotic relationship that promotes oxygen consumption rather than build-up. Our results suggest that once oxygenic photosynthesis evolved, microaerophilic chemolithotrophic iron(II)-oxidizers were likely important drivers of iron(III) mineralization in ancient oceans.

Zebrafish in the sea of mineral (iron, zinc, and copper) metabolism

PubMed Central

Zhao, Lu; Xia, Zhidan; Wang, Fudi

2014-01-01

Iron, copper, zinc, and eight other minerals are classified as essential trace elements because they present in minute in vivo quantities and are essential for life. Because either excess or insufficient levels of trace elements can be detrimental to life (causing human diseases such as iron-deficiency anemia, hemochromatosis, Menkes syndrome and Wilson's disease), the endogenous levels of trace minerals must be tightly regulated. Many studies have demonstrated the existence of systems that maintain trace element homeostasis, and these systems are highly conserved in multiple species ranging from yeast to mice. As a model for studying trace mineral metabolism, the zebrafish is indispensable to researchers. Several large-scale mutagenesis screens have been performed in zebrafish, and these screens led to the identification of a series of metal transporters and the generation of several mutagenesis lines, providing an in-depth functional analysis at the system level. Moreover, because of their developmental advantages, zebrafish have also been used in mineral metabolism-related chemical screens and toxicology studies. Here, we systematically review the major findings of trace element homeostasis studies using the zebrafish model, with a focus on iron, zinc, copper, selenium, manganese, and iodine. We also provide a homology analysis of trace mineral transporters in fish, mice and humans. Finally, we discuss the evidence that zebrafish is an ideal experimental tool for uncovering novel mechanisms of trace mineral metabolism and for improving approaches to treat mineral imbalance-related diseases. PMID:24639652

Minerals, haem and non-haem iron contents of rhea meat.

PubMed

Ramos, A; Cabrera, M C; Del Puerto, M; Saadoun, A

2009-01-01

Mineral contents, haem and non-haem iron of rhea (Rhea americana) muscles Obturatorius medialis (OM), Iliotibialis lateralis (IL) and Iliofibularis (I) were determined. No differences between the three muscles were observed for calcium, phosphorus, magnesium and sodium. There is more potassium, zinc and copper in IL muscle than in OM and I muscles. For Manganese, OM and IL muscles show a higher content in comparison with I muscle. For selenium, IL and I muscles show the highest content compared to OM muscle. For total, haem and non-haem iron, the IL muscle shows the highest content respect to the other muscles. When compared to other meats, the minerals content of rhea meat show an elevated level in phosphorus, selenium and total and haem iron. The human health concern due to the deficient diet in selenium and iron, and their high contents in rhea meat will be of great importance in the promotion of this meat.

What do we really know about the role of microorganisms in iron sulfide mineral formation?

USGS Publications Warehouse

Picard, Aude A.; Gartman, Amy; Girguis, Peter R.

2016-01-01

Iron sulfide mineralization in low-temperature systems is a result of biotic and abiotic processes, though the delineation between these two modes of formation is not always straightforward. Here we review the role of microorganisms in the precipitation of extracellular iron sulfide minerals. We summarize the evidence that links sulfur-metabolizing microorganisms and sulfide minerals in nature and we present a critical overview of laboratory-based studies of the nucleation and growth of iron sulfide minerals in microbial cultures. We discuss whether biologically derived minerals are distinguishable from abiotic minerals, possessing attributes that are uniquely diagnostic of biomineralization. These inquiries have revealed the need for additional thorough, mechanistic and high-resolution studies to understand microbially mediated formation of a variety of sulfide minerals across a range of natural environments.

Mineralized iron oxidizing bacteria from hydrothermal vents: targeting biosignatures on Mars

NASA Astrophysics Data System (ADS)

Leveille, R. J.

2010-12-01

Putative hydrothermal systems have been identified on Mars based on orbital imagery and rover-based analyses. Based on Earth analogs, hydrothermal systems on Mars would be highly attractive for their potential for preserving organic and inorganic biosignatures. For example, iron oxidizing bacteria are ubiquitous in marine and terrestrial hydrothermal systems, where they often display distinctive cell morphologies and are commonly encrusted by minerals, especially bacteriogenic iron oxides and silica. Microfossils of iron oxidizing bacteria have been found in ancient Si-Fe deposits and iron oxidation may be an ancient and widespread metabolic pathway. In order to investigate mineralized iron oxidizing bacteria as a biosignature, we have examined samples collected from extinct hydrothermal vents along Explorer Ridge, NE Pacific Ocean. In addition, microaerophilic iron oxidizing bacteria, isolated from active Pacific hydrothermal vents, were grown in a Fe-enriched seawater medium at constant pH (6.5) and O2 concentration (5%) in a controlled bioreactor system. Samples and experimental products were examined with a combination of variable-pressure and field-emission scanning electron microscopy (SEM), in some cases by preparing samples with a focused ion beam (FIB) milling system. Light-toned seafloor samples display abundant filamentous forms resembling, in both size and shape (1-5 microns in diameter and up to several microns in length), the twisted stalks of Gallionella and the elongated filaments of Leptothrix. Some samples consist entirely of low-density masses of silica (>90% Si) encrusted filamentous forms. The presence of unmineralized filamentous matter rich in C and Fe suggests that these are the remains of iron oxidizing bacteria. Mineralized filaments sectioned by FIB show variable internal material within semi-hollow, tubular-like features. Silica encrustations also show pseudo-concentric growth bands. In the bioreactor runs, abundant microbial growth and

Improvement in gold grade from iron-oxide mineral using reduction roasting and magnetic separation

NASA Astrophysics Data System (ADS)

Kim, Hyun-soo; On, Hyun-sung; Lim, Dae-hack; Myung, Eun-ji; Park, Cheon-young

2017-04-01

Microwave has a wide range of applications in mineral technology, metallurgy, etc. It is an established fact that microwave energy has potential for the speedy and efficient heating of minerals and in a commercial context may provide savings in both time and energy. Microwave heating is being developed as a potential thermal pre-treatment process, because of its unique advantages over the differences of ore minerals in absorbing microwaves. The aim of this study was to investigate the improvement in Au grade from iron-oxide mineral using reduction roasting and magnetic separation. The characteristics of iron-oxide mineral were analyzed using chemical, XRD and reflected light microscopy. The reduction roasting using microwave and magnetic separation experiments were examined under various conditions (reducing agent and chemical additive). The results of XRD and reflected light microscopy showed that the iron-oxide mineral mainly composed of illite, quartz and hematite. The iron-oxide mineral had an Au, Ag, Fe contents of 6.4, 35.1 and 155,441.1 mg/kg, respectively. The results demonstrated that the improvement in Au by reduction roasting using microwave (frequency of 2.45GHz, intensity of 5kW) and magnetic separation (magnetic field intensity of 9,000 Gauss) were effective processes. The Au content in iron-oxide mineral from 6.4 mg/kg to 14.2 mg/kg was achieved within microwave exposure time of 10min (reducing agent(PAC) ratio = 50 : 50, 5% of chemical additive(Soda ash)). Acknowledgment : This subject is supported by Korea Ministry of Environment as "Advanced Technology Program for Environmental Industry"

Mass change calculations of hydrothermal alterations within the volcanogenic metasediments hosted Cu-Pb (-Zn) mineralization at Halilar area, NW Turkey

NASA Astrophysics Data System (ADS)

Kiran Yildirim, Demet; Abdelnasser, Amr; Doner, Zeynep; Kumral, Mustafa

2016-04-01

The Halilar Cu-Pb (-Zn) mineralization that is formed in the volcanogenic metasediments of Bagcagiz Formation at Balikesir province, NW Turkey, represents locally vein-type deposit as well as restricted to fault gouge zone directed NE-SW along with the lower boundary of Bagcagiz Formation and Duztarla granitic intrusion in the study area. Furthermore, This granite is traversed by numerous mineralized sheeted vein systems, which locally transgress into the surrounding metasediments. Therefore, this mineralization closely associated with intense hydrothermal alteration within brecciation, and quartz stockwork veining. The ore mineral assemblage includes chalcopyrite, galena, and some sphalerite with covellite and goethite formed during three phases of mineralization (pre-ore, main ore, and supergene) within an abundant gangue of quartz and calcite. The geologic and field relationships, petrographic and mineralogical studies reveal two alteration zones occurred with the Cu-Pb (-Zn) mineralization along the contact between the Bagcagiz Formation and Duztarla granite; pervasive phyllic alteration (quartz, sericite, and pyrite), and selective propylitic alteration (albite, calcite, epidote, sericite and/or chlorite). This work, by using the mass balance calculations, reports the mass/volume changes (gain and loss) of the chemical components of the hydrothermal alteration zones associated with Halilar Cu-Pb (-Zn) mineralization at Balikesir area (Turkey). It revealed that the phyllic alteration has enrichments of Si, Fe, K, Ba, and LOI with depletion of Mg, Ca, and Na reflect sericitization of alkali feldspar and destruction of ferromagnesian minerals. This zone has high Cu and Pb with Zn contents represents the main mineralized zone. On the other hand, the propylitic zone is characterized by addition of Ca, Na, K, Ti, P, and Ba with LOI and Cu (lower content) referring to the replacement of plagioclase and ferromagnesian minerals by albite, calcite, epidote, and sericite

Bioavailability of Cu, Zn and Mn from Mineral Chelates or Blends of Inorganic Salts in Growing Turkeys Fed with Supplemental Riboflavin and/or Pyridoxine.

PubMed

Salami, S A; Oluwatosin, O O; Oso, A O; Fafiolu, A O; Sogunle, O M; Jegede, A V; Bello, F A; Pirgozliev, V

2016-09-01

An 84-day feeding trial was conducted in growing turkeys to measure the bioavailability of Cu, Zn and Mn from a commercial mineral chelate and corresponding inorganic salts in composite feeds containing supplemental riboflavin (B2) and/or pyridoxine (B6). A total of 320, 28-day-old British United Turkeys (BUT) were assigned to eight dietary treatments in a 2 × 4 factorial arrangement comprising two trace mineral sources: chelated trace mineral blend (CTMB) and its corresponding inorganic trace minerals blend (ITMB) fed solely or with supplements of vitamin B2 (8 ppm) or B6 (7 ppm) or 8 ppm B2 + 7 ppm B6. Each treatment was replicated four times with 10 turkeys each. It was observed that turkeys fed with diets supplemented solely with ITMB elicited higher (P < 0.05) Zn excretion than their counterparts fed with diets containing ITMB with supplements of vitamins B2 and/or B6. Manganese retention was lower (P < 0.05) in turkeys fed with diets supplemented solely with ITMB than those fed with diets containing vitamins B2 and/or B6 additives. Combination of CTMB or ITMB with B6 improved (P < 0.05) the concentration of Mn in the liver and Cu in the bone. It was concluded that the minerals in CTMB were more available to the animals than ITMB. Furthermore, vitamins B2 and/or B6 supplementation improved the bioavailability of the inorganic Cu, Zn and Mn in growing turkeys and tended to reduce the concentration of these trace elements in birds' excreta.

Microscopic iron metal on glass and minerals - A tool for studying regolith maturity

NASA Technical Reports Server (NTRS)

Allen, C. C.; Morris, R. V.; Lauer, H. V., Jr.; Mckay, D. S.

1993-01-01

A novel method of producing mixtures of glass or minerals with iron metal is presented. A portion of the Fe(2+) in basaltic glass and minerals can be reduced to metal in a few hours at 1100 C and an oxygen fugacity well below the iron-wustite buffer. Part of the iron metals forms rounded submicrometer blebs on the surfaces and in some cases within the grains. A concentration of such blebs equivalent to 20-30 percent of a grain's surface area can totally dominate the reflectance spectra of basaltic glass, pyroxene, and olivine. The production of optically opaque iron metal blebs, combined with the decline in Fe(2+), affects the glass and mineral reflectance spectra in three ways: by lowering the overall reflectivity, reducing the spectral contrast of absorption features, and producing a continuum with a general rise in reflectivity toward longer wavelengths.

Iron mineralization at the Songhu deposit, Chinese Western Tianshan: a type locality with regional metallogenic implications

NASA Astrophysics Data System (ADS)

Wang, Chun-Long; Wang, Yi-Tian; Dong, Lian-Hui; Qin, Ke-Zhang; Evans, Noreen J.; Zhang, Bing; Ren, Yi

2018-01-01

Hosted by volcaniclastics of the Carboniferous Dahalajunshan Formation, the Songhu iron deposit is located in the central segment of the Awulale metallogenic belt, Chinese Western Tianshan. Mineralization and alteration are structurally controlled by orogen-parallel NWW-striking faults. Integrating with mineralogical and stable isotopic analyses based on paragenetic relationships, two types of iron mineralization have been identified. The deuteric mineralization (Type I) represented by brecciated, banded, and disseminated-vein ores juxtaposed with potassic-calcic alteration in the inner zone, which was formed from a magmatic fluid generated during the late stages of regional volcanism. In contrast, the volcanic-hydrothermal mineralization (Type II) is characterized by hydrothermal features occurring in massive and agglomerated ores with abundant sulfides, and was generated from the magmatic fluid with seawater contamination. Two volcaniclastic samples from the hanging and footwall of the main orebody yield zircon U-Pb ages of 327.8 ± 3.1 and 332.0 ± 2.0 Ma, respectively, which indicate Middle Carboniferous volcanism. Timing for iron mineralization can be broadly placed in the same epoch. By reviewing geological, mineralogical, and geochemical features of the primary iron deposits in the Awulale metallogenic belt, we propose that the two types of iron mineralization in the Songhu iron deposit are representative regionally. A summary of available geochronological data reveals Middle-Late Carboniferous polycyclic ore-related volcanism, and nearly contemporaneous iron mineralization along the belt. Furthermore, petro-geochemistry of volcanic-volcaniclastic host rocks indicates that partial melting of a metasomatized mantle wedge under a continental arc setting could have triggered the continuous volcanic activities and associated metallogenesis.

Bacterial and iron oxide aggregates mediate secondary iron mineral formation: green rust versus magnetite.

PubMed

Zegeye, A; Mustin, C; Jorand, F

2010-06-01

In the presence of methanoate as electron donor, Shewanella putrefaciens, a Gram-negative, facultative anaerobe, is able to transform lepidocrocite (gamma-FeOOH) to secondary Fe (II-III) minerals such as carbonated green rust (GR1) and magnetite. When bacterial cells were added to a gamma-FeOOH suspension, aggregates were produced consisting of both bacteria and gamma-FeOOH particles. Recently, we showed that the production of secondary minerals (GR1 vs. magnetite) was dependent on bacterial cell density and not only on iron reduction rates. Thus, gamma-FeOOH and S. putrefaciens aggregation pattern was suggested as the main mechanism driving mineralization. In this study, lepidocrocite bioreduction experiments, in the presence of anthraquinone disulfonate, were conducted by varying the [cell]/[lepidocrocite] ratio in order to determine whether different types of aggregate are formed, which may facilitate precipitation of GR1 as opposed to magnetite. Confocal laser scanning microscopy was used to analyze the relative cell surface area and lepidocrocite concentration within the aggregates and captured images were characterized by statistical methods for spatial data (i.e. variograms). These results suggest that the [cell]/[lepidocrocite] ratio influenced both the aggregate structure and the nature of the secondary iron mineral formed. Subsequently, a [cell]/[lepidocrocite] ratio above 1 x 10(7) cells mmol(-1) leads to densely packed aggregates and to the formation of GR1. Below this ratio, looser aggregates are formed and magnetite was systematically produced. The data presented in this study bring us closer to a more comprehensive understanding of the parameters governing the formation of minerals in dense bacterial suspensions and suggest that screening mineral-bacteria aggregate structure is critical to understanding (bio)mineralization pathways.

Iron Hydroxide Minerals Drive Organic and Phosphorus Chemistry in Subsurface Redox / pH Gradients

NASA Astrophysics Data System (ADS)

Flores, E.; Barge, L. M.; VanderVelde, D.; Baum, M.

2017-12-01

Iron minerals, particularly iron oxides and oxyhydroxides, are prevalent on Mars and may exist in mixed valence or even reduced states beneath the oxidized surface. Iron (II,III) hydroxides, including green rust, are reactive and potentially catalytic minerals that can absorb and concentrate charged species, while also driving chemical reactions. These minerals are highly redox-sensitive and the presence of organics and/or phosphorus species could affect their mineralogy and/or stability. Conversely, the minerals might be able to drive chemical processes such as amino acid formation, phosphorus oxyanion reactions, or could simply selectively preserve organic species via surface adsorption. In an open aqueous sediment column, soluble products of mineral-driven reactions could also diffuse to sites of different chemical conditions to react even further. We synthesized Fe-hydroxide minerals under various conditions relevant to early Earth and ancient Mars (>3.0 Gyr), anoxically and in the presence of salts likely to have been present in surface or ground waters. Using these minerals we conducted experiments to test whether iron hydroxides could promote amino acid formation, and how the reaction is affected by subsurface gradients of redox, pH, and temperature. We also tested the adsorption of organic and phosphorus species onto Fe-hydroxide minerals at different conditions within the gradients. The suite of organic or phosphorus signatures that may be found in a particular mineral system is a combination of what is synthesized there, what is preferentially concentrated / retained there, and what is preserved against degradation. Further work is needed to determine how these processes could have proceeded on Mars and what mineral-organic signatures, abiotic or otherwise, would be produced from such processes.

Getting rid of the unwanted: highlights of developments and challenges of biobeneficiation of iron ore minerals-a review.

PubMed

Adeleke, Rasheed A

2014-12-01

The quest for quality mineral resources has led to the development of many technologies that can be used to refine minerals. Biohydrometallurgy is becoming an increasingly acceptable technology worldwide because it is cheap and environmentally friendly. This technology has been successfully developed for some sulphidic minerals such as gold and copper. In spite of wide acceptability of this technology, there are limitations to its applications especially in the treatment of non-sulphidic minerals such as iron ore minerals. High levels of elements such as potassium (K) and phosphorus (P) in iron ore minerals are known to reduce the quality and price of these minerals. Hydrometallurgical methods that are non-biological involving the use of chemicals are usually used to deal with this problem. However, recent advances in mining technologies favour green technologies, known as biohydrometallurgy, with minimal impact on the environment. This technology can be divided into two, namely bioleaching and biobeneficiation. This review focuses on Biobeneficiation of iron ore minerals. Biobeneficiation of iron ore is very challenging due to the low price and chemical constitution of the ore. There are substantial interests in the exploration of this technology for improving the quality of iron ore minerals. In this review, current developments in the biobeneficiation of iron ore minerals are considered, and potential solutions to challenges faced in the wider adoption of this technology are proposed.

Surface materials map of Afghanistan: iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Kokaly, Raymond F.; Hoefen, Todd M.; Dudek, Kathleen B.; Livo, Keith E.

2012-01-01

This map shows the distribution of selected iron-bearing minerals and other materials derived from analysis of HyMap imaging spectrometer data of Afghanistan. Using a NASA (National Aeronautics and Space Administration) WB-57 aircraft flown at an altitude of ~15,240 meters or ~50,000 feet, 218 flight lines of data were collected over Afghanistan between August 22 and October 2, 2007. The HyMap data were converted to apparent surface reflectance, then further empirically adjusted using ground-based reflectance measurements. The reflectance spectrum of each pixel of HyMap data was compared to the spectral features of reference entries in a spectral library of minerals, vegetation, water, ice, and snow. This map shows the spatial distribution of iron-bearing minerals and other materials having diagnostic absorptions at visible and near-infrared wavelengths. These absorptions result from electronic processes in the minerals. Several criteria, including (1) the reliability of detection and discrimination of minerals using the HyMap spectrometer data, (2) the relative abundance of minerals, and (3) the importance of particular minerals to studies of Afghanistan's natural resources, guided the selection of entries in the reference spectral library and, therefore, guided the selection of mineral classes shown on this map. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated. Minerals having similar spectral features were less easily discriminated, especially where the minerals were not particularly abundant and (or) where vegetation cover reduced the absorption strength of mineral features. Complications in reflectance calibration also affected the detection and identification of minerals.

The influence of Citrosept addition to drinking water and Scutellaria baicalensis root extract on the content of selected mineral elements in the blood plasma of turkey hens.

PubMed

Rusinek-Prystupa, Elżbieta; Lechowski, Jerzy; Zukiewicz-Sobczak, Wioletta; Sobczak, Paweł; Zawiślak, Kazimierz

2014-01-01

The aim of this research work was to indicate the influence of Citrosept preparation and Scutellaria baicalensis root extract, administered per os to growing turkey hens in 3 different dosages, on the content of selected mineral elements in blood plasma of slaughter turkey hens. An attempt was also made to specify the most effective dosage of the applied preparations with the highest efficiency as regards increased levels of examined macro- and microelements in the birds' blood. The research experiment was conducted on 315 turkey hens randomly divided into seven groups, each consisting of 45 turkey hens. Group K constituted the control group without experimental additions of the above-mentioned preparations. When it comes to turkey hens which belonged to groups II-IV, Citrosept preparation was instilled to water in the following dosages: Group II - 0.011 ml/kg of bm; Group III - 0.021 ml/kg of bm; Group IV - 0.042 ml/kg bm. For birds which belonged to groups V-VII preparation, which was Scutellaria baicalensis root extract, was instilled to water in the following dosages: Group V - 0.009 ml/kg of bm; Group VI - 0.018 ml/kg of bm, Group VII - 0.036 ml/kg bm. In the examined plant extracts and blood plasma of the birds the levels of Na, K, Ca, Mg, Cu, Zn, and Fe were identified. The use of examined extracts influenced the changes in the levels of all tested elements in slaughter turkey hens' blood plasma. An upward tendency was recorded which regarded the level of calcium and magnesium, and a downward tendency of sodium, potassium, copper, zinc, and iron in relation to the results achieved in the control group.

Iron minerals within specific microfossil morphospecies of the 1.88 Ga Gunflint Formation.

PubMed

Lepot, Kevin; Addad, Ahmed; Knoll, Andrew H; Wang, Jian; Troadec, David; Béché, Armand; Javaux, Emmanuelle J

2017-03-23

Problematic microfossils dominate the palaeontological record between the Great Oxidation Event 2.4 billion years ago (Ga) and the last Palaeoproterozoic iron formations, deposited 500-600 million years later. These fossils are often associated with iron-rich sedimentary rocks, but their affinities, metabolism, and, hence, their contributions to Earth surface oxidation and Fe deposition remain unknown. Here we show that specific microfossil populations of the 1.88 Ga Gunflint Iron Formation contain Fe-silicate and Fe-carbonate nanocrystal concentrations in cell interiors. Fe minerals are absent in/on all organically preserved cell walls. These features are consistent with in vivo intracellular Fe biomineralization, with subsequent in situ recrystallization, but contrast with known patterns of post-mortem Fe mineralization. The Gunflint populations that display relatively large cells (thick-walled spheres, filament-forming rods) and intra-microfossil Fe minerals are consistent with oxygenic photosynthesizers but not with other Fe-mineralizing microorganisms studied so far. Fe biomineralization may have protected oxygenic photosynthesizers against Fe 2+ toxicity during the Palaeoproterozoic.

Response of acid mobilization of iron-containing mineral dust to improvement of air quality projected in the future

NASA Astrophysics Data System (ADS)

Ito, A.; Xu, L.

2014-04-01

Acidification of dust aerosols may increase aerosol iron (Fe) solubility, which is linked to mineral properties. Combustion aerosols can also elevate aerosol iron solubility when aerosol loading is low. Here, we use an atmospheric chemical transport model to investigate the deposition of filterable iron and its response to changes in anthropogenic emissions of both combustion aerosols and precursor gases. By introducing three classes of iron-containing minerals into the detailed aerosol chemistry model, we provide a theoretical examination of the effects of different dissolution behaviors on the acid mobilization of iron. Comparisons of modeled Fe dissolution curves with the measured dissolution rates for African, east Asian, and Australian dust samples show overall good agreement under acidic conditions. The improved treatment of Fe in mineral dust and its dissolution scheme results in reasonable predictive capability for iron solubility over the oceans in the Northern Hemisphere. Our model results suggest that the improvement of air quality projected in the future will lead to a decrease of the filterable iron deposition from iron-containing mineral dust to the eastern North Pacific due to less acidification in Asian dust, which is mainly associated with the reduction of nitrogen oxides (NOx) emissions. These results could have important implications for iron fertilization of phytoplankton growth, and highlight the necessity of improving the process-based quantitative understanding of the response of the chemical modification in iron-containing minerals to environmental changes.

Iron Oxide Minerals in Dust: New Insights from Magnetism, Spectroscopy, and Microscopy

NASA Astrophysics Data System (ADS)

Reynolds, R. L.; Moskowitz, B. M.; Goldstein, H. L.; Cattle, S.; Bristow, C. S.; Berquo, T. S.; Kokaly, R. F.

2016-12-01

Although iron oxide minerals typically compose only a few weight percent of bulk atmospheric dust, they exert important effects on weather, climate, melting of snow and ice, and ocean fertilization. Moreover, the partition between hematite and goethite is important to know to improve models for radiative effects of ferric oxide minerals. The combination of magnetic property measurements, Mössbauer spectroscopy, reflectance spectroscopy, chemical analysis, and scanning electron microscopy at 9-nm resolution reveals types, sizes, abundances, and occurrences of iron oxide minerals in samples from the 2009 "Red Dawn" dust storm (Australia), the Bodélé Depression (Chad), and dust and dust-source sediments in the American West. In each case, discrete nano-phase and microcrystalline iron oxides, hematite and (or) goethite were identified on and within clay coatings on composite dust particles. "Red Dawn" dust samples across eastern Australia each contained hematite, goethite, and magnetite. Goethite and hematite composed approximately 25-45% of the Fe-bearing phases as indicated by Mössbauer spectroscopy at 300K and 4.2K. Magnetite concentrations (as much as 0.29 wt %) were much higher in eastern, urban sites than in remote western sites (0.01 wt %), suggesting local addition of magnetite from urban sources. In samples from the Bodélé Depression, dominant goethite and subordinate hematite composed about 2% of yellow-reddish dust-source sediments. Magnetite was ubiquitous (0.002-0.57 wt %). The average iron apportionment was 32% in ferric oxide minerals, 1.4 % in magnetite, and 65% in ferric silicates. In all cases, high abundance of ferric oxides correlated with low reflectance, indicating their capacity to absorb solar radiation. Moreover, the high surface-to-volume ratios of ferric oxide nanoparticles may facilitate atmospheric processing and affect iron solubility and bioavailability in marine ecosystems and in human lungs.

Iron utilization and liver mineral concentrations in rats fed safflower oil, flaxseed oil, olive oil, or beef tallow in combination with different concentrations of dietary iron.

PubMed

Shotton, Andrea D; Droke, Elizabeth A

2004-03-01

Diets with a higher proportion of polyunsaturated fatty acids (i.e., linoleic acid) have decreased iron absorption and utilization compared with diets containing a higher proportion of the saturated fatty acid stearic acid (e.g., beef tallow). However, less is known regarding the influence of other polyunsaturated or monounsaturated fatty acids, along with higher dietary iron, on iron absorption and utilization. The present study was conducted to compare the effects of dietary fat sources known to vary in (n-3), (n-6), and (n-9) fatty acids on iron utilization and liver mineral concentrations. Male weanling rats were fed a diet containing 10, 35, or 100 microg/g iron in combination with safflower oil, flaxseed oil, olive oil, or beef tallow for 8 wk. Indicators of iron status, iron utilization, and liver iron concentrations were unaffected by an interaction between the fat source and iron concentration. Plasma copper was the only variable affected by an interaction between the fat source and dietary iron. Findings of this study demonstrate that flaxseed oil and olive oil may alter tissue minerals and affect iron utilization. Further studies should be conducted to establish the effect of varying (n-3), (n-6), and (n-9) fatty acids on trace mineral status and iron utilization.

Copper(II)-rubeanic acid coprecipitation system for separation-preconcentration of trace metal ions in environmental samples for their flame atomic absorption spectrometric determinations.

PubMed

Soylak, Mustafa; Erdogan, Nilgun D

2006-09-21

A simple and facile preconcentration procedure based on the coprecipitation of trace heavy metal ions with copper(II)-rubeanic acid complex has been developed. The analytical parameters including pH, amounts of rubeanic acid, sample volume, etc. was investigated for the quantitative recoveries of Pb(II), Fe(III), Cd(II), Au(III), Pd(II) and Ni(II). No interferic effects were observed from the concomitant ions. The detection limits for analyte ions by 3 sigma were in the range of 0.14 microg/l for iron-3.4 microg/l for lead. The proposed coprecipitation method was successfully applied to water samples from Palas Lake-Kayseri, soil and sediment samples from Kayseri and Yozgat-Turkey.

Adsorption of Trametes versicolor laccase to soil iron and aluminum minerals: enzyme activity, kinetics and stability studies.

PubMed

Wu, Yue; Jiang, Ying; Jiao, Jiaguo; Liu, Manqiang; Hu, Feng; Griffiths, Bryan S; Li, Huixin

2014-02-01

Laccases play an important role in the degradation of soil phenol or phenol-like substance and can be potentially used in soil remediation through immobilization. Iron and aluminum minerals can adsorb extracellular enzymes in soil environment. In the present study, we investigated the adsorptive interaction of laccase, from the white-rot fungus Trametes versicolor, with soil iron and aluminum minerals and characterized the properties of the enzyme after adsorption to minerals. Results showed that both soil iron and aluminum minerals adsorbed great amount of laccase, independent of the mineral specific surface areas. Adsorbed laccases retained 26-64% of the activity of the free enzyme. Compared to the free laccase, all adsorbed laccases showed higher Km values and lower Vmax values, indicating a reduced enzyme-substrate affinity and a lower rate of substrate conversion in reactions catalyzed by the adsorbed laccase. Adsorbed laccases exhibited increased catalytic activities compared to the free laccase at low pH, implying the suitable application of iron and aluminum mineral-adsorbed T. versicolor laccase in soil bioremediation, especially in acid soils. In terms of the thermal profiles, adsorbed laccases showed decreased thermal stability and higher temperature sensitivity relative to the free laccase. Moreover, adsorption improved the resistance of laccase to proteolysis and extended the lifespan of laccase. Our results implied that adsorbed T. versicolor laccase on soil iron and aluminum minerals had promising potential in soil remediation. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Iron minerals within specific microfossil morphospecies of the 1.88 Ga Gunflint Formation

PubMed Central

Lepot, Kevin; Addad, Ahmed; Knoll, Andrew H.; Wang, Jian; Troadec, David; Béché, Armand; Javaux, Emmanuelle J.

2017-01-01

Problematic microfossils dominate the palaeontological record between the Great Oxidation Event 2.4 billion years ago (Ga) and the last Palaeoproterozoic iron formations, deposited 500–600 million years later. These fossils are often associated with iron-rich sedimentary rocks, but their affinities, metabolism, and, hence, their contributions to Earth surface oxidation and Fe deposition remain unknown. Here we show that specific microfossil populations of the 1.88 Ga Gunflint Iron Formation contain Fe-silicate and Fe-carbonate nanocrystal concentrations in cell interiors. Fe minerals are absent in/on all organically preserved cell walls. These features are consistent with in vivo intracellular Fe biomineralization, with subsequent in situ recrystallization, but contrast with known patterns of post-mortem Fe mineralization. The Gunflint populations that display relatively large cells (thick-walled spheres, filament-forming rods) and intra-microfossil Fe minerals are consistent with oxygenic photosynthesizers but not with other Fe-mineralizing microorganisms studied so far. Fe biomineralization may have protected oxygenic photosynthesizers against Fe2+ toxicity during the Palaeoproterozoic. PMID:28332570

Numerical Modeling of Arsenic Mobility during Reductive Iron-Mineral Transformations.

PubMed

Rawson, Joey; Prommer, Henning; Siade, Adam; Carr, Jackson; Berg, Michael; Davis, James A; Fendorf, Scott

2016-03-01

Millions of individuals worldwide are chronically exposed to hazardous concentrations of arsenic from contaminated drinking water. Despite massive efforts toward understanding the extent and underlying geochemical processes of the problem, numerical modeling and reliable predictions of future arsenic behavior remain a significant challenge. One of the key knowledge gaps concerns a refined understanding of the mechanisms that underlie arsenic mobilization, particularly under the onset of anaerobic conditions, and the quantification of the factors that affect this process. In this study, we focus on the development and testing of appropriate conceptual and numerical model approaches to represent and quantify the reductive dissolution of iron oxides, the concomitant release of sorbed arsenic, and the role of iron-mineral transformations. The initial model development in this study was guided by data and hypothesized processes from a previously reported,1 well-controlled column experiment in which arsenic desorption from ferrihydrite coated sands by variable loads of organic carbon was investigated. Using the measured data as constraints, we provide a quantitative interpretation of the processes controlling arsenic mobility during the microbial reductive transformation of iron oxides. Our analysis suggests that the observed arsenic behavior is primarily controlled by a combination of reductive dissolution of ferrihydrite, arsenic incorporation into or co-precipitation with freshly transformed iron minerals, and partial arsenic redox transformations.

Radium Adsorption to Iron Bearing Minerals in Variable Salinity Waters

NASA Astrophysics Data System (ADS)

Chen, M.; Kocar, B. D.

2014-12-01

Radium is a common, naturally occurring radioactive metal found in many subsurface environments. Radium isotopes are a product of natural uranium and thorium decay, and are particularly abundant within groundwaters where minimal flux leads to accumulation within porewaters. Radium has been used as a natural tracer to estimate submarine groundwater discharge (SGD) [1], where the ratios of various radium isotopes are used to estimate total groundwater flux to and from the ocean [2]. Further, it represents a substantial hazard in waste water produced after hydraulic fracturing for natural gas extraction [3], resulting in a significant risk of environmental release and increased cost for water treatment or disposal. Adsorption to mineral surfaces represents a primary pathway of radium retention within subsurface environments. For SGD studies, it is important to understand adsorption processes to correctly estimate GW fluxes, while in hydraulic fracturing, radium adsorption to aquifer solids will mediate the activities of radium within produced water. While some studies of radium adsorption to various minerals have been performed [4], there is a limited understanding of the surface chemistry of radium adsorption, particularly to iron-bearing minerals such as pyrite, goethite and ferrihydrite. Accordingly, we present the results of sorption experiments of radium to a suite of iron-bearing minerals representative of those found within deep saline and near-surface (freshwater) aquifers, and evaluate impacts of varying salinity solutions through the use of artificial groundwater, seawater, and shale formation brine. Further, we explore the impacts of pyrite oxidation and ferrihydrite transformation to other iron-bearing secondary minerals on the retention of radium. This work lays the groundwork for further study of radium use as a tracer for SGD, as well as understanding mechanisms of radium retention and release from deep aquifer materials following hydraulic fracturing

Theoretical Analysis of an Iron Mineral-Based Magnetoreceptor Model in Birds

PubMed Central

Solov'yov, Ilia A.; Greiner, Walter

2007-01-01

Sensing the magnetic field has been established as an essential part of navigation and orientation of various animals for many years. Only recently has the first detailed receptor concept for magnetoreception been published based on histological and physical results. The considered mechanism involves two types of iron minerals (magnetite and maghemite) that were found in subcellular compartments within sensory dendrites of the upper beak of several bird species. But so far a quantitative evaluation of the proposed receptor is missing. In this article, we develop a theoretical model to quantitatively and qualitatively describe the magnetic field effects among particles containing iron minerals. The analysis of forces acting between these subcellular compartments shows a particular dependence on the orientation of the external magnetic field. The iron minerals in the beak are found in the form of crystalline maghemite platelets and assemblies of magnetite nanoparticles. We demonstrate that the pull or push to the magnetite assemblies, which are connected to the cell membrane, may reach a value of 0.2 pN—sufficient to excite specific mechanoreceptive membrane channels in the nerve cell. The theoretical analysis of the assumed magnetoreceptor system in the avian beak skin clearly shows that it might indeed be a sensitive biological magnetometer providing an essential part of the magnetic map for navigation. PMID:17496012

Synthetic effect between iron oxide and sulfate mineral on the anaerobic transformation of organic substance.

PubMed

Chen, Tian-Hu; Wang, Jin; Zhou, Yue-Fei; Yue, Zheng-Bo; Xie, Qiao-Qin; Pan, Min

2014-01-01

Synthetic effect between sulfate minerals (gypsum) and iron oxide (hematite) on the anaerobic transformation of organic substance was investigated in the current study. The results showed that gypsum was completely decomposed while hematite was partially reduced. The mineral phase analysis results showed that FeS and CaCO3 was the major mineralization product. Methane generation process was inhibited and inorganic carbon contents in the precipitates were enhanced compared to the control without hematite and gypsum. The inorganic carbon content increased with the increasing of hematite dosages. Co-addition of sulfate minerals and iron oxide would have a potential application prospect in the carbon sequestration area and reduction of the greenhouse gas release. The results would also reveal the role of inorganic mineral in the global carbon cycle. Copyright © 2013 Elsevier Ltd. All rights reserved.

Electrochemical analyses of redox-active iron minerals: a review of nonmediated and mediated approaches.

PubMed

Sander, Michael; Hofstetter, Thomas B; Gorski, Christopher A

2015-05-19

Redox-active minerals are ubiquitous in the environment and are involved in numerous electron transfer reactions that significantly affect biogeochemical processes and cycles as well as pollutant dynamics. As a consequence, research in different scientific disciplines is devoted to elucidating the redox properties and reactivities of minerals. This review focuses on the characterization of mineral redox properties using electrochemical approaches from an applied (bio)geochemical and environmental analytical chemistry perspective. Establishing redox equilibria between the minerals and working electrodes is a major challenge in electrochemical measurements, which we discuss in an overview of traditional electrochemical techniques. These issues can be overcome with mediated electrochemical analyses in which dissolved redox mediators are used to increase the rate of electron transfer and to facilitate redox equilibration between working electrodes and minerals in both amperometric and potentiometric measurements. Using experimental data on an iron-bearing clay mineral, we illustrate how mediated electrochemical analyses can be employed to derive important thermodynamic and kinetic data on electron transfer to and from structural iron. We summarize anticipated methodological advancements that will further contribute to advance an improved understanding of electron transfer to and from minerals in environmentally relevant redox processes.

The effect of bonding environment on iron isotope fractionation between minerals at high temperature

NASA Astrophysics Data System (ADS)

Sossi, Paolo A.; O'Neill, Hugh St. C.

2017-01-01

Central to understanding the processes that drive stable isotope fractionation in nature is their quantification under controlled experimental conditions. The polyvalent element iron, given its abundance in terrestrial rocks, exerts controls on the structural and chemical properties of minerals and melts. The iron isotope compositions of typical high temperature minerals are, however, poorly constrained and their dependence on intensive (e.g. fO2) and extensive (e.g. compositional) variables is unknown. In this work, experiments involving a reference phase, 2 M FeCl2·4H2O(l), together with an oxide mix corresponding to the bulk composition of the chosen mineral were performed in a piston cylinder in Ag capsules. The oxide mix crystallised in situ at 1073 K and 1 GPa, in equilibrium with the iron chloride, and was held for 72 h. In order to characterise the effect of co-ordination and oxidation state on the isotope composition independently, exclusively Fe2+ minerals were substituted in: VIII-fold almandine, VI-fold ilmenite, fayalite and IV-fold chromite and hercynite. Δ57FeMin-FeCl2 increases in the order VIII < VI < IV, consistent with a decrease in the mean Fe-O bond length. Magnetite, which has mixed VI- and IV-fold co-ordination, has the heaviest Δ57Fe by virtue of 2/3 of its iron being the smaller, ferric ion. The composition of the VIFe2+-bearing minerals is similar to that of the aqueous FeCl2 fluid. To the degree that this represents the speciation of iron in fluids exsolving from magmas, the fractionation between them should be small, unless the iron is hosted in magnetite. By contrast, predominantly Fe2+-bearing mantle garnets should preserve a much lighter δ57Fe than their lower pressure spinel counterparts, a signature that may be reflected in partial melts from these lithologies. As the Fe-O bond lengths in fayalite and ilmenite are comparable, their isotope compositions overlap, suggesting that high Ti mare basalts acquired their heavy isotopic

A microbial-mineralization approach for syntheses of iron oxides with a high specific surface area.

PubMed

Yagita, Naoki; Oaki, Yuya; Imai, Hiroaki

2013-04-02

Of minerals and microbes: A microbial-mineralization-inspired approach was used to facilitate the syntheses of iron oxides with a high specific surface area, such as 253 m(2)g(-1) for maghemite (γ-Fe(2)O(3)) and 148 m(2)g(-1) for hematite (α-Fe(2)O(3)). These iron oxides can be applied to electrode material of lithium-ion batteries, adsorbents, and catalysts. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enlightening mineral iron sensing in Pseudomonas fluorescens by surface active maghemite nanoparticles: Involvement of the OprF porin.

PubMed

Magro, Massimiliano; Fasolato, Luca; Bonaiuto, Emanuela; Andreani, Nadia Andrea; Baratella, Davide; Corraducci, Vittorino; Miotto, Giovanni; Cardazzo, Barbara; Vianello, Fabio

2016-10-01

Mineral iron(III) recognition by bacteria is considered a matter of debate. The peculiar surface chemistry of novel naked magnetic nanoparticles, called SAMNs (surface active maghemite nanoparticles) characterized by solvent exposed Fe(3+) sites on their surface, was exploited for studying mineral iron sensing in Pseudomonas fluorescens. SAMNs were applied for mimicking Fe(3+) ions in solution, acting as magnetically drivable probes to evaluate putative Fe(3+) recognition sites on the microorganism surface. Culture broths and nano-bio-conjugates were characterized by UV-Vis spectroscopy and mass spectrometry. The whole heritage of a membrane porin (OprF) of P. fluorescens Ps_22 cells was recognized and firmly bound by SAMNs. The binding of nanoparticles to OprF porin was correlated to a drastic inhibition of a siderophore (pyoverdine) biosynthesis and to the stimulation of the production and rate of formation of a secondary siderophore. The analysis of metabolic pathways, based on P. fluorescens Ps_22 genomic information, evidenced that this putative secondary siderophore does not belong to a selection of the most common siderophores. In the scenario of an adhesion mechanism, it is plausible to consider OprF as the biological component deputed to the mineral iron sensing in P. fluorescens Ps_22, as well as one key of siderophore regulation. The present work sheds light on mineral iron sensing in microorganisms. Peculiar colloidal naked iron oxide nanoparticles offer a useful approach for probing the adhesion of bacterial surface on mineral iron for the identification of the specific recognition site for this iron uptake regulation in microorganisms. Copyright © 2016 Elsevier B.V. All rights reserved.

Abiotic transformation of high explosives by freshly precipitated iron minerals in aqueous Fe¹¹ solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boparai, Hardiljeet K.; Comfort, Steve; Satapanajaru, Tunlawit

Zerovalent iron barriers have become a viable treatment for field-scale cleanup of various ground water contaminants. While contact with the iron surface is important for contaminant destruction, the interstitial pore water within and near the iron barrier will be laden with aqueous, adsorbed and precipitated FeII phases. These freshly precipitated iron minerals could play an important role in transforming high explosives (HE). Our objective was to determine the transformation of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), and TNT (2,4,6-trinitrotoluene) by freshly precipitated iron FeII/FeIII minerals. This was accomplished by quantifying the effects of initial FeII concentration, pH, and the presence of aquifermore » solids (FeIII phases) on HE transformation rates. Results showed that at pH 8.2, freshly precipitated iron minerals transformed RDX, HMX, and TNT with reaction rates increasing with increasing FeII concentrations. RDX and HMX transformations in these solutions also increased with increasing pH (5.8-8.55). By contrast, TNT transformation was not influenced by pH (6.85-8.55) except at pH values <6.35. Transformations observed via LC/MS included a variety of nitroso products (RDX, HMX) and amino degradation products (TNT). XRD analysis identified green rust and magnetite as the dominant iron solid phases that precipitated from the aqueous FeII during HE treatment under anaerobic conditions. Geochemical modeling also predicted FeII activity would likely be controlled by green rust and magnetite. These results illustrate the important role freshly precipitated FeII/FeIII minerals in aqueous FeII solutions play in the transformation of high explosives.« less

Kinetics and Efficiency of H2O2 Activation by Iron-Containing Minerals and Aquifer Materials

PubMed Central

Pham, Anh Le-Tuan; Doyle, Fiona M.; Sedlak, David L.

2014-01-01

To gain insight into factors that control H2O2 persistence and ˙OH yield in H2O2-based in situ chemical oxidation systems, the decomposition of H2O2 and transformation of phenol were investigated in the presence of iron-containing minerals and aquifer materials. Under conditions expected during remediation of soil and groundwater, the stoichiometric efficiency, defined as the amount of phenol transformed per mole of H2O2 decomposed, varied from 0.005 to 0.28%. Among the iron-containing minerals, iron oxides were 2 to 10 times less efficient in transforming phenol than iron-containing clays and synthetic iron-containing catalysts. In both iron-containing mineral and aquifer materials systems, the stoichiometric efficiency was inversely correlated with the rate of H2O2 decomposition. In aquifer materials systems, the stoichiometric efficiency was also inversely correlated with the Mn content, consistent with the fact that the decomposition of H2O2 on manganese oxides does not produce ˙OH. Removal of iron and manganese oxide coatings from the surface of aquifer materials by extraction with citrate-bicarbonate-dithionite slowed the rate of H2O2 decomposition on aquifer materials and increased the stoichiometric efficiency. In addition, the presence of 2 mM of dissolved SiO2 slowed the rate of H2O2 decomposition on aquifer materials by over 80% without affecting the stoichiometric efficiency. PMID:23047055

Kinetics and efficiency of H2O2 activation by iron-containing minerals and aquifer materials.

PubMed

Pham, Anh Le-Tuan; Doyle, Fiona M; Sedlak, David L

2012-12-01

To gain insight into factors that control H(2)O(2) persistence and ·OH yield in H(2)O(2)-based in situ chemical oxidation systems, the decomposition of H(2)O(2) and transformation of phenol were investigated in the presence of iron-containing minerals and aquifer materials. Under conditions expected during remediation of soil and groundwater, the stoichiometric efficiency, defined as the amount of phenol transformed per mole of H(2)O(2) decomposed, varied from 0.005 to 0.28%. Among the iron-containing minerals, iron oxides were 2-10 times less efficient in transforming phenol than iron-containing clays and synthetic iron-containing catalysts. In both iron-containing mineral and aquifer materials systems, the stoichiometric efficiency was inversely correlated with the rate of H(2)O(2) decomposition. In aquifer materials systems, the stoichiometric efficiency was also inversely correlated with the Mn content, consistent with the fact that the decomposition of H(2)O(2) on manganese oxides does not produce ·OH. Removal of iron and manganese oxide coatings from the surface of aquifer materials by extraction with citrate-bicarbonate-dithionite slowed the rate of H(2)O(2) decomposition on aquifer materials and increased the stoichiometric efficiency. In addition, the presence of 2 mM of dissolved SiO(2) slowed the rate of H(2)O(2) decomposition on aquifer materials by over 80% without affecting the stoichiometric efficiency. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of Mineralogy on Dissolution and Speciation of Iron Containing Mineral Oxides in Atmospheric Aerosol Dust

NASA Astrophysics Data System (ADS)

Hettiarachchi, E.; Rubasinghege, G. R. S.; Reynolds, R. L.; Goldstein, H. L.; Moskowitz, B. M.

2017-12-01

Iron is one of the important trace elements for the life. Though it is the fourth most abundant element in the terrestrial crust, given higher pH ( 8.5) in the ocean, the direct dissolution of iron from the Earth crust is limited. Despite this limitation, ocean contains about 2 nM of dissolved iron that is 20-fold greater. Therefore, it is hypothesized most iron comes to the ocean via atmosphere, and dissolution occurs in the acidic atmospheric environments. The current work focuses on the effect of minerology on atmospheric processing of Fe-containing mineral dust using four authentic dust samples, collected from different parts of the world, along with three model systems, hematite (α-Fe2O3), magnetite (Fe3O4) and ilmenite (FeTiO3). Here, spectroscopic methods are combined with batch reactor studies to investigate total iron dissolution and speciation, with a specific focus on source material i.e. particle size, mineralogy, and environmental conditions, i.e. pH, temperature and solar flux. Our data suggests that the presence of Ti metal enhances the dissolution of iron regardless the total %Fe in the mineral. The surface area normalized total iron dissolution in ilmenite, under the dark conditions, in the presence of nitric acid (HNO3) is 3-fold higher than that of hematite. In authentic samples, similar effects were observed for samples containing %Ti. Further, 74% of the dissolved iron in ilmenite remained as Fe(II), bioavailable iron, whereas it was only 60% for magnetite and 8% for hematite. In this study, these results were used to interpret similar trends observed for authentic dust samples with high magnetite content. Thus, the findings of the current study highlight important, yet unconsidered, factors in the atmospheric processing of iron-containing mineral dust aerosol.

Complex electrical monitoring of biopolymer and iron mineral precipitation for microbial enhanced hydrocarbon recovery

NASA Astrophysics Data System (ADS)

Wu, Y.; Hubbard, C. G.; Dong, W.; Hubbard, S. S.

2011-12-01

Microbially enhanced hydrocarbon recovery (MEHR) mechanisms are expected to be impacted by processes and properties that occur over a wide range of scales, ranging from surface interactions and microbial metabolism at the submicron scale to changes in wettability and pore geometry at the pore scale to geological heterogeneities at the petroleum reservoir scale. To eventually ensure successful, production-scale implementation of laboratory-developed MEHR procedures under field conditions, it is necessary to develop approaches that can remotely monitor and accurately predict the complex microbially-facilitated transformations that are expected to occur during MEHR treatments in reservoirs (such as the evolution of redox profiles, oil viscosity or matrix porosity/permeability modifications). Our initial studies are focused on laboratory experiments to assess the geophysical signatures of MEHR-induced biogeochemical transformations, with an ultimate goal of using these approaches to monitor field treatments. Here, we explore the electrical signatures of two MEHR processes that are designed to produce end-products that will plug high permeability zones in reservoirs and thus enhance sweep efficiency. The MEHR experiments to induce biopolymers (in this case dextran) and iron mineral precipitates were conducted using flow-through columns. Leuconostoc mesenteroides, a facultative anaerobe, known to produce dextran from sucrose was used in the biopolymer experiments. Paused injection of sucrose, following inoculation and initial microbial attachment, was carried out on daily basis, allowing enough time for dextran production to occur based on batch experiment observations. Electrical data were collected on daily basis and fluid samples were extracted from the column for characterization. Changes in electrical signal were not observed during initial microbial inoculation. Increase of electrical resistivity and decrease of electrical phase response were observed during the

A case–control study of mesothelioma in Minnesota iron ore (taconite) miners

PubMed Central

Lambert, Christine S; Alexander, Bruce H; Ramachandran, Gurumurthy; MacLehose, Richard F; Nelson, Heather H; Ryan, Andrew D; Mandel, Jeffrey H

2018-01-01

Objectives An excess of mesothelioma has been observed in iron ore miners in Northeastern Minnesota. Mining and processing of taconite iron ore generate exposures that include elongate mineral particles (EMPs) of amphibole and non-amphibole origin. We conducted a nested case–control study of mesothelioma in a cohort of 68 737 iron ore miners (haematite and taconite ore miners) to evaluate the association between mesothelioma, employment and EMP exposures from taconite mining. Methods Mesothelioma cases (N=80) were identified through the Minnesota Cancer Surveillance System (MCSS) and death certificates. Four controls of similar age were selected for each case with 315 controls ultimately eligible for inclusion. Mesothelioma risk was evaluated by estimating rate ratios and 95% CIs with conditional logistic regression in relation to duration of taconite industry employment and cumulative EMP exposure [(EMP/cc)×years], defined by the National Institute for Occupational Safety and Health (NIOSH) 7400 method. Models were adjusted for employment in haematite mining and potential exposure to commercial asbestos products used in the industry. Results All mesothelioma cases were male and 57 of the cases had work experience in the taconite industry. Mesothelioma was associated with the number of years employed in the taconite industry (RR=1.03, 95% CI 1.00 to 1.06) and cumulative EMP exposure (RR=1.10, 95% CI 0.97 to –1.24). No association was observed with employment in haematite mining. Conclusions These results support an association between mesothelioma and employment duration and possibly EMP exposure in taconite mining and processing. The type of EMP was not determined. The potential role of commercial asbestos cannot be entirely ruled out. PMID:26655961

Airway inflammation in iron ore miners exposed to dust and diesel exhaust.

PubMed

Adelroth, E; Hedlund, U; Blomberg, A; Helleday, R; Ledin, M-C; Levin, J O; Pourazar, J; Sandström, T; Järvholm, B

2006-04-01

The aim of the present study was to investigate if underground miners exposed to dust and diesel exhaust in an iron ore mine would show signs of airway inflammation as reflected in induced sputum. In total, 22 miners were studied, once after a holiday of at least 2 weeks and the second time after 3 months of regular work. Control subjects were 21 "white-collar" workers. All subjects completed a questionnaire regarding medical and occupational history, and underwent lung function testing and induced sputum collection. Total and differential cell counts and analyses of the fluid phase of the induced sputum were performed. Sampling of personal exposure to elemental carbon, nitrogen dioxide and inhalable dust was recorded. The average concentrations of inhalable dust, nitrogen dioxide and elemental carbon were 3.2 mg.m-3, 0.28 mg.m-3 and 27 microg.m-3, respectively. Miners had increased numbers of inflammatory cells, mainly alveolar macrophages and neutrophils, and increased concentrations of fibronectin, metalloproteinase-9 and interleukin-10 in induced sputum compared with controls. In conclusion, miners in an underground iron ore mine demonstrated persistent airway inflammation that was as pronounced after a 4-week holiday as after a 3-month period of work underground in the mine.

Epidemiology and genetic characterization of BVDV, BHV-1, BHV-4, BHV-5 and Brucella spp. infections in cattle in Turkey

PubMed Central

ASLAN, Muhammet Eren; AZKUR, Ahmet Kursat; GAZYAGCI, Serkal

2015-01-01

The aim of the study was to determine the epidemiological data of bovine viral diarrhea virus (BVDV), bovine herpesvirus-1 (BHV-1), bovine herpesvirus-4 (BHV-4), bovine herpesvirus-5 (BHV-5) and Brucella–associated cattle that were previously reported to have abortion and infertility problems in Ankara, Corum, Kirikkale and Yozgat provinces, Turkey. Whole blood and sera samples were obtained from 656 cattle, and antibodies against Brucella spp. were detected in 45 (6.86%) and 41 (6.25%) animals by Rose Bengal plate and serum tube agglutination tests, respectively. The seropositivity rates against BVDV, BHV-1 and BHV-4 were 70.89%, 41.3% and 28.78%, respectively. RT-PCR and PCR were performed to detect RNA and DNA viruses in blood samples, respectively. The BVDV 5′-untranslated region and BHV-1 gB gene detected in this study were phylogenetically analyzed. The BVDV strains analyzed in this study were closely related to those previously reported from Turkey. The nucleotide sequence from the BHV-1 strain detected in this study is the first nucleotide sequence of BHV-1 circulating in this area of Turkey deposited in the GenBank. The presence of Brucella spp. and prevalence of BHV-1, BHV-4 and BVDV in cattle should be further investigated throughout these regions. PMID:26096964

Evaluation of constitutive iron reductase (AtFRO2) expression on mineral accumulation and distribution in soybean (Glycine max. L)

PubMed Central

Vasconcelos, Marta W.; Clemente, Thomas E.; Grusak, Michael A.

2014-01-01

Iron is an important micronutrient in human and plant nutrition. Adequate iron nutrition during crop production is central for assuring appropriate iron concentrations in the harvestable organs, for human food or animal feed. The whole-plant movement of iron involves several processes, including the reduction of ferric to ferrous iron at several locations throughout the plant, prior to transmembrane trafficking of ferrous iron. In this study, soybean plants that constitutively expressed the AtFRO2 iron reductase gene were analyzed for leaf iron reductase activity, as well as the effect of this transgene’s expression on root, leaf, pod wall, and seed mineral concentrations. High Fe supply, in combination with the constitutive expression of AtFRO2, resulted in significantly higher concentrations of different minerals in roots (K, P, Zn, Ca, Ni, Mg, and Mo), pod walls (Fe, K, P, Cu, and Ni), leaves (Fe, P, Cu, Ca, Ni, and Mg) and seeds (Fe, Zn, Cu, and Ni). Leaf and pod wall iron concentrations increased as much as 500% in transgenic plants, while seed iron concentrations only increased by 10%, suggesting that factors other than leaf and pod wall reductase activity were limiting the translocation of iron to seeds. Protoplasts isolated from transgenic leaves had three-fold higher reductase activity than controls. Expression levels of the iron storage protein, ferritin, were higher in the transgenic leaves than in wild-type, suggesting that the excess iron may be stored as ferritin in the leaves and therefore unavailable for phloem loading and delivery to the seeds. Also, citrate and malate levels in the roots and leaves of transgenic plants were significantly higher than in wild-type, suggesting that organic acid production could be related to the increased accumulation of minerals in roots, leaves, and pod walls, but not in the seeds. All together, these results suggest a more ubiquitous role for the iron reductase in whole-plant mineral accumulation and

Dirt in the Wound: Evaluating the Role of Iron in Antibacterial Minerals

NASA Astrophysics Data System (ADS)

Morrison, K. D.; Williams, L. B.

2013-12-01

The recent discovery of antibacterial clay deposits which are effective in killing antibiotic resistant bacteria may lead to the discovery of mineral based antibacterial mechanisms. These antibacterial clays have been shown to prevent the growth of a broad spectrum of bacteria, including methicillin-resistant Staphylococcus aureus MRSA and extended-spectrum beta lactamase (ESBL) Escherichia coli (antibiotic resistant strains) when tested in vitro. This study investigates the first antibacterial mineral deposit identified in the United States, the Oregon Mineral Technologies (OMT) mine, which formed from the hydrothermal alteration of porphyry andesites. Our hypothesis is that mixed-layered clay minerals containing nano-iron sulfides can release soluble transition metals at low pH which are antibacterial due to the rapid influx and precipitation of intracellular metal-oxides while generating reactive oxygen species (ROS) and damaging bacterial membranes. To test this hypothesis, E. coli (ATCC 25922) was reacted with clay suspensions and clay leachates (solutions equilibrated with clays for 24 hrs). Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the soluble transition metals that are leaching from the clays. Bioimaging using scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS) and scanning transmission X-ray microscopy (STXM) were used to investigate the precipitation of intracellular mineral particles and redox state of the soluble metals reacting with the bacteria. Reactive oxygen species (ROS) were measured using a spectrophotometric hydrogen peroxide assay (H2O2) assay. Aldehydes were measured using HPLC-UV-Vis (high-performance liquid chromatography-ultraviolet-visible). Antibacterial susceptibility testing and ICP-MS elemental analysis of the leachates reveals that low pH (2.5-3.1) samples containing mM levels of soluble Fe, Al and Ca are antibacterial. All other potential toxins are below the

Modeling the Influence of Different Processes on Iron Solubilization in Mineral Aerosols: From the Gobi Desert to the North Pacific Ocean

NASA Astrophysics Data System (ADS)

Meskhidze, N.; Chameides, W. L.; Chen, G.

2002-12-01

Atmospheric transport is the only known means to deliver dissolved iron from the continents to remote oceanic areas. Dissolved iron is one of the necessary nutrients for photosynthesis of microscopic, single-celled marine organisms (phytoplankton) that grow abundantly in oceans around the world. Alteration of dissolved iron fluxes may substantially affect ocean ecosystem productivity and even exert a global-scale influence on climate by affecting the rate at which atmospheric CO2 is fixed by oceanic biota. On continents, iron mainly exists in forms of highly insoluble minerals (iron-oxides and iron-aluminosilicates) and the processes that can solubilize iron in mineral aerosols during their long-range transport remain poorly understood. In this work we attempt to elucidate the key processes that control the solubilization of iron in mineral aerosols using a simple Lagrangian box model to simulate the transport and chemical alteration of iron-containing mineral aerosols as they are transported from the east coast of China to the remote western North Pacific Ocean. Model parameters and initial conditions are set using a combination of soil and aerosol data from the Gobi Desert, as well as from measurements made during specific PEM-West B flights that encountered dust storm plumes over the Pacific Ocean that had originated in China. Our preliminary results indicate that the amount of acidic pollutants in the air along the dust transport pathways can have a significant effect on the amount of iron that is solubilized in advecting mineral aerosols. This suggests that there may be a link between the flux of the dissolved iron to the remote North Pacific Ocean and the rate at which pollutants such as sulfur dioxide, nitrogen oxides, and ammonia are emitted in East Asia.

A case-control study of mesothelioma in Minnesota iron ore (taconite) miners.

PubMed

Lambert, Christine S; Alexander, Bruce H; Ramachandran, Gurumurthy; MacLehose, Richard F; Nelson, Heather H; Ryan, Andrew D; Mandel, Jeffrey H

2016-02-01

An excess of mesothelioma has been observed in iron ore miners in Northeastern Minnesota. Mining and processing of taconite iron ore generate exposures that include elongate mineral particles (EMPs) of amphibole and non-amphibole origin. We conducted a nested case-control study of mesothelioma in a cohort of 68,737 iron ore miners (haematite and taconite ore miners) to evaluate the association between mesothelioma, employment and EMP exposures from taconite mining. Mesothelioma cases (N=80) were identified through the Minnesota Cancer Surveillance System (MCSS) and death certificates. Four controls of similar age were selected for each case with 315 controls ultimately eligible for inclusion. Mesothelioma risk was evaluated by estimating rate ratios and 95% CIs with conditional logistic regression in relation to duration of taconite industry employment and cumulative EMP exposure [(EMP/cc)×years], defined by the National Institute for Occupational Safety and Health (NIOSH) 7400 method. Models were adjusted for employment in haematite mining and potential exposure to commercial asbestos products used in the industry. All mesothelioma cases were male and 57 of the cases had work experience in the taconite industry. Mesothelioma was associated with the number of years employed in the taconite industry (RR=1.03, 95% CI 1.00 to 1.06) and cumulative EMP exposure (RR=1.10, 95% CI 0.97 to -1.24). No association was observed with employment in haematite mining. These results support an association between mesothelioma and employment duration and possibly EMP exposure in taconite mining and processing. The type of EMP was not determined. The potential role of commercial asbestos cannot be entirely ruled out. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Respiratory interactions of soil bacteria with (semi)conductive iron-oxide minerals.

PubMed

Kato, Souichiro; Nakamura, Ryuhei; Kai, Fumiyoshi; Watanabe, Kazuya; Hashimoto, Kazuhito

2010-12-01

Pure-culture studies have shown that dissimilatory metal-reducing bacteria are able to utilize iron-oxide nanoparticles as electron conduits for reducing distant terminal acceptors; however, the ecological relevance of such energy metabolism is poorly understood. Here, soil microbial communities were grown in electrochemical cells with acetate as the electron donor and electrodes (poised at 0.2 V versus Ag/AgCl) as the electron acceptors in the presence and absence of iron-oxide nanoparticles, and respiratory current generation and community structures were analysed. Irrespective of the iron-oxide species (hematite, magnetite or ferrihydrite), the supplementation with iron-oxide minerals resulted in large increases (over 30-fold) in current, while only a moderate increase (∼10-fold) was observed in the presence of soluble ferric/ferrous irons. During the current generation, insulative ferrihydrite was transformed into semiconductive goethite. Clone-library analyses of 16S rRNA gene fragments PCR-amplified from the soil microbial communities revealed that iron-oxide supplementation facilitated the occurrence of Geobacter species affiliated with subsurface clades 1 and 2. We suggest that subsurface-clade Geobacter species preferentially thrive in soil by utilizing (semi)conductive iron oxides for their respiration. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Method for the production of mineral wool and iron from serpentine ore

DOEpatents

O'Connor, William K [Albany, OR; Rush, Gilbert E [Scio, OR; Soltau, Glen F [Lebanon, OR

2011-10-11

Magnesium silicate mineral wools having a relatively high liquidus temperature of at least about 1400.degree. C. and to methods for the production thereof are provided. The methods of the present invention comprise melting a magnesium silicate feedstock (e.g., comprising a serpentine or olivine ore) having a liquidus temperature of at least about 1400.degree. C. to form a molten magnesium silicate, and subsequently fiberizing the molten magnesium silicate to produce a magnesium silicate mineral wool. In one embodiment, the magnesium silicate feedstock contains iron oxide (e.g., up to about 12% by weight). Preferably, the melting is performed in the presence of a reducing agent to produce an iron alloy, which can be separated from the molten ore. Useful magnesium silicate feedstocks include, without limitation, serpentine and olivine ores. Optionally, silicon dioxide can be added to the feedstock to lower the liquidus temperature thereof.

Thermomagnetic identification of manganese and iron minerals present in soils and industrial dusts

NASA Astrophysics Data System (ADS)

Wawer, Małgorzata; Rachwał, Marzena; Jabłońska, Mariola; Krzykawski, Tomasz; Magiera, Tadeusz

2017-04-01

Many industries (e.g. metallurgy, power, cement, and coking plants) constitute a sources of industrial dusts containing technogenic magnetic particles (TMP). TMP are mostly iron oxides with ferrimagnetic or antiferromagnetic properties, therefore their presence in dusts, soils and sediments can be easily detected by magnetic susceptibility measurements. TMP, thanks their specific mineral and magnetic properties, and well developed specific surface area, are characterized by a chemical affinity for some elements like heavy metals. The main objective of this study was identification of manganese and iron (hydro)oxides occurring in industrial dusts and soils being under their deposition for long time period. In principle, Mn and Fe (hydro)oxides present in these samples originate from high-temperature technological processes. Soils samples (collected from different soil horizons) taken from surroundings of power station, iron/steel and non-ferrous plants as well as metallurgical dusts and fly ashes from power stations were subjected to investigation. During the studies temperature dependent magnetic susceptibility measurements and X-ray powder diffraction analyses were applied. Thermomagnetic analyses (K-T) revealed differences between samples from particular industries, however an inflexion at 450-500°C of all curves was observed indicating a probable occurrence of maghemite- or titanomagnetite-like phases. The curves of TMP emitted by power plants have inflection at 580 °C indicating that magnetite was the main magnetic phase. In case of TMP originated from non-ferrous metal smelting additional curve deflection at 130 and 210 °C occurred relating to intermediate titanomagnetite or iron sulfides. X-ray diffraction proved the occurrence of magnetite and maghemite in almost all samples, especially connected with power industry and iron/steel metallurgy. Mineral analysis revealed that kind of industrial process influenced on the dominating mineral forms found in

Arabidopsis glutaredoxin s17 contributes to vegetative growth, mineral accumulation, and redox balance during iron deficiency

USDA-ARS?s Scientific Manuscript database

Iron (Fe) is an essential mineral nutrient and a metal cofactor required for many proteins and enzymes involved in the processes of DNA synthesis, respiration, and photosynthesis. Iron limitation can have detrimental effects on plant growth and development. Such effects are mediated, at least in par...

Controls on radium transport by adsorption to iron minerals

NASA Astrophysics Data System (ADS)

Chen, M.; Wang, T.; Kocar, B. D.

2015-12-01

Radium is a naturally occurring radioactive metal found in many subsurface environments. Radium isotopes are generated by uranium and thorium decay, and are particularly abundant within groundwaters where minimal porewater flux leads to accumulation. These isotopes are used as natural tracers for estimating submarine groundwater discharge (SGD) [1], allowing for large scale estimation of GW fluxes into and out of the ocean [2]. They also represent a substantial hazard in wastewater produced after hydraulic fracturing for natural gas extraction [3], resulting in a significant risk of environmental release to surface and near-surface waters, and increased cost for water treatment or disposal. Adsorption to mineral surfaces represents a dominant pathway of radium retention in subsurface environments. For SGD studies, adsorption processes impact estimates of GW fluxes, while in hydraulic fracturing, radium adsorption to aquifer solids mediates wastewater radium activities. Analysis of past sorption studies revealed large variability in partition coefficients [4], while examination of radium adsorption kinetics and surface complexation have only recently started [5]. Accordingly, we present the results of sorption and column experiments of radium with a suite of iron minerals representative of those found within deep saline and near-surface (freshwater) aquifers, and evaluate impacts of varying salinity solutions through artificial waters. Further, we explore the impacts of pyrite oxidation and ferrihydrite transformation to other iron-bearing secondary minerals on the transport and retention of radium. These results will provide critical information on the mineralogical controls on radium retention in subsurface environments, and will therefore improve predictions of radium groundwater transport in natural and contaminated systems. [1] Charette, M.A., Buesseler, K.O. & Andrews, J.E., Limnol. Oceanogr. (2001). [2] Moore, W.S., Ann. Rev. Mar. Sci. (2010). [3] Vengosh, A

Exploring Turkish Mathematics Teachers' Content Knowledge of Quadrilaterals

ERIC Educational Resources Information Center

Butuner, Suphi Onder; Filiz, Mehmet

2017-01-01

The aim of this research was to examine mathematics teachers' performances in defining special types of quadrilaterals, identifying their family and hierarchically classifying them. In this vein, 33 of 58 primary school mathematics teachers working in the province of Yozgat, Turkey were voluntarily recruited for this survey, and they were asked to…

Mars surface weathering products and spectral analogs: Palagonites and synthetic iron minerals

NASA Technical Reports Server (NTRS)

Golden, D. C.; Ming, D. W.; Morris, R. V.; Lauer, H. V., Jr.

1992-01-01

There are several hypotheses regarding the formation of Martian surface fines. These surface fines are thought to be products of weathering processes occurring on Mars. Four major weathering environments of igneous rocks on Mars have been proposed; (1) impact induced hydrothermal alterations; (2) subpermafrost igneous intrusion; (3) solid-gas surface reactions; and (4) subaerial igneous intrusion over permafrost. Although one or more of these processes may be important on the Martian surface, one factor in common for all these processes is the reaction of solid or molten basalt with water (solid, liquid, or gas). These proposed processes, with the exception of solid-gas surface reactions, are transient processes. The most likely product of transient hydrothermal processes are layer silicates, zeolites, hydrous iron oxides and palagonites. The long-term instability of hydrous clay minerals under present Martian conditions has been predicted; however, the persistence of such minerals due to slow kinetics of dehydration, or entrapment in permafrost, where the activity of water is high, can not be excluded. Anhydrous oxides of iron (e.g., hematite and maghemite) are thought to be stable under present Martian surface conditions. Oxidative weathering of sulfide minerals associated with Martian basalts has been proposed. Weathering of sulfide minerals leads to a potentially acidic permafrost and the formation of Fe(3) oxides and sulfates. Weathering of basalts under acidic conditions may lead to the formation of kaolinite through metastable halloysite and metahalloysite. Kaolinite, if present, is thought to be a thermodynamically stable phase at the Martian surface. Fine materials on Mars are important in that they influence the surface spectral properties; these fines are globally distributed on Mars by the dust storms and this fraction will have the highest surface area which should act as a sink for most of the absorbed volatiles near the surface of Mars. Therefore

Hydrothermal titanite from the Chengchao iron skarn deposit: temporal constraints on iron mineralization, and its potential as a reference material for titanite U-Pb dating

NASA Astrophysics Data System (ADS)

Hu, Hao; Li, Jian-Wei; McFarlane, Christopher R. M.

2017-09-01

Uranium-lead isotopes and trace elements of titanite from the Chengchao iron skarn deposit (Daye district, Eastern China), located along the contact zones between Triassic marine carbonates and an early Cretaceous intrusive complex consisting of granite and quartz diorite, were analyzed using laser ablation inductively coupled plasma mass spectrometry to provide temporal constraints on iron mineralization and to evaluate its potential as a reference material for titanite U-Pb geochronology. Titanite grains from mineralized endoskarn have simple growth zoning patterns, exhibit intergrowth with magnetite, diopside, K-feldspar, albite and actinolite, and typically contain abundant primary two-phase fluid inclusions. These paragenetic and textural features suggest that these titanite grains are of hydrothermal origin. Hydrothermal titanite is distinct from the magmatic variety from the ore-related granitic intrusion in that it contains unusually high concentrations of U (up to 2995 ppm), low levels of Th (12.5-453 ppm), and virtually no common Pb. The REE concentrations are much lower, as are the Th/U and Lu/Hf ratios. The hydrothermal titanite grains yield reproducible uncorrected U-Pb ages ranging from 129.7 ± 0.7 to 132.1 ± 2.7 Ma (2σ), with a weighted mean of 131.2 ± 0.2 Ma [mean standard weighted deviation (MSWD) = 1.7] that is interpreted as the timing of iron skarn mineralization. This age closely corresponds to the zircon U-Pb age of 130.9 ± 0.7 Ma (MSWD = 0.7) determined for the quartz diorite, and the U-Pb ages for zircon and titanite (130.1 ± 1.0 Ma and 131.3 ± 0.3 Ma) in the granite, confirming a close temporal and likely genetic relationship between granitic magmatism and iron mineralization. Different hydrothermal titanite grains have virtually identical uncorrected U-Pb ratios suggestive of negligible common Pb in the mineral. The homogeneous textures and U-Pb characteristics of Chengchao hydrothermal titanite suggest that the mineral might be a

Iron alteration minerals in the visible and near-infrared spectra of low-albedo asteroids

NASA Technical Reports Server (NTRS)

Vilas, Faith; Jarvis, Kandy S.; Gaffey, Michael J.

1994-01-01

Absorption features centered near 0.60-0.65 and 0.80-0.90 micrometers have been identified in the spectra of five low-albedo main-belt and outer-belt asteroids. These absorption features are attributed respectively to the (6)A(sub 1) goes to (4)T(sub 2)(G) and (6)A(sub 1) goes to (4)T(sub 1)(G) charge transfer transitions in minerals such as goethite, hematite, and jarosite that are products of the aqueous alteration of anhydrous silicates. A shoulder near 0.63 micrometers has also been identified in the absorption feature centered near 0.7 micrometers attributed to oxidized iron in phyllosilicates found predominantly in C- and G-class asteroids reflectance spectra. The coexistence of iron oxides with phyllosilicates in asteroids believed to have undergone aqueous alteration would be expected based upon analogy with terrestrial aqueous alteration and the observed mineralogy of carbonaceous chondrites. The number of low-albedo asteroids having only iron alteration absorption features compared to the number of low-albedo asteroids having spectral characteristics indicative of phyllosilicates is small. Either the conditions under which these asteroids formed are rare, or the iron alteration minerals could be formed in the interiors of objects where phyllosilicates dominate the surface mineralogy.

Magnetic Properties of Iron Oxide Minerals in Atmospheric Dust and Source Sediments from Western US

NASA Astrophysics Data System (ADS)

Moskowitz, B. M.; Yauk, K.; Till, J. L.; Berquo, T. S.; Banerjee, S. K.; Reynolds, R. L.; Goldstein, H. L.

2011-12-01

Atmospheric dust contains iron oxide minerals that can play important roles in various physical and biological processes affecting atmospheric and surface temperatures, marine phytoplankton productivity, and human health. Iron oxide minerals in dust deposited on mountain snow cover are especially important because these minerals absorb solar and IR radiation leading to changes in albedo and affecting the timing and rate of spring and summer snowpack melting. As part of an ongoing project to study physical and chemical properties of dust from sources to sinks in the western US, we will describe one approach to characterize iron oxide mineralogy using magnetic property measurements and Mossbauer spectroscopy. Magnetic property measurements over a wide range of temperatures (2-300 K) and magnetic fields (0-5 T) are particularly sensitive to composition, particle size (from nanometer to micrometer), and concentration of iron oxide and oxyhydroxide minerals. The high sensitivity of magnetic measurements to target minerals allows the measurement of bulk samples preventing any aliasing of composition or grain size resulting from attempts at prior magnetic separation. In addition, different magnetic measurement protocols can isolate different particle-size assemblages and different compositions in multicomponent mixtures and help to identify dust-source areas. These techniques have been applied to dust deposited on snow (DOS) cover of the San Juan Mountains, Colorado (collected 2005-2010) and Wasatch Mountains, Utah (collected 2010) and possible dust-source sediments from the North American Great Basin and Colorado Plateau deserts. Results show that all samples contain a high coercivity phase consistent with hematite and/or goethite as the dominate ferric oxide mineral plus minor amounts of magnetite (<0.5 wt%). The presence of magnetite was determined from the detection of the characteristic Verwey transition (T=121 K) on low-temperature (< 300 K) remanence and

Iron Mineral Catalyzed C-H Activation As a Potential Pathway for Halogenation Processes

NASA Astrophysics Data System (ADS)

Tubbesing, C.; Schoeler, H. F.; Benzing, K.; Krause, T.; Lippe, S.; Rudloff, M.

2014-12-01

Due to increasing drinking water demand of mankind and an expected climate change the impact of salt lakes and salt deserts will increase within the next decades. Furthermore, a rising sea level influences coastal areas like salt marshes and abets processes which will lead to elevated organohalogen formation. An additional increase of the global warming potential, of particle formation and stratospheric ozone depletion is expected. Understanding these multifaceted processes is essential for mankind to be prepared for these alterations of the atmosphere. For example, Keppler et al. (2000) described the production of volatile halogenated organic compounds via oxidation of organic matter driven by ferric iron. However, the formation of long-chained alkyl halides in salt lakes is yet undisclosed. Despite the relative "inertness" of alkanes a direct halogenation of these compounds might be envisaged. In 2005 Vaillancourt et al. discovered a nonheme iron enzyme which is able to halogenate organic compounds via generating the high valent ferryl cation as reaction center. Based on various publications about C-H activation (Bergman, 2007) we postulate a halogenation process in which an iron containing minerals catalyse the C-H bond cleavage of organic compounds in soils. The generated organic radicals are highly reactive towards halides connected to the iron complex. We suggest that next to diagenetically altered iron containing enzymes, minerals such as oxides, hydroxides and sulfides are involved in abiotic halogenation processes. We applied the amino acid methionine as organic model compound and soluble iron species as reactants. All samples were incubated in aqueous phases containing various NaCl concentrations. As a result various halogenated ethanes and ethenes were identified as reaction products. References Bergman, R. G. (2007) Nature, 446(7134) 391-393 Keppler, F., et al. (2000) Nature, 403(6767) 298-301 Vaillancourt, F. H., et al. (2005) Nature, 436(7054) 1191-1194

Tibial bone mineral distribution as influenced by calcium, phosphorus, and vitamin D feeding levels in the growing turkey

NASA Technical Reports Server (NTRS)

Spurrell, F. A.; Brenes, J.; Waibel, P.

1974-01-01

Roentgen signs, subperiosteal, endosteal, and trabecular bone growth are evaluated in turkeys fed phosphorus at the 0.5, 0.56, 0.68, 0.90, and 2.70 percent levels. Calcium levels of 0.30, 0.40, 0.60, 1.2, and 3.60 percent were also tested. Vitamin D levels of 0, 100, 300, 900 and 27,000 I.U. per day were likewise evaluated. Roentgen signs, bone mineral as measured by T-125 gamma ray absorption, and bone mineral growth patterns as shown by radiograph area projection are correlated with calcium, phosphorus, and vitamin D feeding levels. Differences in bone growth at the various feeding levels were observed which were not reflected by differences in other studied parameters.

Microbial Communities Associated with Biogenic Iron Oxide Mineralization in Circumneutral pH Environments

NASA Astrophysics Data System (ADS)

Chan, C. S.; Banfield, J. F.

2002-12-01

Lithotrophic growth on iron is a metabolism that has been found in a variety of neutral pH environments and is likely important in sustaining life in microaerophilic solutions, especially those low in organics. The composition of the microbial communities, especially the organisms that are responsible for iron oxidation, and carbon and nitrogen fixation, are not known, yet the ability to recognize these contributions is vital to our understanding of iron cycling in natural environments. Our approach has been to study the microbial community structure, mineralogy, and geochemistry of ~20 cm thick, 100's meters long, fluffy iron oxide-encrusted biological mats growing in the Piquette Mine tunnel, and to compare the results to those from geochemically similar environments. In situ measurements (Hydrolab) and geochemical characterization of bulk water samples and peepers (dialysis sampling vials) indicate that the environment is microaerobic, with micromolar levels of iron, high carbonate and sulfate, and typical groundwater nitrate and nitrite concentrations. 16S rDNA clone libraries show that the microbial mat and water contain communities with considerable diversity within the Bacterial domain, a large proportion of Nitrospira and Betaproteobacteria, and no Archaea. Because clone library data are not necessarily indicative of actual abundance, fluorescence in-situ hybridization (FISH) was performed on water, mat, and sediment samples from the Piquette mine and two circumneutral iron- and carbonate-rich springs in the Oregon Cascade Range. Domain- and phylum-level probes were chosen based on the clone library results (Nitrospira, Beta- and Gammaproteobacteria, Acidobacteria, Actinobacteria, Chloroflexi, and Planctomyces). FISH data reveal spatial associations between specific microbial groups and mineralized structures. The organisms responsible for making the mineralized sheaths that compose the bulk of the iron oxide mat are Betaproteobacteria (probably Leptothrix

Using the concentration-volume (C-V) fractal model in the delineation of gold mineralized zones within the Tepeoba porphyry Cu-Mo-Au, Balikesir, NW Turkey

NASA Astrophysics Data System (ADS)

Kumral, Mustafa; Abdelnasser, Amr; Karaman, Muhittin; Budakoglu, Murat

2016-04-01

The Tepeoba porphyry Cu-Mo-Au mineralization that located at the Biga peninsula (W Turkey) developed around the Eybek pluton concentrated at its southern contact. This mineralization that hosted in the hornfels rocks of Karakaya Complex is associated with three main alteration zones; potassic, phyllic and propylitic alterations along the fault controlled margins of the Eybek pluton and quartz stockwork veining as well as brecciation zones. As well as two mineralized zones were occurred in the mine area; hypogene and oxidation/supergene zone. The hypogene zone has differentiated alteration types; high potassic and low phyllic alteration, while the oxidation/supergene zone has high phyllic and propylitic alterations. This work deals with the delineation of gold mineralized zone within this porphyry deposit using the concentration-volume (C-V) fractal model. Five zones of gold were calculated using its power-law C-V relationship that revealed that the main phase of gold mineralization stated at 5.3083 ppm Au concentration. In addition, the C-V log-log plot shows that the highly and moderately Au mineralization zone developed in western part of deposit correlated with oxidation zone related to propylitic alteration. On the other hand, its weakly mineralization zone has a widespread in the hypogene zone related to potassic alteration. This refers to the enrichment of gold and depletion of copper at the oxidation/supergene zone is due to the oxidation/supergene alteration processes that enrich the deposits by the meteoric water. Keywords: Concentration-volume (C-V) fractal model; gold mineralized zone; Tepeoba porphyry Cu-Mo-Au; Balikesir; NW Turkey.

Magnetite-apatite mineralization in Khanlogh iron deposit, northwest of Neyshaboor, NE Iran

NASA Astrophysics Data System (ADS)

Najafzadeh Tehrani, Parvin; Asghar Calagari, Ali; Velasco Roldan, Francisco; Simmonds, Vartan; Siahcheshm, Kamal

2016-04-01

Khanlogh iron deposit lies on Sabzehvar-Ghoochan Cenozoic magmatic belt in northwest of Neyshaboor, NE Iran. The lithologic units in this area include a series of sub-volcanic intrusive rocks like diorite porphyry, quartz-diorite porphyry, and micro-granodiorite of Oligocene age. Mineralization in this area occurred as veins, dissemination, and open space filling in brecciated zones within the host sub-volcanic intrusive bodies. Three distinct types of mineral associations can be distinguished, (1) diopside-magnetite, (2) magnetite-apatite, and (3) apatite-calcite. Microscopic examinations along with SEM and EPMA studies demonstrated that magnetite is the most common ore mineral occurring as solitary crystals. The euhedral magnetite crystals are accompanied by lamellar destabilized ilmenite and granular fluorapatite in magnetite-apatite ores. The results of EPMA revealed that the lamellar ilmenite, relative to host magnetite crystal, is notably enriched in MgO and MnO (average of 3.3 and 2.6 wt%, respectively; n=5), whereas magnetite is slighter enriched in Ti (TiO2 around 1.8 wt%) being average of MgO, MnO and V2O3 of 0.6wt%, 0.2wt%, and 0.6 wt% (respectively; n=20). Minerals such as chlorapatite, calcite, and chalcedony are also present in the magnetite-apatite ores. The samples from apatite-calcite ores contain coarse crystals of apatite and rhomboedral calcite. The plot of the EPMA data of Khanlogh iron ore samples on diagram of TiO2-V2O5 (Hou et al, 2011) illustrated that the data points lies between the well-known Kiruna and El Laco (Chile) iron deposits. The magnetite crystals in the sub-volcanic host rocks were possibly formed by immiscible iron oxide fluids during magmatic stage. However, the magnetite and apatite existing in the veins and breccia zones may have developed by high temperature hydrothermal fluids. Studies done by Purtov and Kotelnikova (1993) proved that the proportion of Ti in magnetite is related to fluoride complex in the hydrothermal

Metabauxite horizons containing remobilized-origin gem diaspore and related mineralization, Milas-Muğla province, SW Turkey

NASA Astrophysics Data System (ADS)

Hatipoğlu, Murat; Türk, Necdet; Chamberlain, Steven C.; Murat Akgün, A.

2010-10-01

Remobilized-origin gem diaspore and related minerals occur as infill within structurally controlled voids that developed in the upper of two distinct karst unconformity-type metabauxite (diasporite) horizons in the İlbir Mountains area of the Milas-Muğla province, SW Turkey. Colour-change diaspore (trademarked as zultanite) and associated mineral specimens (greenish muscovite, chloritoid, donbassite, specular hematite, ilmenite, goethite, and younger calcite) occur in fracture zones (veins and open structures) that cross-cut the metabauxite horizons. The mineralized fracture zones do not extend into the enclosing marbles, probably because of the ductility contrast between the brittle bauxite and relatively plastic carbonate beds. Thick, white to light gray and dark gray limestone beds were deposited in the İlbir Mountains area during the Cretaceous (146-65 Ma), and contain two stratigraphically distinct karst-fill bauxite horizons. Al-, Fe-, Si- and Ti-rich solutions that infiltrated the karstified limestone probably originated from altered schist and gneiss that surround the basin. The limestone beds (>2000 m thick) were subjected to burial metamorphism, forming marble. Subsequently, the marble block was folded during nappe emplacement toward the SSW as part of late Alpine contractional deformation during the Paleogene (65-23.8 Ma). The upper bauxite horizons within the folded block were cross-cut by fracture zones because of their relatively brittle rheology. At this time, increased pressure and temperature in the bauxite horizons resulted in remobilization of the primary constituents of the bauxite within an aqueous complex, resulting in the crystallization of coarse-grained assemblages in the cross-cutting structures. Ultimately, erosion and mineral exploration revealed the steeply dipping bauxite outcrops and mine workings evident today. This paper focuses on the mine geology of surface outcrops of diasporic bauxite, the upper bauxite horizon within

Testing the Prediction of Iron Alteration Minerals on Low Albedo Asteroids

NASA Technical Reports Server (NTRS)

Jarvis, K. S.; Vilas, Faith; Howell, E.; Kelley, M.; Cochran, A.

1999-01-01

Absorption features centered near 0.60 - 0.65 and 0.80 - 0.90 micron were identified in the spectra of three low-albedo main-belt (165, 368, 877) and two low-albedo outer-belt (225, 334) asteroids (Vilas et al., Icarus, v. 109,274,1994). The absorption features were attributed to charge transfer transitions in iron alteration minerals such as goethite, hematite, and jarosite, all products of aqueous alteration. Concurrently, Jarvis et al. (LPSC XXIV, 715, 1993) presented additional spectra of low-albedo asteroids that had absorption features centered near 0.60 - 0.65 micron without the longer wavelength feature. Since these two features in iron oxides originate from the same ground state, and the longer wavelength feature requires less energy to exist, the single shorter wavelength feature cannot be caused by the iron alteration minerals. In addition, spectra of minerals such as hematite and goethite show a rapid increase in reflectance beginning near 0.5 micron absent in the low-albedo asteroid spectra. The absence of this rise has been attributed to its suppresion from opaques in the surface material. Spectra on more than one night were available for only one of these five asteroids, 225 Henrietta, and showed good repeatability of the 0.65-micron feature. We have acquired additional spectra of all five asteroids in order to test the repeatability of the 0.65-micron feature, and the presence and repeatability of the features centered near 0.8 - 0.9 micron. We specifically will test the possibility that longer wavelength features could be caused by incomplete removal of telluric water. Asteroid 877 Walkure is a member of the Nysa-Hertha family, and will be compared to spectra of other members of that family. Data were acquired in 1996 and 1999 on the 2.1-m telescope with a facility cassegrain spectrograph, McDonald Observatory, Univ. Of Texas, and the 1.5-m telescope with facility cassegrain spectrograph at CTIO. This research is supported by the NASA Planetary

Microbial Variants from Iron Ore Slimes: Mineral Specificity and pH Tolerance.

PubMed

Abhilash; Ghosh, A; Pandey, B D; Sarkar, S

2015-12-01

This paper describes the isolation of the native bacterial strains from the iron ore mines slime pond and its extremophilic characteristics. The two microbial isolates designated as CNIOS-1 and CNIOS-2 were grown in selective silicate broth at pH 7.0 and the organisms were tested for their selective adhesion on silicate and alumina minerals. The silicate bacteria with their exopolymers are very potent to grow over aluminosilicates. It was established that CNIOS-1 grew preferentially in the presence of silicate mineral compared to CNIOS-2 which grew in the presence of alumina. The organisms were tested for growth at various pH and trials were carried to define their efficacy for eventual applications to remove gangue minerals of silica and alumina from the raw material.

The chemical environment of iron in mineral fibres. A combined X-ray absorption and Mössbauer spectroscopic study.

PubMed

Pollastri, Simone; D'Acapito, Francesco; Trapananti, Angela; Colantoni, Ivan; Andreozzi, Giovanni B; Gualtieri, Alessandro F

2015-11-15

Although asbestos represents today one of the most harmful contaminant on Earth, in 72% of the countries worldwide only amphiboles are banned while controlled use of chrysotile is allowed. Uncertainty on the potential toxicity of chrysotile is due to the fact that the mechanisms by which mineral fibres induces cyto- and geno-toxic damage are still unclear. We have recently started a long term project aimed at the systematic investigation of the crystal-chemistry, bio-interaction and toxicity of the mineral fibres. This work presents a systematic structural investigation of iron in asbestos and erionite (considered the most relevant mineral fibres of social and/or economic-industrial importance) using synchrotron X-ray absorption and Mössbauer spectroscopy. In all investigated mineral fibres, iron in the bulk structure is found in octahedral sites and can be made available at the surface via fibre dissolution. We postulate that the amount of hydroxyl radicals released by the fibers depends, among other factors, upon their dissolution rate; in relation to this, a ranking of ability of asbestos fibres to generate hydroxyl radicals, resulting from available surface iron, is advanced: amosite > crocidolite ≈ chrysotile > anthophyllite > tremolite. Erionite, with a fairly high toxicity potential, contains only octahedrally coordinated Fe(3+). Although it needs further experimental evidence, such available surface iron may be present as oxide nanoparticles coating and can be a direct cause of generation of hydroxyl radicals when such coating dissolves. Copyright © 2015 Elsevier B.V. All rights reserved.

Causes of Different Vivid Colors in Chalcedonies: Kutahya-Turkey

NASA Astrophysics Data System (ADS)

Ozcan Kilic, Cumhur; Kagan Kadıoglu, Yusuf

2016-04-01

Chalcedony is a silicate mineral which is a mixture of fibrous quartz (trigonal) and granular moganite (monoclinic) minerals. They are both SiO2 in composition but differs in crystal system. Chalcedony is widely used as semi-precious gemstone in many countries. It has many different kinds due to their various colors and structures. The colour changes in mineral depends on different causes. Most important causes are transition metal impurities in minerals chemical composition and charge transfer between ions. Different chalcedony types have different colors due to their elemental composition. Chalcedony can be show almost every colour strating from white, black, gray, red, blue, green to brown or a combinations of more than one color in case of agates and jasper formations. Although they have same major oxide compositions,chrysopras (green chalcedony) have Ni which gives the green color and carnelian (orange chalcedony) have Fe+3 which gives the orange color. Kutahya, Eskisehir, Ankara, Manisa, Balıkesir, Canakkale and Yozgat represent the most cities which chalcedony can be mostly observed in Turkey. In Kutahya, chalcedony occurs in cavity or vein fillings in pyroclastic rocks such as tuff and formed by precipitation of silica bearing fluids in low temperatures. They can be also formed within the hydrothermal alteration zone of ultramafic rocks. Although chalcedonies in Kutahya form under almost same condition, they have various colors within the same unit. To specify the cause of the different colors, chemical analysis and Confocal Raman studies performed on Kutahya chalcedonies. Firstly, samples are crushed to 2 mm. size. After that, different colors of chalcedonies are separated by hand picking under binocular microscope and grouped into different color sets such as white, blue, dark yellow, light orange, dark orange and claret red. Each color set is measured by PED-XRF method to obtain chemical compositions. Also Raman studies performed to identify the effect

Iron Homeostasis and Nutritional Iron Deficiency123

PubMed Central

Theil, Elizabeth C.

2011-01-01

Nonheme food ferritin (FTN) iron minerals, nonheme iron complexes, and heme iron contribute to the balance between food iron absorption and body iron homeostasis. Iron absorption depends on membrane transporter proteins DMT1, PCP/HCP1, ferroportin (FPN), TRF2, and matriptase 2. Mutations in DMT1 and matriptase-2 cause iron deficiency; mutations in FPN, HFE, and TRF2 cause iron excess. Intracellular iron homeostasis depends on coordinated regulation of iron trafficking and storage proteins encoded in iron responsive element (IRE)-mRNA. The noncoding IRE-mRNA structures bind protein repressors, IRP1 or 2, during iron deficiency. Integration of the IRE-RNA in translation regulators (near the cap) or turnover elements (after the coding region) increases iron uptake (DMT1/TRF1) or decreases iron storage/efflux (FTN/FPN) when IRP binds. An antioxidant response element in FTN DNA binds Bach1, a heme-sensitive transcription factor that coordinates expression among antioxidant response proteins like FTN, thioredoxin reductase, and quinone reductase. FTN, an antioxidant because Fe2+ and O2 (reactive oxygen species generators) are consumed to make iron mineral, is also a nutritional iron concentrate that is an efficiently absorbed, nonheme source of iron from whole legumes. FTN protein cages contain thousands of mineralized iron atoms and enter cells by receptor-mediated endocytosis, an absorption mechanism distinct from transport of nonheme iron salts (ferrous sulfate), iron chelators (ferric-EDTA), or heme. Recognition of 2 nutritional nonheme iron sources, small and large (FTN), will aid the solution of iron deficiency, a major public health problem, and the development of new policies on iron nutrition. PMID:21346101

Relative contribution of iron reduction to sediments organic matter mineralization in contrasting habitats of a shallow eutrophic freshwater lake.

PubMed

Chen, Mo; Jiang, He-Long

2016-06-01

Iron reduction is one of the important organic matter (OM) mineralization pathway in sediments. Here we investigated the rates and the relative contribution of iron reduction to OM mineralization in Zhushan bay (ZSB, cyanobacterial bloom biomass (CBB)-dominated habitats) and East Taihu Lake (ETL, submerged macrophypes (SM)-dominated habitats) of Lake Taihu, China. Anaerobic microcosm incubation revealed that the rate of iron reduction at ZSB (4.42 μmol cm(-3) d(-1)) in summer was almost 1.5 times higher than at ETL (3.13 μmol cm(-3) d(-1)). Iron reduction accounted for 66.5% (ZSB) and 31.8% (ETL) of total anaerobic carbon mineralization, respectively. No detectable methanogenesis was found at ZSB, while methanogenesis was responsible for 16.7% of total anaerobic respiration in sediments of ETL. Geochemical analysis of solid phase constituents indicated that ZSB surface sediments experienced highly oxidizing conditions with much higher amorphous Fe(III) (71 mmol m(-2)) than ETL (11 mmol m(-2)). Conversely, AVS inventories at ETL (38 mmol m(-2)) were up to 30 times higher than at ZSB (1.27 mmol m(-2)), indicating significant sulfate reduction in sediments of ETL. Overall results suggested that varying carbon sources and distinct geochemical characterizations of the sediments in contrasting habitats significantly influenced the rate of iron reduction and the pathway of C mineralization in a large freshwater lake. Copyright © 2016 Elsevier Ltd. All rights reserved.

Women with Fibromyalgia Have Lower Levels of Calcium, Magnesium, Iron and Manganese in Hair Mineral Analysis

PubMed Central

Kim, Young-Sang; Kim, Kwang-Min; Lee, Duck-Joo; Kim, Bom-Taeck; Park, Sat-Byul; Cho, Doo-Yeoun; Suh, Chang-Hee; Kim, Hyoun-Ah; Park, Rae-Woong

2011-01-01

Little is known about hair mineral status in fibromyalgia patients. This study evaluated the characteristics of hair minerals in female patients with fibromyalgia compared with a healthy reference group. Forty-four female patients diagnosed with fibromyalgia according to the American College of Rheumatology criteria were enrolled as the case group. Ageand body mass index-matched data were obtained from 122 control subjects enrolled during visit for a regular health check-up. Hair minerals were analyzed and compared between the two groups. The mean age was 43.7 yr. General characteristics were not different between the two groups. Fibromyalgia patients showed a significantly lower level of calcium (775 µg/g vs 1,093 µg/g), magnesium (52 µg/g vs 72 µg/g), iron (5.9 µg/g vs 7.1 µg/g), copper (28.3 µg/g vs 40.2 µg/g) and manganese (140 ng/g vs 190 ng/g). Calcium, magnesium, iron, and manganese were loaded in the same factor using factor analysis; the mean of this factor was significantly lower in fibromyalgia group in multivariate analysis with adjustment for potential confounders. In conclusion, the concentrations of calcium, magnesium, iron, and manganese in the hair of female patients with fibromyalgia are lower than of controls, even after adjustment of potential confounders. PMID:22022174

A study of iron mineral transformation to reduce red mud tailings.

PubMed

Li, L Y

2001-01-01

This study examines the effects of iron mineral transformation in an aluminum extraction process on the settling behavior, and the physical and chemical properties of the resulting red mud slurry that must be disposed of. By producing a red mud with a higher solid content, the total volume of mud slurry will also be reduced for a given alumina production rate and more caustic soda will be recovered. The settling behavior and the mineralogical, physical, and physico-chemical properties of one bauxite and three red muds processed under varying conditions were analyzed based on examination of the iron mineral transformations. The properties of red muds derived from the same bauxite can differ markedly due to variations in operating conditions of the Bayer process, such as temperature and the addition of a reducing agent. The settling of red mud can be improved by converting goethite into hematite and/or magnetite to produce a mud of larger particle size, smaller specific surface area, and larger specific gravity, characteristics which reduce the total volume of mud slurry to be disposed of and which allow for less potential contamination from caustic soda. This study also found that the by-product--Bayer sodalite--has the high exchange capacity for Na+ that might contribute to the long-term environmental problems.

Iron mineralization and associated skarn development around southern contact of the Eğrigöz pluton (northern Menderes Massif-Turkey)

NASA Astrophysics Data System (ADS)

Uǧurcan, Okşan Gökçen; Oyman, Tolga

2016-11-01

reflects host rock composition. The Katrandağ area differs from Kalkan and Karaağıl deposits in terms of initial metal content and gossan alteration due to the supergene alteration of galena dominated mineralization. In the Katrandağ, skarn that associated with iron and lead mineralization, both contain clinopyroxene and garnet. In the Kalkan skarn, fluid inclusion assemblages of prograde skarn association yield homogenization temperatures from 379 °C to over 600 °C, whereas those of retrograde minerals vary between 235 °C and 412 °C. Salinity values of the inclusions which obtained from prograde and retrograde assemblages are 9.2-22.4 and 6.4-20.1 wt%NaCl eq., respectively. Homogenization temperatures and salinity values of inclusions in clinopyroxene of Karaağıl calcic skarn are 420 to over 600 °C and 21-30 wt%NaCl eq., respectively.

Marine sulfate-reducing bacteria cause serious corrosion of iron under electroconductive biogenic mineral crust

PubMed Central

Enning, Dennis; Venzlaff, Hendrik; Garrelfs, Julia; Dinh, Hang T; Meyer, Volker; Mayrhofer, Karl; Hassel, Achim W; Stratmann, Martin; Widdel, Friedrich

2012-01-01

Iron (Fe0) corrosion in anoxic environments (e.g. inside pipelines), a process entailing considerable economic costs, is largely influenced by microorganisms, in particular sulfate-reducing bacteria (SRB). The process is characterized by formation of black crusts and metal pitting. The mechanism is usually explained by the corrosiveness of formed H2S, and scavenge of ‘cathodic’ H2 from chemical reaction of Fe0 with H2O. Here we studied peculiar marine SRB that grew lithotrophically with metallic iron as the only electron donor. They degraded up to 72% of iron coupons (10 mm × 10 mm × 1 mm) within five months, which is a technologically highly relevant corrosion rate (0.7 mm Fe0 year−1), while conventional H2-scavenging control strains were not corrosive. The black, hard mineral crust (FeS, FeCO3, Mg/CaCO3) deposited on the corroding metal exhibited electrical conductivity (50 S m−1). This was sufficient to explain the corrosion rate by electron flow from the metal (4Fe0 → 4Fe2+ + 8e−) through semiconductive sulfides to the crust-colonizing cells reducing sulfate (8e− + SO42− + 9H+ → HS− + 4H2O). Hence, anaerobic microbial iron corrosion obviously bypasses H2 rather than depends on it. SRB with such corrosive potential were revealed at naturally high numbers at a coastal marine sediment site. Iron coupons buried there were corroded and covered by the characteristic mineral crust. It is speculated that anaerobic biocorrosion is due to the promiscuous use of an ecophysiologically relevant catabolic trait for uptake of external electrons from abiotic or biotic sources in sediments. PMID:22616633

Emission inventory of primary air pollutants in 2010 from industrial processes in Turkey.

PubMed

Alyuz, Ummugulsum; Alp, Kadir

2014-08-01

The broad objective of this study was to develop CO2, PM, SOx, CO, NOx, VOC, NH3 and N2O emission inventory of organic and inorganic chemicals, mineral products, metallurgical, petroleum refining, wood products, food industries of Turkey for 2010 for both co]ntrolled and uncontrolled conditions. In this study, industries were investigated in 7 main categories and 53 sub-sectors and a representative number of pollutants per sub-sector were considered. Each industry was evaluated in terms of emitted emissions only from industrial processes, and fuel combustion activities were excluded (except cement industry). The study employed an approach designed in four stages; identification of key categories; activity data & emission factor search; emission factor analyzing; calculation of emissions. Emission factor analyzing required aggregate and firm analysis of sectors and sub-sectors and deeper insights into underlying specific production methods used in the industry to decide on the most representative emission factor. Industry specific abatement technologies were considered by using open-source documents and industry specific reports. Regarding results of this study, mineral industry and iron & steel industry were determined as important contributors of industrial emissions in Turkey in 2010. Respectively, organic chemicals, petroleum refining, and pulp & paper industries had serious contributions to Turkey's air pollutant emission inventory from industrial processes. The results showed that calculated CO2 emissions for year 2010 was 55,124,263 t, also other emissions were 48,853 t PM, 24,533 t SOx, 79,943 t NOx, 31,908 t VOC, 454 t NH3 and 2264 t N2O under controlled conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Pleural abnormalities and exposure to elongate mineral particles in Minnesota iron ore (taconite) workers.

PubMed

Perlman, David; Mandel, Jeffrey H; Odo, Nnaemeka; Ryan, Andy; Lambert, Christine; MacLehose, Richard F; Ramachandran, Gurumurthy; Alexander, Bruce H

2018-05-01

Iron ore (taconite) mining and processing are an important industry in northern Minnesota and western Michigan. Concerns around exposures have centered largely on exposure to non-asbestiform amphibole elongate mineral particles (EMPs) found in the eastern portion of the Minnesota iron range. A cross sectional survey was undertaken of current and former taconite workers and spouses along with a detailed exposure assessment. Participants provided an occupational history and had a chest radiograph performed. A total of 1188 workers participated. Potential exposures to non-amphibole EMPs were evident across multiple jobs in all active mines. Pleural abnormalities were found in 16.8% of workers. There was an association of pleural abnormalities with cumulative EMP exposure that was not specific to the eastern portion of the range. There was evidence of a mild to moderate increase in pleural abnormalities in this population of miners, associated with geographically non-specific cumulative EMP exposure. © 2018 Wiley Periodicals, Inc.

The Effect Of Local Coal And Smelting Sponge Iron On Iron Content Of Pig Iron

NASA Astrophysics Data System (ADS)

Oediyani, Soesaptri; Juwita Sari, Pramita; Hadi P, Djoko

2018-03-01

The new regulation on mineral resources was announced by Ministry of Energy and Mineral resources (ESDM) of Indonesia at 2014 which it called Permen ESDM No 1/2014. Therefore, this research was conducted to add the value of local iron ores by using smelting technology. The objective of the research is to produce pig iron that meet the requirement of the new regulation of mineral resources such as 90% Fe. First, iron ores and coal mixed together with lime as a flux, then smelted in a Electric Arc Furnace at 1800°C. The process variables are (1; 1.25; 1.5; 1.75; 2.0) and the composition of coal (0.8%, 1.6%, 3.0%). The type of coal that used in this research was bituminous coal from Kalimantan and also the iron ores from Kalimantan. The products of the smelting technology are Pig iron and slag. Both pig iron and slag then analyzed by SEM-EDS to measure the iron content. The result shows that the maximum iron content on pig iron is about 95.04% meanwhile the minimum iron content on slag is about 3.66%. This result achieved at 1.6% coal and 2.0.

Ferric iron-bearing sediments as a mineral trap for CO2 sequestration: Iron reduction using sulfur-bearing waste gas

USGS Publications Warehouse

Palandri, J.L.; Kharaka, Y.K.

2005-01-01

We present a novel method for geologic sequestration of anthropogenic CO2 in ferrous carbonate, using ferric iron present in widespread redbeds and other sediments. Iron can be reduced by SO2 that is commonly a component of flue gas produced by combustion of fossil fuel, or by adding SO2 or H2S derived from other industrial processes to the injected waste gas stream. Equilibrium and kinetically controlled geochemical simulations at 120 bar and 50 and 100 ??C with SO2 or H2S show that iron can be transformed almost entirely to siderite thereby trapping CO2, and simultaneously, that sulfur can be converted predominantly to dissolved sulfate. If there is an insufficient amount of sulfur-bearing gas relative to CO2 as for typical flue gas, then some of the iron is not reduced, and some of the CO2 is not sequestered. If there is an excess of sulfur-bearing gas, then complete iron reduction is ensured, and some of the iron precipitates as pyrite or other solid iron sulfide, depending on their relative precipitation kinetics. Gas mixtures with insufficient sulfur relative to CO2 can be used in sediments containing Ca, Mg, or other divalent metals capable of precipitating carbonate minerals. For quartz arenite with an initial porosity of 21% and containing 0.25 wt.% Fe2O3, approximately 0.7 g of CO2 is sequestered per kg of rock, and the porosity decrease is less than 0.03%. Sequestration of CO2 using ferric iron has the advantage of disposing of SO2 that may already be present in the combustion gas. ?? 2005 Published by Elsevier B.V.

Mineral ecophysiological evidence for microbial activity in banded iron formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Dr. Yi-Liang; Konhauser, Dr, Kurt; Cole, David R

2011-01-01

The phosphorus composition of banded-iron formations (BIFs) has been used as a proxy for Precambrian seawater composition and the paleoeredox state of Earth's surface environment. However, it is unclear whether the phosphorus in BIFs originally entered the sediment as a sorbed component of the iron oxyhydroxide particles, or whether it was incorporated into the biomass of marine phytoplankton. We conducted high-resolution mineral analyses and report here the first detection of an Fe(III) acetate salt, as well as nanocrystals of apatite in association with magnetite, in the 2.48 Ga Dales Gorge Member of the Brockman Iron Formation (a BIF), Hamersley, Westernmore » Australia. The clusters of apatite are similar in size and morphology to biogenic apatite crystals resulting from biomass decay in Phanerozoic marine sediments, while the formation of an Fe(III) acetate salt and magnetite not only implies the original presence of biomass in the BIF sediments, but also that organic carbon likely served as an electron donor during bacterial Fe(III) reduction. This study is important because it suggests that phytoplankton may have played a key role in the transfer of phosphorus (and other trace elements) from the photic zone to the seafloor.« less

Synthesis and Characterization of Chukanovite, Fe2CO3(OH)2(s): An Elusive Ferrous Iron Carbonate Hydroxide Mineral

NASA Astrophysics Data System (ADS)

Jang, J. J. H.; Kim, S.; Burton, H.; Knox, J.; Marrs, C.; Sisk-Scott, C.

2017-12-01

The long-term effectiveness of an underground waste repository relies on understanding the chemical reaction products between intrusive brine and the reactive media in the repository. One such component of the stored media, iron, forms mineral precipitates in brine through anoxic corrosion. Chukanovite, Fe2CO3(OH)2(s), could be one of the precipitates and not much is known regarding its formation and thermodynamic stability. Thus, we have investigated eight mixtures of FeCl2 and NaHCO3 with NaOH for the synthesis of chukanovite in an anoxic glovebox. X-ray diffraction (XRD) scans of ten-month aged samples showed the paragenesis of three ferrous iron minerals in all tested conditions; siderite (FeCO3(s)), ferrous iron hydroxide (Fe(OH)2(s)), and chukanovite. Chukanovite was present alongside the two other minerals in between the pH values of 6 and 11. Comparison of relative intensities of major XRD peak heights of three minerals illustrated that the highest phase purity of chukanovite was achieved when the solution pH was approximately 9. XRD and solubility analysis will be performed periodically to determine when the experiments in the eight conditions reach steady state. Solid samples will be further characterized using Mossbauer and Raman spectroscopy.

Preservation of protein globules and peptidoglycan in the mineralized cell wall of nitrate-reducing, iron(II)-oxidizing bacteria: a cryo-electron microscopy study.

PubMed

Miot, J; Maclellan, K; Benzerara, K; Boisset, N

2011-11-01

Iron-oxidizing bacteria are important actors of the geochemical cycle of iron in modern environments and may have played a key role all over Earth's history. However, in order to better assess that role on the modern and the past Earth, there is a need for better understanding the mechanisms of bacterial iron oxidation and for defining potential biosignatures to be looked for in the geologic record. In this study, we investigated experimentally and at the nanometre scale the mineralization of iron-oxidizing bacteria with a combination of synchrotron-based scanning transmission X-ray microscopy (STXM), scanning transmission electron microscopy (STEM) and cryo-transmission electron microscopy (cryo-TEM). We show that the use of cryo-TEM instead of conventional microscopy provides detailed information of the successive iron biomineralization stages in anaerobic nitrate-reducing iron-oxidizing bacteria. These results suggest the existence of preferential Fe-binding and Fe-oxidizing sites on the outer face of the plasma membrane leading to the nucleation and growth of Fe minerals within the periplasm of these cells that eventually become completely encrusted. In contrast, the septa of dividing cells remain nonmineralized. In addition, the use of cryo-TEM offers a detailed view of the exceptional preservation of protein globules and the peptidoglycan within the Fe-mineralized cell walls of these bacteria. These organic molecules and ultrastructural details might be protected from further degradation by entrapment in the mineral matrix down to the nanometre scale. This is discussed in the light of previous studies on the properties of Fe-organic interactions and more generally on the fossilization of mineral-organic assemblies. © 2011 Blackwell Publishing Ltd.

Magnetism, iron minerals, and life on Mars.

PubMed

Rochette, P; Gattacceca, J; Chevrier, V; Mathé, P E; Menvielle, M

2006-06-01

A short critical review is provided on two questions linking magnetism and possible early life on Mars: (1) Did Mars have an Earth-like internal magnetic field, and, if so, during which period and was it a requisite for life? (2) Is there a connection between iron minerals in the martian regolith and life? We also discuss the possible astrobiological implications of magnetic measurements at the surface of Mars using two proposed instruments. A magnetic remanence device based on magnetic field measurements can be used to identify Noachian age rocks and lightning impacts. A contact magnetic susceptibility probe can be used to investigate weathering rinds on martian rocks and identify meteorites among the small regolith rocks. Both materials are considered possible specific niches for microorganisms and, thus, potential astrobiological targets. Experimental results on analogues are presented to support the suitability of such in situ measurements.

Impact of Bioreduction on Remobilization of Adsorbed Cadmium on Iron Minerals in Anoxic Condition.

PubMed

Ghorbanzadeh, Nasrin; Lakzian, Amir; Halajnia, Akram; Choi, Ui-Kyu; Kim, Ki-Hyun; Kim, Jong-Oh; Kurade, Mayur; Jeon, Byong-Hun

2017-06-01

  The impact of bioreduction on the remobilization of adsorbed cadmium Cd(II) on minerals, including hematite, goethite, and two iron(III)-rich clay minerals nontronites (NAU-1 and NAU-2) under anoxic conditions was investigated. Langmuir isotherm equation better described the sorption of Cd(II) onto the all minerals. The maximum adsorption capacity was 6.2, 18.1, 3.6, and 4 mg g-1 for hematite, goethite, NAU-1 and NAU-2, respectively. The desorption of Cd(II) was due to the production of Fe(II) as a result of bioreduction of structural Fe(III) in the minerals by Shewanella putrefaciens. The bioreduction of Cd(II)-loaded Fe(III) minerals was negligible during the initial 5 days followed by a rapid increase up to 20 days. The amount of Cd(II) in solution phase at the end of 30 days increased up to 0.07 mmol L-1 for hematite, NAU-1, and NAU-2 and 0.02 mmol L-1 for goethite. The X-ray diffraction study showed negligible changes in bioreduced minerals phases.

Fat content, fatty acid pattern and iron content in livers of turkeys with hepatic lipidosis.

PubMed

Visscher, Christian; Middendorf, Lea; Günther, Ronald; Engels, Alexandra; Leibfacher, Christof; Möhle, Henrik; Düngelhoef, Kristian; Weier, Stefan; Haider, Wolfram; Radko, Dimitri

2017-05-30

The so-called "hepatic lipidosis" in turkeys is an acute progressive disease associated with a high mortality rate in a very short time. Dead animals show a massive fatty degeneration of the liver. The cause is still unclear. Previous findings suggest that there may be parallels to human non-alcoholic fatty liver disease. The object of the study was to examine the changes in the fat contents, the fatty acid composition and the iron content in livers of animals, which have died from hepatic lipidosis. The conspicuous livers (n = 85) were collected from 20 flocks where the phenomenon of massive increased animal losses accompanied by marked macroscopically visible pathological liver steatosis suddenly occurred. For comparison and as a reference, livers (n = 16) of two healthy flocks were taken. Healthy and diseased flocks were fed identical diets concerning official nutrient recommendations and were operating under standardized, comparable conventional conditions. Compared to livers of healthy animals, in the livers of turkeys died from hepatic lipidosis there were found massively increased fat levels (130 ± 33.2 vs. 324 ± 101 g/kg dry matter-DM). In all fatty livers, different fatty acids concentrations were present in significantly increased concentrations compared to controls (palmitic acid: 104 g/kg DM, +345%; palmitoleic acid: 18.0 g/kg DM, + 570%; oleic acid: 115 g/kg DM, +437%). Fatty acids concentrations relevant for liver metabolism and inflammation were significantly reduced (arachidonic acid: 2.92 g/kg DM, -66.6%; eicosapentaenoic acid: 0.141 g/kg DM, -78.3%; docosahexaenoic acid: 0.227 g/kg DM, -90.4%). The ratio of certain fatty acids to one another between control and case livers changed analogously to liver diseases in humans (e.g.: C18:0/C16:0 - 0.913 against 0.311; C16:1n7/C16:0 - 0.090 against 0.165; C18:1/C18:0 - 0.938 against 4.03). The iron content in the liver tissue also increased massively (271 ± 51.5 vs 712 ± 214 mg/kg DM). The hepatic

Effect of β-hydroxy-β-methylbutyrate (HMB) administration on volumetric bone mineral density, and morphometric and mechanical properties of tibia in male turkeys.

PubMed

Tatara, M R

2009-12-01

This study was performed to investigate the effects of β-hydroxy-β-methylbutyrate (HMB) administration on skeletal system properties in turkeys. Thirty-two males were randomly divided into two groups at the age of 35 days of life. The first group included control turkeys (n = 16) treated with placebo, while the second group of birds (HMB group; n = 16) was administered orally with calcium salt of HMB during the last 15 weeks of life. The turkeys were sacrificed at the age of 20 weeks and tibia was isolated for analysis of bone geometrical parameters, volumetric bone mineral density (vBMD) and mechanical properties. Furthermore, assessment of free amino acid concentrations in plasma was performed. The results showed a 6.3% increase of vBMD of tibia in response to HMB treatment (p < 0.01). Cross-sectional area, second moment of inertia, maximum elastic strength and ultimate strength of tibia were significantly increased in HMB-treated turkeys by 21.3%, 49.0%, 27.2% and 28.3%, respectively (p ≤ 0.01). β-hydroxy-β-methylbutyrate administration increased plasma concentrations of proline,glutamate, leucine, isoleucine, valine, alanine, aspartate, phenylalanine and cysteic acid (p < 0.05). These results indicate that long-term administration of HMB improves vBMD, and geometrical and mechanical properties of skeletal system in turkeys, and that these effects are associated with improved plasma amino acid concentrations.

Levels of selected minerals, nitric oxide, and vitamins in aborted Sakis sheep raised under semitropical conditions

PubMed Central

Aypak, Serap Unubol

2010-01-01

The serum levels of calcium, phosphorus, magnesium, copper, zinc and iron and of nitric oxide, retinol, and β-carotene were determined in Sakiz ewes that had experienced an abortion and in healthy controls. Ten healthy and 25 aborted Sakiz sheep were selected from Afyon zone in western Turkey. Their ages ranged between 2 and 4 years weighing between 40 and 60 kg at the time of experiment. All of the abortions occurred in October. The concentrations of retinol, β-carotene, phosphorus, and zinc were significantly lower and those of calcium and nitric oxide were increased in aborted ewes relative to healthy controls. The serum levels of iron, copper, and magnesium were not significantly different among the two groups. In conclusion, abortion is an important problem in commercially important species of ruminants in many regions in the tropics including of western Turkey. Deficiencies of retinol, β-carotene, phosphorus and zinc, and the increase of calcium and nitric oxide concentration may play an important role in the etiology of abortion in ewes. Prophylactic measures such as vitamin and mineral supplementation may be of help to prevent or reduce the incidence of abortion in sheep. PMID:21076941

Iron-Coupled Anaerobic Oxidation of Methane Performed by a Mixed Bacterial-Archaeal Community Based on Poorly Reactive Minerals.

PubMed

Bar-Or, Itay; Elvert, Marcus; Eckert, Werner; Kushmaro, Ariel; Vigderovich, Hanni; Zhu, Qingzeng; Ben-Dov, Eitan; Sivan, Orit

2017-11-07

Anaerobic oxidation of methane (AOM) was shown to reduce methane emissions by over 50% in freshwater systems, its main natural contributor to the atmosphere. In these environments iron oxides can become main agents for AOM, but the underlying mechanism for this process has remained enigmatic. By conducting anoxic slurry incubations with lake sediments amended with 13 C-labeled methane and naturally abundant iron oxides the process was evidenced by significant 13 C-enrichment of the dissolved inorganic carbon pool and most pronounced when poorly reactive iron minerals such as magnetite and hematite were applied. Methane incorporation into biomass was apparent by strong uptake of 13 C into fatty acids indicative of methanotrophic bacteria, associated with increasing copy numbers of the functional methane monooxygenase pmoA gene. Archaea were not directly involved in full methane oxidation, but their crucial participation, likely being mediators in electron transfer, was indicated by specific inhibition of their activity that fully stopped iron-coupled AOM. By contrast, inhibition of sulfur cycling increased 13 C-methane turnover, pointing to sulfur species involvement in a competing process. Our findings suggest that the mechanism of iron-coupled AOM is accomplished by a complex microbe-mineral reaction network, being likely representative of many similar but hidden interactions sustaining life under highly reducing low energy conditions.

Influence of a soil enzyme on iron-cyanide complex speciation and mineral adsorption.

PubMed

Zimmerman, Andrew R; Kang, Dong-Hee; Ahn, Mi-Youn; Hyun, Seunghun; Banks, M Katherine

2008-01-01

Cyanide is commonly found as ferrocyanide [Fe(II)(CN)(6)](-4) and in the more mobile form, ferricyanide [Fe(III)(CN)(6)](-3) in contaminated soils and sediments. Although soil minerals may influence ferrocyanide speciation, and thus mobility, the possible influence of soil enzymes has not been examined. In a series of experiments conducted under a range of soil-like conditions, laccase, a phenoloxidase enzyme derived from the fungi Trametes versicolor, was found to exert a large influence on iron-cyanide speciation and mobility. In the presence of laccase, up to 93% of ferrocyanide (36-362ppm) was oxidized to ferricyanide within 4h. No significant effect of pH (3.6 and 6.2) or initial ferrocyanide concentration on the extent or rate of oxidation was found and ferrocyanide oxidation did not occur in the absence of laccase. Relative to iron-cyanide-mineral systems without laccase, ferrocyanide adsorption to aluminum hydroxide and montmorillonite decreased in the presence of laccase and was similar to or somewhat greater than that of ferricyanide without laccase. Laccase-catalyzed conversion of ferrocyanide to ferricyanide was extensive though up to 33% of the enzyme was mineral-bound. These results demonstrate that soil enzymes can play a major role in ferrocyanide speciation and mobility. Biotic soil components must be considered as highly effective oxidation catalysts that may alter the mobility of metals and metal complexes in soil. Immobilized enzymes should also be considered for use in soil metal remediation efforts.

[Mineral migration from stainless steel, cast iron and soapstone (steatite) Brazilian pans to food preparations].

PubMed

Quintaes, Késia Diego; Farfan, Jaime Amaya; Tomazini, Fernanda Mariana; Morgano, Marcelo Antônio

2006-09-01

Culinary utensils may release some inorganic elements during food preparation. Mineral migration can be beneficial for as long as it occurs in amounts adequate to the needs of the consumer or no toxicological implications are involved. In this study, the migrations of Fe, Mg, Mn, Cr, Ni and Ca, along seven cooking cycles were evaluated for two food preparations (polished rice and commercial tomato sauce, the latter as an acid food), performed in unused stainless steel, cast iron and soapstone pans, taking refractory glass as a blank. Minerals were determined by inductively coupled plasma optical emission spectrometry (ICP OES). The utensils studied exhibited different rates, patterns and variability of migration depending on the type of food. Regression analysis of the data revealed that, as a function of the number of cycles, the iron pans released increasing amounts of iron when tomato sauce was cooked (y = 70.76x + 276.75; R2 = 0.77). The soapstone pans released calcium (35 and 26 mg/kg), magnesium (25 and 15 mg/kg) into the tomato sauce and rice preparations, respectively. Additionally, the commercial tomato sauce drew manganese (3.9 and 0.6 mg/kg) and some undesirable nickel (1.0 mg/kg) from the soapstone material, whereas the stainless steel pans released nickel at a lower rate than steatite and in a diminishing fashion with the number o cooking cycles, while still transferring some iron and chromium to the food. We conclude that while cast iron and glass could be best for the consumer's nutritional health, stainless steel and steatite can be used with relatively low risk, provided acid foods are not routinely prepared in those materials.

Iron Redox Cycling Drives Decomposition of Mineral-Associated C in Humid Tropical Forest Soils

NASA Astrophysics Data System (ADS)

Hall, S. J.; Mcnicol, G.; Silver, W. L.

2013-12-01

The stabilization of soil carbon (C) by reactive minerals and an inhibition of decomposition due to oxygen (O2) limitation (reducing conditions) have been proposed as drivers of the high soil C concentrations characteristic of humid tropical forests, which constitute a major terrestrial C reservoir. Here, we examined relationships between these factors and spatial patterns of C concentrations and C turnover (using radiocarbon modeling) in surface soils of the Luquillo Experimental Forest, Puerto Rico. We used concentrations of reduced iron (Fe(II)) as an index of reducing conditions given the importance of Fe reduction to anaerobic metabolism in these soils. Concentrations of Fe(II), reactive iron and aluminum (Al) minerals, interactions between Fe(II) and Al, and live fine root biomass explained most variation in C concentrations across the landscape (pseudo R2 = 0.84). Carbon increased with chelatable "poorly crystalline" Fe, in agreement with previous research, but C decreased with citrate/ascorbate extractable Fe, an index of Fe oxides susceptible to microbial reduction. We suggest that availability of Fe oxides to sustain anaerobic respiration partially offsets soil C accumulation in these ecosystems, despite the role of a subset of reactive Fe in promoting C stabilization. We estimated decomposition rates of mineral-associated C using 14C content of the heavy soil density fraction from a subset of samples. Turnover times averaged 108 years but decreased with Fe(II) concentrations. Thus, our data suggest that Fe redox cycling in soil microsites is associated with increased turnover of mineral-associated C in this fluctuating-oxygen environment, implying that the capacity of reactive metals to stabilize C may be partially contingent on O2 dynamics. Our results suggest a multifaceted role for reactive minerals in soil C cycling, emphasizing the importance of ecosystem-scale interactions among geochemical, physical, and biological factors.

ARSENIC LEACHING FROM IRON RICH MINERAL PROCESSING WASTE: INFLUENCE OF PH AND REDOX POTENTIAL

EPA Science Inventory

This paper presents the effect of pH and redox potential on the potential mobility of arsenic (As) from a contaminated mineral processing waste. The selected waste contained about 0.47 g kg^-1 of As and 66.2 g kg^-1 of iron (Fe). The characteristic of the wast...

Iron overdose

MedlinePlus

... 1222) from anywhere in the United States. Poisonous Ingredient Iron can be harmful in large amounts. Where Found Iron is an ingredient in many mineral and vitamin supplements. Iron supplements ...

Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria

PubMed Central

2018-01-01

A sandstone outcrop exposed to freshwater seepage supports a diverse assemblage of photosynthetic microbes. Dominant taxa are two cyanophytes (Oscillatoria sp., Rivularia sp.) and a unicellular green alga (Palmellococcus sp.). Less abundant taxa include a filamentous green alga, Microspora, and the desmid Cosmarium. Biologic activity is evidenced by measured levels of chlorophyll and lipids. Bioassay methods confirm the ability of these microbes to dissolve and metabolize Fe from ferruginous minerals. Chromatographic analysis reveals citric acid as the likely chelating agent; this low molecular weight organic acid is detectable in interstitial fluid in the sandstone, measured as 0.0756 mg/mL. Bioassays using a model organism, Synechoccus elongates strain UTEX 650, show that Fe availability varies among different ferruginous minerals. In decreasing order of Fe availability: magnetite > limonite > biotite > siderite > hematite. Biotite was selected for detailed study because it is the most abundant iron-bearing mineral in the sandstone. SEM images support the microbiologic evidence, showing weathering of biotite compared to relatively undamaged grains of other silicate minerals. PMID:29342973

Mineral resource potential map of the Bell Mountain Wilderness Study Area, Iron County, Missouri

USGS Publications Warehouse

Pratt, Walden P.; Erickson, Ralph L.; Ellis, Clarence E.

1982-01-01

Under the provisions of the Wilderness Act (Public Law 88-577, September 3, 1964) and the Joint Conference Report on Senate Bill 4, 88th Congress, the U.S. Geological Survey and U.S. Bureau of Mines have been conducting mineral surveys of wilderness and primitive areas. Areas officially designated as "wilderness," "wild," or "canoe" when the Act was passed were incorporated into the National Wilderness Preservation System, and some of them are presently being studied. The Act provided that areas under consideration for wilderness designation should be studied for suitability for incorporation into the Wilderness System. The mineral surveys constitute one aspect of the suitability studies. This report discusses the results of a mineral survey of some national forest lands in the Bell Mountain Wilderness Study Area, Iron County, Missouri.

Green Clay Minerals

NASA Astrophysics Data System (ADS)

Velde, B.

2003-12-01

Color is a problem for scientific study. One aspect is the vocabulary one used to describe color. Mint green, bottle green, and Kelly green are nice names but not of great utility in that people's physical perception of color is not always the same. In some industries, such as colored fabric manufacture, current use is to send a set of standard colors which are matched by the producer. This is similar to the use of the Munsell color charts in geology. None of these processes makes use of physical optical spectral studies. The reason is that they are difficult to obtain and interpret. For a geologist, color is very important but we rarely have the possibility to standardize the method of our color perception. One reason is that color is both a reflective and transmission phenomenon. The thickness of the sample is critical to any transmission characteristics. Hence, a field color determination is different from one made by using a petrographic microscope. Green glauconite in a hand specimen is not the same color in 30 μm thick thin section seen with a microscope using transmitted light.A second problem is that color in a spectral identification is the result of several absorption emissions,with overlapping signal, forming a complicated spectrum. Interpretation depends very greatly on the spectrum of the light source and the conditions of transmission-reflection of the sample. As a result, for this text, we will not attempt to analyze the physical aspect of green in green clays. In the discussion which follows, reference is made concerning color, to thin section microscopic perception.Very briefly, green clay minerals are green, because they contain iron. This is perhaps not a great revelation to mineralogists, but it is the key to understanding the origin and stability of green clay minerals. In fact, iron can color minerals either red or green or in various shades of orange and brown. The color most likely depends upon the relative abundance of the iron ion valence

Iron speciation in peats: Chemical and spectroscopic evidence for the co-occurrence of ferric and ferrous iron in organic complexes and mineral precipitates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattacharyya, Amrita; Schmidt, Michael P.; Stavitski, Eli

The speciation of iron (Fe) in organic matter (OM)-rich environments under in situ variable redox conditions is largely unresolved. Peatlands provide a natural setting to study Fe–OM interactions. Utilizing chemical, spectroscopic and theoretical modeling approaches, we report the chemical forms, oxidation states and local coordination environment of naturally occurring Fe in the vertically redox-stratified Manning peatlands of western New York. In addition, we report dominant carbon, sulfur and nitrogen species that can potentially stabilize the various Fe species present in these peatlands. Our results provide clear direct and indirect evidence for the co-occurrence of ferrous (Fe 2+) and ferric (Femore » 3+) iron species in peats under both oxic and anoxic conditions. Iron is mostly present within the operationally defined organic and amorphous (i.e., short range ordered, SRO) fractions; ferric iron primarily as magnetically isolated paramagnetic Fe 3+ in Fe(III)-organic complexes, but also in mineral forms such as ferrihydrite; ferrous iron in tetrahedral coordination in Fe(II)-organic complexes with minor contribution from pyrite. All of the Fe species identified stabilize Fe(III) and/or Fe(II) in anoxic and oxic peats. Fundamental differences are also observed in the relative proportion of C, S and N functionalities of OM in oxic and anoxic peats. Aromatic C=C, ester, phenol and anomeric C (R-O-C-O-R), as well as thiol, sulfide and heterocyclic N functionalities are more prevalent in anoxic peats. Collectively, our experimental evidence suggests iron forms coordination complexes with O-, S- and N-containing functional groups of OM. We posit the co-occurrence of organic and mineral forms of Fe(II) and Fe(III) in both oxic and anoxic peat layers results from dynamic complexation and hydrolysis-precipitation reactions that occur under variable redox conditions. In conclusion, our findings aid in understanding the crucial role OM plays in determining Fe

Iron speciation in peats: Chemical and spectroscopic evidence for the co-occurrence of ferric and ferrous iron in organic complexes and mineral precipitates

DOE PAGES

Bhattacharyya, Amrita; Schmidt, Michael P.; Stavitski, Eli; ...

2017-10-31

The speciation of iron (Fe) in organic matter (OM)-rich environments under in situ variable redox conditions is largely unresolved. Peatlands provide a natural setting to study Fe–OM interactions. Utilizing chemical, spectroscopic and theoretical modeling approaches, we report the chemical forms, oxidation states and local coordination environment of naturally occurring Fe in the vertically redox-stratified Manning peatlands of western New York. In addition, we report dominant carbon, sulfur and nitrogen species that can potentially stabilize the various Fe species present in these peatlands. Our results provide clear direct and indirect evidence for the co-occurrence of ferrous (Fe 2+) and ferric (Femore » 3+) iron species in peats under both oxic and anoxic conditions. Iron is mostly present within the operationally defined organic and amorphous (i.e., short range ordered, SRO) fractions; ferric iron primarily as magnetically isolated paramagnetic Fe 3+ in Fe(III)-organic complexes, but also in mineral forms such as ferrihydrite; ferrous iron in tetrahedral coordination in Fe(II)-organic complexes with minor contribution from pyrite. All of the Fe species identified stabilize Fe(III) and/or Fe(II) in anoxic and oxic peats. Fundamental differences are also observed in the relative proportion of C, S and N functionalities of OM in oxic and anoxic peats. Aromatic C=C, ester, phenol and anomeric C (R-O-C-O-R), as well as thiol, sulfide and heterocyclic N functionalities are more prevalent in anoxic peats. Collectively, our experimental evidence suggests iron forms coordination complexes with O-, S- and N-containing functional groups of OM. We posit the co-occurrence of organic and mineral forms of Fe(II) and Fe(III) in both oxic and anoxic peat layers results from dynamic complexation and hydrolysis-precipitation reactions that occur under variable redox conditions. In conclusion, our findings aid in understanding the crucial role OM plays in determining Fe

Remote-sensing data processing with the multivariate regression analysis method for iron mineral resource potential mapping: a case study in the Sarvian area, central Iran

NASA Astrophysics Data System (ADS)

Mansouri, Edris; Feizi, Faranak; Jafari Rad, Alireza; Arian, Mehran

2018-03-01

This paper uses multivariate regression to create a mathematical model for iron skarn exploration in the Sarvian area, central Iran, using multivariate regression for mineral prospectivity mapping (MPM). The main target of this paper is to apply multivariate regression analysis (as an MPM method) to map iron outcrops in the northeastern part of the study area in order to discover new iron deposits in other parts of the study area. Two types of multivariate regression models using two linear equations were employed to discover new mineral deposits. This method is one of the reliable methods for processing satellite images. ASTER satellite images (14 bands) were used as unique independent variables (UIVs), and iron outcrops were mapped as dependent variables for MPM. According to the results of the probability value (p value), coefficient of determination value (R2) and adjusted determination coefficient (Radj2), the second regression model (which consistent of multiple UIVs) fitted better than other models. The accuracy of the model was confirmed by iron outcrops map and geological observation. Based on field observation, iron mineralization occurs at the contact of limestone and intrusive rocks (skarn type).

Mössbauer study of iron minerals transformations by Fuchsiella ferrireducens

NASA Astrophysics Data System (ADS)

Gracheva, M. A.; Chistyakova, N. I.; Antonova, A. V.; Rusakov, V. S.; Zhilina, T. N.; Zavarzina, D. G.

2017-11-01

Biogenic transformations of iron-containing minerals synthesized ferrihydrite, magnetite and hydrothermal siderite by anaerobic alkaliphilic bacterium Fuchsiella ferrireducens (strain Z-7101T) were studied by 57Fe Mössbauer spectroscopy. Mössbauer investigations of solid phase samples obtained after microbial transformation were carried out at room temperature and at 82 K. It was found that all tested minerals transformed during bacterial growth. In the presence of synthesized ferrihydrite, added as an electron acceptor, a mixture of large (more than 100 nm) and small (˜5 nm) particles of magnetically ordered phase and siderite was formed. Synthesized magnetite that contains both Fe3+ and Fe2+ forms could serve as electron acceptor as well as an electron donor for F.ferrireducens growth. As a result of its biotransformation, no siderite formation was observed while small particles of magnetite were formed. In the case of the addition of siderite as an electron donor formation of a small amount of a new phase containing Fe2+ caused by recrystallization of siderite during bacterial growth was detected.

Serum fibroblast growth factor 23, serum iron and bone mineral density in premenopausal women

PubMed Central

Imel, Erik A.; Liu, Ziyue; McQueen, Amie K.; Acton, Dena; Acton, Anthony; Padgett, Leah R.; Peacock, Munro; Econs, Michael J.

2016-01-01

Fibroblast growth factor 23 (FGF23) circulates as active protein and inactive fragments. Low iron status increases FGF23 gene expression, and iron deficiency is common. We hypothesized that in healthy premenopausal women, serum iron influences C-terminal and intact FGF23 concentrations, and that iron and FGF23 associate with bone mineral density (BMD). Serum iron, iron binding capacity, percent iron saturation, phosphorus, and other biochemistries were measured in stored fasting samples from healthy premenopausal white (n=1898) and black women (n= 994), age 20–55 years. Serum C-terminal and intact FGF23 were measured in a subset (1631 white and 296 black women). BMD was measured at the lumbar spine and femur neck. Serum phosphorus, calcium, alkaline phosphatase and creatinine were lower in white women than black women (p<0.001). Serum iron (p<0.0001) and intact FGF23 (p< 0.01) were higher in white women. C-terminal FGF23 did not differ between races. Phosphorus correlated with intact FGF23 (white women, r=0.120, p<0.0001; black women r=0.163, p<0.01). However, phosphorus correlated with C-terminal FGF23 only in black women (r=0.157, p<0.01). Intact FGF23 did not correlate with iron. C-terminal FGF23 correlated inversely with iron (white women r=−0.134, p<0.0001; black women r=−0.188, p<0.01), having a steeper slope at iron <50 mcg/dl than >50 mcg/dl. Longitudinal changes in iron predicted changes in C-terminal FGF23. Spine BMD correlated with iron negatively (r=−0.076, p<0.01) in white women; femur neck BMD correlated with iron negatively (r=−0.119, p<0.0001) in black women. Both relationships were eliminated in weight-adjusted models. BMD did not correlate with FGF23. Serum iron did not relate to intact FGF23, but was inversely related to C-terminal FGF23. Intact FGF23 correlated with serum phosphorus. In weight-adjusted models, BMD was not related to intact FGF23, C-terminal FGF23 or iron. The influence of iron on FGF23 gene expression is not important

Minerals in thalassaemia major patients: An overview.

PubMed

Ozturk, Zeynep; Genc, Gizem Esra; Gumuslu, Saadet

2017-05-01

Thalassaemia major (TM) is a hereditary blood disease characterised by reduced or absent production of beta globin chains. Erythrocyte transfusions are given to raise the haemoglobin level in patients with thalassaemia major. However, transfusions have been related to increased risk of iron overload and tissue damage related to excess iron. Both elevated oxidative stress due to iron overload and increased hemolysis lead to over utilisation of minerals required for antioxidant enzymes activities. Iron chelators have been used to prevent iron overload in thalassaemia major patients, but these chelators have the possibility of removing minerals from the body. Thalassaemia patients are more at risk for mineral deficiency because of increased oxidative stress and iron chelation therapies. Growth and maturational delay, cardiomyopathy, endocrinopathies and osteoporosis are the complications of thalassaemia. Minerals may play a particular role to prevent these complications. In the current review, we provide an overview of minerals including zinc (Zn), copper (Cu), selenium (Se), magnesium (Mg) and calcium (Ca) in thalassaemia major patients. We, also, underline that some complications of thalassaemia can be caused by an increased need for minerals or lack of the minerals. Copyright © 2017 Elsevier GmbH. All rights reserved.

Mapping the distribution of ferric iron minerals on a vertical mine face using derivative analysis of hyperspectral imagery (430-970 nm)

NASA Astrophysics Data System (ADS)

Murphy, Richard J.; Monteiro, Sildomar T.

2013-01-01

Hyperspectral imagery is used to map the distribution of iron and separate iron ore from shale (a waste product) on a vertical mine face in an open-pit mine in the Pilbara, Western Australia. Vertical mine faces have complex surface geometries which cause large spatial variations in the amount of incident and reflected light. Methods used to analyse imagery must minimise these effects whilst preserving any spectral variations between rock types and minerals. Derivative analysis of spectra to the 1st-, 2nd- and 4th-order is used to do this. To quantify the relative amounts and distribution of iron, the derivative spectrum is integrated across the visible and near infrared spectral range (430-970 nm) and over those wavelength regions containing individual peaks and troughs associated with specific iron absorption features. As a test of this methodology, results from laboratory spectra acquired from representative rock samples were compared with total amounts of iron minerals from X-ray diffraction (XRD) analysis. Relationships between derivatives integrated over the visible near-infrared range and total amounts (% weight) of iron minerals were strongest for the 4th- and 2nd-derivative (R2 = 0.77 and 0.74, respectively) and weakest for the 1st-derivative (R2 = 0.56). Integrated values of individual peaks and troughs showed moderate to strong relationships in 2nd- (R2 = 0.68-0.78) and 4th-derivative (R2 = 0.49-0.78) spectra. The weakest relationships were found for peaks or troughs towards longer wavelengths. The same derivative methods were then applied to imagery to quantify relative amounts of iron minerals on a mine face. Before analyses, predictions were made about the relative abundances of iron in the different geological zones on the mine face, as mapped from field surveys. Integration of the whole spectral curve (430-970 nm) from the 2nd- and 4th-derivative gave results which were entirely consistent with predictions. Conversely, integration of the 1st

Acidic processing of mineral dust iron by anthropogenic compounds over the north Pacific Ocean

NASA Astrophysics Data System (ADS)

Solmon, F.; Chuang, P. Y.; Meskhidze, N.; Chen, Y.

2009-01-01

Atmospheric processing of mineral aerosol by anthropogenic pollutants may be an important process by which insoluble iron can be transformed into soluble forms and become available to oceanic biota. Observations of the soluble iron fraction in atmospheric aerosol exhibit large variability, which is poorly represented in models. In this study, we implemented a dust iron dissolution scheme in a global chemistry transport model (GEOS-Chem). The model is applied over the North Pacific Ocean during April 2001, a period when concentrations of dust and pollution within the east Asia outflow were high. Simulated fields of many key chemical constituents compare reasonably well with available observations, although some discrepancies are identified and discussed. In our simulations, the production of soluble iron varies temporally and regionally depending on pollution-to-dust ratio, primarily due to strong buffering by calcite. Overall, we show that the chemical processing mechanism produces significant amounts of dissolved iron reaching and being deposited in remote regions of the Pacific basin, with some seasonal variability. Simulated enhancements in particulate soluble iron fraction range from 0.5% to 6%, which is consistent with the observations. According to our simulations, ˜30% to 70% of particulate soluble iron over the North Pacific Ocean basin can be attributed to atmospheric processing. On the basis of April 2001 monthly simulations, sensitivity tests suggest that doubling SO2 emissions can induce a significant increase (13% on average, up to 40% during specific events) in dissolved iron production and deposition to the remote Pacific. We roughly estimate that half of the primary productivity induced by iron deposition in a north Pacific high-nutrient low-chlorophyll region is due to soluble iron derived from anthropogenic chemical processing of Asian aerosol.

Direct evidence of spatially selective iron mineralization using an immobilized ferritin protein cage.

PubMed

Uto, Koichiro; Yamamoto, Kazuya; Kishimoto, Naoko; Muraoka, Masahiro; Aoyagi, Takao; Yamashita, Ichiro

2014-04-01

(Apo)ferritins are cage-shaped proteins which have recently received a great deal of attention because the inner cavity of the protein shell can be used as a size-restricted reaction field for the synthesis of nanomaterials. The biomineralization behavior and inorganic nanoparticle (NP) synthesis mechanism of (apo)ferritin in solution systems have been studied but the mineralization behavior of (apo)ferritin on the substrates has not yet been well studied. Here, we conducted quantitative and kinetic analyses of the mineralization behavior of immobilized (apo)ferritin on a polyelectrolyte multilayer (PEM) using quartz crystal microbalance (QCM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) techniques. We demonstrated that the (apo)ferritin immobilized on a substrate synthesizes a ferrihydrite core within the confines of the protein cage; similar to a solution dispersed system. In addition, we applied a ferritin/apoferritin blended monolayer to the study of iron mineralization and revealed that biomineralization in this system is spatially selective. It is important to understand the mineralization mechanisms for the synthesis of other functional NPs as this approach has potential for a broad range of magnetic, catalytic, and biomedical sensing applications.

Investigating the effect of ascorbate on the Fe(II)-catalyzed transformation of the poorly crystalline iron mineral ferrihydrite.

PubMed

Xiao, Wei; Jones, Adele M; Collins, Richard N; Waite, T David

2018-05-09

The inorganic core of the iron storage protein, ferritin, is recognized as being analogous to the poorly crystalline iron mineral, ferrihydrite (Fh). Fh is also abundant in soils where it is central to the redox cycling of particular soil contaminants and trace elements. In geochemical circles, it is recognized that Fh can undergo Fe(II)-catalyzed transformation to form more crystalline iron minerals, vastly altering the reactivity of the iron oxide and, in some cases, the redox poise of the system. Of relevance to both geochemical and biological systems, we investigate here if the naturally occurring reducing agent, ascorbate, can effect such an Fe(II)-catalyzed transformation of Fh at 25 °C and circumneutral pH. The transformation of ferrihydrite to possible secondary Fe(III) mineralization products was quantified using Fourier transform infrared (FTIR) spectroscopy, with supporting data obtained using X-ray absorbance spectroscopy (XAS) and X-ray diffraction (XRD). Whilst the amount of Fe(II) formed in the presence of ascorbate has resulted in Fh transformation in previous studies, no transformation of Fh to more crystalline Fe(III) (oxyhydr)oxides was observed in this study. Further experiments indicated this was due to the ability of ascorbate to inhibit the formation of goethite, lepidocrocite and magnetite. The manner in which ascorbate associated with Fh was investigated using FTIR and total organic carbon (TOC) analysis. The majority of ascorbate was found to adsorb to the Fh surface under anoxic conditions but, under oxic conditions, ascorbate was initially adsorbed then became incorporated within the Fe(III) (oxyhydr)oxide structure (i.e., co-precipitated) over time. Copyright © 2018 Elsevier B.V. All rights reserved.

Clay Mineral Crystal Structure Tied to Composition

NASA Image and Video Library

2016-12-13

This diagram illustrates how the dimensions of clay minerals' crystal structure are affected by which ions are present in the composition of the mineral. Different clay minerals were identified this way at two sites in Mars' Gale Crater: "Murray Buttes" and "Yellowknife Bay." In otherwise identical clay minerals, a composition that includes aluminum and ferric iron ions (red dots) results in slightly smaller crystalline unit cells than one that instead includes magnesium and ferrous iron ions (green dots). Ferric iron is more highly oxidized than ferrous iron. Crystalline cell units are the basic repeating building blocks that define minerals. X-ray diffraction analysis, a capability of the Chemistry and Mineralogy (CheMin) instrument on NASA's Curiosity Mars rover, identifies minerals from their crystalline structure. http://photojournal.jpl.nasa.gov/catalog/PIA21148

Reduced mortality rates in a cohort of long-term underground iron-ore miners.

PubMed

Björ, Ove; Jonsson, Håkan; Damber, Lena; Wahlström, Jens; Nilsson, Tohr

2013-05-01

Historically, working in iron-ore mines has been associated with an increased risk of lung cancer and silicosis. However, studies on other causes of mortality are inconsistent and in the case of cancer incidence, sparse. The aim of this study was to examine the association between iron-ore mining, mortality and cancer incidence. A 54-year cohort study on iron-ore miners from mines in northern Sweden was carried out comprising 13,000 workers. Standardized rate ratios were calculated comparing the disease frequency, mortality, and cancer incidence with that of the general population of northern Sweden. Poisson regression was used to evaluate the association between the durations of employment and underground work, and outcome. Underground mining was associated with a significant decrease in adjusted mortality rate ratios for cerebrovascular and digestive system diseases, and stroke. For several outcomes, elevated standardized rate ratios were observed among blue-collar workers relative to the reference population. However, only the incidence of lung cancer increased with employment time underground (P < 0.001). Long-term iron-ore mining underground was associated with lower rates regarding several health outcomes. This is possibly explained by factors related to actual job activities, environmental exposure, or the selection of healthier workers for long-term underground employment. Copyright © 2013 Wiley Periodicals, Inc.

Removal of Iron and Manganese from Natural Groundwater by Continuous Reactor Using Activated and Natural Mordenite Mineral Adsorption

NASA Astrophysics Data System (ADS)

Zevi, Y.; Dewita, S.; Aghasa, A.; Dwinandha, D.

2018-01-01

Mordenite minerals derived from Sukabumi natural green stone founded in Indonesia was tested in order to remove iron and manganese from natural groundwater. This research used two types of adsorbents which were consisted of physically activated and natural mordenite. Physical activation of the mordenite was carried out by heating at 400-600°C for two hours. Batch system experiments was also conducted as a preliminary experiment. Batch system proved that both activated and natural mordenite minerals were capable of reducing iron and manganese concentration from natural groundwater. Then, continuous experiment was conducted using down-flow system with 45 ml/minute of constant flow rate. The iron & manganese removal efficiency using continuous reactor for physically activated and natural mordenite were 1.38-1.99%/minute & 0.8-1.49%/minute and 2.26%/minute & 1.37-2.26%/minute respectively. In addition, the regeneration treatment using NH4Cl solution managed to improve the removal efficiency of iron & manganese to 1.98%/minute & 1.77-1.90%/minute and 2.25%/minute & 2.02-2.21%/minute on physically activated mordenite and natural mordenite respectively. Subsequently, the activation of the new mordenite was carried out by immersing mordenite in NH4Cl solution. This chemical activation showed 2.42-2.75%/minute & 0.96 - 2.67 %/minute and 2.66 - 2.78 %/minute & 1.34 - 2.32 %/minute of iron & manganese removal efficiency per detention time for chemically activated and natural mordenite respectively.

Abiotic versus biotic iron mineral transformation studied by a miniaturized backscattering Mössbauer spectrometer (MIMOS II), X-ray diffraction and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Markovski, C.; Byrne, J. M.; Lalla, E.; Lozano-Gorrín, A. D.; Klingelhöfer, G.; Rull, F.; Kappler, A.; Hoffmann, T.; Schröder, C.

2017-11-01

Searching for biomarkers or signatures of microbial transformations of minerals is a critical aspect for determining how life evolved on Earth, and whether or not life may have existed in other planets, including Mars. In order to solve such questions, several missions to Mars have sought to determine the geochemistry and mineralogy on the Martian surface. This research includes the two miniaturized Mössbauer spectrometers (MIMOS II) on board the Mars Exploration Rovers Spirit and Opportunity, which have detected a variety of iron minerals on Mars, including magnetite (Fe2+Fe3+2O4) and goethite (α-FeO(OH)). On Earth, both minerals can derive from microbiological activity (e.g. through dissimilatory iron reduction of ferrihydrite by Fe(III)-reducing bacteria). Here we used a lab based MIMOS II to characterize the mineral products of biogenic transformations of ferrihydrite to magnetite by the Fe(III)-reducing bacteria Geobacter sulfurreducens. In combination with Raman spectroscopy and X-ray diffraction (XRD), we observed the formation of magnetite, goethite and siderite. We compared the material produced by biogenic transformations to abiotic samples in order to distinguish abiotic and biotic iron minerals by techniques that are or will be available onboard Martian based laboratories. The results showed the possibility to distinguish the abiotic and biotic origin of the minerals. Mossbauer was able to distinguish the biotic/abiotic magnetite with the interpretation of the geological context (Fe content mineral assemblages and accompanying minerals) and the estimation of the particle size in a non-destructive way. The Raman was able to confirm the biotic/abiotic principal peaks of the magnetite, as well as the organic principal vibration bands attributed to the bacteria. Finally, the XRD confirmed the particle size and mineralogy.

[Vitamin and mineral supplements in the diet of military personnel: effect on the balance of iron, copper and manganese, immune reactivity and physical work-capacity].

PubMed

Zaĭtseva, I P; Nosolodin, V V; Zaĭtsev, O N; Gladkikh, I P; Koznienko, I V; Beliakov, R A; Arshinov, N P

2012-03-01

Conducted with the participation of 50 students of military educational study the effect of various vitamin and mineral complexes for the provision by the body naturally iron, copper and manganese on the immune and physical status. Found that diets enriched BMV was accompanied by a significant delay in the micro-elements, mainly iron, which indicates a deficiency of these bioelements in chickens Santo during the summer. Under the influence of vitamin-mineral complexes significantly increased rates of natural and specific immunity. As the delay increases significantly increased iron medical indicators of immunological reaction efficiency and physical performance.

Mineral Tells Tale of Watery Past

NASA Technical Reports Server (NTRS)

2004-01-01

This spectrum, taken by the Mars Exploration Rover Opportunity's Moessbauer spectrometer, shows the presence of an iron-bearing mineral called jarosite in the collection of rocks dubbed 'El Capitan.' 'El Capitan' is located within the rock outcrop that lines the inner edge of the small crater where Opportunity landed. The pair of yellow peaks specifically indicates a jarosite phase, which contains water in the form of hydroxyl as a part of its structure. These data suggest water-driven processes exist on Mars. Three other phases are also identified in this spectrum: a magnetic phase (blue), attributed to an iron-oxide mineral; a silicate phase (green), indicative of minerals containing double-ionized iron (Fe 2+); and a third phase (red) of minerals with triple-ionized iron (Fe 3+).

A genetic link between magnetite mineralization and diorite intrusion at the El Romeral iron oxide-apatite deposit, northern Chile

NASA Astrophysics Data System (ADS)

Rojas, Paula A.; Barra, Fernando; Reich, Martin; Deditius, Artur; Simon, Adam; Uribe, Francisco; Romero, Rurik; Rojo, Mario

2018-01-01

El Romeral is one of the largest iron oxide-apatite (IOA) deposits in the Coastal Cordillera of northern Chile. The Cerro Principal magnetite ore body at El Romeral comprises massive magnetite intergrown with actinolite, with minor apatite, scapolite, and sulfides (pyrite ± chalcopyrite). Several generations of magnetite were identified by using a combination of optical and electron microscopy techniques. The main mineralization event is represented by zoned magnetite grains with inclusion-rich cores and inclusion-poor rims, which form the massive magnetite ore body. This main magnetite stage was followed by two late hydrothermal events that are represented by magnetite veinlets that crosscut the massive ore body and by disseminated magnetite in the andesite host rock and in the Romeral diorite. The sulfur stable isotope signature of the late hydrothermal sulfides indicates a magmatic origin for sulfur (δ34S between - 0.8 and 2.9‰), in agreement with previous δ34S data reported for other Chilean IOA and iron oxide-copper-gold deposits. New 40Ar/39Ar dating of actinolite associated with the main magnetite ore stage yielded ages of ca. 128 Ma, concordant within error with a U-Pb zircon age for the Romeral diorite (129.0 ± 0.9 Ma; mean square weighted deviation = 1.9, n = 28). The late hydrothermal magnetite-biotite mineralization is constrained at ca. 118 Ma by 40Ar/39Ar dating of secondary biotite. This potassic alteration is about 10 Ma younger than the main mineralization episode, and it may be related to post-mineralization dikes that crosscut and remobilize Fe from the main magnetite ore body. These data reveal a clear genetic association between magnetite ore formation, sulfide mineralization, and the diorite intrusion at El Romeral (at 129 Ma), followed by a late and more restricted stage of hydrothermal alteration associated with the emplacement of post-ore dikes at ca. 118 Ma. Therefore, this new evidence supports a magmatic-hydrothermal model for the

LREE Enrichments of Altered Alkaline Pyroclastics at Kuyubasi Region Burdur, SW Turkey

NASA Astrophysics Data System (ADS)

Budakoglu, Murat; Tugcan Unluer, Ali; Doner, Zeynep; Kocaturk, Huseyin; Sezai Kırıkoǧlu, M.

2017-04-01

ABSTRACT In the Kuyubasi region of Burdur, Bucak district, Inner Isparta Apex, SW Anatolia, Turkey, the investigation carried out for the potential in-situ enrichments of REE in highly altered alkaline tuffs originated from Golcuk volcano. This volcano is the most significant product of the widely known post collisional, Afyon-Isparta potassic-ultrapotassic volcanic province in southwestern Turkey. Partial melting of oceanic crust and subcontinental lithospheric mantle resulted in the formation of florocarbonates and pyrochlore group minerals which are responsible for the LREE enrichment in Golcuk volcanics. These extrusive rocks are mainly trachyandesites, augite-trachytes, porphyry trachytes and tephriphonolite dikes which are formed in several eruptive cycles. Pyroclastics from the last eruptions can be encountered in various locations beneath the Isparta apex. The pyroclastics in study area described as mafic crystal metatuffs which predominantly consist of calcic-plagioclase with clinopyroxene, K-feldspar, and quartz set in a hyalo-microcrystalline tuffaceous matrix of microcrystalline aggregates of kaolinized and sericitized feldspar, biotite, chlorite, quartz, and dusty iron oxide. The results indicate high values for the LREE elements such as La (251-369 ppm), Ce (412-660 ppm), Sc (45-48 ppm). The average ΣREE content of samples are 1012 ppm. These results are compatible with the samples from Golcuk Caldera which is located 30 km north of study area in terms of LREE contents (La and Ce values are 400-500 ppm and 500-600 ppm respectively). Key words: Rare earth elements (REE), Pyroclastic occurrences, Bucak region, Burdur, Southwest Turkey *This research was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) project. Principal Investigator (PI) of this ongoing TUBITAK, CAYDAG-114Y646 project is Prof.Dr. M. Sezai KIRIKOGLU.

Study on accumulation ability of two lichen species Hypogymnia physodes and Usnea hirta at iron-steel factory site, Turkey.

PubMed

Cansaran-Duman, Demet

2011-11-01

The use of biological responses to contaminant exposure by lichen species has become a useful tool in environmental quality evaluation and risk assesment. Lichen Hypogymnia physodes and Usnea hirta samples were collected in 2006 from 10 sites around iron-steel factory in Karabük, Turkey. H. physodes and U. hirta samples from Yenice forest were used as a control. The aim of present study was to evaluate the bioaccumulation ability and to determine the environmental impact of an iron-steel factory in Karabük. Seven elements (Zn, Cu, Mn, Fe, Pb, Ni, Cr and Cd) were analysed by atomic absorption spectrometry (AAS). The analytical results were compared statistically by using SPSS. As expected, the study area (Yenice forest, Karabük) chosen as control site (site no 11) showed significantly lower impact in comparison to other site (site no 1-10). Compared with the two lichen species, H. physodes showed highest metal accumulating capacity while U. hirta showed lowest. These criteria attested the best suitability for H. physodes, followed by U. hirta.

Red Dawn: Characterizing Iron Oxide Minerals in Atmospheric Dust

NASA Astrophysics Data System (ADS)

Yauk, K.; Ottenfeld, C. F.; Reynolds, R. L.; Goldstein, H.; Cattle, S.; Berquo, T. S.; Moskowitz, B. M.

2012-12-01

Atmospheric dust is comprised of many components including small amounts of iron oxide minerals. Although the iron oxides make up a small weight percent of the bulk dust, they are important because of their roles in ocean fertilization, controls on climate, and as a potential health hazard to humans. Here we report on the iron oxide mineralogy in dust from a large dust storm, dubbed Red Dawn, which engulfed eastern Australia along a 3000 km front on 23 September 2009. Red Dawn originated from the lower Lake Eyre Basin of South Australia, western New South Wales (NSW) and southwestern Queensland and was the worst dust storm to have hit the city of Sydney in more than 60 years. Dust samples were collected from various locations across eastern Australia (Lake Cowal, Orange, Hornsby, Sydney) following the Red Dawn event. Our dust collection provides a good opportunity to study the physical and mineralogical properties of iron oxides from Red Dawn using a combination of reflectance spectroscopy, Mössbauer spectroscopy (MB), and magnetic measurements. Magnetization measurements from 20-400 K reveal that magnetite/maghemite, hematite and goethite are present in all samples with magnetite occurring in trace amounts (< 0.5wt%). However, the amount of magnetite/maghemite even in trace concentrations generally increases from Lake Cowal from west to east (0.01 to 0.29 wt%), with highest magnetite contents in the urban-Sydney sites. These observations indicate the additions of magnetite from local urban sources. Variable temperature Mössbauer spectroscopy (300 K and 4.2 K) indicate that goethite and hematite compose approximately 25-45 % of the Fe-bearing phases in the Orange and Lake Cowal samples. Goethite is more abundant than hematite in the Lake Cowal samples whereas the opposite is observed for Orange. Hematite is observed at both temperatures but goethite only at 4.2 K. The identification of goethite in Mössbauer analyses at low-temperature but not at room temperature

Geology of the Biwabik Iron Formation and Duluth Complex.

PubMed

Jirsa, Mark A; Miller, James D; Morey, G B

2008-10-01

The Biwabik Iron Formation is a approximately 1.9 billion year-old sequence of iron-rich sedimentary rocks that was metamorphosed at its eastern-most extent by approximately 1.1 billion year-old intrusions of the Duluth Complex. The metamorphic recrystallization of iron-formation locally produced iron-rich amphiboles and other fibrous iron-silicate minerals. The presence of these minerals in iron-formation along the eastern part of what is known as the Mesabi Iron Range, and their potential liberation by iron mining has raised environmental health concerns. We describe here the geologic setting and mineralogic composition of the Biwabik Iron Formation in and adjacent to the contact metamorphic aureole of the Duluth Complex. The effects of metamorphism are most pronounced within a few kilometers of the contact, and decrease progressively away from it. The contact aureole has been divided into four metamorphic zones-each characterized by the composition and crystal structure of the metamorphic minerals it contains. The recrystallization of iron-formation to iron-rich amphibole minerals (grunerite and cummingtonite) and iron-pyroxene minerals (hedenbergite and ferrohypersthene) is best developed in zones that are most proximal to the Duluth Complex contact.

Geology of the Biwabik Iron Formation and Duluth Complex

USGS Publications Warehouse

Jirsa, M.A.; Miller, J.D.; Morey, G.B.

2008-01-01

The Biwabik Iron Formation is a ???1.9 billion year-old sequence of iron-rich sedimentary rocks that was metamorphosed at its eastern-most extent by ???1.1 billion year-old intrusions of the Duluth Complex. The metamorphic recrystallization of iron-formation locally produced iron-rich amphiboles and other fibrous iron-silicate minerals. The presence of these minerals in iron-formation along the eastern part of what is known as the Mesabi Iron Range, and their potential liberation by iron mining has raised environmental health concerns. We describe here the geologic setting and mineralogic composition of the Biwabik Iron Formation in and adjacent to the contact metamorphic aureole of the Duluth Complex. The effects of metamorphism are most pronounced within a few kilometers of the contact, and decrease progressively away from it. The contact aureole has been divided into four metamorphic zones-each characterized by the composition and crystal structure of the metamorphic minerals it contains. The recrystallization of iron-formation to iron-rich amphibole minerals (grunerite and cummingtonite) and iron-pyroxene minerals (hedenbergite and ferrohypersthene) is best developed in zones that are most proximal to the Duluth Complex contact. ?? 2007 Elsevier Inc. All rights reserved.

Microbe-Clay Mineral Reactions and Characterization Techniques

NASA Astrophysics Data System (ADS)

Dong, H.; Zhang, G.; Ji, S.; Jaisi, D.; Kim, J.

2008-12-01

Clays and clay minerals are ubiquitous in soils, sediments, and sedimentary rocks. They play an important role in environmental processes such as nutrient cycling, plant growth, contaminant migration, organic matter maturation, and petroleum production. The changes in the oxidation state of the structural iron in clay minerals, in part, control their physical and chemical properties in natural environments, such as clay particle flocculation, dispersion, swelling, hydraulic conductivity, surface area, cation and anion exchange capacity, and reactivity towards organic and inorganic contaminants. The structural ferric iron [Fe(III)] in clay minerals can be reduced either chemically or biologically. Many different chemical reductants have been tried, but the most commonly used agent is dithionite. Biological reductants are bacteria, including dissimilatory iron reducing prokaryotes (DIRP) and sulfate-reducing bacteria (SRB). A wide variety of DIRP have been used to reduce ferric iron in clay minerals, including mesophilic, thermophilic, and hyperthermophilic prokaryotes. Multiple clay minerals have been used for microbial reduction studies, including smectite, nontronite (iron-rich smectite variety), illite, illite/smectite, chlorite, and their various mixtures. All these clay minerals are reducible by microorganisms under various conditions with smectite (nontronite) being the most reducible. The reduction extent and rate of ferric iron in clay minerals are measured by wet chemistry, and the reduced clay mineral products are typically characterized with chemical methods, X-ray diffraction, scanning and transmission electron microscopy, Mössbauer spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), UV-vis spectroscopy, and synchrotron-based techniques (such as EXAFS). Microbially reduced smectites (nontronites) have been found to be reactive in reducing a variety of organic and inorganic contaminants. Degradable organic contaminants include pesticides

Effect of different iron compounds on rheological and technological parameters as well as bioaccessibility of minerals in whole wheat bread.

PubMed

Rebellato, Ana Paula; Bussi, Jéssica; Silva, Joyce Grazielle Siqueira; Greiner, Ralf; Steel, Caroline Joy; Pallone, Juliana Azevedo Lima

2017-04-01

This study aimed at investigating the effect of iron compounds used in whole wheat flour (WWF) fortification, both on rheological properties of the dough and on bread technological quality. Furthermore, bioaccessibility of iron (Fe), zinc (Zn) and calcium (Ca) in the final breads was determined. Rheological properties (mainly dough development time, stability, mixing tolerance index, resistance to extension and ratio number) of the dough and the technological quality of bread (mainly oven spring and cut opening) were altered. However, producing roll breads fortified with different iron compounds was still possible. NaFeEDTA (ferric sodium ethylene diamine tetra acetic acid) proved to be the most effective iron compound in the fortification of WWF, since it presented the highest levels of solubility (44.80%) and dialysability (46.14%), followed by microencapsulated ferrous fumarate (FFm). On the other hand, the microencapsulated ferrous sulfate (FSm) and reduced iron presented the lowest solubility (5.40 and 18.30%, respectively) and dialysability (33.12 and 31.79%, respectively). Zn dialysis was positively influenced by NaFeEDTA, FSm, and ferrous fumarate. As for Ca, dialysis was positively influenced by FSm and negatively influenced by FFm. The data indicated that there is a competitive interaction for the absorption of these minerals in whole wheat roll breads, but all studied minerals can be considered bioaccessible. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nitrogen mineralization in a high altitude ecosystem in the mediterranean phytogeographical region of Turkey.

PubMed

Guleryuz, Gurcan; Gucel, Salih; Ozturk, Munir

2010-07-01

Interrelations exist in the terrestrial ecosystems between the plant type and characteristics of nutrient uptake. Annual net nitrogen mineralization in soils of different plant communities in the high altitude zone of Spil mountain located in the Mediterranean phytogeographical region of Turkey was investigated throughout one year by field incubation method. Seasonal fluctuations resulting from field incubation were markedly higher in autumn and spring than summer. These are mainly associated with the changes in soil moisture being at minimum in the Mediterranean summer. A significant correlation was developed between the net Nitrate (kg NO3(-)-N ha week(-1)) production and soil water content (p<0.05; r = 0.316 in soil of 0-5 cm; r = 0.312 in soil of 5-15 cm). The results showed that the annual productivity of nitrogen mineralization shows different values depending on communities. Annual net ammonium (NH4(+)-N) production in the soils of each community was negatively estimated. However annual net nitrate (NO3(-)-N) production (0-15 cm) was higher in grassland (27.8 kg ha y(-1)) and shrub (25.0 kg ha y(-1)) than forest (12.4 kg ha y(-1)) community. While annual net N(min) values were close to each other in grassland (14.5 kg ha y(-1)) and shrub (14.1 kg ha y(-1)), but negative in forest community (-3.6 kg ha y(-1)). The reasons for these differences are discussed.

Serum levels of iron in Sør-Varanger, Northern Norway--an iron mining municipality.

PubMed

Broderstad, Ann R; Smith-Sivertsen, Tone; Dahl, Inger Marie S; Ingebretsen, Ole Christian; Lund, Eiliv

2006-12-01

The purpose of this study was to investigate iron status in a population with a high proportion of miners in the northernmost part of Norway. Cross-sectional, population-based study performed in order to investigate possible health effects of pollution in the population living on both sides of the Norwegian-Russian border. All individuals living in the community of Sør-Varanger were invited for screening in 1994. In 2000, blood samples from 2949 participants (response rate 66.8 %), age range 30-69 years, were defrosted. S-ferritin and transferrin saturation were analysed in samples from 1548 women and 1401 men. About 30 % (n = 893) were employed in the iron mining industry, 476 of whom were miners and 417 had other tasks in the company. Type and duration of employment and time since last day of work at the company were used as indicators of exposure. Both s-ferritin levels and transferrin saturation were higher in men than in women. S-ferritin increased with increasing age in women, while the opposite was true for men. Iron deficiency occurred with higher frequencies in women (16 %) than in men (4 %). Iron overload was uncommon in both sexes. Adjustment for smoking and self-reported pulmonary diseases did not show any effect on iron levels. Miners had non-significant higher mean s-ferritin and transferrin saturation than non-miners. Neither duration, nor time since employment in the mine, had any impact on iron status. Our analyses did not show any associations between being a miner in the iron mining industry and serum iron levels compared to the general population.

Persulfate activation by subsurface minerals.

PubMed

Ahmad, Mushtaque; Teel, Amy L; Watts, Richard J

2010-06-25

Persulfate dynamics in the presence of subsurface minerals was investigated as a basis for understanding persulfate activation for in situ chemical oxidation (ISCO). The mineral-mediated decomposition of persulfate and generation of oxidants and reductants was investigated with four iron and manganese oxides and two clay minerals at both low pH (<7) and high pH (>12). The manganese oxide birnessite was the most effective initiator of persulfate for degrading the oxidant probe nitrobenzene, indicating that oxidants are generated at both low and high pH regimes. The iron oxide goethite was the most effective mineral for degrading the reductant probe hexachloroethane. A natural soil and two soil fractions were used to confirm persulfate activation by synthetic minerals. The soil and soil fractions did not effectively promote the generation of oxidants or reductants. However, soil organic matter was found to promote reductant generation at high pH. The results of this research demonstrate that synthetic iron and manganese oxides can activate persulfate to generate reductants and oxidants; however, iron and manganese oxides in the natural soil studied do not show the same reactivity, most likely due to the lower masses of the metal oxides in the soil relative to the masses studied in isolated mineral systems. 2010. Published by Elsevier B.V.

Mineral Tells Tale of Watery Past-2

NASA Technical Reports Server (NTRS)

2004-01-01

This spectrum, taken by the Mars Exploration Rover Opportunity's Moessbauer spectrometer, shows the presence of an iron-bearing mineral called jarosite in the collection of rocks dubbed 'El Capitan.' 'El Capitan' is located within the outcrop that lines the inner edge of the small crater where Opportunity landed. The pair of yellow peaks specifically indicates a jarosite phase, which contains water in the form of hydroxyl as a part of its structure. These data suggest water-driven processes exist on Mars. Three other phases are also identified in this spectrum: a magnetic phase (blue), attributed to an iron-oxide mineral; a silicate phase (green), indicative of minerals containing double-ionized iron (Fe 2+); and a third phase (red) of minerals with triple-ionized iron (Fe 3+).

Mineral resource assessment of the Iron River 1 degree x 2 degrees Quadrangle, Michigan and Wisconsin

USGS Publications Warehouse

Cannon, William F.

1983-01-01

The Iron River 1? x 2? quadrangle contains identified resources of copper and iron. Copper-rich shale beds in the north part of the quadrangle contain 12.2 billion pounds (5.5 billion kilograms) of copper in well-studied deposits including 9.2 billion pounds (4.2 billion kilograms) that are economically minable by 1980 standards. At least several billion pounds of copper probably exist in other parts of the same shale beds, but not enough data are available to measure the amount. A small amount, about 250 million pounds (113 million kilograms), of native copper is known to remain in one abandoned mine, and additional but unknown amounts remain in other abandoned mines. About 13.25 billion tons (12.02 billion metric tons) of banded iron-formation averaging roughly 30 percent iron are known within 500 feet (152.4 meters) of the surface in the Gogebic, Marquette, and Iron River-Crystal Falls districts. A small percentage of that might someday be minable as taconite, but none is now believed to be economic. Some higher grade iron concentrations exist in the same iron-formations. Such material was the basis of former mining of iron in the region, but a poor market for such ore and depletion of many deposits have led to the decline of iron mining in the quadrangle. Iron mines of the quadrangle were not being worked in 1980. Many parts of the quadrangle contain belts of favorable host rocks for mineral deposits. Although deposits are not known in these belts, undiscovered deposits of copper, zinc, lead, silver, uranium, phosphate, nickel, chromium, platinum, gold, and diamonds could exist.

Mineral resource of the month: Vermiculite

USGS Publications Warehouse

Tanner, Arnold O.

2014-01-01

Vermiculite comprises a group of hydrated, laminar magnesium-aluminum-iron silicate minerals resembling mica. They are secondary minerals, typically altered biotite, iron-rich phlogopite or other micas or clay-like minerals that are themselves sometimes alteration products of amphibole, chlorite, olivine and pyroxene. Vermiculite deposits are associated with volcanic ultramafic rocks rich in magnesium silicate minerals, and flakes of the mineral range in color from black to shades of brown and yellow. The crystal structure of vermiculite contains water molecules, a property that is critical to its processing for common uses.

Kinetics and Products of Chromium(VI) Reduction by Iron(II/III)-Bearing Clay Minerals.

PubMed

Joe-Wong, Claresta; Brown, Gordon E; Maher, Kate

2017-09-05

Hexavalent chromium is a water-soluble pollutant, the mobility of which can be controlled by reduction of Cr(VI) to less soluble, environmentally benign Cr(III). Iron(II/III)-bearing clay minerals are widespread potential reductants of Cr(VI), but the kinetics and pathways of Cr(VI) reduction by such clay minerals are poorly understood. We reacted aqueous Cr(VI) with two abiotically reduced clay minerals: an Fe-poor montmorillonite and an Fe-rich nontronite. The effects of ionic strength, pH, total Fe content, and the fraction of reduced structural Fe(II) [Fe(II)/Fe(total)] were examined. The last variable had the largest effect on Cr(VI) reduction kinetics: for both clay minerals, the rate constant of Cr(VI) reduction varies by more than 3 orders of magnitude with Fe(II)/Fe(total) and is described by a linear free energy relationship. Under all conditions examined, Cr and Fe K-edge X-ray absorption near-edge structure spectra show that the main Cr-bearing product is a Cr(III)-hydroxide and that Fe remains in the clay structure after reacting with Cr(VI). This study helps to quantify our understanding of the kinetics of Cr(VI) reduction by Fe(II/III)-bearing clay minerals and may improve predictions of Cr(VI) behavior in subsurface environments.

Maxi- and mini-ferritins: minerals and protein nanocages.

PubMed

Bevers, Loes E; Theil, Elizabeth C

2011-01-01

Ferritins synthesize ferric oxide biominerals and are central to all life for concentrating iron and protection against oxidative stress from the ferrous and oxidant chemistry. The ferritin protein nanocages and biomineral synthesis are discussed in terms of wide biological distribution of the maxi-ferritins (24 subunit ± heme) and mini-ferritins (Dps) (12 subunit), conservations of the iron/oxygen catalytic sites in the protein cages, mineral formation (step i. Fe(II) entry and binding, step ii. O(2) or H(2)O(2) binding and formation of transition intermediates, step iii. release of differric oxo mineral precursors from active sites, step iv. nucleation and mineralization) properties of the minerals, and protein control of mineral dissolution and release of Fe(II). Pores in ferritin protein cages control iron entry for mineralization and iron exit after mineral dissolution. The relationship between phosphate or the presence of catalytically inactive subunits (animal L subunits) and ferritin iron mineral disorder is developed based on new information about contributions of ferritin protein cage structure to nucleation in protein cage subunit channels that exit close enough to those of other subunits and exiting mineral nuclei to facilitate bulk mineral formation. How and where protons move in and out of the protein during mineral synthesis and dissolution, how ferritin cage assembly with 12 or 24 subunits is encoded in the widely divergent ferritin amino acid sequences, and what is the role of the protein in synthesis of the bulk mineral are all described as problems requiring new approaches in future investigations of ferritin biominerals.

Avian magnetoreception: elaborate iron mineral containing dendrites in the upper beak seem to be a common feature of birds.

PubMed

Falkenberg, Gerald; Fleissner, Gerta; Schuchardt, Kirsten; Kuehbacher, Markus; Thalau, Peter; Mouritsen, Henrik; Heyers, Dominik; Wellenreuther, Gerd; Fleissner, Guenther

2010-02-16

The magnetic field sensors enabling birds to extract orientational information from the Earth's magnetic field have remained enigmatic. Our previously published results from homing pigeons have made us suggest that the iron containing sensory dendrites in the inner dermal lining of the upper beak are a candidate structure for such an avian magnetometer system. Here we show that similar structures occur in two species of migratory birds (garden warbler, Sylvia borin and European robin, Erithacus rubecula) and a non-migratory bird, the domestic chicken (Gallus gallus). In all these bird species, histological data have revealed dendrites of similar shape and size, all containing iron minerals within distinct subcellular compartments of nervous terminals of the median branch of the Nervus ophthalmicus. We also used microscopic X-ray absorption spectroscopy analyses to identify the involved iron minerals to be almost completely Fe III-oxides. Magnetite (Fe II/III) may also occur in these structures, but not as a major Fe constituent. Our data suggest that this complex dendritic system in the beak is a common feature of birds, and that it may form an essential sensory basis for the evolution of at least certain types of magnetic field guided behavior.

Iron Speciation in Minerals and Melts at High Pressure: Implications for the Redox Evolution of the Early Mantle

NASA Astrophysics Data System (ADS)

Armstrong, K.; Frost, D. J.; McCammon, C. A.; Rubie, D. C.; Boffa Ballaran, T.; Miyajima, N.

2016-12-01

During the differentiation of the early Earth, the silicates of the mantle must have been in equilibrium with core-forming metal iron, as indicated by the depletion of siderophile elements from the mantle. Studies of ancient rocks suggest that by at least 3.9 Ga, the upper mantle was 4-5 log units more oxidized than metal saturation implies (Delano 2001). The process(es) by which the mantle was oxidized is unclear, but has implications for the timing of accretion, differentiation, and volatile delivery to the early Earth, as well as evolution of the early atmosphere. One plausible oxidation mechanism is suggested by the tendency of high-pressure silicate minerals to favor Fe3+ over Fe2+ in their structures, even at metal saturation. This preference in the lower mantle mineral bridgmanite has been proposed to drive the disproportionation reaction of FeO to form Fe­2O3 and iron metal (Frost and McCammon 2008). We have performed experiments at the Ru-RuO2 fO2 buffer which show that silicate melts may mirror this behavior and Fe3+ may be stabilized with pressure for a constant fO2; by 21 GPa, the previously observed trend of Fe3+ decreasing with pressure (O'Neill, 2006) reverses and ferric iron content had increased. If this is also the case at lower oxygen fugacities, FeO disproportionation may have occurred at the base of an early magma ocean, establishing a redox gradient similar to what is presumed for the mantle today. Here we report results of further multianvil and diamond anvil cell experiments exploring the plausibility of FeO disproportionation driving mantle oxidation. Experiments investigating Fe speciation in high pressure melts at variable fO2 will be discussed along with results of diamond anvil cell experiments investigating ferric iron content of lower mantle minerals at metal saturation.

Adsorption of Se species on crushed granite: a direct linkage with its internal iron-related minerals.

PubMed

Jan, Yi-Lin; Wang, Tsing-Hai; Li, Ming-Hsu; Tsai, Shih-Chin; Wei, Yuan-Yaw; Teng, Shi-Ping

2008-01-01

The adsorption of selenium species on crushed granite is investigated directly linking to its internal iron-related minerals. Experimental results demonstrated that granite has higher affinity toward Se(IV) adsorption than Se(VI) adsorption. Se(IV) adsorption on granite is insensitive to background electrolytes while the effect of ionic strength on Se(VI) adsorption is not observed, which is attributed to the overloading of Se(VI) ions. Results of chemical sequential extraction showed that the removal of crystalline iron oxides dramatically reduces Se(IV) adsorption, which corresponds to the disappearance of goethite signal within XRD pattern. Based on our results, it is proposed that goethite within granite dominates Se adsorption in crushed granite. Although these goethites probably stem from some sample preparation processes including drilling in situ, crushing, washing and drying granite samples in laboratory, the formation of goethite enhances the granite affinity toward Se species adsorption. Images of SEM/EDS furthermore revealed that goethite is embedded within the fractures. In addition, quantification by standard addition method by spiking goethite suspension indicates that only around 20% of goethite minerals are available during Se(IV) adsorption.

Clay minerals behaviour in thin sandy clay-rich lacustrine turbidites (Lake Hazar, Turkey)

NASA Astrophysics Data System (ADS)

El Ouahabi, Meriam; Hubert-Ferrari, Aurelia; Lamair, Laura; Hage, Sophie

2017-04-01

Turbidites have been extensively studied in many different areas using cores or outcrop, which represent only an integrated snapshot of a dynamic evolving flow. Laboratory experiments provide the missing relationships between the flow characteristics and their deposits. In particular, flume experiments emphasize that the presence of clay plays a key role in turbidity current dynamics. Clay fraction, in small amount, provides cohesive strength to sediment mixtures and can damp turbulence. However, the degree of flocculation is dependent on factors such as the amount and size of clay particles, the surface of clay particles, chemistry and pH conditions in which the clay particles are dispersed. The present study focuses on thin clayey sand turbidites found in Lake Hazar (Turkey) occurring in stacked thin beds. Depositional processes and sources have been previously studied and three types were deciphered, including laminar flows dominated by cohesion, transitional, and turbulence flow regimes (Hage et al., in revision). For the purpose of determine the clay behavior in the three flow regimes, clay mineralogical, geochemical measurements on the cores allow characterising the turbidites. SEM observations provide further information regarding the morphology of clay minerals and other clasts. The study is particularly relevant given the highly alkaline and saline water of the Hazar Lake. Clay minerals in Hazar Lake sediments include kaolinite (1:1-type), illite and chlorite (2:1-type). Hazar lake water is alkaline having pH around 9.3, in such alkaline environment, a cation-exchange reaction takes place. Furthermore, in saline water (16‰), salts can act as a shield and decrease the repulsive forces between clay particle surfaces. So, pH and salt content jointly impact the behaviour of clays differently. Since the Al-faces of clay structures have a negative charge in basic solutions. At high pH, all kaolinite surfaces become negative-charged, and then kaolinite

Atmospheric transport of mineral dust from the Indo-Gangetic Plain: Temporal variability, acid processing, and iron solubility

NASA Astrophysics Data System (ADS)

Srinivas, Bikkina; Sarin, M. M.; Rengarajan, R.

2014-08-01

transport of chemical constituents from the Indo-Gangetic Plain (IGP) to the Bay of Bengal is a conspicuous seasonal feature that occurs during the late NE-monsoon (December-March). With this perspective, aerosol composition and abundance of mineral dust have been studied during November 2009 to March 2010 from a sampling site (Kharagpur: 22.3°N, 87.3°E) in the IGP, representing the atmospheric outflow to the Bay of Bengal. The chemical composition of PM2.5 suggests the dominance of nss-SO42- (6.9-24.3 µg m-3); whereas the abundance of mineral dust varied from 3 to 18 µg m-3. The concentration of aerosol iron (FeTot) and its fractional solubility (Fews % = Fews/FeTot *100, where Fews is the water-soluble fraction of FeTot) varied from 60 to 1144 ng m-3 and from 6.7 to 26.5%, respectively. A striking similarity in the temporal variability of total inorganic acidity (TIA = NO3- + nss-SO42-) and Fews (%) provides evidence for acid processing of mineral dust (alluvium) during atmospheric transport from the IGP. The contribution of TIA to water-soluble inorganic species [(nss-SO42- + NO3-)/ΣWSIS], mass ratios of Ca/Al and Fe/Al, and abundance of dust (%) and Fews (%) in the IGP-outflow are similar to the aerosol composition over the Bay of Bengal. With the rapid increase in anthropogenic activities over south and south-east Asia, the enhanced fractional solubility of aerosol iron (attributed to acid processing of mineral dust) has implications to further increase in the air-sea deposition of Fe to the Ocean surface.

Mineral resource of the month: Iron and steel

USGS Publications Warehouse

Fenton, Michael D.

2014-01-01

Iron is one of the most abundant elements on Earth, but it does not occur in nature in a useful metallic form. Although ancient people may have recovered some iron from meteorites, it wasn’t until smelting was invented that iron metal could be derived from iron oxides. After the beginning of the Iron Age in about 1200 B.C., knowledge of iron- and steelmaking spread from the ancient Middle East through Greece to the Roman Empire, then to Europe and, in the early 17th century, to North America. The first successful furnace in North America began operating in 1646 in what is now Saugus, Mass. Introduction of the Bessemer converter in the mid-19th century made the modern steel age possible.

Microstructures of the Kirsehir Complex, Central Turkey

NASA Astrophysics Data System (ADS)

ISIK, V.; Caglayan, A.; Uysal, T.; Bolhar, R.

2011-12-01

Turkey is positioned on the boundary between the Eurasian and African/Arabian plates, providing an ideal natural laboratory for learning passive and active earth processes such as deformation, metamorphism, earthquakes and volcanism. Central Turkey historically has played an important role in evolution of the Alpine orogeny. The Kirsehir Complex is one of three Mesozoic-Early Tertiary metamorphic and plutonic mid-crustal basement units exposed in central Turkey. The most common lithology of the metamorphites are the banded gneisses, which are intercalated with layers of schists, amphibolites and quartzite, and marbles representing the structurally the highest metamorphites of the study area. The metamorphites are characterized by multiple folding episodes and overprinting faults (thrust, normal and strike-slip). These metamorphites reached peak metamorphic conditions of upper amphibolite facies, as indicated by local presence of clinopyroxene, sillimanite, hornblende, andalusite and garnet. Later, retrograde greenschist facies conditions were attained characterized by the alteration of feldspar and mafic minerals to muscovite and chlorite/actinolite, respectively. The microstructures of selected minerals can be used to bracket the metamorphic grade during which microstructure formed. Quartz displays undulose extinction, deformation bands, subgrains and deformation lamellae, and recrystallisation. The presence of lobate grain boundaries of quartz indicates that GBM recrystallisation occurred. Undulose extinction and recrystallisation are common in micas. Recrystallisation, core-mantle structures in feldspar, myrmekites in K-feldspars within the gneisses suggest that deformation occurred within the amphibolite facies. Garnet occurs as slightly elliptical porphroclats. Sillimanite is present as fibrolite growing near biotite and microboudinaged. Andalusite porphyroblast/porphroclats are elongate and microboudinaged. Kinematic indicators (asymmetric mantled grains, S

The effects of metamorphism on iron mineralogy and the iron speciation redox proxy

NASA Astrophysics Data System (ADS)

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

Fe-Impregnated Mineral Colloids for Peroxide Activation: Effects of Mineral Substrate and Fe Precursor.

PubMed

Li, Yue; Machala, Libor; Yan, Weile

2016-02-02

Heterogeneous iron species at the mineral/water interface are important catalysts for the generation of reactive oxygen species at circumneutral pH. One significant pathway leading to the formation of such species arises from deposition of dissolved iron onto mineral colloids due to changes in redox conditions. This study investigates the catalytic properties of Fe impregnated on silica, alumina, and titania nanoparticles (as prototypical mineral colloids). Fe impregnation was carried out by immersing the mineral nanoparticles in dilute Fe(II) or Fe(III) solutions at pH 6 and 3, respectively, in an aerobic environment. The uptake of iron per unit surface area follows the order of nTiO2 > nAl2O3 > nSiO2 for both types of Fe precursors. Impregnation of mineral particles in Fe(II) solutions results in predominantly Fe(III) species due to efficient surface-mediated oxidation. The catalytic activity of the impregnated solids to produce hydroxyl radical (·OH) from H2O2 decomposition was evaluated using benzoic acid as a probe compound under dark conditions. Invariably, the rates of benzoic acid oxidation with different Fe-laden particles increase with the surface density of Fe until a critical density above which the catalytic activity approaches a plateau, suggesting active Fe species are formed predominantly at low surface loadings. The critical surface density of Fe varies with the mineral substrate as well as the aqueous Fe precursor. Fe impregnated on TiO2 exhibits markedly higher activity than its Al2O3 and SiO2 counterparts. The speciation of interfacial Fe is analyzed with diffuse reflectance UV-vis analysis and interpretation of the data in the context of benzoic oxidation rates suggests that the surface activity of the solids for ·OH generation correlates strongly with the isolated (i.e., mononuclear) Fe species. Therefore, iron dispersed on mineral colloids is a significant form of reactive iron surfaces in the aquatic environment.

Characterization of iron and manganese minerals and their associated microbiota in different mine sites to reveal the potential interactions of microbiota with mineral formation.

PubMed

Park, Jin Hee; Kim, Bong-Soo; Chon, Chul-Min

2018-01-01

Different environmental conditions such as pH and dissolved elements of mine stream induce precipitation of different minerals and their associated microbial community may vary. Therefore, mine precipitates from various environmental conditions were collected and their associated microbiota were analyzed through metagenomic DNA sequencing. Various Fe and Mn minerals including ferrihydrite, schwertmannite, goethite, birnessite, and Mn-substituted δ-FeOOH (δ-(Fe 1-x , Mn x )OOH) were found in the different environmental conditions. The Fe and Mn minerals were enriched with toxic metal(loid)s including As, Cd, Ni and Zn, indicating they can act as scavengers of toxic metal(loid)s in mine streams. Under acidic conditions, Acidobacteria was dominant phylum and Gallionella (Fe oxidizing bacteria) was the predominant genus in these Fe rich environments. Manganese oxidizing bacteria, Hyphomicrobium, was found in birnessite forming environments. Leptolyngbya within Cyanobacteria was found in Fe and Mn oxidizing environments, and might contribute to Fe and Mn oxidation through the production of molecular oxygen. The potential interaction of microbial community with minerals in mine sites can be traced by analysis of microbial community in different Fe and Mn mineral forming environments. Iron and Mn minerals contribute to the removal of toxic metal(loid)s from mine water. Therefore, the understanding characteristics of mine precipitates and their associated microbes helps to develop strategies for the management of contaminated mine water. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mineral resource of the month: iron oxide pigments

USGS Publications Warehouse

,

2008-01-01

The article discusses iron oxide pigments, which have been used as colorants since human began painting as they resist color change due to sunlight exposure, have good chemical resistance and are stable under normal ambient conditions. Cyprus, Italy and Spain are among the countries that are known for the production of iron oxide pigments. Granular forms of iron oxides and nano-sized materials are cited as developments in the synthetic iron oxide pigment industry which are being used in computer disk drives and nuclear magnetic resonance imaging.

Binding of heavy metal ions in aggregates of microbial cells, EPS and biogenic iron minerals measured in-situ using metal- and glycoconjugates-specific fluorophores

NASA Astrophysics Data System (ADS)

Hao, Likai; Guo, Yuan; Byrne, James M.; Zeitvogel, Fabian; Schmid, Gregor; Ingino, Pablo; Li, Jianli; Neu, Thomas R.; Swanner, Elizabeth D.; Kappler, Andreas; Obst, Martin

2016-05-01

Aggregates consisting of bacterial cells, extracellular polymeric substances (EPS) and Fe(III) minerals formed by Fe(II)-oxidizing bacteria are common at bulk or microscale chemical interfaces where Fe cycling occurs. The high sorption capacity and binding capacity of cells, EPS, and minerals controls the mobility and fate of heavy metals. However, it remains unclear to which of these component(s) the metals will bind in complex aggregates. To clarify this question, the present study focuses on 3D mapping of heavy metals sorbed to cells, glycoconjugates that comprise the majority of EPS constituents, and Fe(III) mineral aggregates formed by the phototrophic Fe(II)-oxidizing bacteria Rhodobacter ferrooxidans SW2 using confocal laser scanning microscopy (CLSM) in combination with metal- and glycoconjugates-specific fluorophores. The present study evaluated the influence of glycoconjugates, microbial cell surfaces, and (biogenic) Fe(III) minerals, and the availability of ferrous and ferric iron on heavy metal sorption. Analyses in this study provide detailed knowledge on the spatial distribution of metal ions in the aggregates at the sub-μm scale, which is essential to understand the underlying mechanisms of microbe-mineral-metal interactions. The heavy metals (Au3+, Cd2+, Cr3+, CrO42-, Cu2+, Hg2+, Ni2+, Pd2+, tributyltin (TBT) and Zn2+) were found mainly sorbed to cell surfaces, present within the glycoconjugates matrix, and bound to the mineral surfaces, but not incorporated into the biogenic Fe(III) minerals. Statistical analysis revealed that all ten heavy metals tested showed relatively similar sorption behavior that was affected by the presence of sorbed ferrous and ferric iron. Results in this study showed that in addition to the mineral surfaces, both bacterial cell surfaces and the glycoconjugates provided most of sorption sites for heavy metals. Simultaneously, ferrous and ferric iron ions competed with the heavy metals for sorption sites on the organic

Mixed-valence iron minerals on Venus: Fe(2+)-Fe(3+) oxides and oxy-silicates formed by surface-atmosphere interactions

NASA Technical Reports Server (NTRS)

Burns, Roger G.; Straub, Darcy W.

1992-01-01

Inferences from these investigations are that Fe(3+)-bearing minerals such as hematite magnesioferrite, acmite, and epidote are thermodynamically unstable, and that magnetite is the predominant mixed-valence iron oxide mineral on venus. Recently, the Fe(2+)-Fe(3+) silicate mineral laihunite was proposed to be a reaction product of olivine with the venusian atmosphere. This possibility is discussed further here. We suggest that other mixed-valence Fe(2+)-Fe(3+)-Oz-OH(-) silicates could also result from surface-atmosphere interactions on Venus. Topics discussed include the following: (1) conversion of hematite to magnetite; (2) stability of laihunite; (3) the possible existence of oxy-amphiboles and oxy-micas on Venus; and (4) other mixed-valence Fe(2+)-Fe(3+) silicates likely to exist on Venus.

Raman Spectroscopic Characterisation of Australian Banded Iron Formation and Iron Ore

NASA Astrophysics Data System (ADS)

Wells, M. A.; Ramanaidou, E. R.

2012-04-01

In Australia and world-wide over the past 5-10 years, declining reserves of premium, high-grade (>64% Fe), low-P bearing iron ore, have seen iron ore producers increase their utilisation of lower Fe-grade, higher P/Al/Si ore. In Australia, the channel iron deposits (CID), bedded iron deposits (BID) and, more recently, BIF-derived magnetite iron deposits (MID) have seen increased usage driven mainly by the increased demand from Chinese steel mills (Ramanaidou and Wells, 2011). Efficient exploitation and processing of these lower-grade iron ores requires a detailed understanding of their iron oxide and gangue mineralogy and geochemistry. The common Fe-bearing minerals (e.g., hematite, magnetite, goethite and kenomagnetite) in these deposits, as well as gangue minerals such as quartz and carbonates, are all strongly Raman active (e.g., de Faria et al., 1997). Their distinct Raman spectra enable them to be easily detected and mapped in situ in either unprepared material or samples prepared as polished blocks. In this paper, using representative examples of Australian CID ore, martite-goethite bedded iron deposit (BID) ore and banded iron formation (BIF) examined as polished blocks, we present a range of Raman spectra of the key iron ore minerals, and discuss how Raman spectroscopy can be applied to characterising iron ore mineralogy. Raman imaging micrographs, obtained using a StreamLine Plus Raman imaging system, clearly identified the main Fe-oxide and gangue components in the CID, BID and BIF samples when compared to optical micrographs. Raman analysis enabled the unequivocal identification of diamond in the CID ore as a contaminant from the polishing paste used to prepare the sample, and confirmed the presence of hematite in the BID ore in the form of martite, which can be morphologically similar to magnetite and, thus, difficult to otherwise distinguish. Image analysis of Raman mineral maps could be used to quantify mineral abundance based on the number of 'pixels

Role of glutaredoxin 3 in iron homeostasis

USDA-ARS?s Scientific Manuscript database

Iron is an essential mineral nutrient that is tightly regulated through mechanisms involving iron regulatory genes, intracellular storage, and iron recycling. Dysregulation of these mechanisms often results in either excess tissue iron accumulation (overload) or iron deficiency (anemia). Many bioche...

Mineral resource of the month: feldspar

USGS Publications Warehouse

,

2011-01-01

The article focuses on feldspar, a mineral that composes of potassium, sodium, or a fusion of the two, and its various applications. According to estimates by scientists, the mineral is present at 60 percent of the crust of Earth, wherein it is commonly used for making glass and ceramics. Global mining of feldspar was about 20 million metric tons in 2010, wherein Italy, Turkey, and China mine 55 percent of the feldspar worldwide.

An Example of Cyprus type Volcanogenic Massive Sulfide Deposit in the Southeast of Turkey

NASA Astrophysics Data System (ADS)

Kang, J.; Lee, I.; Donmez, C.; Yildirim, N.; Chang, S.

2013-12-01

Ortaklar mineral deposit of Gaziantep province in Turkey is located in the Southeast Anatolian orogenic belt which was developed as a result of closure of Neotethyan ocean, between Tauride (at north) and Arabian platform (at south), during upper Cretaceous-Miocene periods. Copper mineralization is in spilitic basalt and pillow lavas of Kocali complex. The complex includes oceanic fragments that represent serpentinite, mafic and ultramafic cumulates, isotropic gabbros, sheeted dyke complexes, spilitic basalt, pillow lavas, and radiolarian chert. The deposit is generally parallel to the thrust lines (E-W/30-60 North). Ore minerals occur in massive form and also as stockwork or disseminated forms at subsurface. Oxidized zone appears about 1 km in width at surface. The orebody is underlain and contacted with radiolarian chert. The samples mainly have been collected from open pit but also include some core samples. The samples were examined with unaided eyes and under microscope. In basalts, clino-pyroxenes subophitically enclose laths of plagioclases. Amygdales are filled with calcite in spilitic basalts and it is heavily chloritized and cut by calcite veins. In some parts of basalt, crystobalite is intergrowth with plagioclas. Globules between laths of plagioclase are also observed due to liquid immiscibility. Cherts have spherical radiolaria skeletons and their long thin spines. A lot of carbonate veinlets are developed as well. Few samples of cherts have radialfibrous quartz, known as chalcedonic quartz. Serpentinites in the study area are divided into two types on the basis of the existence of relics of the original minerals. One has relict crystals of olivine or pyroxene within the network of serpenitine and the other has no mineral remnants. Both types have opaque iron oxides with some brown stains among small blocks by numerous veinlets. Major ore minerals consist of chalcopyrite, pyrite, magnetite, and hematite. Minor ore minerals are composed of bornite

Occurrence and problems of high fluoride waters in Turkey: an overview.

PubMed

Oruc, Nazmi

2008-08-01

Endemic dental fluorosis was first observed in Turkey in Isparta Province, located in the SW of Anatolia, with mottled enamel related to the high levels of fluoride (1.5-4.0 ppm) in drinking waters, about 55 years ago. The origin of fluoride was attributed to the contents of minerals in volcanic rocks, consisting of pyroxene, hornblende, biotite, fluorapatite and glassy groundmass minerals. It was also reported about 35 years ago that severe dental and skeletal fluorosis has been observed in human beings and livestock in Dogubeyazit and Caldiran areas, located around Tendurek Volcano in eastern Turkey, where natural waters contained fluoride levels between 2.5 and 12.5 ppm. It was hypothesised that fluoride, which might be transported by fumaroles or escaped from devitrified lavas, could be held on the surface of some minerals and then exchanged with OH(-) in ground waters with high pH at the foothills of the young Tendurek Volcano. Endemic dental and skeletal fluorosis was also observed in the inhabitants in Kizilcaoren Village of Beylikova Town in Eskişehir Province situated in the midwest of Turkey, where the fluoride content of the drinking waters ranged from 3.9 to 4.8 ppm. The origin of high fluoride in the natural waters was related to the fluorspar deposits, occurring in the catchment area near the village. During the survey in the Güllü Village of Esme-Usak, located in south-midwest of Turkey, it was observed that most of the inhabitants born and raised in the village and aged between 10 and 30 years, showed mild to moderate levels of mottled enamel. The fluoride contents of the deep well waters used for drinking in the village, varied from 0.7 to 2.0 ppm. Amorphous microscopic fluorite existing in the Pliocene lake limestones was considered as a possible origin of fluoride in the waters.

Activation of Hydrogen Peroxide by Iron-Containing Minerals and Catalysts in Circumneutral pH Solutions: Implications for ex situ and in situ Treatment of Contaminated Water and Soil

NASA Astrophysics Data System (ADS)

Pham, Anh Le Tuan

The decomposition of hydrogen peroxide (H2O2) on iron minerals can generate hydroxyl radical (•OH), a strong oxidant capable of transforming a wide range of contaminants. This reaction is critical to ex situ advanced oxidation processes employed in waste treatment systems, as well as in situ chemical oxidation processes used for soil and groundwater remediation. Unfortunately, the process in the ex situ treatment systems is relatively inefficient at circumneutral pH values. In this research, the development of iron-containing catalysts with improved efficiency was investigated. In addition, little is known about the factors that control the performance of in situ treatment systems. Another aim of this dissertation was to elucidate those factors to provide a basis for improving the efficiency of the remediation method. Two types of silica- and alumina-containing iron (hydr)oxide catalysts were synthesized by sol-gel processing techniques (Chapter 2). Relative to iron oxides, such as hematite and goethite, these catalysts were 10 to 80 times more effective in catalyzing the production of •OH from H2O2 under circumneutral conditions. The higher efficiency makes these catalysts promising candidates for ex situ advanced oxidation processes. Moreover, because alumina and silica alter the reactivity of the iron oxides with H2O2, understanding the activity of iron associated with natural aluminosilicates and silica-containing minerals in the subsurface is crucial to explaining the variability of •OH production observed in in situ treatment systems. In addition to the sol-gel technique used in Chapter 2, silica-containing iron (hydr)oxide catalysts were synthesized by immobilizing iron oxide onto mesoporous silica supports, such as SBA-15 (Chapter 5). The iron-containing SBA-15 was 10 times more effective than iron oxides in catalyzing the production of •OH from H2O2. Moreover, this catalyst could be employed for selective oxidation of small organic contaminants

Are iron-phosphate minerals a sink for phosphorus in anoxic Black Sea sediments?

PubMed

Dijkstra, Nikki; Kraal, Peter; Kuypers, Marcel M M; Schnetger, Bernhard; Slomp, Caroline P

2014-01-01

Phosphorus (P) is a key nutrient for marine organisms. The only long-term removal pathway for P in the marine realm is burial in sediments. Iron (Fe) bound P accounts for a significant proportion of this burial at the global scale. In sediments underlying anoxic bottom waters, burial of Fe-bound P is generally assumed to be negligible because of reductive dissolution of Fe(III) (oxyhydr)oxides and release of the associated P. However, recent work suggests that Fe-bound P is an important burial phase in euxinic (i.e. anoxic and sulfidic) basin sediments in the Baltic Sea. In this study, we investigate the role of Fe-bound P as a potential sink for P in Black Sea sediments overlain by oxic and euxinic bottom waters. Sequential P extractions performed on sediments from six multicores along two shelf-to-basin transects provide evidence for the burial of Fe-bound P at all sites, including those in the euxinic deep basin. In the latter sediments, Fe-bound P accounts for more than 20% of the total sedimentary P pool. We suggest that this P is present in the form of reduced Fe-P minerals. We hypothesize that these minerals may be formed as inclusions in sulfur-disproportionating Deltaproteobacteria. Further research is required to elucidate the exact mineral form and formation mechanism of this P burial phase, as well as its role as a sink for P in sulfide-rich marine sediments.

Iron Determination in Meat Using Ferrozine Assay

NASA Astrophysics Data System (ADS)

Carpenter, Charles; Ward, Robert

Chromogens are chemicals that react with compounds of interest and form colored products that can be quantified using spectroscopy. Several chromogens that selectively react with minerals are available. In this lab, ferrozine is used to measure ferrous iron in an ashed food sample. The relationship between the absorbance of the chromogen-mineral complex is described by Beer's Law; in this procedure, a standard curve is generated with a stock iron solution to quantify the mineral in beef samples.

Electron Transfer Strategies Regulate Carbonate Mineral and Micropore Formation.

PubMed

Zeng, Zhirui; Tice, Michael M

2018-01-01

Some microbial carbonates are robust biosignatures due to their distinct morphologies and compositions. However, whether carbonates induced by microbial iron reduction have such features is unknown. Iron-reducing bacteria use various strategies to transfer electrons to iron oxide minerals (e.g., membrane-bound enzymes, soluble electron shuttles, nanowires, as well as different mechanisms for moving over or attaching to mineral surfaces). This diversity has the potential to create mineral biosignatures through manipulating the microenvironments in which carbonate precipitation occurs. We used Shewanella oneidensis MR-1, Geothrix fermentans, and Geobacter metallireducens GS-15, representing three different strategies, to reduce solid ferric hydroxide in order to evaluate their influence on carbonate and micropore formation (micro-size porosity in mineral rocks). Our results indicate that electron transfer strategies determined the morphology (rhombohedral, spherical, or long-chained) of precipitated calcium-rich siderite by controlling the level of carbonate saturation and the location of carbonate formation. Remarkably, electron transfer strategies also produced distinctive cell-shaped micropores in both carbonate and hydroxide minerals, thus producing suites of features that could potentially serve as biosignatures recording information about the sizes, shapes, and physiologies of iron-reducing organisms. Key Words: Microbial iron reduction-Micropore-Electron transfer strategies-Microbial carbonate. Astrobiology 18, 28-36.

Near-infrared spectral reflectance of mineral mixtures - Systematic combinations of pyroxenes, olivine, and iron oxides

NASA Technical Reports Server (NTRS)

Singer, R. B.

1981-01-01

Near-infrared spectral reflectance data are presented for systematic variations in weight percent of two component mixtures of ferromagnesium and iron oxide minerals used to study the dark materials on Mars. Olivine spectral features are greatly reduced in contrast by admixture of other phases but remain distinctive even for low olivine contents. Clinopyroxene and orthopyroxene mixtures show resolved pyroxene absorptions near 2 microns. Limonite greatly modifies pyroxene and olivine reflectance, but does not fully eliminate distinctive spectral characteristics. Using only spectral data in the 1 micron region, it is difficult to differentiate orthopyroxene and limonite in a mixture. All composite mineral absorptions were either weaker than or intermediate in strength to the end-member absorptions and have bandwidths greater than or equal to those for the end members. In general, spectral properties in an intimate mixture combine in a complex, nonadditive manner, with features demonstrating a regular but usually nonlinear variation as a function of end-member phase proportions.

Culturable microorganisms associated with Sishen iron ore and their potential roles in biobeneficiation.

PubMed

Adeleke, Rasheed; Cloete, T E; Khasa, D P

2012-03-01

With one of the largest iron ore deposits in the world, South Africa is recognised to be among the top ten biggest exporters of iron ore. Increasing demand and consumption of this mineral triggered search for processing technologies, which can be utilised to "purify" the low-grade iron ore minerals that contain high levels of unwanted potassium (K) and phosphorus (P). This study investigated a potential biological method that can be further developed for the full biobeneficiation of low-grade iron ore minerals. Twenty-three bacterial strains that belong to Proteobacteria, Firmicutes, Bacteroidetes and Actinobateria were isolated from the iron ore minerals and identified with sequence homology and phylogenetic methods. The abilities of these isolates to lower the pH of the growth medium and solubilisation of tricalcium phosphate were used to screen them as potential mineral solubilisers. Eight isolates were successfully screened with this method and utilised in shake flask experiments using iron ore minerals as sources of K and P. The shake flask experiments revealed that all eight isolates have potentials to produce organic acids that aided the solubilisation of the iron ore minerals. In addition, all eight isolates produced high concentrations of gluconic acid followed by relatively lower concentrations of acetic, citric and propanoic acid. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analyses also indicated extracellular polymeric substances could play a role in mineral solubilisation.

X-ray photoelectron spectroscopic study of water adsorption on iron sulphide minerals

NASA Astrophysics Data System (ADS)

Knipe, S. W.; Mycroft, J. R.; Pratt, A. R.; Nesbitt, H. W.; Bancroff, G. M.

1995-03-01

Samples of natural pyrrhotite and pyrite were fractured within the analytical chamber of an X-ray photoelectron spectrometer. The pristine mineral surfaces were then exposed, in the absence of oxygen, to total doses of 100, 200, 400, 800, 1400, 28,000, and 300,000 Langmuirs (L) of D2O. X-ray photoelectron spectroscopic (XPS) analyses were performed between each water dose, to investigate the interaction of these iron sulphide surfaces with water vapour. Recorded Fe and S photoelectron spectra showed no evidence of oxidation products on either mineral, even at highest D2O doses, nor could an oxide oxygen signal be fitted in the spectra for either mineral. On pyrrhotite, the O 1s spectra are composed of contributions from dominantly hydroxyl (at 532.0 ± 0.2 eV ) and subordinate chemisorbed water (at 533.5 ± 0.2 eV) signals. The main O is peak on pyrite is also formed from hydroxyl (531.0 ± 0.3 eV) and adsorbed water/hydroxyl (at 532.3 eV) signals. However, some O is spectra recorded on pyrite have peaks at anomalously high binding energies (>535 eV ). The anomalous high binding energy species are attributed to electrically-isolated OH/H2O, as reported elsewhere, and to liquid-like water, which has not previously been described in the literature. Pyrrhotite and pyrite interact with water via fundamentally different processes. Pyrrhotite reaction involves the donation of electron charge through Fe vacancies, whereas the water species detected on pyrite interact with the Fe 3d (eg) molecular orbital, and it is suggested that hydrogen bonding with the disulphide moiety may be important.

Rare earth element content of cryptocrystalline magnesites of Konya, Turkey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zedef, Veysel, E-mail: vzedef@selcuk.edu.tr; Russell, Michael

We examined the rare earth element content of several cryptocrystalline magnesites as well as hydromagnesite, host rock serpentinites, lake water and hot spring water from Turkey. Southwestern Turkey hosts cryptocrystalline magnesites, sedimentary magnesites with presently forming, biologically mediated hydromagnesites and travertines. Our results show the REE content of the minerals, rocks and waters are well below detection limits. One hydromagnesite sample from Lake Salda has slightly high La (2.38ppb), Ce (3.91 ppb) and Nd (1.68 ppb) when compared to other samples, but these are also still below detection limits of the method we followed.

Effects of Radiation and a High Iron Load on Bone Mineral Density

NASA Technical Reports Server (NTRS)

Yuen, E.; Morgan, J. L. L.; Zwart, S. R.; Gonzales, E.; Camp, K.; Smith, S. M.; Bloomfield, S. A.

2012-01-01

Astronauts on long duration space flight missions to the moon or mars are exposed to radiation and have increase iron (Fe) stores, both of which can independently induce oxidative stress and may exacerbate bone mass loss and strength. We hypothesize a high Fe diet and a fractionated gamma radiation exposure would increase oxidative stress and lower bone mass. Three mo-old, SD rats (n=32) were randomized to receive an adequate Fe diet (45 mg Fe/kg diet) or a high Fe diet (650 mg Fe/kg diet) for 4 wks and either a cumulative 3 Gy dose (fractionated 8 x 0.375 Gy) of gamma radiation (Cs-137) or sham exposure starting on day 14. Elisa kit assessed serum catalase, clinical analyzer assessed serum Fe status and ex vivo pQCT scans measured bone parameters in the proximal/midshaft tibia and femoral neck. Mechanical strength was assessed by 3-pt bending and femoral neck test. There is a significant decrease in trabecular bone mineral density (BMD) from radiation (p less than 0.05) and a trend in diet (p=0.05) at the proximal tibia. There is a significant interaction in cortical BMD from the combined treatments at the midshaft tibia (p less than 0.05). There is a trending decrease in total BMD from diet (p=0.07) at the femoral neck. In addition, high serum Fe was correlated to low trabecular BMD (p less than 0.05) and high serum catalase was correlated to low BMD at all 3 bone sites (p less than 0.05). There was no difference in the max load of the tibia or femoral neck. Radiation and a high iron diet increases iron status and catalase in the serum and decreases BMD.

Role of evaporitic sulfates in iron skarn mineralization: a fluid inclusion and sulfur isotope study from the Xishimen deposit, Handan-Xingtai district, North China Craton

NASA Astrophysics Data System (ADS)

Wen, Guang; Bi, Shi-Jian; Li, Jian-Wei

2017-04-01

The Xishimen iron skarn deposit in the Handan-Xingtai district, North China Craton, contains 256 Mt @ 43 % Fe (up to 65 %). The mineralization is dominated by massive magnetite ore along the contact zone between the early Cretaceous Xishimen diorite stock and middle Ordovician dolomite and dolomitic limestones with numerous intercalations of evaporitic beds. Minor lenticular magnetite-dominated bodies also occur in the carbonate rocks proximal to the diorite stock. Hydrothermal alteration is characterized by extensive albitization within the diorite stock and extreme development of magnesian skarn along the contact zone consisting of diopside, forsterite, serpentine, tremolite, phlogopite, and talc. Magmatic quartz and amphibole from the diorite and hydrothermal diopside from the skarns contain abundant primary or pseudosecondary fluid inclusions, most of which have multiple daughter minerals dominated by halite, sylvite, and opaque phases. Scanning electron microscopy (SEM) and laser Raman spectrometry confirm that pyrrhotite is the predominant opaque phase in most fluid inclusions, in both the magmatic and skarn minerals. These fluid inclusions have total homogenization temperatures of 416-620 °C and calculated salinities of 42.4-74.5 wt% NaCl equiv. The fluid inclusion data thus document a high-temperature, high-salinity, ferrous iron-rich, reducing fluid exsolved from a cooling magma likely represented by the Xishimen diorite stock. Pyrite from the iron ore has δ34S values ranging from 14.0 to 18.6 ‰, which are significantly higher than typical magmatic values (δ34S = 0 ± 5 ‰). The sulfur isotope data thus indicate an external source for the sulfur, most likely from the evaporitic beds in the Ordovician carbonate sequences that have δ34S values of 24 to 29 ‰. We suggest that sulfates from the evaporitic beds have played a critically important role by oxidizing ferrous iron in the magmatic-hydrothermal fluid, leading to precipitation of massive

Application Of Bacterial Iron Reduction For The Removal Of Iron Impurities From Industrial Silica Sand And Kaolin

NASA Astrophysics Data System (ADS)

Zegeye, A.; Yahaya, S.; Fialips, C. I.; White, M.; Manning, D. A.; Gray, N.

2008-12-01

Biogeochemical evidence exists to support the potential importance of crystalline or amorphous Fe minerals as electron acceptor for Fe reducing bacteria in soils and subsurface sediments. This microbial metabolic activity can be exploited as alternative method in different industrial applications. For instance, the removal of ferric iron impurities from minerals for the glass and paper industries currently rely on physical and chemical treatments having substantial economical and environmental disadvantages. The ability to remove iron by other means, such as bacterial iron reduction, may reduce costs, allow lower grade material to be mined, and improve the efficiency of mineral processing. Kaolin clay and silica sand are used in a wide range of industrial applications, particularly in paper, ceramics and glass manufacturing. Depending on the geological conditions of deposition, they are often associated with iron (hydr)oxides that are either adsorbed to the mineral surfaces or admixed as separate iron bearing minerals. In this study, we have examined the Fe(III) removal efficiency from kaolin and silica sand by a series of iron- reducing bacteria from the Shewanella species (S. alga BrY, S. oneidensis MR-1, S. putrefaciens CN32 and S. putrefaciens ATCC 8071) in the presence of anthraquinone 2,6 disulfonate (AQDS). We have also investigated the effectiveness of a natural organic matter, extracted with the silica sand, as a substitute to AQDS for enhancing Fe(III) reduction kinetics. The microbial reduction of Fe(III) was achieved using batch cultures under non-growth conditions. The rate and the extent of Fe(III) reduction was monitored as a function of the initial Fe(III) content, Shewanella species and temperature. The bacterially- treated minerals were analyzed by transmission electron microscopy (TEM) and X-ray diffraction (XRD) to observe any textural and mineralogical transformation. The whiteness and ISO brightness of the kaolin was also measured by

Coupling of iron and organic matter under fluctuation redox conditions: implications for carbon turnover, mineral formation, and contaminant transport

NASA Astrophysics Data System (ADS)

Nico, P. S.

2015-12-01

Interactions between naturally occurring organic matter and minerals surfaces play a determining role on the transport, chemical composition, and bio-availability of reduced carbon. These processes are controlled on the molecular scale by mineral dissolution and precipitation dynamics which are in turn controlled by both changing solution chemistry and redox regime. The presentation will highlight recent work by our group and others on elucidating some of these mechanisms with particular emphasis on the impacts of redox cycling and Fe mineral transformation. We are particular interested in how the form of organic matter impacts the formation and transformation of iron minerals and vis-a-versa under fluctuating redox conditions, and how that in turn impacts the transport of other elements controlled by Fe surfaces, e.g. uranium. In two different field conditions, in a ground water well and at a ground water-surface water interface, Fe(II) was oxidized in an organic rich environment leading to different types of Fe-organic matter co-precipitates. We followed the evolution of those participates under a return to reduced conditions in order to understand the transformations, or lack thereof, of the Fe minerals and the fate of the associated organic matter.

Use of Bacteria To Stabilize Archaeological Iron

PubMed Central

Comensoli, Lucrezia; Maillard, Julien; Albini, Monica; Sandoz, Frederic

2017-01-01

ABSTRACT Iron artifacts are common among the findings of archaeological excavations. The corrosion layer formed on these objects requires stabilization after their recovery, without which the destruction of the item due to physicochemical damage is likely. Current technologies for stabilizing the corrosion layer are lengthy and generate hazardous waste products. Therefore, there is a pressing need for an alternative method for stabilizing the corrosion layer on iron objects. The aim of this study was to evaluate an alternative conservation-restoration method using bacteria. For this, anaerobic iron reduction leading to the formation of stable iron minerals in the presence of chlorine was investigated for two strains of Desulfitobacterium hafniense (strains TCE1 and LBE). Iron reduction was observed for soluble Fe(III) phases as well as for akaganeite, the most troublesome iron compound in the corrosion layer of archaeological iron objects. In terms of biogenic mineral production, differential efficiencies were observed in assays performed on corroded iron coupons. Strain TCE1 produced a homogeneous layer of vivianite covering 80% of the corroded surface, while on the coupons treated with strain LBE, only 10% of the surface was covered by the same mineral. Finally, an attempt to reduce iron on archaeological objects was performed with strain TCE1, which led to the formation of both biogenic vivianite and magnetite on the surface of the artifacts. These results demonstrate the potential of this biological treatment for stabilizing archaeological iron as a promising alternative to traditional conservation-restoration methods. IMPORTANCE Since the Iron Age, iron has been a fundamental material for the building of objects used in everyday life. However, due to its reactivity, iron can be easily corroded, and the physical stability of the object built is at risk. This is particularly true for archaeological objects on which a potentially unstable corrosion layer is

Biogenic iron oxide transformation by hyperthermophiles: spectral and physiological potentials

NASA Astrophysics Data System (ADS)

Kashyap, S.; Sklute, E.; Dyar, M. D.; Holden, J. F.

2017-12-01

It is likely that any putative life in our Solar System beyond Earth, extinct or extant, is microbial. However, to detect such life, distinct organic or mineral biosignatures need to be established. Microbe-mineral interactions and mineral transformations deserve further examination in this regard. This study focused on hyperthermophilic iron oxide-reducing archaea and addressed the types of iron-oxide minerals that are favored for growth, the kinetics of such reactions, and the mineral transformations that occur depending upon the electron acceptor. Two hyperthermophilic archaea (Pyrodictium delaneyi and Pyrobaculum islandicum) and six laboratory-synthesized nanophase iron oxide minerals (2-line ferrihydrite, lepidocrocite, akaganéite, goethite, hematite and maghemite) were tested for cell growth and Fe(II) production. The mineral end-products were further characterized by examining the spectral signatures associated with these transformations using reflectance, Raman, and Mössbauer spectroscopies and electron diffraction patterns. Additionally, we critically examined how sample preparation techniques influence the end products of these transformations by comparing freeze-dried samples against those still in solution. Results showed that both organisms utilize all six nanophase iron oxides, although with varying success. The best candidates for microbial reduction were ferrihydrite, akaganéite, and lepidocrocite. The mineral transformation products and the extent of reduction varied and showed subtle differences based on organism and the type of iron oxide used. The subtle spectral differences were best characterized using combined spectroscopy techniques. This research provides new insights into microbe-mineral interactions and the discrimination of potential biosignatures in the search for life beyond Earth.

Major and trace element composition of copiapite-group minerals and coexisting water from the Richmond mine, Iron Mountain, California

USGS Publications Warehouse

Jamieson, H.E.; Robinson, C.; Alpers, Charles N.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Peterson, Ronald C.

2005-01-01

Copiapite-group minerals of the general formula AR4 (SO4)6(OH)2??nH2O, where A is predominantly Mg, Fe2+, or 0.67Al3+, R is predominantly Fe3+, and n is typically 20, are among several secondary hydrous Fe sulfates occurring in the inactive mine workings of the massive sulfide deposit at Iron Mountain, CA, a USEPA Superfund site that produces extremely acidic drainage. Samples of copiapite-group minerals, some with coexisting water, were collected from the Richmond mine. Approximately 200 mL of brownish pore water with a pH of -0.9 were extracted through centrifugation from a 10-L sample of moist copiapite-group minerals taken from pyritic muck piles. The pore water is extremely rich in ferric iron (Fe3+=149 g L-1, FeT=162 g L-1 and has a density of 1.52 g mL-1. The composition of the pore water is interpreted in the context of published phase relations in the Fe2O3- SO3-H2O system and previous work on the chemistry of extremely acid mine waters and associated minerals in the Richmond mine. Two distinct members of the copiapite mineral group were identified in the samples with coexisting water: (1) abundant magnesiocopiapite consisting of platy crystals 10 to 50 ??m and (2) minor aluminocopiapite present as smaller platy crystals that form spheroidal aggregates. The average composition (n=5) of the magnesiocopiapite is (Mg0.90Fe0.172+ Zn0.02Cu0.01)???1.10(Fe3.833+Al0.09)???3.92(SO4) 6.00(OH)1.96??20H2O. Bulk compositions determined by digestion and wet-chemical analysis are consistent with the microanalytical results. These results suggest that magnesiocopiapite is the least soluble member of the copiapite group under the prevailing conditions. Micro-PIXE analysis indicates that the copiapite-group minerals in this sample sequester Zn (average 1420 ppm), with lesser amounts of Cu (average 270 ppm) and As (average 64 ppm). ?? 2004 Elsevier B.V. All rights reserved.

Exploring Iron Silicate Precursors of Ancient Iron Formations through Rock Record, Laboratory and Field Analogue Investigations

NASA Astrophysics Data System (ADS)

Johnson, J. E.; Rasmussen, B.; Muhling, J.; Benzerara, K.; Jezequel, D.; Cosmidis, J.; Templeton, A. S.

2016-12-01

In direct contrast to today's oceans, iron-rich chemical precipitates dominate the deep marine sedimentary record > 2.3 billion years ago. The deposition of these minerals resulted in massive iron formations and indicate that the ocean was previously ferruginous and largely anoxic. To precipitate and concentrate iron in the sediments, many hypotheses have centered on the oxidation of soluble Fe(II) to solid Fe(III)-oxyhydroxides; these ideas have stimulated extensive research using iron-oxidizing bacteria to produce Fe(III)-oxides and trace metal sorption experiments on Fe(III)-oxides, leading to inferences of trace metal availability and implications for enzymatic and microbial evolution as well as pO2 levels and seawater chemistry. However, recent discoveries of disseminated iron-silicate nanoparticles in early-silicifying chert indicate that iron-silicates may have instead been the primary precipitates from these Archean ferruginous oceans (Rasmussen et al, 2015). Considering the significant paradigm shift this discovery implies for interpretations of Archean elemental cycling, redox state and potential microbial metabolisms, we investigated these iron-silicate inclusions and their implications for ancient seawater chemistry in a multi-faceted approach using spectroscopic- and diffraction-based techniques. The crystal structure, Fe oxidation state and Fe coordination environment of iron-silicate nanoparticles have been interrogated using microscale X-ray absorption spectroscopy, TEM and nanoscale scanning transmission X-ray microscopy. To further explore the chemical and potential biological controls on iron-silicate formation, we have also performed laboratory experiments to mimic Archean seawater and precipitate iron-bearing silicate minerals under abiotic conditions and in the presence of iron-oxidizing bacteria. In a complementary study, sediments from a natural Archean analogue system were sampled to determine if iron-silicate minerals form in Mexican

Electron Transfer Strategies Regulate Carbonate Mineral and Micropore Formation

NASA Astrophysics Data System (ADS)

Zeng, Zhirui; Tice, Michael M.

2018-01-01

Some microbial carbonates are robust biosignatures due to their distinct morphologies and compositions. However, whether carbonates induced by microbial iron reduction have such features is unknown. Iron-reducing bacteria use various strategies to transfer electrons to iron oxide minerals (e.g., membrane-bound enzymes, soluble electron shuttles, nanowires, as well as different mechanisms for moving over or attaching to mineral surfaces). This diversity has the potential to create mineral biosignatures through manipulating the microenvironments in which carbonate precipitation occurs. We used Shewanella oneidensis MR-1, Geothrix fermentans, and Geobacter metallireducens GS-15, representing three different strategies, to reduce solid ferric hydroxide in order to evaluate their influence on carbonate and micropore formation (micro-size porosity in mineral rocks). Our results indicate that electron transfer strategies determined the morphology (rhombohedral, spherical, or long-chained) of precipitated calcium-rich siderite by controlling the level of carbonate saturation and the location of carbonate formation. Remarkably, electron transfer strategies also produced distinctive cell-shaped micropores in both carbonate and hydroxide minerals, thus producing suites of features that could potentially serve as biosignatures recording information about the sizes, shapes, and physiologies of iron-reducing organisms.

Iron oxide minerals in dust-source sediments from the Bodélé Depression, Chad: Implications for radiative properties and Fe bioavailability of dust plumes from the Sahara

USGS Publications Warehouse

Moskowitz, Bruce M; Reynolds, Richard L.; Goldstein, Harland L.; Beroquo, Thelma; Kokaly, Raymond F.; Bristow, Charlie S

2016-01-01

Atmospheric mineral dust can influence climate and biogeochemical cycles. An important component of mineral dust is ferric oxide minerals (hematite and goethite) which have been shown to influence strongly the optical properties of dust plumes and thus affect the radiative forcing of global dust. Here we report on the iron mineralogy of dust-source samples from the Bodélé Depression (Chad, north-central Africa), which is estimated to be Earth’s most prolific dust producer and may be a key contributor to the global radiative budget of the atmosphere as well as to long-range nutrient transport to the Amazon Basin. By using a combination of magnetic property measurements, Mössbauer spectroscopy, reflectance spectroscopy, chemical analysis, and scanning electron microscopy, we document the abundance and relative amounts of goethite, hematite, and magnetite in dust-source samples from the Bodélé Depression. The partition between hematite and goethite is important to know to improve models for the radiative effects of ferric oxide minerals in mineral dust aerosols. The combination of methods shows (1) the dominance of goethite over hematite in the source sediments, (2) the abundance and occurrences of their nanosize components, and (3) the ubiquity of magnetite, albeit in small amounts. Dominant goethite and subordinate hematite together compose about 2% of yellow-reddish dust-source sediments from the Bodélé Depression and contribute strongly to diminution of reflectance in bulk samples. These observations imply that dust plumes from the Bodélé Depression that are derived from goethite-dominated sediments strongly absorb solar radiation. The presence of ubiquitous magnetite (0.002–0.57 wt%) is also noteworthy for its potentially higher solubility relative to ferric oxide and for its small sizes, including PM < 0.1 μm. For all examined samples, the average iron apportionment is estimated at about 33% in ferric oxide minerals, 1.4% in magnetite, and 65

Phosphorus K-edge XANES spectroscopy of mineral standards

PubMed Central

Ingall, Ellery D.; Brandes, Jay A.; Diaz, Julia M.; de Jonge, Martin D.; Paterson, David; McNulty, Ian; Elliott, W. Crawford; Northrup, Paul

2011-01-01

Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy was performed on phosphate mineral specimens including (a) twelve specimens from the apatite group covering a range of compositional variation and crystallinity; (b) six non-apatite calcium-rich phosphate minerals; (c) 15 aluminium-rich phosphate minerals; (d) ten phosphate minerals rich in either reduced iron or manganese; (e) four phosphate minerals rich in either oxidized iron or manganese; (f) eight phosphate minerals rich in either magnesium, copper, lead, zinc or rare-earth elements; and (g) four uranium phosphate minerals. The identity of all minerals examined in this study was independently confirmed using X-ray powder diffraction. Minerals were distinguished using XANES spectra with a combination of pre-edge features, edge position, peak shapes and post-edge features. Shared spectral features were observed in minerals with compositions dominated by the same specific cation. Analyses of apatite-group minerals indicate that XANES spectral patterns are not strongly affected by variations in composition and crystallinity typical of natural mineral specimens. PMID:21335905

Mineral ecophysiological evidence for biogeochemical cycles in 2461-2495 million year old banded iron formations (BIF).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Y; Konhauser, Dr, Kurt; Cole, David

2011-01-01

The phosphorus composition of banded-iron formations (BIFs) has been used as a proxy for Precambrian seawater composition and the paleoeredox state of Earth's surface environment. However, it is unclear whether the phosphorus in BIFs originally entered the sediment as a sorbed component of the iron oxyhydroxide particles, or whether it was incorporated into the biomass of marine phytoplankton. We conducted high-resolution mineral analyses and report here the first detection of an Fe(III) acetate salt, as well as nanocrystals of apatite in association with magnetite, in the 2.48 Ga Dales Gorge Member of the Brockman Iron Formation (a BIF), Hamersley, Westernmore » Australia. The clusters of apatite are similar in size and morphology to biogenic apatite crystals resulting from biomass decay in Phanerozoic marine sediments, while the formation of an Fe(III) acetate salt and magnetite not only implies the original presence of biomass in the BIF sediments, but also that organic carbon likely served as an electron donor during bacterial Fe(III) reduction. This study is important because it suggests that phytoplankton may have played a key role in the transfer of phosphorus (and other trace elements) from the photic zone to the seafloor.« less

Vitamins, Minerals, and Mood

ERIC Educational Resources Information Center

Kaplan, Bonnie J.; Crawford, Susan G.; Field, Catherine J.; Simpson, J. Steven A.

2007-01-01

In this article, the authors explore the breadth and depth of published research linking dietary vitamins and minerals (micronutrients) to mood. Since the 1920s, there have been many studies on individual vitamins (especially B vitamins and Vitamins C, D, and E), minerals (calcium, chromium, iron, magnesium, zinc, and selenium), and vitamin-like…

Iron Isotopic Fractionation in Earth's Lower Mantle

NASA Astrophysics Data System (ADS)

Yang, H.; Lin, J. F.; Hu, M. Y.; Bi, W.; Zhao, J.; Alp, E. E.; Roskosz, M.; Dauphas, N.; Okuchi, T.

2017-12-01

The Earth's bulk chemical composition is vital for deciphering the origin of this planet. Our estimation of the iron isotopic composition of the bulk Earth relies on the iron isotopic composition difference between the metallic core and silicate mantle. Previous studies1,2,3 on this fractionation scale have mostly focused on the alloying effects of light elements in the iron metal phases, while the pressure effects of the silicate mantle phases especially due to iron partitioning4 in the lower mantle minerals have not been fully addressed. For instance, Polyakov (2009) simply assumed equal iron distribution between ferropericlase and post-perovskite in his model. Shahar et al. (2016) only used bridgmanite as a proxy for the mantle while another lower mantle mineral ferropericlase was neglected. Here we have investigated the force constant of iron bonds in lower-mantle ferropericlase and bridgmanite crystals up to 104GPa using NRIXS(Nuclear Resonant Inelastic X-ray Scattering) and SMS(Synchrotron Mössbauer Spectroscopy) in a diamond anvil cell at sector-3 of the Advance Photon Source. These results are used to evaluate the pressure effects as well as the spin/valence states of iron5,6 on the force constant of iron bonds and the iron isotope distributions within the lower mantle and at the core-mantle boundary. We found that the liquid-solid iron isotopic fractionation during magma ocean crystallization was limited, however, the inter-mineral fractionation between ferropericlase and bridgmanite could be significant influenced by the spin/valence states at the lowermost mantle conditions. 1.Polyakov, V. B. Science 323, 912-914 (2009). 2.Shahar, A. et al. Science 352, 580-582 (2016). 3.Liu, J. et al. Nat. Commun. 8, 14377 (2017). 4.Irifune, T. et al. Science 327, 193-195 (2010). 5.Lin, J. F., Speziale, S., Mao, Z. & Marquardt, Rev. Geophys. 51, 244-275 (2013). 6.Mao, Z. et al. Am. Mineral. 102 (2017).

The status of mineral trioxide aggregate in endodontics education in dental schools in Turkey.

PubMed

Tanalp, Jale; Karapinar-Kazandag, Meriç; Ersev, Handan; Bayirli, Gündüz

2012-06-01

The aim of this study was to assess the current status of mineral trioxide aggregate (MTA) as an educational material in dental schools in Turkey. A survey was sent to senior members of the endodontic departments of seventeen dental schools; fourteen responded. All respondents reported that they used MTA in their clinical practice, with apexification, perforations, retrograde fillings, and root resorptions being the most frequently occurring treatment procedures. All reported that information was given to students regarding MTA mainly as part of the curriculum. The third and fourth years were the periods when MTA was introduced to students in most of the schools. Twelve schools reported that students had the opportunity to observe procedures in which MTA was used, but students had the chance to use the material in a very minor proportion of the schools, mainly under the supervision of clinical instructors. Ten schools agreed that MTA should be included in the regular endodontic curriculum. Financial constraints seemed to be the predominant reason for those who answered this question negatively, followed by difficult handling properties and low radiopacity of the material. Within the limitations of this study, it can be concluded that ways should be sought to prevent financial difficulties from depriving dental students of the opportunity to receive information about contemporary methodologies such as MTA utilization.

Lithotrophic iron-oxidizing bacteria produce organic stalks to control mineral growth: implications for biosignature formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chan, Clara S; Fakra, Sirine C; Emerson, David

Neutrophilic Fe-oxidizing bacteria (FeOB) are often identified by their distinctive morphologies, such as the extracellular twisted ribbon-like stalks formed by Gallionella ferruginea or Mariprofundus ferrooxydans. Similar filaments preserved in silica are often identified as FeOB fossils in rocks. Although it is assumed that twisted iron stalks are indicative of FeOB, the stalk's metabolic role has not been established. To this end, we studied the marine FeOB M. ferrooxydans by light, X-ray and electron microscopy. Using time-lapse light microscopy, we observed cells excreting stalks during growth (averaging 2.2 {micro}m h(-1)). Scanning transmission X-ray microscopy and near-edge X-ray absorption fine structure (NEXAFS)more » spectroscopy show that stalks are Fe(III)-rich, whereas cells are low in Fe. Transmission electron microscopy reveals that stalks are composed of several fibrils, which contain few-nanometer-sized iron oxyhydroxide crystals. Lepidocrocite crystals that nucleated on the fibril surface are much larger ({approx}100 nm), suggesting that mineral growth within fibrils is retarded, relative to sites surrounding fibrils. C and N 1s NEXAFS spectroscopy and fluorescence probing show that stalks primarily contain carboxyl-rich polysaccharides. On the basis of these results, we suggest a physiological model for Fe oxidation in which cells excrete oxidized Fe bound to organic polymers. These organic molecules retard mineral growth, preventing cell encrustation. This model describes an essential role for stalk formation in FeOB growth. We suggest that stalk-like morphologies observed in modern and ancient samples may be correlated confidently with the Fe-oxidizing metabolism as a robust biosignature.« less

Formation of secondary minerals in a lysimeter approach - A mineral-microbe interaction

NASA Astrophysics Data System (ADS)

Schäffner, F.; Merten, D.; De Giudici, G.; Beyer, A.; Akob, D. M.; Ricci, P. C.; Küsel, K.; Büchel, G.

2012-04-01

Heavy metal contamination of large areas due to uranium mining operations poses a serious long-term environmental problem. In the Ronneburg district (eastern Thuringia, Germany), leaching of low grade uranium bearing ores (uranium content < 300 g/t) occurred from 1972 to 1990 using acid mine drainage (AMD; pH 2.7-2.8) and diluted sulphuric acid (10 g/l). Secondary mineral phases like birnessite, todorokite and goethite occur within a natural attenuation process associated with enrichment of heavy metals, especially Cd, Ni, Co, Cu and Zn due to a residual contamination even after remediation efforts. To reveal the processes of secondary mineral precipitation in the field a laboratory lysimeter approach was set up under in situ-like conditions. Homogenized soil from the field site and pure quartz sand were used as substrates. In general, in situ measurements of redox potentials in the substrates showed highly oxidizing conditions (200-750 mV). Water was supplied to the lysimeter from below via a mariottés bottle containing contaminated groundwater from the field. Evaporation processes were allowed, providing a continuous flow of water. This led to precipitation of epsomite and probably aplowite on the top layer of substrate, similar to what is observed in field investigations. After 4 weeks, the first iron and manganese bearing secondary minerals became visible. Soil water samples were used to monitor the behaviour of metals within the lysimeter. Saturation indices (SI) for different secondary minerals were calculated with PHREEQC. The SI of goethite showed oversaturation with respect to the soil solution. SEM-EDX analyses and IR spectroscopy confirmed the formation of goethite. Geochemical data revealed that goethite formation was mainly dominated by Eh/pH processes and that heavy metals, e.g. Zn and U, could be enriched in this phase. Although Eh/pH data does not support formation of manganese minerals, Mn(II)-oxidizing bacteria (MOB) could be isolated from field

Selenium, copper, zinc, iron levels and mortality in patients with sepsis and systemic inflammatory response syndrome in Western Black Sea Region, Turkey.

PubMed

Ayoglu, Hilal; Sezer, Ustun; Akin, Mehmet; Okyay, Dilek; Ayoglu, Ferruh; Can, Murat; Kucukosman, Gamze; Piskin, Ozcan; Aydin, Bengu; Cimencan, Murat; Gur, Abdullah; Turan, Isil

2016-04-01

To evaluate the changing levels of selenium, copper, zinc and iron in patients with sepsis and systemic inflammatory response syndrome and their influence on mortality. The prospective study was conducted at a tertiary care university hospital in Zonguldak city in the western Black Sea region of Turkey from January 2012 to December 2013, and comprised patients with sepsis and systemic inflammatory response syndrome. Blood samples were taken on 1st, 3rd, 5th and 7th days to measure serum selenium, copper, zinc and iron levels. Patients' demographic data, presence of additional diseases and mortality were recorded. Of the 57 patients, 28(49.1%) were female and 29(50.9%) were male, with an overall mean age of 60.3±19.4 years, mean height of 166.1±11.4cm, mean weight of 76.5±17.5kg. Copper and zinc levels were in the normal range, while selenium and iron levels were lower than the limit values at all measuring periods. There was no significant difference between first and other days in accordance with element levels (p>0.05). Baseline copper levels in patients with malignancy were lower than patients without malignancy (p< 0.05). In hypertensive patients, baseline copper levels were higher and 7th day levels were lower than non-hypertensive (p< 0.05). Baseline selenium levels of those who died were lower than the other patients (p< 0.05). Selenium and iron levels were decreased in patients with sepsis-systemic inflammatory response syndrome and copper levels were lower in patients with malignancy, hypertension and chronic obstructive pulmonary disease (p< 0.05). There was no change in zinc levels of the patients. Reduced basal selenium levels of patients with sepsis and systemic inflammatory response syndrome were associated with mortality.

Solubility relationships of aluminum and iron minerals associated with acid mine drainage

NASA Astrophysics Data System (ADS)

Sullivan, Patrick J.; Yelton, Jennifer L.; Reddy, K. J.

1988-06-01

The ability to properly manage the oxidation of pyritic minerals and associated acid mine drainage is dependent upon understanding the chemistry of the disposal environment. One accepted disposal method is placing pyritic-containing materials in the groundwater environment. The objective of this study was to examine solubility relationships of Al and Fe minerals associated with pyritic waste disposed in a low leaching aerobic saturated environment. Two eastern oil shales were used in this oxidizing equilibration study, a New Albany Shale (unweathered, 4.6 percent pyrite), and a Chattanooga Shale (weathered, 1.5 percent pyrite). Oil shale samples were equilibrated with distilled-deionized water from 1 to 180 d with a 1∶1 solid-to-solution ratio. The suspensions were filtered and the clear filtrates were analyzed for total cations and anions. Ion activities were calculated from total concentrations. Below pH 6.0, depending upon SO{4/2-} activity, Al3+ solubility was controlled by AlOHSO4 (solid phase) for both shales. Initially, Al3+ solubility for the New Albany Shale showed equilibrium with amorphous Al(OH)3. The pH decreased with time, and Al3+ solubility approached equilibrium with AlOHSO4(s). Below pH 6.0, Fe3+ solubility appeared to be regulated by a basic iron sulfate solid phase with the stoichiometric composition of FeOHSO4(s). The results of this study indicate that below pH 6.0, Al3+ solubilities, are limited by basic Al and Fe sulfate solid phases (AlOHSO4(s) and FeHSO4(s)). The results from this study further indicate that the acidity in oil shale waters is produced from the hydrolysis of Al3+ and Fe3+ activities in solution. These results indicate a fundamental change in the stoichiometric equations used to predict acidity from iron sulfide oxidation. The results of this study also indicate that water quality predictions associated with acid mine drainage can be based on fundamental thermodynamic relationships. As a result, waste management decisions

Coal fly ash as a source of iron in atmospheric dust.

PubMed

Chen, Haihan; Laskin, Alexander; Baltrusaitis, Jonas; Gorski, Christopher A; Scherer, Michelle M; Grassian, Vicki H

2012-02-21

Anthropogenic coal fly ash (FA) aerosol may represent a significant source of bioavailable iron in the open ocean. Few measurements have been made that compare the solubility of atmospheric iron from anthropogenic aerosols and other sources. We report here an investigation of iron dissolution for three FA samples in acidic aqueous solutions and compare the solubilities with that of Arizona test dust (AZTD), a reference material for mineral dust. The effects of pH, simulated cloud processing, and solar radiation on iron solubility have been explored. Similar to previously reported results on mineral dust, iron in aluminosilicate phases provides the predominant component of dissolved iron. Iron solubility of FA is substantially higher than of the crystalline minerals comprising AZTD. Simulated atmospheric processing elevates iron solubility due to significant changes in the morphology of aluminosilicate glass, a dominant material in FA particles. Iron is continuously released into the aqueous solution as FA particles break up into smaller fragments. These results suggest that the assessment of dissolved atmospheric iron deposition fluxes and their effect on the biogeochemistry at the ocean surface should be constrained by the source, environmental pH, iron speciation, and solar radiation.

Oxygen Extraction from Minerals

NASA Technical Reports Server (NTRS)

Muscatello, Tony

2017-01-01

Oxygen, whether used as part of rocket bipropellant or for astronaut life support, is a key consumable for space exploration and commercialization. In Situ Resource Utilization (ISRU) has been proposed many times as a method for making space exploration more cost effective and sustainable. On planetary and asteroid surfaces the presence of minerals in the regolith that contain oxygen is very common, making them a potential oxygen resource. The majority of research and development for oxygen extraction from minerals has been for lunar regolith although this work would generally be applicable to regolith at other locations in space. This presentation will briefly survey the major methods investigated for oxygen extraction from regolith with a focus on the current status of those methods and possible future development pathways. The major oxygen production methods are (1) extraction from lunar ilmenite (FeTiO3) with either hydrogen or carbon monoxide, (2) carbothermal reduction of iron oxides and silicates with methane, and (3) molten regolith electrolysis (MRE) of silicates. Methods (1) and (2) have also been investigated in a two-step process using CO reduction and carbon deposition followed by carbothermal reduction. All three processes have byproducts that could also be used as resources. Hydrogen or carbon monoxide reduction produce iron metal in small amounts that could potentially be used as construction material. Carbothermal reduction also makes iron metal along with silicon metal and a glass with possible applications. MRE produces iron, silicon, aluminum, titanium, and glass, with higher silicon yields than carbothermal reduction. On Mars and possibly on some moons and asteroids, water is present in the form of mineral hydrates, hydroxyl (-OH) groups on minerals, andor water adsorbed on mineral surfaces. Heating of the minerals can liberate the water which can be electrolyzed to provide a source of oxygen as well. The chemistry of these processes, some key

Spectral variations in rocks and soils containing ferric iron hydroxide and(or) sulfate minerals as seen by AVIRIS and laboratory spectroscopy

USGS Publications Warehouse

Rockwell, Barnaby W.

2004-01-01

Analysis of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data covering the Big Rock Candy Mountain area of the Marysvale volcanic field, west-central Utah, identified abundant rocks and soils bearing jarosite, goethite, and chlorite associated with volcanic rocks altered to propylitic grade during the Miocene (2321 Ma). Propylitically-altered rocks rich in pyrite associated with the relict feeder zones of convecting, shallow hydrothermal systems are currently undergoing supergene oxidation to natrojarosite, kaolinite, and gypsum. Goethite coatings are forming at the expense of jarosite where most pyrite has been consumed through oxidation in alluvium derived from pyrite-bearing zones. Spectral variations in the goethite-bearing rocks that resemble variations found in reference library samples of goethites of varying grain size were observed in the AVIRIS data. Rocks outside of the feeder zones have relatively low pyrite content and are characterized by chlorite, epidote, and calcite, with local copper-bearing quartz-calcite veins. Iron-bearing minerals in these rocks are weathering directly to goethite. Laboratory spectral analyses were applied to samples of iron-bearing rock outcrops and alluvium collected from the area to determine the accuracy of the AVIRIS-based mineral identification. The accuracy of the iron mineral identification results obtained by analysis of the AVIRIS data was confirmed. In general, the AVIRIS analysis results were accurate in identifying medium-grained goethite, coarse-grained goethite, medium- to coarse-grained goethite with trace jarosite, and mixtures of goethite and jarosite. However, rock fragments from alluvial areas identified as thin coatings of goethite with the AVIRIS data were found to consist mainly of medium- to coarse-grained goethite based on spectral characteristics in the visible and near-infrared. To determine if goethite abundance contributed to the spectral variations observed in goethite-bearing rocks

Biomineralogy and Morphology of the Marine Iron-oxidizing Bacterium Mariprofundus ferrooxydans

NASA Astrophysics Data System (ADS)

Chan, C. S.; Emerson, D.; Edwards, K. J.

2006-12-01

Mariprofundus ferrooxydans strain PV-1 is a lithoautotrophic iron-oxidizing proteobacterium isolated from the Loihi Seamount in Hawaii. As cells grow, they form filaments upon which iron minerals are deposited. Based on similarities in morphology, these structures appear to accumulate and form the bulk of iron mats at Loihi. Furthermore, Mariprofundus has been observed in a number of other seafloor mat samples (e.g. by microscopy and 16S rRNA gene sequencing of East Pacific Rise samples, C. M. Santelli unpublished data), suggesting that the occurrence of Mariprofundus is widespread. To learn about the effect of Mariprofundus on iron cycling, we are studying the processes by which it oxidizes iron and influences iron mineral formation. We are conducting studies on the spatial relationships between the cells, stalks, and minerals using scanning and transmission electron microscopy (SEM and TEM). Identification and imaging of stalk-bound, nanometer-sized iron oxyhydroxide minerals is being performed by high-resolution transmission electron microscopy (HRTEM). We have developed sample preparation methods to preserve in vivo spatial relationships, involving direct colonization of sample holders in cultures and in the environment. Method development has been performed on stalk-forming, iron-oxidizing Gallionella ferruginea cultures and terrestrial iron mats. Gallionella is morphologically and physiologically very similar to Mariprofundus, although 16S rRNA gene phylogeny shows that they are not closely related. Comparison of the terrestrial and marine iron-oxidizing bacteria (FeOB) gives us insight into adaptations that are particular to marine iron-oxidizers and those that are common to all FeOB. Light and fluorescence microscopy of Mariprofundus cultures has shown that a single bean-shaped cell lies at the end of each filament. SEM and TEM results have revealed that the filament is ribbon-like, sometimes twisted as with the classic Gallionella stalk, but sometimes not

The effects of maternal iron deficiency on infant fibroblast growth factor-23 and mineral metabolism

PubMed Central

Braithwaite, V.S.; Prentice, A.; Darboe, M.K.; Prentice, A.M.; Moore, S.E.

2016-01-01

Fibroblast growth factor-23 (FGF23), a phosphate(Phos)-regulating hormone, is abnormally elevated in hypophosphataemic syndromes and an elevated FGF23 is a predictor of mortality in kidney disease. Recent findings suggest iron deficiency as a potential mediator of FGF23 expression and murine studies have shown in utero effects of maternal iron deficiency on offspring FGF23 and phosphate metabolism. Our aim was to investigate the impact of maternal iron status on infant FGF23 and mineral metabolites over the first 2 years of life. Infants born to mothers with normal (NIn = 25,) and low (LIn = 25) iron status during pregnancy, from a mother-infant trial (ISRCTN49285450) in rural Gambia, West Africa, had blood and plasma samples analysed at 12, 24, 52, 78 and 104 weeks (wk) of age. Circulating intact-FGF23 (I-FGF23), Phos, total alkaline phosphatase (TALP) and haemoglobin (Hb) decreased and estimated glomerular filtration rate increased over time [all P ≤ 0.0001)]. C-terminal-FGF23 (C-FGF23) and TALP were significantly higher in LI compared with NI, from 52 wk for C-FGF23 [Beta coefficient (SE) 18.1 (0.04) %, P = 0.04] and from 24 wk for TALP [44.7 (29.6) U/L, P = 0.04]. Infant Hb was the strongest negative predictor of C-FGF23 concentration [− 21% (4%) RU/mL, P ≤ 0.0001], Phos was the strongest positive predictor of I-FGF23 [32.0(3.9) pg/mL, P ≤ 0.0001] and I-FGF23 did not predict C-FGF23 over time [− 0.5% (0.5%), P = 0.3]. In conclusion, this study suggests that poor maternal iron status is associated with a higher infant C-FGF23 and TALP but similar I-FGF23 concentrations in infants and young children. These findings further highlight the likely public health importance of preventing iron deficiency during pregnancy. Whether or not children who are born to iron deficient mothers have persistently high concentrations of these metabolites and are more likely to be at risk of impaired bone development and pre-disposed to rickets

Reactive iron in marine sediments

NASA Technical Reports Server (NTRS)

Canfield, Donald E.

1989-01-01

The influence of reactive iron oxides on sediment pore-water chemistry is considered in detail. A carefully calibrated extraction scheme is used to determine the depth distributions of reactive iron phases at two very different localities: the relatively iron-rich Mississippi Delta and the relatively iron-poor FOAM site in Long Island Sound. Closed system incubations are used to characterize the rates of reaction between sulfide and both naturally occurring and pure iron mineral phases. Rates of iron liberation to pore solution are measured in the presence and absence of sulfate reduction, and the origin of dissolved iron in organic-rich sediments is speculated upon.

Preserved Filamentous Microbial Biosignatures in the Brick Flat Gossan, Iron Mountain, California.

PubMed

Williams, Amy J; Sumner, Dawn Y; Alpers, Charles N; Karunatillake, Suniti; Hofmann, Beda A

2015-08-01

A variety of actively precipitating mineral environments preserve morphological evidence of microbial biosignatures. One such environment with preserved microbial biosignatures is the oxidized portion of a massive sulfide deposit, or gossan, such as that at Iron Mountain, California. This gossan may serve as a mineralogical analogue to some ancient martian environments due to the presence of oxidized iron and sulfate species, and minerals that only form in acidic aqueous conditions, in both environments. Evaluating the potential biogenicity of cryptic textures in such martian gossans requires an understanding of how microbial textures form biosignatures on Earth. The iron-oxide-dominated composition and morphology of terrestrial, nonbranching filamentous microbial biosignatures may be distinctive of the underlying formation and preservation processes. The Iron Mountain gossan consists primarily of ferric oxide (hematite), hydrous ferric oxide (HFO, predominantly goethite), and jarosite group minerals, categorized into in situ gossan, and remobilized iron deposits. We interpret HFO filaments, found in both gossan types, as HFO-mineralized microbial filaments based in part on (1) the presence of preserved central filament lumina in smooth HFO mineral filaments that are likely molds of microbial filaments, (2) mineral filament formation in actively precipitating iron-oxide environments, (3) high degrees of mineral filament bending consistent with a flexible microbial filament template, and (4) the presence of bare microbial filaments on gossan rocks. Individual HFO filaments are below the resolution of the Mars Curiosity and Mars 2020 rover cameras, but sinuous filaments forming macroscopic matlike textures are resolvable. If present on Mars, available cameras may resolve these features identified as similar to terrestrial HFO filaments and allow subsequent evaluation for their biogenicity by synthesizing geochemical, mineralogical, and morphological analyses. Sinuous

Preserved filamentous microbial biosignatures in the Brick Flat gossan, Iron Mountain, California

USGS Publications Warehouse

Williams, Amy J.; Sumner, Dawn Y.; Alpers, Charles N.; Karunatillake, Suniti; Hofmann, Beda A

2015-01-01

A variety of actively precipitating mineral environments preserve morphological evidence of microbial biosignatures. One such environment with preserved microbial biosignatures is the oxidized portion of a massive sulfide deposit, or gossan, such as that at Iron Mountain, California. This gossan may serve as a mineralogical analogue to some ancient martian environments due to the presence of oxidized iron and sulfate species, and minerals that only form in acidic aqueous conditions, in both environments. Evaluating the potential biogenicity of cryptic textures in such martian gossans requires an understanding of how microbial textures form biosignatures on Earth. The iron-oxide-dominated composition and morphology of terrestrial, nonbranching filamentous microbial biosignatures may be distinctive of the underlying formation and preservation processes. The Iron Mountain gossan consists primarily of ferric oxide (hematite), hydrous ferric oxide (HFO, predominantly goethite), and jarosite group minerals, categorized into in situ gossan, and remobilized iron deposits. We interpret HFO filaments, found in both gossan types, as HFO-mineralized microbial filaments based in part on (1) the presence of preserved central filament lumina in smooth HFO mineral filaments that are likely molds of microbial filaments, (2) mineral filament formation in actively precipitating iron-oxide environments, (3) high degrees of mineral filament bending consistent with a flexible microbial filament template, and (4) the presence of bare microbial filaments on gossan rocks. Individual HFO filaments are below the resolution of the Mars Curiosity and Mars 2020 rover cameras, but sinuous filaments forming macroscopic matlike textures are resolvable. If present on Mars, available cameras may resolve these features identified as similar to terrestrial HFO filaments and allow subsequent evaluation for their biogenicity by synthesizing geochemical, mineralogical, and morphological analyses. Sinuous

The composition of coexisting jarosite-group minerals and water from the Richmond mine, Iron Mountain, California

USGS Publications Warehouse

Jamieson, Heather E.; Robinson, Clare; Alpers, Charles N.; Nordstrom, D. Kirk; Poustovetov, Alexei; Lowers, Heather A.

2005-01-01

Jarosite-group minerals accumulate in the form of stalactites and fine-grained mud on massive pyrite in the D drift of the Richmond mine, Iron Mountain, California. Water samples were collected by placing beakers under the dripping stalactites and by extracting pore water from the mud using a centrifuge. The water is rich in Fe3+ and SO4 2−, with a pH of approximately 2.1, which is significantly higher than the extremely acidic waters found elsewhere in the mine. Electron-microprobe analysis and X-ray mapping indicate that the small crystals (<10 μm in diameter) are compositionally zoned with respect to Na and K, and include hydronium jarosite corresponding to the formula (H3O)0.6K0.3Na0.1Fe3 3+(SO4)2(OH)6. The proton-microprobe analyses indicate that the jarosite-group minerals contain significant amounts of As, Pb and Zn, and minor levels of Bi, Rb, Sb, Se, Sn and Sr. Speciation modeling indicates that the drip waters are supersaturated with respect to jarosite-group minerals. The expected range in composition of jarosite-group solid-solution in equilibrium with the pore water extracted from the mud was found to be consistent with the observed range in composition.

Atmospheric Transport and Input of Iron to the Southern Ocean

NASA Astrophysics Data System (ADS)

Tindale, N. W.

2002-12-01

While Australia is not generally considered to be a major source of mineral dust to the atmosphere, at least compared to Asian and African desert regions, it does appear to be the main source of mineral material to the Southern Ocean region south of Australia and New Zealand. In common with most of the greater Southern Ocean, this region contains high nitrate, low chlorophyll (HNLC) waters. Recent open ocean iron enrichment experiments in this region have demonstrated that phytoplankton growth and biomass are limited by iron availability. However the flux of atmospheric iron to this open ocean region is poorly known with very few direct measurements of mineral aerosol levels and input. Using mineral aerosol samples collected on Macquarie Island and at Cape Grim, together with other chemical data, air mass trajectories and satellite data, the spatial and temporal variability of aerosol iron transport and input to the Southern Ocean region south of Australia is estimated.

Determination of acid forming potential of massive sulfide minerals and the tailings situated in lead/zinc mining district of Balya (NW Turkey)

NASA Astrophysics Data System (ADS)

Çelebi, E. Ender; Öncel, M. Salim

2016-12-01

Weathering of sulfide minerals is a major source of acid production in nature and especially in mining territories. Pyrite is not the only principal mineral that generates acid drainage: other sulfide minerals (sphalerite, galena, chalcopyrite, etc.) may also be responsible for acid production. In addition to massive sulfide minerals, sulfide-bearing mine tailings may also produce acid drainage due to oxidation and hydrolysis reactions in waste dumps. The lead/zinc (Pb/Zn) mining region in Balya and Balıkesir, in Turkey, has operated mines intensively since the 1860s; so that characterization of the sulfide minerals and tailings situated and formed around the mining site is of great importance to secure a sustainable environment. For this purpose, acid production and neutralization potentials of massive sulfide ores of the region, and in the Pb/Zn process facility mine tailings from ten different points of tailings dam, have been determined by applied conventional Acid-Base Accounting (ABA) and Net Acid Generation (NAG) static tests after chemical and mineralogical analysis. The NAG pH and net acid production potential (NAPP) values were compared on a chart in order to classify the samples as either acid generating or non-acid generating. According to the comparisons, the sulfide minerals were classified as potentially acid forming (PAF). Massive pyrite had the highest NAPP and NAG pH value of 1966.6 kg H2SO4/ton and 1.91, respectively and the galena had the lowest NAPP value of 558.9 kg H2SO4/ton. However, the sphalerite NAG leachate pH value of 4.30 was the highest in sulfide minerals so that the sphalerite plotted near the uncertainty reference border in the PAF zone. In the mine tailings, NAPP values of 105.9 kg H2SO4/ton on average and the NAG pH values of over 7.5 were determined. In addition to these tests, water leaching (agitation test) was carried out on tailings in order to generate more information. The tailings did not generate acidic leachates as

Iron, ferritin, and nutrition.

PubMed

Theil, Elizabeth C

2004-01-01

Ferritin, a major form of endogenous iron in food legumes such as soybeans, is a novel and natural alternative for iron supplementation strategies where effectiveness is limited by acceptability, cost, or undesirable side effects. A member of the nonheme iron group of dietary iron sources, ferritin is a complex with Fe3+ iron in a mineral (thousands of iron atoms inside a protein cage) protected from complexation. Ferritin illustrates the wide range of chemical and biological properties among nonheme iron sources. The wide range of nonheme iron receptors matched to the structure of the iron complexes that occurs in microorganisms may, by analogy, exist in humans. An understanding of the chemistry and biology of each type of dietary iron source (ferritin, heme, Fe2+ ion, etc.), and of the interactions dependent on food sources, genes, and gender, is required to design diets that will eradicate global iron deficiency in the twenty-first century.

Iron biofortification of maize grain

USDA-ARS?s Scientific Manuscript database

Mineral nutrient deficiencies are a worldwide problem that is directly correlated with poverty and food insecurity. The most common of these is iron deficiency; more than one-third of the world’s population suffers from iron deficiency-induced anemia, 80% of which are in developing countries. The de...

Iron biofortification of maize grain

USDA-ARS?s Scientific Manuscript database

Mineral nutrient deficiencies are a worldwide problem that is directly correlated with poverty and food insecurity. The most common of these is iron deficiency; more than one-third of the world’s population suffers from iron deficiency-induced anemia, 80% of which are in developing countries. The co...

A Hexanuclear Iron(II) Layer with Two Square-Planar FeO4 Units Spanned by Tetrasiloxide Ligands: Mimicking of Minerals and Catalysts.

PubMed

Manicke, N; Hoof, S; Keck, M; Braun-Cula, B; Feist, M; Limberg, C

2017-07-17

A hexanuclear iron(II) siloxide complex has been prepared by reacting an incompletely condensed silsesquioxane first with NaOMe and then with Fe(OTf) 2 . In the process of product formation, the siloxane framework undergoes a transformation and it was shown that this happens already upon addition of base: Treatment of the ligand precursor with NaOMe leads to a completely condensed silsesquioxane cage with 12 Si atoms that is composed of 2 equiv of the tetrasiloxide ligands found in the product complex. Its iron centers form a two-dimensional array reminiscent of the situations found in minerals and two-dimensional oxide films caused by segregation of FeO x and silica. As the hexairon(II) assembly contains two high-spin square-planar FeO 4 units-suggested to represent the active sites in Fe-zeolites, which react with N 2 O to generate strongly oxidizing sites-it was treated with Me 3 NO. This led to the oxidation of two of the iron centers to the oxidation state +III and elimination of one iron ion, so that a pentanuclear, mixed valent iron siloxide was formed. All complexes were fully characterized.

Iron and manganese oxide mineralization in the Pacific

USGS Publications Warehouse

Hein, J. R.; Koschinsky, A.; Halbach, P.; Manheim, F. T.; Bau, M.; Jung-Keuk, Kang; Lubick, N.

1997-01-01

Iron, manganese, and iron-manganese deposits occur in nearly all geomorphologic and tectonic environments in the ocean basins and form by one or more of four processes: (1) hydrogenetic precipitation from cold ambient seawater, (2) precipitation from hydrothermal fluids, (3) precipitation from sediment pore waters that have been modified from bottom water compositions by diagenetic reactions in the sediment column and (4) replacement of rocks and sediment. These processes are discussed.

Low-Fe(III) Greenalite Was a Primary Mineral From Neoarchean Oceans

NASA Astrophysics Data System (ADS)

Johnson, Jena E.; Muhling, Janet R.; Cosmidis, Julie; Rasmussen, Birger; Templeton, Alexis S.

2018-04-01

Banded iron formations (BIFs) represent chemical precipitation from Earth's early oceans and therefore contain insights into ancient marine biogeochemistry. However, BIFs have undergone multiple episodes of alteration, making it difficult to assess the primary mineral assemblage. Nanoscale mineral inclusions from 2.5 billion year old BIFs and ferruginous cherts provide new evidence that iron silicates were primary minerals deposited from the Neoarchean ocean, contrasting sharply with current models for BIF inception. Here we used multiscale imaging and spectroscopic techniques to characterize the best preserved examples of these inclusions. Our integrated results demonstrate that these early minerals were low-Fe(III) greenalite. We present potential pathways in which low-Fe(III) greenalite could have formed through changes in saturation state and/or iron oxidation and reduction. Future constraints for ancient ocean chemistry and early life's activities should include low-Fe(III) greenalite as a primary mineral in the Neoarchean ocean.

Recent trends in the nonfuel minerals industry of Iran

USGS Publications Warehouse

Hastorun, Sinan; Renaud, Karine M.; Lederer, Graham W.

2016-07-11

The U.S. Geological Survey estimated that Iran held globally significant reserves of feldspar (2d largest in the world), barite (5th largest), gypsum (5th largest), fluorspar (8th largest), and iron ore (10th largest). The Government of Iran claimed to also have significant reserves of chromium, copper, gold, manganese, phosphate rock, and zinc. In 2014, Iran was the second-leading producer of gypsum and the sixth-leading producer of barite, with 6.1 percent and 3.6 percent of world output, respectively. Iran was also the world’s 7th-leading producer of cement, feldspar, and fluorspar; 8th-leading producer of bentonite; 9th-leading producer of molybdenum; 11th-leading producer of iron ore; and 14th-leading producer of crude steel. The Government of Iran plans to quadruple the output of aluminum, copper cathode, direct-reduced iron, and iron ore pellets; triple that of crude steel and gold; and double that of cement, pig iron, and zinc by 2025. It also plans to double the contribution of mining and to quadruple that of mineral processing to the national economy in the next decade. In order to achieve these major goals, the construction and expansion of several mines and mineral facilities are planned or under development. Whether Iran’s annual mineral production increases as rapidly as envisioned by the Government will depend largely on the amount of foreign investment into the minerals industry; integration of modern technology into mineral facilities; and availability of energy to aluminum, copper, and steel plants at competitive prices to international investors.

Linking microcracks and mineral zoning of detachment-exhumed granites to their tectonomagmatic history: Evidence from the Salihli and Turgutlu plutons in western Turkey (Menderes Massif)

NASA Astrophysics Data System (ADS)

Catlos, Elizabeth J.; Baker, Courteney B.; Sorensen, Sorena S.; Jacob, Lauren; Çemen, Ibrahim

2011-05-01

The Menderes Massif (western Turkey) is a metamorphic core complex that displays linked syntectonic plutonism and detachment faulting. Fabrics in S-type peraluminous granites (Salihli and Turgutlu) in the detachment (Alaşehir) footwall change from isotropic to protomylonitic to mylonitic towards the structure. Samples from the isotropic and protomylonitic zones were imaged in transmitted light, cathodoluminescence (CL), backscattered (BSE), and secondary electrons (SE), and show that these rocks contain abundant microcracks, and that plagioclase grains have zoning consistent with magma mixing. The granites contain fluid inclusion planes (FIPs), myrmekite replacing plagioclase, and the removal of blue luminescence in K-feldspar along microcracks and grain boundaries. Calcite and hydrous minerals commonly fill microcracks. The samples record features that formed due to (1) magma crystallization and ductile deformation (FIPs, mineral zoning), (2) changes in P and/or T (impingement and stress-induced microcracks in protomylonitic rocks), and (3) differences in intrinsic mineral properties (radial, cleavage, blunted, and deflected microcracks). Overprinted microcracks indicate exhumation during pulses. The Middle Miocene ages of these granites reported elsewhere are similar to those from large-scale extensional structures in Greece's Cycladic Massif. The Menderes and Cycladic core complexes may have developed simultaneously due to the widespread intrusion of subduction-related granitoids.

Stable isotopes and iron oxide mineral products as markers of chemodenitrification.

PubMed

Jones, L Camille; Peters, Brian; Lezama Pacheco, Juan S; Casciotti, Karen L; Fendorf, Scott

2015-03-17

When oxygen is limiting in soils and sediments, microorganisms utilize nitrate (NO3-) in respiration--through the process of denitrification--leading to the production of dinitrogen (N2) gas and trace amounts of nitrous (N2O) and nitric (NO) oxides. A chemical pathway involving reaction of ferrous iron (Fe2+) with nitrite (NO2-), an intermediate in the denitrification pathway, can also result in production of N2O. We examine the chemical reduction of NO2- by Fe(II)--chemodenitrification--in anoxic batch incubations at neutral pH. Aqueous Fe2+ and NO2- reacted rapidly, producing N2O and generating Fe(III) (hydr)oxide mineral products. Lepidocrotite and goethite, identified by synchrotron X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) spectroscopy, were produced from initially aqueous reactants, with two-line ferrihydrite increasing in abundance later in the reaction sequence. Based on the similarity of apparent rate constants with different mineral catalysts, we propose that the chemodenitrification rate is insensitive to the type of Fe(III) (hydr)oxide. With stable isotope measurements, we reveal a narrow range of isotopic fractionation during NO2- reduction to N2O. The location of N isotopes in the linear N2O molecule, known as site preference, was also constrained to a signature range. The coexistence of Fe(III) (hydr)oxide, characteristic 15N and 18O fractionation, and N2O site preference may be used in combination to qualitatively distinguish between abiotic and biogenically emitted N2O--a finding important for determining N2O sources in natural systems.

The Iron Hill (Powderhorn) Carbonatite Complex, Gunnison County, Colorado - A Potential Source of Several Uncommon Mineral Resources

USGS Publications Warehouse

Van Gosen, Bradley S.

2009-01-01

A similar version of this slide show was presented on three occasions during 2008: two times to local chapters of the Society for Mining, Metallurgy, and Exploration (SME), as part of SME's Henry Krumb lecture series, and the third time at the Northwest Mining Association's 114th Annual Meeting, held December 1-5, 2008, in Sparks (Reno), Nevada. In 2006, the U.S. Geological Survey (USGS) initiated a study of the diverse and uncommon mineral resources associated with carbonatites and associated alkaline igneous rocks. Most of these deposit types have not been studied by the USGS during the last 25 years, and many of these mineral resources have important applications in modern technology. The author chose to begin this study at Iron Hill in southwestern Colorado because it is the site of a classic carbonatite complex, which is thought to host the largest known resources of titanium and niobium in the United States.

The Role of Iron-Bearing Minerals in NO2 to HONO Conversion on Soil Surfaces.

PubMed

Kebede, Mulu A; Bish, David L; Losovyj, Yaroslav; Engelhard, Mark H; Raff, Jonathan D

2016-08-16

Nitrous acid (HONO) accumulates in the nocturnal boundary layer where it is an important source of daytime hydroxyl radicals. Although there is clear evidence for the involvement of heterogeneous reactions of NO2 on surfaces as a source of HONO, mechanisms remain poorly understood. We used coated-wall flow tube measurements of NO2 reactivity on environmentally relevant surfaces (Fe (hydr)oxides, clay minerals, and soil from Arizona and the Saharan Desert) and detailed mineralogical characterization of substrates to show that reduction of NO2 by Fe-bearing minerals in soil can be a more important source of HONO than the putative NO2 hydrolysis mechanism. The magnitude of NO2-to-HONO conversion depends on the amount of Fe(2+) present in substrates and soil surface acidity. Studies examining the dependence of HONO flux on substrate pH revealed that HONO is formed at soil pH < 5 from the reaction between NO2 and Fe(2+)(aq) present in thin films of water coating the surface, whereas in the range of pH 5-8 HONO stems from reaction of NO2 with structural iron or surface complexed Fe(2+) followed by protonation of nitrite via surface Fe-OH2(+) groups. Reduction of NO2 on ubiquitous Fe-bearing minerals in soil may explain HONO accumulation in the nocturnal boundary layer and the enhanced [HONO]/[NO2] ratios observed during dust storms in urban areas.

Ferritin: the protein nanocage and iron biomineral in health and in disease.

PubMed

Theil, Elizabeth C

2013-11-04

At the center of iron and oxidant metabolism is the ferritin superfamily: protein cages with Fe(2+) ion channels and two catalytic Fe/O redox centers that initiate the formation of caged Fe2O3·H2O. Ferritin nanominerals, initiated within the protein cage, grow inside the cage cavity (5 or 8 nm in diameter). Ferritins contribute to normal iron flow, maintenance of iron concentrates for iron cofactor syntheses, sequestration of iron from invading pathogens, oxidant protection, oxidative stress recovery, and, in diseases where iron accumulates excessively, iron chelation strategies. In eukaryotic ferritins, biomineral order/crystallinity is influenced by nucleation channels between active sites and the mineral growth cavity. Animal ferritin cages contain, uniquely, mixtures of catalytically active (H) and inactive (L) polypeptide subunits with varied rates of Fe(2+)/O2 catalysis and mineral crystallinity. The relatively low mineral order in liver ferritin, for example, coincides with a high percentage of L subunits and, thus, a low percentage of catalytic sites and nucleation channels. Low mineral order facilitates rapid iron turnover and the physiological role of liver ferritin as a general iron source for other tissues. Here, current concepts of ferritin structure/function/genetic regulation are discussed and related to possible therapeutic targets such as mini-ferritin/Dps protein active sites (selective pathogen inhibition in infection), nanocage pores (iron chelation in therapeutic hypertransfusion), mRNA noncoding, IRE riboregulator (normalizing the ferritin iron content after therapeutic hypertransfusion), and protein nanovessels to deliver medicinal or sensor cargo.

Inhibition of iron (III) minerals and acidification on the reductive dechlorination of trichloroethylene.

PubMed

Paul, Laiby; Smolders, Erik

2014-09-01

Reductive dechlorination of chlorinated ethenes is inhibited by acidification and by the presence of Fe (III) as a competitive electron acceptor. Synergism between both factors on dechlorination is predicted as reductive dissolution of Fe (III) minerals is facilitated by acidification. This study was set-up to assess this synergism for two common aquifer Fe (III) minerals, goethite and ferrihydrite. Anaerobic microbial dechlorination of trichloroethylene (TCE) by KB-1 culture and formate as electron donor was investigated in anaerobic batch containers at different solution pH values (6.2-7.2) in sand coated with these Fe minerals and a sand only as control. In the absence of Fe, lowering substrate pH from 7.2 to 6.2 increased the time for 90% TCE degradation from 14±1d to 42±4d. At pH 7.2, goethite did not affect TCE degradation time while ferrihydrite increased the degradation time to 19±1d compared to the no Fe control. At pH 6.2, 90% degradation was at 78±1 (ferrihydrite) or 131±1d (goethite). Ferrous iron production in ferrihydrite treatment increased between pH 7.2 and 6.5 but decreased by further lowering pH to 6.2, likely due to reduced microbial activity. This study confirms that TCE is increasingly inhibited by the combined effect of acidification and bioavailable Fe (III), however no evidence was found for synergistic inhibition since Fe reduction did not increase as pH decreases. To the best of our knowledge, this is the first study where effect of pH and Fe (III) reduction on TCE was simultaneously tested. Acid Fe-rich aquifers need sufficient buffering and alkalinity to ensure swift degradation of chlorinated ethenes. Copyright © 2014. Published by Elsevier Ltd.

Stability and broad-sense heritability of mineral content in potato: Iron

USDA-ARS?s Scientific Manuscript database

Iron deficiency in humans occurs in all regions of the world. Potatoes are a modest source of iron. The purpose of this study was to determine if genetic variation for potato tuber iron content exists. Iron content in potato was measured in 33 clones, including varieties and advanced breeding sele...

Redistribution of Iron and Titanium in High-Pressure Ultramafic Rocks

NASA Astrophysics Data System (ADS)

Crossley, Rosalind J.; Evans, Katy A.; Reddy, Steven M.; Lester, Gregory W.

2017-11-01

The redox state of iron in high-pressure serpentinites, which host a significant proportion of Fe3+ in subduction zones, can be used to provide an insight into iron cycling and constrain the composition of subduction zone fluids. In this study, we use oxide and silicate mineral textures, interpretation of mineral parageneses, mineral composition data, and whole rock geochemistry of high-pressure retrogressed ultramafic rocks from the Zermatt-Saas Zone to constrain the distribution of iron and titanium, and iron oxidation state. These data provide an insight on the oxidation state and composition of fluids at depth in subduction zones. Oxide minerals host the bulk of iron, particularly Fe3+. The increase in mode of magnetite and observation of magnetite within antigorite veins in the investigated ultramafic samples during initial retrogression is most consistent with oxidation of existing iron within the samples during the infiltration of an oxidizing fluid since it is difficult to reconcile addition of Fe3+ with the known limited solubility of this species. However, high Ti contents are not typical of serpentinites and also cannot be accounted for by simple mixing of a depleted mantle protolith with the nearby Allalin gabbro. Titanium-rich phases coincide with prograde metamorphism and initial exhumation, implying the early seafloor and/or prograde addition and late mobilization of Ti. If Ti addition has occurred, then the introduction of Fe3+, also generally considered to be immobile, cannot be disregarded. We explore possible transport vectors for Ti and Fe through mineral texture analysis.

Preserved Filamentous Microbial Biosignatures in the Brick Flat Gossan, Iron Mountain, California

PubMed Central

Sumner, Dawn Y.; Alpers, Charles N.; Karunatillake, Suniti; Hofmann, Beda A.

2015-01-01

Abstract A variety of actively precipitating mineral environments preserve morphological evidence of microbial biosignatures. One such environment with preserved microbial biosignatures is the oxidized portion of a massive sulfide deposit, or gossan, such as that at Iron Mountain, California. This gossan may serve as a mineralogical analogue to some ancient martian environments due to the presence of oxidized iron and sulfate species, and minerals that only form in acidic aqueous conditions, in both environments. Evaluating the potential biogenicity of cryptic textures in such martian gossans requires an understanding of how microbial textures form biosignatures on Earth. The iron-oxide-dominated composition and morphology of terrestrial, nonbranching filamentous microbial biosignatures may be distinctive of the underlying formation and preservation processes. The Iron Mountain gossan consists primarily of ferric oxide (hematite), hydrous ferric oxide (HFO, predominantly goethite), and jarosite group minerals, categorized into in situ gossan, and remobilized iron deposits. We interpret HFO filaments, found in both gossan types, as HFO-mineralized microbial filaments based in part on (1) the presence of preserved central filament lumina in smooth HFO mineral filaments that are likely molds of microbial filaments, (2) mineral filament formation in actively precipitating iron-oxide environments, (3) high degrees of mineral filament bending consistent with a flexible microbial filament template, and (4) the presence of bare microbial filaments on gossan rocks. Individual HFO filaments are below the resolution of the Mars Curiosity and Mars 2020 rover cameras, but sinuous filaments forming macroscopic matlike textures are resolvable. If present on Mars, available cameras may resolve these features identified as similar to terrestrial HFO filaments and allow subsequent evaluation for their biogenicity by synthesizing geochemical, mineralogical, and morphological analyses

Formation of iron nanoparticles and increase in iron reactivity in mineral dust during simulated cloud processing.

PubMed

Shi, Zongbo; Krom, Michael D; Bonneville, Steeve; Baker, Alex R; Jickells, Timothy D; Benning, Liane G

2009-09-01

The formation of iron (Fe) nanoperticles and increase in Fe reactivity in mineral dust during simulated cloud processing was investigated using high-resolution microscopy and chemical extraction methods. Cloud processing of dust was experimentally simulated via an alternation of acidic (pH 2) and circumneutral conditions (pH 5-6) over periods of 24 h each on presieved (<20 microm) Saharan soil and goethite suspensions. Microscopic analyses of the processed soil and goethite samples reveal the neo-formation of Fe-rich nanoparticle aggregates, which were not found initially. Similar Fe-rich nanoparticles were also observed in wet-deposited Saharen dusts from the western Mediterranean but not in dry-deposited dust from the eastern Mediterranean. Sequential Fe extraction of the soil samples indicated an increase in the proportion of chemically reactive Fe extractable by an ascorbate solution after simulated cloud processing. In addition, the sequential extractions on the Mediterranean dust samples revealed a higher content of reactive Fe in the wet-deposited dust compared to that of the dry-deposited dust These results suggestthat large variations of pH commonly reported in aerosol and cloud waters can trigger neo-formation of nanosize Fe particles and an increase in Fe reactivity in the dust

Iron isotope fractionation during hydrothermal ore deposition and alteration

NASA Astrophysics Data System (ADS)

Markl, Gregor; von Blanckenburg, Friedhelm; Wagner, Thomas

2006-06-01

Iron isotopes fractionate during hydrothermal processes. Therefore, the Fe isotope composition of ore-forming minerals characterizes either iron sources or fluid histories. The former potentially serves to distinguish between sedimentary, magmatic or metamorphic iron sources, and the latter allows the reconstruction of precipitation and redox processes. These processes take place during ore formation or alteration. The aim of this contribution is to investigate the suitability of this new isotope method as a probe of ore-related processes. For this purpose 51 samples of iron ores and iron mineral separates from the Schwarzwald region, southwest Germany, were analyzed for their iron isotope composition using multicollector ICP-MS. Further, the ore-forming and ore-altering processes were quantitatively modeled using reaction path calculations. The Schwarzwald mining district hosts mineralizations that formed discontinuously over almost 300 Ma of hydrothermal activity. Primary hematite, siderite and sulfides formed from mixing of meteoric fluids with deeper crustal brines. Later, these minerals were partly dissolved and oxidized, and secondary hematite, goethite and iron arsenates were precipitated. Two types of alteration products formed: (1) primary and high-temperature secondary Fe minerals formed between 120 and 300 °C, and (2) low-temperature secondary Fe minerals formed under supergene conditions (<100 °C). Measured iron isotope compositions are variable and cover a range in δ56Fe between -2.3‰ and +1.3‰. Primary hematite ( δ56Fe: -0.5‰ to +0.5‰) precipitated by mixing oxidizing surface waters with a hydrothermal fluid that contained moderately light Fe ( δ56Fe: -0.5‰) leached from the crystalline basement. Occasional input of CO 2-rich waters resulted in precipitation of isotopically light siderite ( δ56Fe: -1.4 to -0.7‰). The difference between hematite and siderite is compatible with published Fe isotope fractionation factors. The observed

Redox Transformations of Iron at Extremely Low pH: Fundamental and Applied Aspects.

PubMed

Johnson, D Barrie; Kanao, Tadayoshi; Hedrich, Sabrina

2012-01-01

Many different species of acidophilic prokaryotes, widely distributed within the domains Bacteria and Archaea, can catalyze the dissimilatory oxidation of ferrous iron or reduction of ferric iron, or can do both. Microbially mediated cycling of iron in extremely acidic environments (pH < 3) is strongly influenced by the enhanced chemical stability of ferrous iron and far greater solubility of ferric iron under such conditions. Cycling of iron has been demonstrated in vitro using both pure and mixed cultures of acidophiles, and there is considerable evidence that active cycling of iron occurs in acid mine drainage streams, pit lakes, and iron-rich acidic rivers, such as the Rio Tinto. Measurements of specific rates of iron oxidation and reduction by acidophilic microorganisms show that different species vary in their capacities for iron oxido-reduction, and that this is influenced by the electron donor provided and growth conditions used. These measurements, and comparison with corresponding data for oxidation of reduced sulfur compounds, also help explain why ferrous iron is usually used preferentially as an electron donor by acidophiles that can oxidize both iron and sulfur, even though the energy yield from oxidizing iron is much smaller than that available from sulfur oxidation. Iron-oxidizing acidophiles have been used in biomining (a technology that harness their abilities to accelerate the oxidative dissolution of sulfidic minerals and thereby facilitate the extraction of precious and base metals) for several decades. More recently they have also been used to simultaneously remediate iron-contaminated surface and ground waters and produce a useful mineral by-product (schwertmannite). Bioprocessing of oxidized mineral ores using acidophiles that catalyze the reductive dissolution of ferric iron minerals such as goethite has also recently been demonstrated, and new biomining technologies based on this approach are being developed.

Redox Transformations of Iron at Extremely Low pH: Fundamental and Applied Aspects

PubMed Central

Johnson, D. Barrie; Kanao, Tadayoshi; Hedrich, Sabrina

2012-01-01

Many different species of acidophilic prokaryotes, widely distributed within the domains Bacteria and Archaea, can catalyze the dissimilatory oxidation of ferrous iron or reduction of ferric iron, or can do both. Microbially mediated cycling of iron in extremely acidic environments (pH < 3) is strongly influenced by the enhanced chemical stability of ferrous iron and far greater solubility of ferric iron under such conditions. Cycling of iron has been demonstrated in vitro using both pure and mixed cultures of acidophiles, and there is considerable evidence that active cycling of iron occurs in acid mine drainage streams, pit lakes, and iron-rich acidic rivers, such as the Rio Tinto. Measurements of specific rates of iron oxidation and reduction by acidophilic microorganisms show that different species vary in their capacities for iron oxido-reduction, and that this is influenced by the electron donor provided and growth conditions used. These measurements, and comparison with corresponding data for oxidation of reduced sulfur compounds, also help explain why ferrous iron is usually used preferentially as an electron donor by acidophiles that can oxidize both iron and sulfur, even though the energy yield from oxidizing iron is much smaller than that available from sulfur oxidation. Iron-oxidizing acidophiles have been used in biomining (a technology that harness their abilities to accelerate the oxidative dissolution of sulfidic minerals and thereby facilitate the extraction of precious and base metals) for several decades. More recently they have also been used to simultaneously remediate iron-contaminated surface and ground waters and produce a useful mineral by-product (schwertmannite). Bioprocessing of oxidized mineral ores using acidophiles that catalyze the reductive dissolution of ferric iron minerals such as goethite has also recently been demonstrated, and new biomining technologies based on this approach are being developed. PMID:22438853

Improving the Representation of Soluble Iron in Climate Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perez Garcia-Pando, Carlos

2016-03-13

Mineral dust produced in the arid and semi-arid regions of the world is the dominant source of iron (Fe) in atmospheric aerosol inputs to the open ocean. The bioavailable Fe fraction of atmospheric dust is thought to regulate and occasionally limit the primary productivity in large oceanic regions, which influences the CO2 uptake from the atmosphere affecting the Earth’s climate. Because Fe bioavailability cannot be directly measured, it is assumed that the dissolved Fe or highly reactive Fe in the dust is bioavailable. The fraction of soluble Fe in dust is mainly controlled by: (1) the mineral composition of themore » soils and the emitted dust from the source areas; (2) the atmospheric processing that converts the Fe in Fe-bearing minerals into highly soluble forms of Fe. The project has mainly focused on constraining the mineral composition of dust aerosols (1), a previously neglected, yet a key issue to constrain the deposition of soluble iron. Deriving aerosol mineral composition requires global knowledge of the soil mineral content, which is available from poorly constrained global atlases. In addition, the mineral content of the emitted aerosol differs from that of the parent soil. Measurements of soil mineral fractions are based upon wet sedimentation (or ’wet sieving’) techniques that disturb the soil sample, breaking aggregates that are found in the original, undispersed soil that is subject to wind erosion. Wet sieving alters the soil size distribution, replacing aggregates that are potentially mobilized as aerosols with a collection of smaller particles. A major challenge is to derive the size-distributed mineral fractions of the emitted dust based upon their fractions measured from wet-sieved soils. Finally, representations of dust mineral composition need to account for mixtures of minerals. Examination of individual particles shows that iron, an element that is central to many climate processes, is often found as trace impurities of iron

Chemical and morphological comparison of erionite from Oregon, North Dakota, and Turkey

USGS Publications Warehouse

Lowers, Heather; Adams, David T.; Meeker, Gregory P.; Nutt, Constance J.

2010-01-01

Erionite, a fibrous zeolite, occurs in pediment gravel deposits near Killdeer Mountain, North Dakota. Material from these pediment deposits has been excavated for use as roadbed throughout Dunn County, North Dakota. Erionite also occurs in the Cappadocian region of Turkey, where a link between malignant mesothelioma and inhalation of this mineral has been established. The U.S. Environmental Protection Agency (EPA), Region 8, requested that the U.S. Geological Survey (USGS) compare the chemistry and morphology of erionite collected from the Killdeer Mountains to those collected from villages in Turkey and from Rome, Oregon, which has also been linked to disease in animal studies.

Evaluation of minerals content of drinking water in Malaysia.

PubMed

Azlan, Azrina; Khoo, Hock Eng; Idris, Mohd Aizat; Ismail, Amin; Razman, Muhammad Rizal

2012-01-01

The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water.

Evaluation of Minerals Content of Drinking Water in Malaysia

PubMed Central

Azlan, Azrina; Khoo, Hock Eng; Idris, Mohd Aizat; Ismail, Amin; Razman, Muhammad Rizal

2012-01-01

The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water. PMID:22649292

Reduction of jarosite by Shewanella oneidensis MR-1 and secondary mineralization

NASA Astrophysics Data System (ADS)

Bingjie, Ouyang; Xiancai, Lu; Huan, Liu; Juan, Li; Tingting, Zhu; Xiangyu, Zhu; Jianjun, Lu; Rucheng, Wang

2014-01-01

Jarosite is a common mineral in a variety of environments formed by the oxidation of iron sulfide normally accompanying with the generation of acid mine drainage (AMD) in mining areas or acid rock drainages (ARD) in many localities. Decomposition of jarosite by dissimilatory iron reducing bacteria (DIRB) influences the mobility of many heavy metals generally accommodated in natural jarosite. This study examined the anaerobic reduction of synthesized jarosite by Shewanella oneidensis strain MR-1, a typical facultative bacteria. The release of ferrous and ferric ion, as well as sulfate and potassium, in the inoculated experimental group lasting 80 days is much higher than that in abiotic control groups. The detection of bicarbonate and acetate in experimental solution further confirms the mechanism of microbial reduction of jarosite, in which lactate acts as the electron donor. The produced ferrous iron stimulates the subsequent secondary mineralization, leading to precipitation and transformation of various iron-containing minerals. Green rust and goethite are the intermediate minerals of the microbial reduction process under anoxic conditions, and the end products include magnetite and siderite. In aerobic environments, goethite, magnetite and siderite were also detected, but the contents were relatively lower. While in abiotic experiments, only goethite has been detected as a product. Thus, the microbial reduction and subsequent mineral transformation can remarkably influence the geochemical cycling of iron and sulfur in supergene environments, as well as the mobility of heavy metals commonly accommodated in jarosite.

U.S. Geological Survey Mineral Resources Program - Science Supporting Mineral Resource Stewardship

USGS Publications Warehouse

Kropschot, S.J.

2007-01-01

The United States is the world's largest user of mineral resources. We use them to build our homes and cities, fertilize our food crops, and create wealth that allows us to buy goods and services. Individuals rarely use nonfuel mineral resources in their natural state - we buy light bulbs, not the silica, soda ash, lime, coal, salt, tungsten, copper, nickel, molybdenum, iron, manganese, aluminum, and zinc used to convert electricity into light. The USGS Mineral Resources Program (MRP) is the sole Federal source of scientific information and unbiased research on nonfuel mineral potential, production, and consumption, as well as on the environmental effects of minerals. The MRP also provides baseline geochemical, geophysical, and mineral-deposit data used to understand environmental issues related to extraction and use of mineral resources. Understanding how minerals, water, plants, and organisms interact contributes to our understanding of the environment, which is essential for maintaining human and ecosystem health. To support creation of economic and national security policies in a global context, MRP collects and analyzes data on essential mineral commodities from around the world.

Mineral Analysis of Whole Grain Total Cereal

ERIC Educational Resources Information Center

Hooker, Paul

2005-01-01

The quantitative analysis of elemental iron in Whole Grain Total Cereal using visible spectroscopy is suitable for a general chemistry course for science or nonscience majors. The more extensive mineral analysis, specifically for the elements iron, calcium and zinc, is suitable for an instrumental or quantitative analysis chemistry course.

Effects of a silica-based feed supplement on performance, health, and litter quality of growing turkeys.

PubMed

Tran, S T; Bowman, M E; Smith, T K

2015-08-01

Poor litter quality is a potential challenge to footpad health as well as the primary cause of ammonia volatilization. High ambient ammonia concentration is one of the most significant factors negatively affecting poultry production today. Some minerals have been reported to reduce ammonia release from poultry litter. Silicon dioxide, a highly pure and natural mineral, shows promise in decreasing ammonia volatilization and improving litter quality. The objective of the current study was to investigate the effects of feed-borne silicon dioxide on litter quality and how this impacts bird performance, general health and footpad health throughout a 12-wk posthatching turkey study. Supplementing the diet with silicon dioxide was found to significantly improve turkey BW gain and the efficiency of feed conversion. The severity of footpad dermatitis was monitored throughout the experimental period but no significant effect of diet was seen. The feeding of silicon dioxide reduced litter pH which decreased the conversion of NH4⁺ to NH3 thereby reducing nitrogen losses from litter. It was concluded that, under our study conditions, the feeding of 0.02% silicon dioxide offers potential economic benefits to turkey producers. © 2015 Poultry Science Association Inc.

Radon exposure and cancers other than lung cancer in Swedish iron miners.

PubMed Central

Darby, S C; Radford, E P; Whitley, E

1995-01-01

Data are presented on the risks of cancers other than lung cancer in a cohort of iron miners from northern Sweden occupationally exposed to elevated levels of the radioactive gas radon. Compared with rates for the four northernmost counties of Sweden, mortality was increased for all cancers other than lung cancer (ratio of observed to expected deaths 1.21, 95% confidence interval 1.03-1.41), stomach cancer (ratio of observed to expected deaths 1.45, 95% confidence interval 1.04-1.98), and rectal cancer (ratio of observed to expected deaths 1.94, 95% confidence interval 1.03-3.31). Despite these overall increases, mortality was not significantly associated with cumulative exposure to radon, either for all cancers other than lung cancer or for any site of cancer other than lung cancer individually. However, the data from this cohort on its own have limited power; and for several sites of cancer the data in this study would be consistent with a radon-related increase. Further study of cancers other than lung cancer in populations exposed to radon is required. PMID:7614946

Study of Usage Areas of Clay Samples of Asphaltite Quarries in Sirnak, Turkey

NASA Astrophysics Data System (ADS)

Bilgin, Oyku

2017-12-01

The asphaltite of Sirnak, Turkey are in the form of 12 veins and their total reserves are anticipated to be approximately 200 million tons in a field of 25.000 hectares. The asphaltites at the Sirnak region are in the form of fault and crack fillings and take place together with clay minerals at their side rock. The main raw materials used in the production of cement are limestone, clay and marn known as sedimentary rocks. Limestone for CaO and clay minerals for SiO2, Al2O3, and Fe2O3, which are the main compounds of clinker production, are the main raw materials. Other materials containing these four oxides like marn are also used as cement raw material. Conformity levels of the raw materials to be used in cement production vary according to their chemical compounds. The rocks to be used as clay mineral are evaluated by taking the rate of silicate and alumina into consideration. The soils suitable for brick-tile productions are named as sandy clay. Their difference from the ceramic clays is that they are richer in terms of iron, silica and carbonate. These soils are also known under the names such as clay, arid, alluvium, silt, loam and argil. Inside these soils, minerals such as quartz, montmorillonite, kaolinite, calcite, limonite, hidromika, sericite, illite, and chlorite are available. Some parts of the soils consist of clays in amorphous structure. Limestone parts, gypsums, organic substances and bulky rock residuals spoil the quality. The soils suitable for brick production may not be suitable for tile production. In this case, their sandy soils should be mixed up with the clays with fine granule structure which is high in plasticity. During asphaltite mining in Sirnak region, clays forming side rock are gathered at dump sites. In this study; SQX analyses of the clay samples taken from Avgamasya, Seridahli and Segürük asphaltite veins run in Sirnak region are carried out and their usage areas are searched.

In Vitro Iron Availability from Insects and Sirloin Beef.

PubMed

Latunde-Dada, Gladys O; Yang, Wenge; Vera Aviles, Mayra

2016-11-09

Interest in the consumption of insects (entomophagy) as an alternative environmentally sustainable source of protein in the diet of humans has recently witnessed a surge. Knowledge of the nutrient composition and, in particular, the bioavailability of minerals from insects is currently sparse. This study evaluated the availability of Fe, Ca, Cu, Mg, Mn, and Zn from four commonly eaten insects and compared these to sirloin beef. Soluble iron from the samples was measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Iron bioavailability was determined using an in vitro simulated peptic-pancreatic digestion, followed by measurement of ferritin (a surrogate marker for iron absorption) in Caco-2 cells. Cricket and sirloin beef had comparably higher levels of Fe, Ca, and Mn than grasshopper, meal, and buffalo worms. However, iron solubility was significantly higher from the insect samples than from beef. The complementation of whole-wheat flour with insect or beef protein resulted in overall decreases in mineral content and iron solubility in the composite mixtures. Collectively, the data show that grasshopper, cricket, and mealworms contain significantly higher chemically available Ca, Cu, Mg, Mn, and Zn than sirloin. However, buffalo worms and sirloin exhibited higher iron bioavailability comparable to that of FeSO 4 . Commonly consumed insect species could be excellent sources of bioavailable iron and could provide the platform for an alternative strategy for increased mineral intake in the diets of humans.

Proximate, mineral, and antinutrient compositions of indigenous Okra (Abelmoschus esculentus) pod accessions: implications for mineral bioavailability.

PubMed

Gemede, Habtamu Fekadu; Haki, Gulelat Desse; Beyene, Fekadu; Woldegiorgis, Ashagrie Z; Rakshit, Sudip Kumar

2016-03-01

The promotion and consumption of indigenous vegetables could help to mitigate food insecurity and alleviate malnutrition in developing countries. Nutrient and antinutrient compositions of eight accessions of Okra Pods were investigated. Molar ratios and mineral bioavailability of Okra pod accessions were also calculated and compared to the critical values to predict the implications for mineral bioavailability. Proximate and mineral composition of Okra pod accessions were determined using standard methods of Association of Official Analytical Chemists. The result of the study revealed that the proximate composition (g/100 g) in dry weight basis was significantly (P < 0.05) varied and ranged: moisture/dry matter 9.69-13.33, crude protein 10.25-26.16, crude fat 0.56-2.49, crude fiber 11.97-29.93, crude ash 5.37-11.30, utilizable carbohydrate 36.66-50.97, and gross energy 197.26-245.55 kcal/100 g. The mineral concentrations (mg/100 g) were also significantly (P < 0.05) varied and ranged: calcium (111.11-311.95), Iron (18.30-36.68), potassium (122.59-318.20), zinc (3.83-6.31), phosphorus (25.62-59.72), and sodium (3.33-8.31) on dry weight bases. The Okra Pods of "OPA#6" accession contained significantly higher amounts of crude protein, total ash, crude fat, calcium, iron, and zinc than all other accessions evaluated in this study. The results of antinutrients analysis showed that, except phytate, tannin, and oxalate contents of all the accessions were significantly (P < 0.05) varied. The range of phytate, tannin, and oxalate contents (mg/100 g) for Okra pod accessions studied were as follows: 0.83-0.87, 4.93-9.90, and 0.04-0.53, respectively. The calculated molar ratios of phytate: calcium, phytate: iron, phytate: zinc, oxalate: calcium and [Phytate][Calcium]/[Zinc] were below the critical value and this indicate that the bioavailability of calcium, iron, and zinc in these accessions could be high. The results of the study revealed that Okra pod contain

Hydrothermal oxidation in the Biwabik Iron Formation, MN, USA

NASA Astrophysics Data System (ADS)

Losh, Steven; Rague, Ryan

2018-02-01

Precambrian iron formations throughout the world, notably in Australia, Brazil, and South Africa, show evidence of hypogene (≥ 110 °C, mostly > 250 °C) oxidation, alteration, and silica dissolution as a result of tectonic or magmatic activity. Although hydrothermal oxidation has been proposed for the prototype Lake Superior-type iron formation, the Biwabik Iron Formation in Minnesota (USA), it has not been documented there. By examining oxidized and unoxidized Biwabik Iron Formation in three mines, including material from high-angle faults that are associated with oxidation, we document an early hypogene oxidation event ( 175 °C) involving medium-salinity aqueous fluids (8.4 ± 4.9 wt% NaCl equiv) that infiltrated iron formation along high-angle faults. At the Hibbing Taconite Mine, hydrothermal fluids oxidized iron carbonates and silicates near faults, producing goethite ± quartz. In contrast with much of the oxidized iron ores on the Mesabi Range, silica was not removed but rather recrystallized during this event, perhaps lying in a rock-dominated system at low cumulative fluid flux. During the hydrothermal oxidation event in the Hibbing Taconite deposit, quartz-filled microfractures and irregular inclusions commonly formed in coarse variably oxidized magnetite, currently the ore mineral: these inclusions degrade the ore by introducing excess silica in magnetic concentrate. Hydrothermal oxidation at Hibbing Taconite Mine is overprinted by later, relatively minor supergene oxidation both along faults and near the surface, which locally dissolved quartz. At the Fayal Reserve Mine, widespread silicate and carbonate gangue dissolution and iron oxidation was followed by precipitation of pyrite, Mn-siderite, apatite, and other minerals in void spaces, which prevented post-oxidation compaction and significant volume loss in the sampled rocks. Although definitive temperature data for this assemblage are needed, the weight of evidence indicates that this

Phenazines and Other Redox-Active Antibiotics Promote Microbial Mineral Reduction

PubMed Central

Hernandez, Maria E.; Kappler, Andreas; Newman, Dianne K.

2004-01-01

Natural products with important therapeutic properties are known to be produced by a variety of soil bacteria, yet the ecological function of these compounds is not well understood. Here we show that phenazines and other redox-active antibiotics can promote microbial mineral reduction. Pseudomonas chlororaphis PCL1391, a root isolate that produces phenazine-1-carboxamide (PCN), is able to reductively dissolve poorly crystalline iron and manganese oxides, whereas a strain carrying a mutation in one of the phenazine-biosynthetic genes (phzB) is not; the addition of purified PCN restores this ability to the mutant strain. The small amount of PCN produced relative to the large amount of ferric iron reduced in cultures of P. chlororaphis implies that PCN is recycled multiple times; moreover, poorly crystalline iron (hydr)oxide can be reduced abiotically by reduced PCN. This ability suggests that PCN functions as an electron shuttle rather than an iron chelator, a finding that is consistent with the observation that dissolved ferric iron is undetectable in culture fluids. Multiple phenazines and the glycopeptidic antibiotic bleomycin can also stimulate mineral reduction by the dissimilatory iron-reducing bacterium Shewanella oneidensis MR1. Because diverse bacterial strains that cannot grow on iron can reduce phenazines, and because thermodynamic calculations suggest that phenazines have lower redox potentials than those of poorly crystalline iron (hydr)oxides in a range of relevant environmental pH (5 to 9), we suggest that natural products like phenazines may promote microbial mineral reduction in the environment. PMID:14766572

Growth of Iron(III)-Reducing Bacteria on Clay Minerals as the Sole Electron Acceptor and Comparison of Growth Yields on a Variety of Oxidized Iron Forms†

PubMed Central

Kostka, Joel E.; Dalton, Dava D.; Skelton, Hayley; Dollhopf, Sherry; Stucki, Joseph W.

2002-01-01

(III) oxide minerals and is dependent upon the mineral surface area available. Iron(III) bound in clay minerals should be considered an important electron acceptor supporting the growth of bacteria in soils or sedimentary environments. PMID:12450850

Photoreduction and incorporation of iron into ferritins.

PubMed Central

Laulhère, J P; Labouré, A M; Briat, J F

1990-01-01

Pea seed ferritin is able to incorporate ferrous iron into the mineral core. Fe2+ may be formed by reduction of exogenous Fe3+ with ascorbate or by photoreduction by ferritin and by ferric citrate. In our experimental conditions the bulk of the photoreduction is carried out by ferritin, which is able to photoreduce its endogenous iron. Citrate does not enhance the photoreduction capacity of ferritin, and exogenous ferric citrate improves the yield of the reaction by about 30%. The mineral core of the ferritin is shown to photoreduce actively, and the protein shell does not participate directly in the photoreduction. Low light intensities and low concentration of reducing agents do not allow a release of iron from ferritins, but induce a 'redox mill' of photoreduction and simultaneous ferroxidase-mediated incorporation. High ascorbate concentrations induce the release of ferritin iron. These reactions are accompanied by the correlated occurrence of damage caused by radicals arising from Fenton reactions, leading to specific cleavages in the 28 kDa phytoferritin subunit. This damage caused by radicals occurs during the oxidative incorporation into the mineral core and is prevented by o-phenanthroline or by keeping the samples in the dark. Images Fig. 1. Fig. 2. Fig. 3. Fig. 5. PMID:2375759

Mineral content of complementary foods.

PubMed

Jani, Rati; Udipi, S A; Ghugre, P S

2009-01-01

To document mineral contents iron, zinc, calcium, energy contents and nutrient densities in complementary foods commonly given to young urban slum children. Information on dietary intake was collected from 892 mothers of children aged 13-24 months, using 24 hour dietary recall and standardized measures. Three variations of 27 most commonly prepared recipes were analyzed and their energy (Kcal/g) and nutrient densities (mg/100 Kcal) were calculated. Considerable variations were observed in preparation of all items fed to the children. Cereal-based items predominated their diets with only small amount of vegetables/fruits. Fenugreek was the only leafy vegetable included, but was given to only 1-2% of children. Iron, calcium, zinc contents of staple complementary foods ranged from: 0.33 mg to 3.73 mg, 4 mg to 64 mg, and 0.35 mg to 2.99 mg/100 respectively. Recipes diluted with less water and containing vegetables, spices had higher mineral content. Minerals densities were higher for dals, fenugreek vegetable, khichdi and chapatti. Using the median amounts of the various recipes fed to children, intakes of all nutrients examined especially calcium and iron was low. There is an urgent need to educate mothers about consistency, dilution, quantity, frequency, method of preparation, inclusion of micronutrient-rich foods, energy-dense complementary foods and gender equality.

Morphology of the ferritin iron core by aberration corrected scanning transmission electron microscopy

NASA Astrophysics Data System (ADS)

Jian, Nan; Dowle, Miriam; Horniblow, Richard D.; Tselepis, Chris; Palmer, Richard E.

2016-11-01

As the major iron storage protein, ferritin stores and releases iron for maintaining the balance of iron in fauna, flora, and bacteria. We present an investigation of the morphology and iron loading of ferritin (from equine spleen) using aberration-corrected high angle annular dark field scanning transmission electron microscopy. Atom counting method, with size selected Au clusters as mass standards, was employed to determine the number of iron atoms in the nanoparticle core of each ferritin protein. Quantitative analysis shows that the nuclearity of iron atoms in the mineral core varies from a few hundred iron atoms to around 5000 atoms. Moreover, a relationship between the iron loading and iron core morphology is established, in which mineral core nucleates from a single nanoparticle, then grows along the protein shell before finally forming either a solid or hollow core structure.

Magnetic properties and phase transformations of iron sulfides synthesized under the hydrothermal method

NASA Astrophysics Data System (ADS)

Li, S. H.; Chen, Y. H.

2016-12-01

The iron sulfide nano-minerals possess advantages of high abundance, low cost, and low toxicity. These advantages make them be competitive in the magnetic, electronic, and photoelectric applications. Mackinawite can be used in soil or water remediations. Greigite is very important for paleomagnetic and geochemical environment studies and the anode materials for lithium ion batteries. Besides, greigite is also utilized for hyperthermia and biomedicine. Pyrrhotite can be applied as geothermometry. Due to the above-mentioned reasons, iron sulfide minerals have specific significances and they must be further investigated, like their phase transformations, magnetic properties, and etc. In this study, the iron sulfide minerals were synthesized by using a hydrothermal method. The ex-situ and in-situ X-ray diffraction (XRD) was used to examine the crystal structure and phase transformation of iron sulfide minerals. The Transmission electron microscopy (TEM) and superconducting quantum interference device (SQUID) were carried out to investigate their morphology and magnetic properties, respectively. The results suggested that the phase transformation sequence was followed the order: mackinawite → greigite → (smythite) → pyrrhotite. Two pure mineral phases of greigite and pyrrhotite were obtained under the hydrothermal conditions. The morphology of the pure greigite is granular aggregates with a particle size of approximately 30 nm and pyrrhotite presented a hexagonal sheet stacking with a particle size of thousands nanometers. The greigite had a ferri-magnetic behavior and pyrrhotite was weak ferro-magnetic. Both of them had a pseudo-single magnetic domain (PSD) based on the Day's plot from SQUID data. The complete phase-transformation pathways and high magnetization of iron sulfide minerals are observed in this study and these kind of iron sulfide minerals are worthy to further study.

Geochemical patterns and microbial contribution to iron plaque formation in the rice plant rhizosphere

NASA Astrophysics Data System (ADS)

Maisch, Markus; Murata, Chihiro; Unger, Julia; Kappler, Andreas; Schmidt, Caroline

2015-04-01

Rice is the major food source for more than half of the world population and 80 percent of the worldwide rice cultivation is performed on water logged paddy soils. The establishment of reducing conditions in the soil and across the soil-water interface not only stimulates the microbial production and release of the greenhouse gas methane. These settings also create optimal conditions for microbial iron(III) reduction and therefore saturate the system with reduced ferrous iron. Through the reduction and dissolution of ferric minerals that are characterized by their high surface activity, sorbed nutrients and contaminants (e.g. arsenic) will be mobilized and are thus available for uptake by plants. Rice plants have evolved a strategy to release oxygen from their roots in order to prevent iron toxification in highly ferrous environments. The release of oxygen to the reduced paddy soil causes ferric iron plaque formation on the rice roots and finally increases the sorption capacity for toxic metals. To this date the geochemical and microbiological processes that control the formation of iron plaque are not deciphered. It has been hypothesized that iron(II)-oxidizing bacteria play a potential role in the iron(III) mineral formation along the roots. However, not much is known about the actual processes, mineral products, and geochemical gradients that establish within the rhizosphere. In the present study we have developed a growth set-up that allows the co-cultivation of rice plants and iron(II)-oxidizing bacteria, as well as the visual observation and in situ measurement of geochemical parameters. Oxygen and dissolved iron(II) gradients have been measured using microelectrodes and show geochemical hot spots that offer optimal growth conditions for microaerophilic iron(II) oxidizers. First mineral identification attempts of iron plaque have been performed using Mössbauer spectroscopy and microscopy. The obtained results on mineraology and crystallinity have been

Mineral Plot from Esperance Target

NASA Image and Video Library

2014-01-23

This plot segregates various minerals examined by NASA Mars Exploration Rover Opportunity according to their different compositions; for example, those with more iron and magnesium oxides are located in the lower right corner.

Phanerozoic Rifting Phases And Mineral Deposits

NASA Astrophysics Data System (ADS)

Hassaan, Mahmoud

2016-04-01

connected with NW,WNW and N-S faults genetically related to volcano-hydrothermal activity associated the Red Sea rifting. At Sherm EL-Sheikh hydrothermal manganese deposit occurs in Oligocene clastics within fault zone. Four iron-manganese-barite mineralization in Esh-Elmellaha plateau are controlled by faults trending NW,NE and nearly E-W intersecting Miocene carbonate rocks. Barite exists disseminated in the ores and as a vein in NW fault. In Shalatee - Halaib district 24 manganese deposits and barite veins with sulphide patches occur within Miocene carbonates distributed along two NW fault planes,trending 240°and 310° and occur in granite and basalt . Uranium -lead-zinc sulfide mineralization occur in Late Proterozoic granite, Late Cretaceous sandstones, and chiefly in Miocene clastic-carbonate-evaporate rocks. The occurrences of uranium- lead-zinc and iron-manganese-barite mineralization have the characteristic features of hypogene cavity filling and replacement deposits correlated with Miocene- Recent Aden volcanic rocks rifting. In western Saudi Arabia barite-lead-zinc mineralization occurs at Lat. 25° 45' and 25° 50'N hosted by Tertiary sediments in limestone nearby basaltic flows and NE-SW fault system. The mineralized hot brines in the Red Sea deeps considered by the author a part of this province. The author considers the constant rifting phases of Pangea and then progressive fragmentation of Western Gondwana during the Late Carboniferous-Lias, Late Jurassic-Early Aptian, Late Aptian - Albian and Late Eocene-Early Miocene and Oligocene-Miocene, responsible for formation of the mineral deposits constituting the M provinces. During these events, rifting, magmatism and hydrothermal activities took place in different peri-continental margins.

Effects of Coating Materials and Mineral Additives on Nitrate Reduction by Zerovalent Iron

NASA Astrophysics Data System (ADS)

Kim, K. H.; Jeong, H. Y.; Lee, S.; Kang, N.; Choi, H. J.; Park, M.

2015-12-01

In efforts to facilitate nitrate removal, a variety of coating materials and mineral additives were assessed for their effects on the nitrate reduction by zerovalent iron (ZVI). Coated ZVIs were prepared by reacting Fe particles with Cr(III), Co(II), Ni(II), Cu(II), and S(-II) solutions under anoxic conditions, with the resultant materials named Cr/Fe, Co/Fe, Ni/Fe, Cu/Fe, and FeS/Fe, respectively. The mineral additives used, synthesized or purchased, included goethite, magnetite, and hydrous ferric oxide (HFO). Kinetic experiments were performed using air-tight serum vials containing 1.0 g Fe (uncoated or coated forms) in 15 mL of 100 mg NO3×N/L solutions with pH buffered at 7.0. To monitor the reaction progress, the solution phase was analyzed for NO3-, NO2-, and NH4+ on an ion chromatography, while the headspace was analyzed for H2, N2, and O2 on a gas chromatography. By uncoated Fe, ca. 60% of nitrate was reductively transformed for 3.6 h, with NH4+ being the predominant product. Compared with uncoated one, Cr/Fe, Co/Fe, and Cu/Fe showed faster removal rates of nitrate. The observed reactivity enhancement was thought to result from additional reduction of nitrate by H atoms adsorbed on the surface of Cr, Co, or Cu metal. In contrast, both Ni/Fe and FeS/Fe showed slower removal of nitrate than uncoated Fe. In both cases, the coating, which highly disfavors the adsorption of nitrate, would form on the Fe surface. When goethite, HFO, and magnetite were amended, the nitrate reduction by Fe was significantly increased, with the effect being most evident with HFO. Although not capable of reducing nitrate, the mineral additives would serve as crystal nuclei for the corrosion products of Fe, thus making the development of passivation layers on the Fe surface less. In the future, we will perform a kinetic modeling of the experimental data to assess the relative contribution of multiple reaction paths in the nitrate reduction by Fe.

Bioavailability of iron in geophagic earths and clay minerals, and their effect on dietary iron absorption using an in vitro digestion/Caco-2 cell model

PubMed Central

Seim, Gretchen L.; Ahn, Cedric I.; Bodis, Mary S.; Luwedde, Flavia; Miller, Dennis D.; Hillier, Stephen; Tako, Elad; Glahn, Raymond P.; Young, Sera L.

2014-01-01

Geophagy, the deliberate consumption of earth, is strongly associated with iron (Fe) deficiency. It has been proposed that geophagy may be practiced as a means to improve Fe status by increasing Fe intakes and, conversely, that geophagy may cause Fe deficiency by inhibiting Fe absorption. We tested these hypotheses by measuring Fe concentration and relative bioavailable Fe content of 12 samples of geophagic earth and 4 samples of pure clay minerals. Further, we assessed the impact of these samples on the bioavailability of Fe from an Fe-rich test meal (cooked white beans, WB). Fe concentrations were measured with inductively coupled plasma atomic emission spectroscopy. Fe bioavailability was determined using an in vitro digestion/Caco-2 cell model in which ferritin formation was used as an index of Fe bioavailability. Geophagic earth and clay mineral samples were evaluated with this model, both alone and in combination with WB (1:16 ratio, sample:WB). Median Fe concentration of the geophagic earth was 3485 (IQR 2462, 14571) μg/g and mean Fe concentration in the clay minerals was 2791 (± 1782) μg/g. All specimens had Fe concentrations significantly higher (p ≤ 0.005) than the Fe concentration of WB (77 μg/g). Ferritin formation (i.e. Fe uptake) in cells exposed to geophagic earths and clay minerals was significantly lower than in cells exposed to WB (p ≤ 0.05) and Fe uptake responses of 11 of the 16 samples were not significantly different from the blank, indicating no bioavailable Fe. When samples were combined with WB, 5 of 16 had mean ferritin levels that were significantly lower (p ≤ 0.05, one tail) than the WB alone, indicating that the samples inhibited Fe uptake from the WB. None of the ferritin responses of cells exposed to both WB and earth/clay were significantly higher than WB alone. Thus, although geophagic earths and mineral clays are high in total Fe, very little of this Fe is bioavailable. Further, some geophagic earth and clay mineral

Mineral resources of Novokuznetsk administrative district of Kemerovo region (metallic and non-metallic minerals)

NASA Astrophysics Data System (ADS)

Gutak, Ja M.

2017-09-01

The article summarizes data on metallic and non-metallic minerals of Novokuznetsk district of Kemerovo region. Consistently reviewed are iron deposits (Tersinskaya group of deposits), gold deposits (placer accumulations and vein gold deposits), mineral water deposits (Tersinskoe deposit), deposit of refractory clay (Barkinskoe) and wide spread mineral deposits such as brick clay, keramzite materials, sand and gravel, building stones, ornamental stones, facing stones, peat, materials for lime production. It is indicated that resource base of metallic and nonmetallic minerals is inferior to that of mineral coal. At the same time it can be of considerable interest to small and medium-size businesses as objects with quick return of investment (facing and ornamental stones). For a number of wide spread mineral resources (brick clay, keramzite materials, sand and gravel) it is an important component of local industry.

Mortality of iron miners in Lorraine (France): relations between lung function and respiratory symptoms and subsequent mortality.

PubMed Central

Chau, N; Benamghar, L; Pham, Q T; Teculescu, D; Rebstock, E; Mur, J M

1993-01-01

An increased mortality from lung and stomach cancer was found in previous studies on Lorraine iron miners. A detailed analysis, however, was not possible due to the lack of data for survivors. In this study the cohort included 1178 workers selected at random from all the 5300 working miners aged between 35 and 55 at the start of the follow up period, which ranged from 1975 to 1985. Occupational exposures and tobacco consumption, lung function tests, and respiratory symptoms were assessed for each subject in 1975, 1980, and 1985. This study confirmed the excess of lung cancer (standardised mortality ratio (SMR) = 389, p < 0.001) and of stomach cancer (SMR = 273, p < 0.05). There was no excess of lung cancer in non-smokers and moderate smokers (< 20 pack-years) or the miners who worked only at the surface or underground for less than 20 years. A significant excess (SMR = 349, p < 0.001) was found in moderate smokers when they worked underground for between 20 and 29 years. Heavy smokers (over 30 pack-years) or subjects who worked underground for more than 30 years experienced a high risk: SMR = 478 (p < 0.001) for moderate smokers who worked underground for over 30 years; 588 (p < 0.001) for heavy smokers who worked underground for between 20 and 29 years; and 877 (p < 0.001) for heavy smokers who worked underground for over 30 years. This showed an interaction between smoking and occupational exposure. The excess mortality from lung cancer was because there were some subjects who died young (from 45 years old). Comparison with the results of a previous study showed that additional hazards produced by diesel engines and explosives increased the mortality from lung cancer. The SMR was higher than 400 (p < 0.001) from 45 years old instead of from 56 years. A relation was found between a decrease in vital capacity (VC), forced expiratory volume in one second (FEV1) and of FEV1/VC and mortality from all causes and from lung cancer in heavy smokers or men who had worked

Reactivity of Uranium and Ferrous Iron with Natural Iron Oxyhydroxides.

PubMed

Stewart, Brandy D; Cismasu, A Cristina; Williams, Kenneth H; Peyton, Brent M; Nico, Peter S

2015-09-01

Determining key reaction pathways involving uranium and iron oxyhydroxides under oxic and anoxic conditions is essential for understanding uranium mobility as well as other iron oxyhydroxide mediated processes, particularly near redox boundaries where redox conditions change rapidly in time and space. Here we examine the reactivity of a ferrihydrite-rich sediment from a surface seep adjacent to a redox boundary at the Rifle, Colorado field site. Iron(II)-sediment incubation experiments indicate that the natural ferrihydrite fraction of the sediment is not susceptible to reductive transformation under conditions that trigger significant mineralogical transformations of synthetic ferrihydrite. No measurable Fe(II)-promoted transformation was observed when the Rifle sediment was exposed to 30 mM Fe(II) for up to 2 weeks. Incubation of the Rifle sediment with 3 mM Fe(II) and 0.2 mM U(VI) for 15 days shows no measurable incorporation of U(VI) into the mineral structure or reduction of U(VI) to U(IV). Results indicate a significantly decreased reactivity of naturally occurring Fe oxyhydroxides as compared to synthetic minerals, likely due to the association of impurities (e.g., Si, organic matter), with implications for the mobility and bioavailability of uranium and other associated species in field environments.

In Situ Mineralization of Magnetite Nanoparticles in Chitosan Hydrogel

NASA Astrophysics Data System (ADS)

Wang, Yongliang; Li, Baoqiang; Zhou, Yu; Jia, Dechang

2009-09-01

Based on chelation effect between iron ions and amino groups of chitosan, in situ mineralization of magnetite nanoparticles in chitosan hydrogel under ambient conditions was proposed. The chelation effect between iron ions and amino groups in CS-Fe complex, which led to that chitosan hydrogel exerted a crucial control on the magnetite mineralization, was proved by X-ray photoelectron spectrum. The composition, morphology and size of the mineralized magnetite nanoparticles were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy and thermal gravity. The mineralized nanoparticles were nonstoichiometric magnetite with a unit formula of Fe2.85O4 and coated by a thin layer of chitosan. The mineralized magnetite nanoparticles with mean diameter of 13 nm dispersed in chitosan hydrogel uniformly. Magnetization measurement indicated that superparamagnetism behavior was exhibited. These magnetite nanoparticles mineralized in chitosan hydrogel have potential applications in the field of biotechnology. Moreover, this method can also be used to synthesize other kinds of inorganic nanoparticles, such as ZnO, Fe2O3 and hydroxyapatite.

Petrogenesis of Permian A-type granitoids in the Cihai iron ore district, Eastern Tianshan, NW China: Constraints on the timing of iron mineralization and implications for a non-plume tectonic setting

NASA Astrophysics Data System (ADS)

Zheng, Jiahao; Mao, Jingwen; Chai, Fengmei; Yang, Fuquan

2016-09-01

The geochronology and geochemistry of granitoids in the Eastern Tianshan, NW China provide important constraints on the timing of iron mineralization, as well as in understanding evolution history of the southern Central Asian Orogenic Belt (CAOB). Here we present results from a detailed study on granitoid rocks from the Cihai iron ore district in the Beishan region, southern part of the Eastern Tianshan. The granitoid rocks are composed of granodiorite, quartz monzonite, granite, and monzonite. Zircon U-Pb analyses yielded the ages of 294.1 ± 2.2 Ma, 286.5 ± 0.7 Ma, 284.3 ± 3.3 Ma, and 265.6 ± 3.0 Ma, respectively, suggesting they were formed in Early-Middle Permian. Among these granitoid rocks, the ages of quartz monzonite and granite are close to the timing of iron mineralization ( 282 Ma), indicating they may provide a source of iron in the Cihai ore district. Geochemically, the granodiorite, granite, and quartz monzonite samples are characterized by high FeOt/(FeOt + MgO) and Ga/Al ratios (0.84-0.94 and 2.28-3.27, respectively), as well as high zircon saturation temperatures (781-908 °C), similar to those of typical A-type granitoids. Isotopically, they display consistently depleted Hf isotopic compositions (εHf(t) = + 1.18 to + 15.37). Geological, geochemical, and isotopic data suggest that the Cihai A-type granitoids were derived from melting of juvenile lower crust. Some Early Permian A-type granitoids were recently identified in the Tarim and Eastern Tianshan with the ages between 294 and 269 Ma. The A-type granitoids in the Eastern Tianshan formed earlier between 294-284 Ma and exhibit characteristics of A2 type granitoids, whereas the A-type granitoids in the Tarim formed later between 277-269 Ma and show A1 granitoids affinity. We suggest that the Permian Tarim mantle plume does not account for the formation of the A-type granitoids in the Eastern Tianshan area, and the Eastern Tianshan was in a non-plume tectonic setting during Early Permian time

Bioweathering of nontronite colloids in hybrid silica gel: implications for iron mobilization.

PubMed

Oulkadi, D; Balland-Bolou-Bi, C; Michot, L J; Grybos, M; Billard, P; Mustin, C; Banon, S

2014-02-01

This study aimed to study biotic iron dissolution using a new hybrid material constituted of well-dispersed mineral colloids in a silica gel matrix. This permitted to prevent adsorption of colloidal mineral particles on bacteria. Hybrid silica gel (HSG) permitted to study bioweathering mechanisms by diffusing molecules. Hybrid silica gel was synthesized through a classical sol-gel procedure in which mineral colloidal particles (NAu-2) were embedded in a porous silica matrix. Rahnella aquatilis RA1, isolated from a wheat rhizosphere was chosen for its ability to dissolve minerals by producing various organic acids and siderophores. Pyruvic, acetic and lactic acids were the major organic acids produced by R. aquatilis RA1 followed by oxalic and citric acids at the end of incubation. Comparison of abiotic and biotic experiments revealed a high efficiency of R. aquatilis RA1 for iron dissolution suggesting an optimized action of different ligands that solubilized or mobilized iron. Hybrid silica gel allowed focusing on the colloidal mineral weathering by metabolites diffusion without mineral adsorption on bacteria. Hybrid silica gels are new and efficient tools to study colloidal mineral bioweathering. Adjusting HSG porosity and hydrophobicity should permit to precise the influence of limiting diffusion of siderophores or aliphatic organic acids on mineral weathering. © 2013 The Society for Applied Microbiology.

Estuarine removal of glacial iron and implications for iron fluxes to the ocean

USGS Publications Warehouse

Schroth, Andrew W.; Crusius, John; Hoyer, Ian; Campbell, Robert

2014-01-01

While recent work demonstrates that glacial meltwater provides a substantial and relatively labile flux of the micronutrient iron to oceans, the role of high-latitude estuary environments as a potential sink of glacial iron is unknown. Here we present the first quantitative description of iron removal in a meltwater-dominated estuary. We find that 85% of “dissolved” Fe is removed in the low-salinity region of the estuary along with 41% of “total dissolvable” iron associated with glacial flour. We couple these findings with hydrologic and geochemical data from Gulf of Alaska (GoA) glacierized catchments to calculate meltwater-derived fluxes of size and species partitioned Fe to the GoA. Iron flux data indicate that labile iron in the glacial flour and associated Fe minerals dominate the meltwater contribution to the Fe budget of the GoA. As such, GoA nutrient cycles and related ecosystems could be strongly influenced by continued ice loss in its watershed.

Biomineralization associated with microbial reduction of Fe3+ and oxidation of Fe2+ in solid minerals

USGS Publications Warehouse

Zhang, G.; Dong, H.; Jiang, H.; Kukkadapu, R.K.; Kim, J.; Eberl, D.; Xu, Z.

2009-01-01

Iron-reducing and oxidizing microorganisms gain energy through reduction or oxidation of iron, and by doing so play an important role in the geochemical cycling of iron. This study was undertaken to investigate mineral transformations associated with microbial reduction of Fe3+ and oxidation of Fe2+ in solid minerals. A fluid sample from the 2450 m depth of the Chinese Continental Scientific Drilling project was collected, and Fe3+-reducing and Fe2+-oxidizing microorganisms were enriched. The enrichment cultures displayed reduction of Fe3+ in nontronite and ferric citrate, and oxidation of Fe2+ in vivianite, siderite, and monosulfide (FeS). Additional experiments verified that the iron reduction and oxidation was biological. Oxidation of FeS resulted in the formation of goethite, lepidocrocite, and ferrihydrite as products. Although our molecular microbiological analyses detected Thermoan-aerobacter ethanolicus as a predominant organism in the enrichment culture, Fe3+ reduction and Fe2+ oxidation may be accomplished by a consortia of organisms. Our results have important environmental and ecological implications for iron redox cycling in solid minerals in natural environments, where iron mineral transformations may be related to the mobility and solubility of inorganic and organic contaminants.

High relative air humidity influences mineral accumulation and growth in iron deficient soybean plants

PubMed Central

Roriz, Mariana; Carvalho, Susana M. P.; Vasconcelos, Marta W.

2014-01-01

Iron (Fe) deficiency chlorosis (IDC) in soybean results in severe yield losses. Cultivar selection is the most commonly used strategy to avoid IDC but there is a clear interaction between genotype and the environment; therefore, the search for quick and reliable tools to control this nutrient deficiency is essential. Several studies showed that relative humidity (RH) may influence the long distance transport of mineral elements and the nutrient status of plants. Thus, we decided to analyze the response of an “Fe-efficient” (EF) and an “Fe-inefficient” (INF) soybean accession grown under Fe-sufficient and deficient conditions under low (60%) and high (90%) RH, evaluating morphological, and physiological parameters. Furthermore, the mineral content of different plant organs was analyzed. Our results showed beneficial effects of high RH in alleviating IDC symptoms as seen by increased SPAD values, higher plant dry weight (DW), increased plant height, root length, and leaf area. This positive effect of RH in reducing IDC symptoms was more pronounced in the EF accession. Also, Fe content in the different plant organs of the EF accession grown under deficient conditions increased with RH. The lower partitioning of Fe to roots and stems of the EF accessions relative to dry matter also supported our hypothesis, suggesting a greater capacity of this accession in Fe translocation to the aerial parts under Fe deficient conditions, when grown under high RH. PMID:25566297

REACTIVE MINERALS IN AQUIFERS: FORMATION PROCESSES AND QUANTITATIVE ANALYSIS

EPA Science Inventory

The presentation will focus on the occurrence, form, and characterization of reactive iron minerals in aquifers and soils. The potential for abiotic reductive transformations of contaminants at the mineral-water interface will be discussed along with available tools for site min...

Spectroscopic characterization of manganese minerals.

PubMed

Lakshmi Reddy, S; Padma Suvarna, K; Udayabhaska Reddy, G; Endo, Tamio; Frost, R L

2014-01-03

Manganese minerals ardenite, alleghanyite and leucopoenicite originated from Madhya Pradesh, India, Nagano prefecture Japan, Sussex Country and Parker Shaft Franklin, Sussex Country, New Jersey respectively are used in the present work. In these minerals manganese is the major constituent and iron if present is in traces only. An EPR study of on all of the above samples confirms the presence of Mn(II) with g around 2.0. Optical absorption spectrum of the mineral alleghanyite indicates that Mn(II) is present in two different octahedral sites and in leucophoenicite Mn(II) is also in octahedral geometry. Ardenite mineral gives only a few Mn(II) bands. NIR results of the minerals ardenite, leucophoenicite and alleghanyite are due to hydroxyl and silicate anions which confirming the formulae of the minerals. Copyright © 2013 Elsevier B.V. All rights reserved.

Occurrence and Characterization Microstructure of Iron Impurities in Halloysite.

PubMed

Liu, Rong; Yan, Chunjie; Wang, Hongquan; Xiao, Guoqi; Tu, Dong

2015-09-01

The quality of the clays and over all halloysite are mostly associated with minor amounts of ferruginous impurities content, since this element gives an undesirable reddish color to the halloysite mineral. Hence, finding out the modes of occurrence of iron in halloysite is of prime importance in the value addition and optimum utilization of halloysite. In order to analyze the occurrence of iron impurities in halloysite, Transmission Electron Microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were combined with wet chemical analysis methods to study the low-grade halloysite. The results indicated that the mineral phases of iron impurities in the concentrates are mainly composed of amounts of magnetite, goethite and hematite. Two types of occurrences for iron impurities have been found. One is single crystalline mineral consist in the halloysite, which contains three different phases of Goethite FeO(OH) (44.75%), Magnetite Fe3O4 (27.43%) and Hematite Fe2O3 (31.96%). The other is amorphous Fe-Al-Si glial materials. This study is of significance in the theoretical research on the halloysite mineralogy and in the developmental practice of halloysite in coal measures.

Genetic and biochemical investigations of the role of MamP in redox control of iron biomineralization in Magnetospirillum magneticum.

PubMed

Jones, Stephanie R; Wilson, Tiffany D; Brown, Margaret E; Rahn-Lee, Lilah; Yu, Yi; Fredriksen, Laura L; Ozyamak, Ertan; Komeili, Arash; Chang, Michelle C Y

2015-03-31

Magnetotactic bacteria have evolved complex subcellular machinery to construct linear chains of magnetite nanocrystals that allow the host cell to sense direction. Each mixed-valent iron nanoparticle is mineralized from soluble iron within a membrane-encapsulated vesicle termed the magnetosome, which serves as a specialized compartment that regulates the iron, redox, and pH environment of the growing mineral. To dissect the biological components that control this process, we have carried out a genetic and biochemical study of proteins proposed to function in iron mineralization. In this study, we show that the redox sites of c-type cytochromes of the Magnetospirillum magneticum AMB-1 magnetosome island, MamP and MamT, are essential to their physiological function and that ablation of one or both heme motifs leads to loss of function, suggesting that their ability to carry out redox chemistry in vivo is important. We also develop a method to heterologously express fully heme-loaded MamP from AMB-1 for in vitro biochemical studies, which show that its Fe(III)-Fe(II) redox couple is set at an unusual potential (-89 ± 11 mV) compared with other related cytochromes involved in iron reduction or oxidation. Despite its low reduction potential, it remains competent to oxidize Fe(II) to Fe(III) and mineralize iron to produce mixed-valent iron oxides. Finally, in vitro mineralization experiments suggest that Mms mineral-templating peptides from AMB-1 can modulate the iron redox chemistry of MamP.

Ferritin protein nanocages use ion channels, catalytic sites, and nucleation channels to manage iron/oxygen chemistry.

PubMed

Theil, Elizabeth C

2011-04-01

The ferritin superfamily is composed of ancient, nanocage proteins with an internal cavity, 60% of total volume, that reversibly synthesize solid minerals of hydrated ferric oxide; the minerals are iron concentrates for cell nutrition as well as antioxidants due to ferrous and oxygen consumption during mineralization. The cages have multiple iron entry/exit channels, oxidoreductase enzyme sites, and, in eukaryotes, Fe(III)O nucleation channels with clustered exits that extend protein activity to include facilitated mineral growth. Ferritin protein cage differences include size, amino acid sequence, and location of the active sites, oxidant substrate and crystallinity of the iron mineral. Genetic regulation depends on iron and oxygen signals, which in animals includes direct ferrous signaling to RNA to release and to ubiquitin-ligases to degrade the protein repressors. Ferritin biosynthesis forms, with DNA, mRNA and the protein product, a feedback loop where the genetic signals are also protein substrates. The ferritin protein nanocages, which are required for normal iron homeostasis and are finding current use in the delivery of nanodrugs, novel nanomaterials, and nanocatalysts, are likely contributors to survival and success during the transition from anaerobic to aerobic life. Copyright © 2011. Published by Elsevier Ltd.

Ferritin Protein Nanocages Use Ion Channels, Catalytic Sites, and Nucleation Channels To Manage Iron/Oxygen Chemistry

PubMed Central

Theil, Elizabeth C.

2011-01-01

The ferritin superfamily is composed of ancient, nanocage proteins with an internal cavity, 60% of total volume, that reversibly synthesize solid minerals of hydrated ferric oxide; the minerals are iron concentrates for cell nutrition as well as antioxidants due to ferrous and oxygen consumption during mineralization. The cages have multiple iron entry/exit channels, oxidoreductase enzyme sites, and, in eukaryotes, Fe(III)O nucleation channels with clustered exits that extend protein activity to include facilitated mineral growth. Ferritin protein cage differences include size, amino acid sequence, and location of the active sites, oxidant substrate and crystallinity of the iron mineral. Genetic regulation depends on iron and oxygen signals, which in animals includes direct ferrous signaling to RNA to release and to ubiquitin-ligases to degrade the protein repressors. Ferritin biosynthesis forms, with DNA, mRNA and the protein product, a feedback loop where the genetic signals are also protein substrates. The ferritin protein nanocages, which are required for normal iron homeostasis and are finding current use in delivery of nanodrugs, novel nanomaterials, and nanocatalysts, are likely contributors to survival and success during the transition from anaerobic to aerobic life. PMID:21296609

Predicting the mineral composition of dust aerosols - Part 1: Representing key processes

NASA Astrophysics Data System (ADS)

Perlwitz, J. P.; Pérez García-Pando, C.; Miller, R. L.

2015-02-01

Soil dust aerosols created by wind erosion are typically assigned globally uniform physical and chemical properties within Earth system models, despite known regional variations in the mineral content of the parent soil. Mineral composition of the aerosol particles is important to their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, coating by heterogeneous uptake of sulfates and nitrates, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Here, aerosol mineral composition is derived by extending a method that provides the composition of a wet-sieved soil. The extension accounts for measurements showing significant differences between the mineral fractions of the wet-sieved soil and the resulting aerosol concentration. For example, some phyllosilicate aerosols are more prevalent at silt sizes, even though they are nearly absent in a soil whose aggregates are dispersed by wet sieving during analysis. We reconstruct the undispersed size distribution of the original soil that is subject to wind erosion. An empirical constraint upon the relative emission of clay and silt is applied that further differentiates the soil and aerosol mineral composition. In addition, a method is proposed for mixing minerals with small impurities composed of iron oxides. These mixtures are important for transporting iron far from the dust source, because pure iron oxides are more dense and vulnerable to gravitational removal than most minerals comprising dust aerosols. A limited comparison to measurements from North Africa shows that the extension brings the model into better agreement, consistent with a more extensive comparison to global observations as well as measurements of elemental composition downwind of the Sahara, as described in companion articles.

Geochemical characterization of acid mine lakes in northwest Turkey and their effect on the environment.

PubMed

Yucel, Deniz Sanliyuksel; Baba, Alper

2013-04-01

Mining activity generates a large quantity of mine waste. The potential hazard of mine waste depends on the host mineral. The tendency of mine waste to produce acid mine drainage (AMD) containing potentially toxic metals depends on the amounts of sulfide, carbonate minerals, and trace-element concentrations found in ore deposits. The acid mine process is one of the most significant environmental challenges and a major source of water pollution worldwide. AMD and its effects were studied in northwest Turkey where there are several sedimentary and hydrothermal mineral deposits that have been economically extracted. The study area is located in Can county of Canakkale province. Canakkale contains marine, lagoon, and lake sediments precipitated with volcanoclastics that occurred as a result of volcanism, which was active during various periods from the Upper Eocene to Plio-Quaternary. Can county is rich in coal with a total lignite reserve >100 million tons and contains numerous mines that were operated by private companies and later abandoned without any remediation. As a result, human intervention in the natural structure and topography has resulted in large open pits and deterioration in these areas. Abandoned open pit mines typically fill with water from runoff and groundwater discharge, producing artificial lakes. Acid drainage waters from these mines have resulted in the degradation of surface-water quality around Can County. The average pH and electrical conductivity of acid mine lakes (AMLs) in this study were found to be 3.03 and 3831.33 μS cm(-1), respectively. Total iron (Fe) and aluminum (Al) levels were also found to be high (329.77 and 360.67 mg L(-1), respectively). The results show that the concentration of most elements, such as Fe and Al in particular, exceed national and international water-quality standards.

Turhan Baytop (1920-2002): A pioneer historian of pharmacy from Turkey.

PubMed

Tekiner, Halil

2017-11-01

Turhan Baytop, a Turkish professor of pharmacognosy (the scientific study of crude drugs of animal, vegetable, and mineral origin), received international acclaim not only for his contributions in collecting and identifying the Anatolian plants, but also for his extensive research shedding light on the history of Turkish pharmacy. As a devoted researcher, collector, and lecturer, T Baytop was a genuine pioneer of the history of pharmacy as a discipline in Turkey.

Mineral Influence on Microbial Survival During Carbon Sequestration

NASA Astrophysics Data System (ADS)

Santillan, E. U.; Shanahan, T. M.; Wolfe, W. W.; Bennett, P.

2012-12-01

CO2 sequestered in a deep saline aquifer will perturb subsurface biogeochemistry by acidifying the groundwater and accelerating mineral diagenesis. Subsurface microbial communities heavily influence geochemistry through their metabolic processes, such as with dissimilatory iron reducing bacteria (DIRB). However, CO2 also acts as a sterilant and will perturb these communities. We investigated the role of mineralogy and its effect on the survival of microbes at high PCO2 conditions using the model DIRB Shewanella oneidensis MR-1. Batch cultures of Shewanella were grown to stationary phase and exposed to high PCO2 using modified Parr reactors. Cell viability was then determined by plating cultures after exposure. Results indicate that at low PCO2 (2 bar), growth and iron reduction are decreased and cell death occurs within 1 hour when exposed to CO2 pressures of 10 bar or greater. Further, fatty acid analysis indicates microbial lipid degradation with C18 fatty acids being the slowest lipids to degrade. When cultures were grown in the presence of rocks or minerals representative of the deep subsurface such as carbonates and silicates and exposed to 25 bar CO2, survival lasted beyond 2 hours. The most effective protecting substratum was quartz sandstone, with cultures surviving beyond 8 hours of CO2 exposure. Scanning electron microscope images reveal biofilm formation on the mineral surfaces with copious amounts of extracellular polymeric substances (EPS) present. EPS from these biofilms acts as a reactive barrier to the CO2, slowing the penetration of CO2 into cells and resulting in increased survival. When biofilm cultures were grown with Al and As to simulate the release of toxic metals from minerals such as feldspars and clays, survival time decreased, indicating mineralogy may also enhance microbial death. Biofilms were then grown on iron-coated quartz sand to determine conversely what influence biofilms may have on mineral dissolution during CO2 perturbation

Mineralogy and autoradiography of selected mineral-spring precipitates in the Western United States

USGS Publications Warehouse

Bove, Dana; Felmlee, J.K.

1982-01-01

X-ray diffaction analysis of 236 precipitate or sediment samples from 97 mineral-spring sites in nine Western States showed the presence of 25 minerals, some precipitated and some detrital. Calcite and (or) aragonite are the most common of all the precipitated minerals. Gypsum and (or) anhydrite, as well as barite and native sulfur, are less common but are also believed to be precipitated minerals. Precipitated manganese and iron oxides, including romanechite, manganite, pyrolusite, goethite, and hematite, were found in some of the samples. Various salts of sodium, including halite and thenardite, were also identified. Dolomite and an unknown type of siliceous material are present in some of the samples and were possibly precipitated at the spring sites. Quartz, feldspar, and mica are present in many of the samples and are believed to be detrital contaminants. An autoradiographic and thin section study of 11 samples from nine of the most radioactive spring sites showed the radioactivity, which is due primarily to radium, to be directly associated with mineral phases containing barium, manganese, iron, and (or) calcium as major constituents. Furthermore, the radioactivity has an exclusive affinity for the manganese-bearing minerals, which in these samples contain a substantial amount of barium, even if calcite or iron oxides are present. Where calcite predominates and manganese- and barium-bearing minerals are absent, the radioactivity shows a close association with the iron oxides present, especially hematite, but also shows a moderate association with the calcite and (or) aragonite cementing phases. In other samples composed predominantly of calcite but lacking iron oxides, the radioactivity is preferentially associated with an early stage of calcite development and is considerably lower in the later cementing stages. The radioactivity observed in all these samples is believed to be caused by radium substituting for barium in mineral lattices, filling

Cell surface characteristics enable encrustation-free survival of neutrophilic iron-oxidizing bacteria

NASA Astrophysics Data System (ADS)

Saini, G.; Chan, C. S.

2011-12-01

Microbial growth in mineralizing environments depends on the cells' ability to evade surface precipitation. Cell-mineral interactions may be required for metabolism, but if unmoderated, cells could become encrusted, which would limit diffusion of nutrients and waste across cell walls. A combination of cell surface charge and hydrophobicity could enable the survival of microbes in such environments by inhibiting mineral attachment. To investigate this mechanism, we characterized the surfaces of two neutrophilic iron-oxidizing bacteria (FeOB): Mariprofundus ferrooxydans, a Zetaproteobacterium from Fe(II)-rich submarine hydrothermal vents and a Betaproteobacterium Gallionellales strain R-1, recently isolated from a ferrous groundwater seep. Both bacteria produce iron oxyhydroxides, yet successfully escape surface encrustation while inhabiting milieu where iron minerals are also produced by abiotic processes. SEM-EDX and TEM-EELS analyses of cultured bacteria revealed no iron on the cell surfaces. Zeta potential measurements showed that these bacteria have very small negative surface charge (0 to -4 mV) over a pH range of 4-9, indicating near-neutrally charged surfaces. Water contact angle measurements and thermodynamic calculations demonstrate that both bacteria and abiotically-formed Fe oxhydroxides are hydrophilic. Extended-DLVO calculations showed that hydrophilic repulsion between cells and minerals dominates over electrostatic and Lifshitz-van der Waals interactions. This leads to overall repulsion between microbes and minerals, thus preventing surface encrustation. Low surface charge and hydrophilicity (determined by microbial adhesion to hydrocarbon assay) were common features for both live and azide-inhibited cells, which shows that surface characteristics do not depend on active metabolism. It is remarkable that these two phylogenetically-distant bacteria from different environments employ similar adaptations to prevent surface mineralization. Our results

Iron-bearing minerals of a rupestrian painting from the Manantial Solís site, Cardiel Lake, Patagonia, Argentina

NASA Astrophysics Data System (ADS)

Duarte Cavalcante, Luis Carlos; Ferraro, Lorena; Hugon, Paulette; Soares Meneses Lage, Maria Conceição; Fabris, José Domingos

2017-11-01

The archaeological site Manantial Solís is located on shores of the Cardiel Lake, Santa Cruz Province, Patagonia, Argentina. The main characteristic of this site is the occurrence of 251 rupestrian paintings, namely abstract figures, anthropomorphic and zoomorphic motifs, painted in different hues of red, but also in yellow, orange, pink, violet and white; these paintings are often formed by overlapping pictorial motifs. The basaltic rock-wall supporting these graphisms has been naturally degraded and, as a consequence, covered with saline efflorescence. The chemical and mineralogical analyses of a micro-sample from a red rupestrian painting were made in the laboratory by (i) energy dispersive X-ray fluorescence; (ii) CHN elemental analysis and (iii) 57Fe transmission Mössbauer spectroscopy at 298 K and 110 K, in an effort to identify the main iron-bearing minerals composing the painting pigments. The stratigraphy of the paint layer was investigated on a polished cross-section. From the Mössbauer spectra of this red painting, two sextets assignable to hematite ( α Fe2O3) were identified. The Fe3+ central doublet is assumed to be due to superparamagnetic phases, more likely as iron (oxyhydr)oxides (likely including some goethite, α FeOOH) in very small particles and paramagnetic iron in the crystalline structure of aluminosilicates. The Fe2+ doublet was interpreted as being due to the basalt rock support of this prehistoric painting.

The Effect of Different Levels of Cu, Zn and Mn Nanoparticles in Hen Turkey Diet on the Activity of Aminopeptidases.

PubMed

Jóźwik, Artur; Marchewka, Joanna; Strzałkowska, Nina; Horbańczuk, Jarosław Olav; Szumacher-Strabel, Małgorzata; Cieślak, Adam; Lipińska-Palka, Paulina; Józefiak, Damian; Kamińska, Agnieszka; Atanasov, Atanas G

2018-05-11

The aim of the study was to estimate the influence of the different levels of Cu, Zn, and Mn nanoparticles on the activity of aminopeptidases in turkey. An experiment was carried out on 144 turkey hen Hybrid Converter. The birds were divided into groups given standard- and nanoparticle-supplementation of different level of copper (Cu 20, 10, 2 mg/kg), zinc (Zn 100, 50, 10 ppm), and manganese (Mn 100, 50, 10 ppm), covering respectively 100%, 50%, and 10% of the physiological demands for those minerals in the diet. The activity of aminopeptidases (alanyl: AlaAP, leucyl: LeuAP and arginyl: ArgAP) after supplementation of minerals was determined in the breast and thigh turkey muscle. The strongest effect of interaction among minerals supplementation form and dose on the activity levels of the aminopeptidases in thigh muscle was observed for nano-Cu already at the lowest dose of 2 mg/kg. In this dose (covering 10% of the birds’ demand) nano form of supplementation significantly increased the activity of Ala-, Leu-, and ArgAP (877, 201, and 719, respectively), compared to standard form of supplementation (461, 90.5, and 576, respectively). In turn, in breast muscle, after supplementation covering 10% of the demand with the nano-Cu, nano-Zn, and nano-Mn compared to the standard form, we did not observe any significant difference in the activity levels of any of the investigated aminopeptidases, except for AlaAP under Zn supplementation. Supplementation with the 20 mg/kg of Nano-Cu (100% of demand) and with 10 mg/kg of Nano-Cu (50% of demand) inhibited the activity of all of the three aminopeptidases in thigh muscle. Supplementation of the minerals in nano form into the diet, especially of Cu and Zn in the dose covering 10% of the demand is relevant to maintain homeostasis in turkey muscles, as indicated by the activity of the aminopeptidases.

Hyperspectral surface materials map of quadrangle 3464, Shahrak (411) and Kasi (412) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3162, Chakhansur (603) and Kotalak (604) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3366, Gizab (513) and Nawer (514) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3362, Shindand (415) and Tulak (416) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3564, Jowand (405) and Gurziwan (406) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3368, Ghazni (515) and Gardez (516) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3770, Faizabad (217) and Parkhaw (218) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3266, Uruzgan (519) and Moqur (520) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3470, Jalalabad (511) and Chaghasaray (512) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Effect of iron supplementation during lactation on maternal iron status and oxidative stress: A randomized controlled trial.

PubMed

Jorgensen, Josh M; Yang, Zhenyu; Lönnerdal, Bo; Chantry, Caroline J; Dewey, Kathryn G

2017-10-01

We examined the effect of iron-containing prenatal vitamin-mineral supplements taken postpartum on biomarkers of iron status and oxidative stress. Lactating women (n = 114) were randomly assigned to consume daily one iron-free prenatal vitamin-mineral supplement plus either 27 mg of iron or placebo for approximately 3.5 months. The placebo group took the tablets between meals, while those given iron took the tablets either with (Fe-W) or between meals (Fe-B). Blood and urine samples were collected before and after the supplementation period to analyze hemoglobin (Hb), ferritin, hepcidin, transferrin saturation (TfSat), total plasma iron, and biomarkers of oxidative stress (isoprostane and 8-hydroxy-2-deoxyguanosine (8-OHdG)) and inflammation (C-reactive protein (CRP) and alpha-1-acid glycoprotein (AGP)). There was a trend toward a greater change in Hb among women in the Fe-B group compared to placebo (+2.5 vs. -3.7 g/L, respectively, p = 0.063). When the iron groups were combined, there was a greater change in Hb (+1.4 g/L) compared to placebo (p = 0.010). There were trends toward greater changes in TfSat (p = 0.087) and total plasma iron (p = 0.065) in the iron groups compared to placebo, yet no significant differences between the three groups in change in hepcidin (p = 0.291), isoprostane (p = 0.319), or 8-OHdG (p = 0.659), nor in change in ferritin among those with elevated CRP at baseline (60% of women; p = 0.946); among those without elevated CRP (40% of women), ferritin increased more in the iron groups compared to placebo (p = 0.001). Iron consumption during lactation moderately increased iron status, particularly among women without elevated CRP, and increased Hb, but did not significantly increase oxidative stress. © 2016 John Wiley & Sons Ltd.

Mineralogical, Physical and Geochemical Factors that Drive Microbial Reduction of Iron Oxides and Diagenesis under Broad Environmental Conditions

NASA Astrophysics Data System (ADS)

Dong, Y.; Sanford, R. A.; Boyanov, M.; Kemner, K. M.; Flynn, T. M.; O'Loughlin, E. J.; George, S.; Fouke, K.; Fouke, B. W.

2016-12-01

Iron reduction by dissimilatory iron-reducing bacteria (DIRB), coupled with the oxidation of organic compounds or H2, causes formation of post-depositional (diagenetic) Fe(II)-containing minerals. Previous studies on the composition, distribution and precipitation rates of secondary minerals during microbial iron reduction have primarily focused on ferrihydrite reduction by Shewanella spp. However, comparatively little is known about these processes by a variety of other DIRB and the effect of specific environmental factors on Fe(II)-bearing mineral diagenesis. Here we examine how environmental conditions influence the reduction of ferric iron minerals by Orenia metallireducens strain Z6, a DIRB from the phylum Firmicutes. This includes the effects of: (1) pH at 6.5-8.5; (2) temperature at 22-50 °C; (3) salinity at 2-20% NaCl; (4) solution chemistry of phosphate and sulfate; (5) electron shuttles (e.g., anthraquinone-2,6-disulfonate (AQDS)); and (6) iron oxides, including ferrihydrite, lepidocrocite, goethite, hematite, and magnetite. For a total of 19 culturing conditions, we measured ferrous iron produced over time using the ferrozine assay and formation of secondary minerals using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), X-Ray Diffraction (XRD), and extended X-ray absorption fine structure spectroscopy (Fe-edge XANES and EXAFS). Results show that both the rate and extent of DIRB reduction of ferrihydrite and lepidocrocite vastly exceeded those of the more crystalline minerals. The microscopic and spectroscopic analyses indicate diversity in the composition and relative abundance of Fe(II)-containing minerals such as green rust, siderite, magnetite and/or vivianite under the different experimental conditions. However, the secondary mineralization products cannot be attributed to either the extent or kinetics of Fe(II) generation. Instead, the composition of these digenetic minerals resulted from the intricate interplay of

Elevated and variable groundwater iron in rural northwestern Bangladesh.

PubMed

Merrill, Rebecca D; Labrique, Alain B; Shamim, Abu Ahmed; Schulze, Kerry; Christian, Parul; Merrill, Robert K; West, Keith P

2010-12-01

Over the past 30 years, tubewells have become a ubiquitous source of potable groundwater in South Asia. Considered safer than surface water, groundwater naturally contains minerals that may impact human health; however, few data exist on tubewell water mineral content or its association with human nutritional or health conditions. We surveyed iron concentration in tubewell water across a 435 km2, contiguous, rural area in northwestern Bangladesh to map and quantify levels of iron in drinking water. One tubewell was randomly sampled from each of 948 adjacent grid cells 675 m2 in size. Water sampling was standardized and iron concentration measured using a field-based colorimetric kit. The median (interquartile range) concentration of iron in tubewell water was 7.6 (1.6, 17.6) mg l(-1). There was high geographic variation (range of 0-46.5 mg l(-1)), and iron in only 3% of surveyed tubewells fell below the WHO aesthetic cut-off of 0.3 mg l(-1) suggesting elevated levels of iron throughout the area. Villagers accurately perceived groundwater iron concentration, based on a 4-point ('none', 'a little', 'medium', 'a lot') scale (p<0.001). Water source iron content can be readily quantified in population settings offering the potential to evaluate the health relevance of groundwater iron exposure in rural communities.

Beliefs and practices of Iranian pregnant mothers regarding vitamins and minerals.

PubMed

Mashayekhi, S O; Dilmaghanizadeh, M; Fardiazar, Z; Bamdad-Moghadam, R; Ghandforoush-Sattari, M

2011-03-01

The objective of this descriptive study was to examine the vitamin and mineral supplements safety beliefs and practices of Iranian pregnant women. Data were collected from 400 randomly chosen women. More than 50% of the participants believed that taking vitamins and minerals during pregnancy was safe; 87% reported taking iron during pregnancy, of which 71.7 % reported their doctor as the main recommender; 21.8% reported first trimester as the most beneficial time for iron supplementation, 13.0% second trimester and 3.0% third trimester. Although an appropriate intake of vitamins and minerals can assure health in pregnancy, excess can be harmful. Educational programmes for women of childbearing age are necessary.

Combining Textural Techniques to Explore Effects of Diagenesis and Low-grade Metamorphism on Iron Mineralogy and Iron Speciation

NASA Astrophysics Data System (ADS)

Slotznick, S. P.; Webb, S.; Eiler, J. M.; Kirschvink, J. L.; Fischer, W. W.

2016-12-01

Iron chemistry and mineralogy in the sedimentary rocks provide a valuable tool for studying paleoenvironmental conditions due to the fact that iron atoms can take on either the +II or +III valence state under geological redox conditions. One method utilizing this redox chemistry is `iron speciation', a bulk chemical sequential extraction technique that maps proportions of iron species to redox conditions empirically calibrated from modern sediments. However, all Precambrian and many Phanerozoic rocks have experienced post-depositional processes; it is vital to explore their effects on iron mineralogy and speciation. We combined light and electron microscopy, magnetic microscopy, (synchrotron-based) microprobe x-ray spectroscopy, and rock magnetic measurements in order to deconvolve secondary overprints from primary phases and provide quantitative measurement of iron minerals. These techniques were applied to excellently-preserved shale and siltstone samples of the 1.4 Ga lower Belt Supergroup, Montana and Idaho, USA, spanning a metamorphic gradient from sub-biotite to garnet zone. Previously measured Silurian-Devonian shales, sandstones, and carbonates in Maine and Vermont, USA spanning from the chlorite to kyanite zone provided additional well-constrained, quantitative data for comparison and to extend our analysis. In all of the studied samples, pyrrhotite formation occurred at the sub-biotite or sub-chlorite zone. Pyrrhotite was interpreted to form from pyrite and/or other iron phases based on lithology; these reactions can affect the paleoredox proxy. Iron carbonates can also severely influence iron speciation results since they often form in anoxic pore fluids during diagenesis; textural analyses of the Belt Supergroup samples highlighted that iron-bearing carbonates were early diagenetic cements or later diagenetic overprints. The inclusion of iron from diagenetic minerals during iron speciation analyses will skew results by providing a view of pore

Bioavailability of iron in geophagic earths and clay minerals, and their effect on dietary iron absorption using an in vitro digestion/Caco-2 cell model.

PubMed

Seim, Gretchen L; Ahn, Cedric I; Bodis, Mary S; Luwedde, Flavia; Miller, Dennis D; Hillier, Stephen; Tako, Elad; Glahn, Raymond P; Young, Sera L

2013-08-01

Geophagy, the deliberate consumption of earth, is strongly associated with iron (Fe) deficiency. It has been proposed that geophagy may be practiced as a means to improve Fe status by increasing Fe intakes and, conversely, that geophagy may cause Fe deficiency by inhibiting Fe absorption. We tested these hypotheses by measuring Fe concentration and relative bioavailable Fe content of 12 samples of geophagic earth and 4 samples of pure clay minerals. Further, we assessed the impact of these samples on the bioavailability of Fe from an Fe-rich test meal (cooked white beans, WB). Fe concentrations were measured with inductively coupled plasma atomic emission spectroscopy. Fe bioavailability was determined using an in vitro digestion/Caco-2 cell model in which ferritin formation was used as an index of Fe bioavailability. Geophagic earth and clay mineral samples were evaluated with this model, both alone and in combination with WB (1 : 16 ratio, sample : WB). Median Fe concentration of the geophagic earth was 3485 (IQR 2462, 14 ,571) μg g⁻¹ and mean Fe concentration in the clay minerals was 2791 (±1782) μg g⁻¹. All specimens had Fe concentrations significantly higher (p ≤ 0.005) than the Fe concentration of WB (77 μg g⁻¹). Ferritin formation (i.e. Fe uptake) in cells exposed to geophagic earths and clay minerals was significantly lower than in cells exposed to WB (p ≤ 0.05) and Fe uptake responses of 11 of the 16 samples were not significantly different from the blank, indicating no bioavailable Fe. When samples were combined with WB, 5 of 16 had mean ferritin levels that were significantly lower (p ≤ 0.05, one tail) than the WB alone, indicating that the samples inhibited Fe uptake from the WB. None of the ferritin responses of cells exposed to both WB and earth/clay were significantly higher than WB alone. Thus, although geophagic earths and mineral clays are high in total Fe, very little of this Fe is bioavailable. Further, some

An Analysis of the Published Mineral Resource Estimates of the Haji-Gak Iron Deposit, Afghanistan

USGS Publications Warehouse

Sutphin, D.M.; Renaud, K.M.; Drew, L.J.

2011-01-01

The Haji-Gak iron deposit of eastern Bamyan Province, eastern Afghanistan, was studied extensively and resource calculations were made in the 1960s by Afghan and Russian geologists. Recalculation of the resource estimates verifies the original estimates for categories A (in-place resources known in detail), B (in-place resources known in moderate detail), and C 1 (in-place resources estimated on sparse data), totaling 110. 8 Mt, or about 6% of the resources as being supportable for the methods used in the 1960s. C 2 (based on a loose exploration grid with little data) resources are based on one ore grade from one drill hole, and P 2 (prognosis) resources are based on field observations, field measurements, and an ore grade derived from averaging grades from three better sampled ore bodies. C 2 and P 2 resources are 1,659. 1 Mt or about 94% of the total resources in the deposit. The vast P 2 resources have not been drilled or sampled to confirm their extent or quality. The purpose of this article is to independently evaluate the resources of the Haji-Gak iron deposit by using the available geologic and mineral resource information including geologic maps and cross sections, sampling data, and the analog-estimating techniques of the 1960s to determine the size and tenor of the deposit. ?? 2011 International Association for Mathematical Geology (outside the USA).

Turkey Meatloaf

MedlinePlus

... this page: https://medlineplus.gov/recipe/turkeymeatloaf.html Turkey Meatloaf To use the sharing features on this ... old dinner favorite. Ingredients 1 lb lean ground turkey 1/2 cup regular oats, dry 1 large ...

The Conterminous United States Mineral Assessment Program; background information to accompany folio of geologic and mineral resource maps of the Silver City 1 degree x 2 degrees Quadrangle, New Mexico and Arizona

USGS Publications Warehouse

Richter, Donald H.; Houser, B.B.; Watts, K.C.; Klein, D.P.; Sharp, W.N.; Drewes, Harald; Hedlund, D.C.; Raines, G.L.; Hassemer, J.R.

1987-01-01

The Silver City 1 ? x 2 ? quadrangle, consisting of about 20,650 km2 in southwestern New Mexico and southeastern Arizona, has been investigated by a multidisciplinary research team for the purpose of assessing its mineral resource potential. The results of this investigation are in a folio of 21 maps that contain detailed information on the geology, geochemistry, geophysics, mineral deposits, and potential mineral resources of the quadrangle. This Circular provides background information on the various studies and integrates the component maps. It contains an extensive selected bibliography pertinent to the geology and mineral deposits of the quadrangle. The quadrangle has produced more than $3.5 billion in mineral products since about 1850 and contains significant resources of gold, silver, copper, molybdenum, lead, zinc, iron, manganese-iron, zeolite minerals, and possibly tin and tungsten.

Microanalysis of iron oxidation state in iron oxides using X Ray Absorption Near Edge Structure (XANES)

NASA Technical Reports Server (NTRS)

Sutton, S. R.; Delaney, J.; Bajt, S.; Rivers, M. L.; Smith, J. V.

1993-01-01

An exploratory application of x ray absorption near edge structure (XANES) analysis using the synchrotron x ray microprobe was undertaken to obtain Fe XANES spectra on individual sub-millimeter grains in conventional polished sections. The experiments concentrated on determinations of Fe valence in a suite of iron oxide minerals for which independent estimates of the iron speciation could be made by electron microprobe analysis and x ray diffraction.

Study of iron deposit using seismic refraction and resistivity in Carajás Mineral Province, Brazil

NASA Astrophysics Data System (ADS)

Nogueira, Pedro Vencovsky; Rocha, Marcelo Peres; Borges, Welitom Rodrigues; Silva, Adalene Moreira; Assis, Luciano Mozer de

2016-10-01

This work comprises the acquisition, processing and interpretation of 2D seismic shallow refraction (P-wave) and resistivity profiles located in the iron ore deposit of N4WS, Carajás Mineral Province (CMP), northern Brazil. The geophysical methods were used to identify the boundaries of the iron ore deposit. Another objective was to evaluate the potentiality of these geophysical methods in that geological context. In order to validate the results, the geophysical lines were located to match a geological borehole line. For the seismic refraction, we used 120 channels, spaced by 10 m, in a line of 1190 m, with seven shot points. The resistivity method used in the acquisition was the electrical resistivity imaging, with pole-pole array, in order to reach greater depths. The resistivity line had a length of 1430 m, with 10 m spacing between electrodes. The seismic results produced a model with two distinct layers. Based on the velocities values, the first layer was interpreted as altered rocks, and the second layer as more preserved rocks. It was not possible to discriminate different lithologies with the seismic method inside each layer. From the resistivity results, a zone of higher resistivity (> 3937 Ω·m) was interpreted as iron ore, and a region of intermediate resistivity (from 816 to 2330 Ω·m) as altered rocks. These two regions represent the first seismic layer. On the second seismic layer, an area with intermediated resistivity values (from 483 to 2330 Ω·m) was interpreted as mafic rocks, and the area with lower resistivity (< 483 Ω·m) as jaspilite. Our results were compared with geological boreholes and show reasonable correlation, suggesting that the geophysical anomalies correspond to the main variations in composition and physical properties of rocks.

Mechanisms of Mineral Substrate Acquisition in a Thermoacidophile.

PubMed

Amenabar, Maximiliano J; Boyd, Eric S

2018-06-15

The thermoacidophile Acidianus is widely distributed in Yellowstone National Park hot springs that span large gradients in pH (1.60 to 4.84), temperature (42 to 90°C), and mineralogical composition. To characterize the potential role of flexibility in mineral-dependent energy metabolism in contributing to the widespread ecological distribution of this organism, we characterized the spectrum of minerals capable of supporting metabolism and the mechanisms that it uses to access these minerals. The energy metabolism of Acidianus strain DS80 was supported by elemental sulfur (S 0 ), a variety of iron (hydr)oxides, and arsenic sulfide. Strain DS80 reduced, oxidized, and disproportionated S 0 Cells growing via S 0 reduction and disproportionation did not require direct access to the mineral to reduce it, whereas cells growing via S 0 oxidation did require direct access, observations that are attributable to the role of H 2 S produced by S 0 reduction/disproportionation in solubilizing and increasing the bioavailability of S 0 Cells growing via iron (hydr)oxide reduction did not require access to the mineral, suggesting that the cells reduce Fe(III) that is being leached by the acidic growth medium. Cells growing via oxidation of arsenic sulfide with Fe(III) did not require access to the mineral to grow. The stoichiometry of reactants to products indicates that cells oxidize soluble As(III) released from oxidation of arsenic sulfide by aqueous Fe(III). Taken together, these observations underscore the importance of feedbacks between abiotic and biotic reactions in influencing the bioavailability of mineral substrates and defining ecological niches capable of supporting microbial metabolism. IMPORTANCE Mineral sources of electron donor and acceptor that support microbial metabolism are abundant in the natural environment. However, the spectrum of minerals capable of supporting a given microbial strain and the mechanisms that are used to access these minerals in support of

Preliminary report on iron ore reserves at Bomi Hills, Liberia

USGS Publications Warehouse

Newhouse, Walter H.; Thayer, Thomas P.; Butler, Arthur P.

1945-01-01

At the request if the Liberian Government made through the Department of State of the United States Government, a party of geologists of the Geological Survey, United States Department of the Interior, was sent to Liberia to examine certain mineral deposits. The party, consisting of Walter H. Newhouse, Thomas P. Thayer, and Arthur P. Butler, Jr., left Washington, D.C., about December 1, 1943, and arrived in Monrovia, Liberia, December 12, 1943. They left Roberts Field, Liberia, May 5, 1944, and returned to Washington May 16, 1944. The geologists left Monrovia for field work in the interior on January 9, the delay of several weeks being due to difficulties in obtaining porters. Mr. Arthur Sherman, Mining Engineer for the Liberian Government, who accompanied the party into the interior, capably participated in the examination of the iron deposits and otherwise rendered invaluable assistance sue to his extensive knowledge of the native tribes and trails. President Tubman requested that the part first examined the iron deposits at Bomi Hills. At the close of the work there he requested that iron deposits in the Kpandemai Mountains be investigated. The party therefore left Bomi Hills on March 25 and arrived at Jordense Camp in the Kpandemai Mountain region on April 6. Four days were spent at this place examining the iron mineralization in the vicinity of Castle Rock, Sugar Loaf, and Mt. Wutivi of Kpandemai Mountains. On April 11 Kpandemai village reached. One day was spent on a long transverse into the Kpandemai Mountains to investigate the iron mineralization. The party left Kpandemai Village April 15 and arrived at Monrovia April 27. The iron mineralization in the portions of the Kpandemai Mountains investigated by the party is believed to be too low in grade and too small in amount to be of any present commercial interest and will not be considered further in this report.

Oxygen isotope exchange kinetics of mineral pairs in closed and open systems: Applications to problems of hydrothermal alteration of igneous rocks and Precambrian iron formations

USGS Publications Warehouse

Gregory, R.T.; Criss, R.E.; Taylor, H.P.

1989-01-01

heat-balance constraints, we can utilize the 18O 16O data on natural mineral assemblages to calculate the kinetic rate constants (k's) and the effective diffusion constants (D's) for mineral-H2O exchange: these calculated values (kqtz ??? 10-14, kfeld ??? 10-13-10-12) agree with experimental determinations of such constants. In nature, once the driving force or energy source for the external infiltrating fluid phase is removed, the disequilibrium mineral-pair arrays will either: (1) remain "frozen" in their existing state, if the temperatures are low enough, or (2) re-equilibrate along specific closed-system exchange vectors determined solely by the temperature path and the mineral modal proportions. Thus, modal mineralogical information is a particularly important parameter in both the open- and closed-system scenarios, and should in general always be reported in stable-isotopic studies of mineral assemblages. These concepts are applied to an analysis of 18O 16O systematics of gabbros (Plagioclase-clinopyroxene and plagioclase-amphibole pairs), granitic plutons (quartz-feldspar pairs), and Precambrian siliceous iron formations (quartz-magnetite pairs). In all these examples, striking regularities are observed on ??-?? and ??-?? plots, but we point out that ??-?? plots have many advantages over their equivalent ??-?? diagrams, as the latter are more susceptible to misinterpretation. Using the equations developed in this study, these regularities can be interpreted to give semiquantitative information on the exchange histories of these rocks subsequent to their formation. In particular, we present a new interpretation indicating that Precambrian cherty iron formations have in general undergone a complex fluid exchange history in which the iron oxide (magnetite precursor?) has exchanged much faster with low-temperature (< 400??C) fluids than has the relatively inert quartz. ?? 1989.

Turkey's High Temperature Geothermal Energy Resources and Electricity Production Potential

NASA Astrophysics Data System (ADS)

Bilgin, Ö.

2012-04-01

Turkey is in the first 7 countries in the world in terms of potential and applications. Geothermal energy which is an alternative energy resource has advantages such as low-cost, clean, safe and natural resource. Geothermal energy is defined as hot water and steam which is formed by heat that accumulated in various depths of the Earth's crust; with more than 20oC temperature and which contain more than fused minerals, various salts and gases than normal underground and ground water. It is divided into three groups as low, medium and high temperature. High-temperature fluid is used in electricity generation, low and medium temperature fluids are used in greenhouses, houses, airport runways, animal farms and places such as swimming pools heating. In this study high temperature geothermal fields in Turkey which is suitable for electricity production, properties and electricity production potential was investigated.

Modeling aqueous ferrous iron chemistry at low temperatures with application to Mars

USGS Publications Warehouse

Marion, G.M.; Catling, D.C.; Kargel, J.S.

2003-01-01

Major uncertainties exist with respect to the aqueous geochemical evolution of the Martian surface. Considering the prevailing cryogenic climates and the abundance of salts and iron minerals on Mars, any attempt at comprehensive modeling of Martian aqueous chemistry should include iron chemistry and be valid at low temperatures and high solution concentrations. The objectives of this paper were to (1) estimate ferrous iron Pitzer-equation parameters and iron mineral solubility products at low temperatures (from < 0 ??C to 25 ??C), (2) incorporate these parameters and solubility products into the FREZCHEM model, and (3) use the model to simulate the surficial aqueous geochemical evolution of Mars. Ferrous iron Pitzer-equation parameters were derived in this work or taken from the literature. Six new iron minerals [FeCl2??4H2O, FeCl2??6H2O, FeSO4??H2O, FeSO4??7H2O, FeCO3, and Fe(OH)3] were added to the FREZCHEM model bringing the total solid phases to 56. Agreement between model predictions and experimental data are fair to excellent for the ferrous systems: Fe-Cl, Fe-SO4, Fe-HCO3, H-Fe-Cl, and H-Fe-SO4. We quantified a conceptual model for the aqueous geochemical evolution of the Martian surface. The five stages of the conceptual model are: (1) carbonic acid weathering of primary ferromagnesian minerals to form an initial magnesium-iron-bicarbonate-rich solution; (2) evaporation and precipitation of carbonates, including siderite (FeCO3), with evolution of the brine to a concentrated NaCl solution; (3) ferrous/ferric iron oxidation; (4) either evaporation or freezing of the brine to dryness; and (5) surface acidification. What began as a dilute Mg-Fe-HCO3 dominated leachate representing ferromagnesian weathering evolved into an Earth-like seawater composition dominated by NaCl, and finally into a hypersaline Mg-Na-SO4-Cl brine. Weathering appears to have taken place initially under conditions that allowed solution of ferrous iron [low O2(g)], but later caused

Iron, transferrin and myelinogenesis

NASA Astrophysics Data System (ADS)

Sergeant, C.; Vesvres, M. H.; Devès, G.; Baron, B.; Guillou, F.

2003-09-01

Transferrin (Tf), the iron binding protein of vertebrates serum, is known to be synthesized by oligodendrocytes (Ols) in the central nervous system. It has been postulated that Tf is involved in Ols maturation and myelinogenesis. This link is particularly important in the understanding of a severe human pathology: the multiple sclerosis, which remains without efficient treatment. We generated transgenic mice containing the complete human Tf gene and extensive regulatory sequences from the 5 ' and 3 ' untranslated regions that specifically overexpress Tf in Ols. Brain cytoarchitecture of the transgenic mice appears to be normal in all brain regions examined, total myelin content is increased by 30% and motor coordination is significantly improved when compared with non-transgenic littermates. Tf role in the central nervous system may be related to its affinity for metallic cations. Normal and transgenic mice were used for determination of trace metals (iron, copper and zinc) and minerals (potassium and calcium) concentration in cerebellum and corpus callosum. The freeze-dried samples were prepared to allow proton-induced X-ray emission and Rutherford backscattering spectrometry analyses with the nuclear microprobe in Bordeaux. Preliminary results were obtained and carbon distribution was revealed as a very good analysis to distinguish precisely the white matter region. A comparison of metallic and mineral elements contents in brain between normal and transgenic mice shows that iron, copper and zinc levels remained constant. This result provides evidence that effects of Tf overexpression in the brain do not solely relate to iron transport.

Iron Oxide Biominerals in Protein Nanocages, the Ferritins: Easing Into Life With Oxygen?

NASA Astrophysics Data System (ADS)

Theil, E. C.

2008-12-01

Organisms with ferritins could represent the progenitors of organisms that successfully made the transition to aerobic life. Ferritins are protein nanocages (8 or 12 nm diameter) that catalyze reactions between Fe(II) and O2 or H2O2 to synthesize ferrihydrite-like biominerals of Fe2O3(H2 O)n; phosphate is sometimes incorporated during mineralization. All groups of organisms, archea, bacteria, plants and animals have ferritins. Catalytic reactions between Fe and O occur in the protein cage with the products moving into the central protein cavity (5 or 8 nm diameter) where mineralization occurs; mineral sizes reach 4500 Fe with more than 7000 O atoms in the large cavities of maxi-ferritins and 500 Fe with more than 800 O atoms in the smaller, mini-ferritins, also called Dps proteins. H2O2 is preferentially used by mini-ferritins in archea and bacteria, contrasting with O2, preferentially used by maxi-ferritins in bacteria plants and animals, and some bacterial mini-ferritins that use either H2O2 or O2, to oxidize Fe(II) during biomineralization. The study of ferritins in contemporary organisms can illuminate mechanisms for oxygen and oxidant responses in changing environments now and in the past. Multiple genes encoding ferritins are often regulated by different environmental stimuli and in multi-cellular organisms, by tissue-specific, differentiation programs. The single celled E.coli has four ferritin genes, encoding three maxi-ferritins, one with a heme cofactor (bacterioferritin), and one mini-ferritin (Dps), expressed at different points in the culture cycle and/or in response to different stresses. Environmental iron, oxygen and peroxide all change the amounts of ferritin. When iron is plentiful, mineralized ferritin accumulates. Ferritin iron is recovered during periods of iron deficiency, apparently by selective unfolding of gated pores in ferritin protein nanocage that expose the mineral to reductants. Gene (DNA) transcription is the genetic target for iron

Eucalyptus obliqua seedling growth in organic vs. mineral soil horizons

PubMed Central

Barry, Karen M.; Janos, David P.; Nichols, Scott; Bowman, David M. J. S.

2015-01-01

Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of organic layer and mineral soil in a glasshouse. Additional treatments of organic soil only, involved fully crossed methyl-bromide fumigation and fertilization. Fertilization comprised chelated iron for 121 days after transplant (DAT) followed by soluble phosphorus. At 357 DAT, whole plant dry weight was three times greater in ambient organic than in mineral soil. In organic soil, fumigation halved ectomycorrhiza abundance and reduced seedling growth at 149 DAT, but by 357 DAT when negative effects of fumigation on seedling growth had disappeared, neither fumigation nor fertilization affected mycorrhiza abundance. Iron fertilization diminished seedling growth, but subsequent phosphorus fertilization improved it. E. obliqua seedlings grow much better in organic layer soil than in mineral soil, although phosphorus remains limiting. The prevalent forestry practice of burning to mineral soil after timber harvest exposes a poor growth medium likely only partially compensated by fire-induced mineral soil alterations. PMID:25750650

Aeromagnetic interpretation and mineral investigations in the Bolu, Canakkale-Karabiga, Demirkoy, Ezine, and Orhaneli areas of northwestern Turkey in 1968

USGS Publications Warehouse

Jacobson, Herbert Samuel; Tumer, Ural; Karahacioglu, Hamit

1972-01-01

This report reviews progress made during 1968 in the continuing Joint Haden Tetkik ve Arama Enstitusu (MSA)-U. S. Geological Survey (USGS) Mineral Exploration and Training Project, Subproject 2. Subproject 2 is concerned with aeromagnetic interpretation of MTA's aeromagnetic surveys, and ground investigations of selected aeromagnetic anomalies. This report includes new aeromagnetic maps for the Bolu, Canakkale-Karabiga, Demirkoy, and Orhaneli areas and reviews ground investigations in five areas. Activities for each area are sunmarized below: 1. Bolu area: The aeromagnetic map shows two belts of anomalies related to regional magnetite-bearing formations and a group of discrete anomalies, some of which may reflect significant concentrations of magnetite. To date three of these anomalies have been checked on the ground and at one a metamorphic rock containing 14 percent magnetite was observed. 2. Canakkale-Karabiga area: Ground checks were made of six aeromagnetic anomalies. At one locality (Cakirly-Koyu) 6 km south of Nazmara Sea a small magnetite deposit was found. The magnetic anomaly over the area is 150 meters long, and about 3 meters deep in the center of the anomaly exposed massive magnetite boulders. 3. Demirkoy area: The aeromagnetic map shows only one significant anomaly which was checked on the ground and found to be caused by minor magnetite at an intrusive contact. 4. Ezine area: A ground survey of 4.5 sq km area was made where magnetite boulders are locally present on the surface. No significant magnetic anomaly or iron mineralization were found. 5. Orhaneli area: The aeromagnetic map o# the area showed regional magnetic anomaly patterns related to magnetite in mafic intrusives, ultramafic rocks, and mafic flow rocks. In addition 16 localized anomalies were identified. Most of these anomalies were checked on the ground but no significant iron deposits were found. The largest deposit found was a one-meter wide magnetite vein. During the 1969 field season

Modelling Iron-Bentonite Interactions

NASA Astrophysics Data System (ADS)

Watson, C.; Savage, D.; Benbow, S.; Wilson, J.

2009-04-01

The presence of both iron canisters and bentonitic clay in some engineered barrier system (EBS) designs for the geological disposal of high-level radioactive wastes creates the potential for chemical interactions which may impact upon the long-term performance of the clay as a barrier to radionuclide migration. Flooding of potential radionuclide sorption sites on the clay by ferrous ions and conversion of clay to non-swelling sheet silicates (e.g. berthierine) are two possible outcomes deleterious to long-term performance. Laboratory experimental studies of the corrosion of iron in clay show that corrosion product layers are generally thin (< 1 µm) with magnetite, siderite, or ‘green rust' occurring depending upon temperature and ambient partial pressure of carbon dioxide. In theory, incorporation of iron into clay alteration products could act as a ‘pump' to accelerate corrosion. However, the results of laboratory experiments to characterise the products of iron-bentonite interaction are less than unequivocal. The type and amounts of solid products appear to be strong functions of time, temperature, water/clay ratio, and clay and pore fluid compositions. For example, the products of high temperature experiments (> 250 °C) are dominated by chlorite, whereas lower temperatures produce berthierine, odinite, cronstedtite, or Fe-rich smectite. Unfortunately, the inevitable short-term nature of laboratory experimental studies introduces issues of metastability and kinetics. The sequential formation in time of minerals in natural systems often produces the formation of phases not predicted by equilibrium thermodynamics. Evidence from analogous natural systems suggests that the sequence of alteration of clay by Fe-rich fluids will proceed via an Ostwald step sequence. The computer code, QPAC, has been modified to incorporate processes of nucleation, growth, precursor cannibalisation, and Ostwald ripening to address the issues of the slow growth of bentonite

Mineral resource of the month: vermiculite

USGS Publications Warehouse

Potter, M.J.

2008-01-01

Vermiculite, a hydrated magnesium-aluminum-iron silicate mineral, has a range of uses that take advantage of its fire resistance, good insulating properties, high liquid absorption capacity, inertness and low density. Most applications for vermiculite use an exfoliated (heat-expanded) form of the mineral. In general, coarser grades of vermiculite are used as loose fill insulation and in horticulture. Finer grades are used in wallboard and plasters and for animal feeds and fertilizers.

Ferritins: dynamic management of biological iron and oxygen chemistry.

PubMed

Liu, Xiaofeng; Theil, Elizabeth C

2005-03-01

Ferritins are spherical, cage-like proteins with nanocavities formed by multiple polypeptide subunits (four-helix bundles) that manage iron/oxygen chemistry. Catalytic coupling yields diferric oxo/hydroxo complexes at ferroxidase sites in maxi-ferritin subunits (24 subunits, 480 kDa; plants, animals, microorganisms). Oxidation occurs at the cavity surface of mini-ferritins/Dps proteins (12 subunits, 240 kDa; bacteria). Oxidation products are concentrated as minerals in the nanocavity for iron-protein cofactor synthesis (maxi-ferritins) or DNA protection (mini-ferritins). The protein cage and nanocavity characterize all ferritins, although amino acid sequences diverge, especially in bacteria. Catalytic oxidation/di-iron coupling in the protein cage (maxi-ferritins, 480 kDa; plants, bacteria and animal cell-specific isoforms) or on the cavity surface (mini-ferritins/Dps proteins, 280 kDa; bacteria) initiates mineralization. Gated pores (eight or four), symmetrically arranged, control iron flow. The multiple ferritin functions combine pore, channel, and catalytic functions in compact protein structures required for life and disease response.

Hyperspectral surface materials map of quadrangle 3164, Lashkar Gah (605) and Kandahar (606) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3166, Jaldak (701) and Maruf-Nawa (702) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral Surface Materials Map of Quadrangle 3268, Khayr Kot (521) and Urgun (522) Quadrangles, Afghanistan, Showing Iron-bearing Minerals and Other Materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3462, Herat (409) and Chishti Sharif (410) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3670, Jurm-Kishim (223) and Zebak (224) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3562, Khawja-Jir (403) and Murghab (404) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Vegetation successfully prevents oxidization of sulfide minerals in mine tailings.

PubMed

Li, Yang; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

2016-07-15

The oxidization of metal sulfide in tailings causes acid mine drainage. However, it remains unclear whether vegetation prevents the oxidization of metal sulfides. The oxidization characteristics and microbial indices of the tailings in the presence of various plant species were investigated to explore the effects of vegetation on the oxidization of sulfide minerals in tailings. The pH, reducing sulfur, free iron oxides (Fed), chemical oxygen consumption (COC) and biological oxygen consumption (BOC) were measured. Key iron- and sulfur-oxidizing bacteria (Acidithiobacillus spp., Leptospirillum spp. and Thiobacillus spp.) were quantified using real-time PCR. The results indicate that vegetation growing on tailings can effectively prevent the oxidization of sulfide minerals in tailings. A higher pH and reducing-sulfur content and lower Fed were observed in the 0-30 cm depth interval in the presence of vegetation compared to bare tailings (BT). The COC gradually decreased with depth in all of the soil profiles; specifically, the COC rapidly decreased in the 10-20 cm interval in the presence of vegetation but gradually decreased in the BT profiles. Imperata cylindrica (IC) and Chrysopogon zizanoides (CZ) profiles contained the highest BOC in the 10-20 cm interval. The abundance of key iron- and sulfur-oxidizing bacteria in the vegetated tailings were significantly lower than in the BT; in particular, IC was associated with the lowest iron- and sulfur-oxidizing bacterial abundance. In conclusion, vegetation successfully prevented the oxidization of sulfide minerals in the tailings, and Imperata cylindrica is the most effective in reducing the number of iron- and sulfur-oxidizing bacteria and helped to prevent the oxidization of sulfide minerals in the long term. Copyright © 2016 Elsevier Ltd. All rights reserved.

Milk protein composition and stability changes affected by iron in water sources.

PubMed

Wang, Aili; Duncan, Susan E; Knowlton, Katharine F; Ray, William K; Dietrich, Andrea M

2016-06-01

Water makes up more than 80% of the total weight of milk. However, the influence of water chemistry on the milk proteome has not been extensively studied. The objective was to evaluate interaction of water-sourced iron (low, medium, and high levels) on milk proteome and implications on milk oxidative state and mineral content. Protein composition, oxidative stability, and mineral composition of milk were investigated under conditions of iron ingestion through bovine drinking water (infused) as well as direct iron addition to commercial milk in 2 studies. Four ruminally cannulated cows each received aqueous infusions (based on water consumption of 100L) of 0, 2, 5, and 12.5mg/L Fe(2+) as ferrous lactate, resulting in doses of 0, 200, 500 or 1,250mg of Fe/d, in a 4×4Latin square design for a 14-d period. For comparison, ferrous sulfate solution was directly added into commercial retail milk at the same concentrations: control (0mg of Fe/L), low (2mg of Fe/L), medium (5mg of Fe/L), and high (12.5mg of Fe/L). Two-dimensional electrophoresis coupled with matrix-assisted laser desorption/ionization-tandem time-of-flight (MALDI-TOF/TOF) high-resolution tandem mass spectrometry analysis was applied to characterize milk protein composition. Oxidative stability of milk was evaluated by the thiobarbituric acid reactive substances (TBARS) assay for malondialdehyde, and mineral content was measured by inductively coupled plasma mass spectrometry. For milk from both abomasal infusion of ferrous lactate and direct addition of ferrous sulfate, an iron concentration as low as 2mg of Fe/L was able to cause oxidative stress in dairy cattle and infused milk, respectively. Abomasal infusion affected both caseins and whey proteins in the milk, whereas direct addition mainly influenced caseins. Although abomasal iron infusion did not significantly affect oxidation state and mineral balance (except iron), it induced oxidized off-flavor and partial degradation of whey proteins. Direct

The mineral content of tap water in United States households

USDA-ARS?s Scientific Manuscript database

The composition of tap water contributes to dietary intake of minerals. The USDA’s Nutrient Data Laboratory (NDL) conducted a study of the mineral content of residential tap water, to generate current data for the USDA National Nutrient Database. Sodium, potassium, calcium, magnesium, iron, copper...

In vitro evaluation of iron solubility and dialyzability of various iron fortificants and of iron-fortified milk products targeted for infants and toddlers.

PubMed

Kapsokefalou, Maria; Alexandropoulou, Isidora; Komaitis, Michail; Politis, Ioannis

2005-06-01

The objectives of the present study were: to compare the solubility and dialyzability of various iron fortificants (iron pyrophosphate, ferrous bis-glycinate, ferrous gluconate, ferrous lactate, ferrous sulfate) added, in the presence of ascorbic acid, to pasteurized milk samples produced under laboratory conditions; and to compare the solubility and dialyzability of iron in commercial pasteurized, UHT and condensed milk products available in the Greek market fortified with various vitamins and minerals including iron and targeted towards infants (6-12 months old) and toddlers. Iron solubility and dialyzability were determined using a simulated gastrointestinal digestive system. Ferrous dialyzable iron (molecular weight lower than 8000) was used as an index for prediction of iron bioavailability. Ferrous dialyzable iron in pasteurized milk samples fortified with iron pyrophosphate, ferrous lactate and ferrous bis-glycinate was higher (P < 0.05) than that in milk samples fortified with ferrous sulfate and ferrous gluconate. In commercial liquid pasteurized or UHT milk products, formation of ferrous dialyzable iron in products fortified with ferrous lactate was not different (P > 0.05) from those fortified with ferrous sulfate. Ferrous dialyzable iron in four condensed commercial milk products was higher (P < 0.05) than the corresponding values of the liquid UHT milk samples fortified with the same fortificant (ferrous sulfate). Ferrous dialyzable iron was higher (P < 0.05) in products targeted for infants compared with those targeted for toddlers. In conclusion, the type of iron source, milk processing and the overall product composition affect formation of ferrous dialyzable iron and may determine the success and effectiveness of iron fortification of milk.

Predicting the Mineral Composition of Dust Aerosols. Part 1; Representing Key Processes

NASA Technical Reports Server (NTRS)

Perlwitz, J. P.; Garcia-Pando, C. Perez; Miller, R. L.

2015-01-01

Soil dust aerosols created by wind erosion are typically assigned globally uniform physical and chemical properties within Earth system models, despite known regional variations in the mineral content of the parent soil. Mineral composition of the aerosol particles is important to their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, heterogeneous formation of sulfates and nitrates, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Here, aerosol mineral composition is derived by extending a method that provides the composition of a wet-sieved soil. The extension accounts for measurements showing significant differences between the mineral fractions of the wetsieved soil and the emitted aerosol concentration. For example, some phyllosilicate aerosols are more prevalent at silt sizes, even though they are nearly absent at these diameters in a soil whose aggregates are dispersed by wet sieving. We calculate the emitted mass of each mineral with respect to size by accounting for the disintegration of soil aggregates during wet sieving. These aggregates are emitted during mobilization and fragmentation of the original undispersed soil that is subject to wind erosion. The emitted aggregates are carried far downwind from their parent soil. The soil mineral fractions used to calculate the aggregates also include larger particles that are suspended only in the vicinity of the source. We calculate the emitted size distribution of these particles using a normalized distribution derived from aerosol measurements. In addition, a method is proposed for mixing minerals with small impurities composed of iron oxides. These mixtures are important for transporting iron far from the dust source, because pure iron oxides are more dense and vulnerable to gravitational removal than most minerals comprising dust aerosols. A limited comparison to

Predicting the mineral composition of dust aerosols - Part 1: Representing key processes

NASA Astrophysics Data System (ADS)

Perlwitz, J. P.; Pérez García-Pando, C.; Miller, R. L.

2015-10-01

Soil dust aerosols created by wind erosion are typically assigned globally uniform physical and chemical properties within Earth system models, despite known regional variations in the mineral content of the parent soil. Mineral composition of the aerosol particles is important to their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, heterogeneous formation of sulfates and nitrates, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Here, aerosol mineral composition is derived by extending a method that provides the composition of a wet-sieved soil. The extension accounts for measurements showing significant differences between the mineral fractions of the wet-sieved soil and the emitted aerosol concentration. For example, some phyllosilicate aerosols are more prevalent at silt sizes, even though they are nearly absent at these diameters in a soil whose aggregates are dispersed by wet sieving. We calculate the emitted mass of each mineral with respect to size by accounting for the disintegration of soil aggregates during wet sieving. These aggregates are emitted during mobilization and fragmentation of the original undispersed soil that is subject to wind erosion. The emitted aggregates are carried far downwind from their parent soil. The soil mineral fractions used to calculate the aggregates also include larger particles that are suspended only in the vicinity of the source. We calculate the emitted size distribution of these particles using a normalized distribution derived from aerosol measurements. In addition, a method is proposed for mixing minerals with small impurities composed of iron oxides. These mixtures are important for transporting iron far from the dust source, because pure iron oxides are more dense and vulnerable to gravitational removal than most minerals comprising dust aerosols. A limited comparison to

Program and Abstracts for Clay Minerals Society 28th Annual Meeting

NASA Technical Reports Server (NTRS)

1991-01-01

This volume contains abstracts that were accepted for presentation at the annual meeting. Some of the main topics covered include: (1) fundamental properties of minerals and methods of mineral analysis; (2) surface chemistry; (3) extraterrestrial clay minerals; (4) geothermometers and geochronometers; (5) smectite, vermiculite, illite, and related reactions; (6) soils and clays in environmental research; (7) kaolinite, halloysite, iron oxides, and mineral transformations; and (8) clays in lakes, basins, and reservoirs.

Wild turkey

Treesearch

William F. Moore; John C. Kilgo; William D. Carlisle; Michael B. Caudell

2005-01-01

Wild turkeys (Meleagris gallopavo) were once abundant throughout the southeast, but unregulated hunting and habitat destruction greatly reduced populations to a few thousand birds by 1930 (Hust and Dickson 1992). Though intensive restocking efforts beginning in the 1950s, protection from hunting, and reforestation, southeastern turkey populations...

Iron Speciation and Mixing in Single Aerosol Particles from the Asian Continental Outflow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moffet, Ryan C.; Furutani, Hiroshi; Rodel, Tobias

2012-04-04

Bioavailable iron from atmospheric aerosol is an essential nutrient that can control oceanic productivity, thereby impacting the global carbon budget and climate. Particles collected on Okinawa Island during an atmospheric pollution transport event from China were analyzed using complementary single particle techniques to determine the iron source and speciation. Comparing the spatial distribution of iron within ambient particles and standard Asian mineral dust, it was determined that field-collected atmospheric Fe-containing particles have numerous sources, including anthropogenic sources such as coal combustion. Fe-containing particles were found to be internally mixed with secondary species such as sulfate, soot, and organic carbon. Themore » mass weighted average Fe(II) fraction (defined as Fe(II)/[Fe(II)+Fe(III)]) was determined to be 0.33 {+-} 0.08. Within the experimental uncertainty, this value lies close to the range of 0.26-0.30 determined for representative Asian mineral dust. Previous studies have indicated that the solubility of iron from combustion is much higher than that from mineral dust. Therefore, chemical and/or physical differences other than oxidation state may help explain the higher solubility of iron in atmospheric particles.« less

Iron (III) Matrix Effects on Mineralization and Immobilization of Actinides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cynthia-May S. Gong; Tyler A. Sullens; Kenneth R. Czerwinski

2006-01-01

Abstract - A number of models for the Yucca Mountain Project nuclear waste repository use studies of actinide sorption onto well-defined iron hydroxide materials. In the case of a waste containment leak, however, a complex interaction between dissolved waste forms and failed containment vessel components can lead to immediate precipitation of migratory iron and uranyl in the silicate rich near-field environment. Use of the Fe(III) and UO22+ complexing agent acetohydroxamic acid (AHA) as a colorimetric agent for visible spectrophotometry is well-known. Using the second derivative of these spectra a distinct shift in iron complexation in the presence of silicate ismore » seen that is not seen with uranyl or alone. Silica also decreases the ability of uranyl and ferric solutions to absorb hydroxide, hastening precipitation. These ferric silicate precipitates are highly amorphous and soluble. Precipitates formed in the presence of uranyl below ~1 mol% exhibit lower solubility than precipitates from up to 50 mol % and of uranyl silicates alone.« less

Characterization and structural properties of iron in plants.

NASA Astrophysics Data System (ADS)

Dewanamuni, Udya; Dehipawala, Sunil; Gafney, Harry

Iron is one of the most abundant metals in the soil and occurs in a wide range of chemical forms. Humans receive iron through either meat products or plants. Non meat eaters depend on plant product for their daily iron requirement. The iron absorption by plants depends on other minerals present in the soil and soil pH value. The amount of iron present in plants grown with different soil compositions were investigated using X-ray absorption spectroscopy (XAS) and Mossbauer spectroscopy. Based on the X-ray absorption data, the amount of iron in plants vary significantly with soil pH value. The Mossbauer spectroscopy reveals that iron present in the samples has the form Fe3+ or electron density at the site of the iron nucleus similar to that of Fe3+. CUNY Research Scholar Program, MSEIP.

Iron and manganese oxide mineralization in the Pacific

USGS Publications Warehouse

Hein, J.R.; Koschinsky, A.; Halbach, P.; Manheim, F.T.; Bau, M.; Kang, J.-K.; Lubick, N.

1997-01-01

Iron, manganese, and iron-manganese deposits occur in nearly all geomorphologic and tectonic environments in the ocean basins and form by one or more of four processes: (1) hydrogenetic precipitation from cold ambient seawater, (2) precipitation from hydrothermal fluids, (3) precipitation from sediment pore waters that have been modified from bottom water compositions by diagenetic reactions in the sediment column and (4) replacement of rocks and sediment. Iron and manganese deposits occur in five forms: nodules, crusts, cements, mounds and sediment-hosted stratabound layers. Seafloor oxides show a wide range of compositions from nearly pure iron to nearly pure manganese end members. Fe/Mn ratios vary from about 24 000 (up to 58% elemental Fe) for hydrothermal seamount ironstones to about 0.001 (up to 52% Mn) for hydrothermal stratabound manganese oxides from active volcanic arcs. Hydrogenetic Fe-Mn crusts that occur on most seamounts in the ocean basins have a mean Fe/Mn ratio of 0.7 for open-ocean seamount crusts and 1.2 for continental margin seamount crusts. Fe-Mn nodules of potential economic interest from the Clarion-Clipperton Zone have a mean Fe/Mn ratio of 0.3, whereas the mean ratio for nodules from elsewhere in the Pacific is about 0.7. Crusts are enriched in Co, Ni and Pt and nodules in Cu and Ni, and both have significant concentrations of Pb, Zn, Ba, Mo, V and other elements. In contrast, hydrothermal deposits commonly contain only minor trace metal contents, although there are many exceptions, for example, with Ni contents up to 0.66%, Cr to 1.2%, and Zn to 1.4%. Chondrite-normalized REE patterns generally show a positive Ce anomaly and abundant ΣREEs for hydrogenetic and mixed hydrogenetic-diagenetic deposits, whereas the Ce anomaly is negative for hydrothermal deposits and ΣREE contents are low. However, the Ce anomaly in crusts may vary from strongly positive in East Pacific crusts to slightly negative in West Pacific crusts, which may reflect

Impact of Aeolian Dry Deposition of Reactive Iron Minerals on Sulfur Cycling in Sediments of the Gulf of Aqaba

PubMed Central

Blonder, Barak; Boyko, Valeria; Turchyn, Alexandra V.; Antler, Gilad; Sinichkin, Uriel; Knossow, Nadav; Klein, Rotem; Kamyshny, Alexey

2017-01-01

The Gulf of Aqaba is an oligotrophic marine system with oxygen-rich water column and organic carbon-poor sediments (≤0.6% at sites that are not influenced by anthropogenic impact). Aeolian dust deposition from the Arabian, Sinai, and Sahara Deserts is an important source of sediment, especially at the deep-water sites of the Gulf, which are less affected by sediment transport from the Arava Desert during seasonal flash floods. Microbial sulfate reduction in sediments is inferred from the presence of pyrite (although at relatively low concentrations), the presence of sulfide oxidation intermediates, and by the sulfur isotopic composition of sulfate and solid-phase sulfides. Saharan dust is characterized by high amounts of iron minerals such as hematite and goethite. We demonstrated, that the resulting high sedimentary content of reactive iron(III) (hydr)oxides, originating from this aeolian dry deposition of desert dust, leads to fast re-oxidation of hydrogen sulfide produced during microbial sulfate reduction and limits preservation of reduced sulfur in the form of pyrite. We conclude that at these sites the sedimentary sulfur cycle may be defined as cryptic. PMID:28676799

Bioavailability of mineral-bound iron to a snow algae-bacteria co-culture and implications for albedo-altering snow algae blooms.

PubMed

Harrold, Z R; Hausrath, E M; Garcia, A H; Murray, A E; Tschauner, O; Raymond, J; Huang, S

2018-01-26

Snow algae can form large-scale blooms across the snowpack surface and near-surface environments. These pigmented blooms can decrease snow albedo, increase local melt rates, and may impact the global heat budget and water cycle. Yet, underlying causes for the geospatial occurrence of these blooms remain unconstrained. One possible factor contributing to snow algae blooms is the presence of mineral dust as a micronutrient source. We investigated the bioavailability of iron (Fe) -bearing minerals, including forsterite (Fo 90 , Mg 1.8 Fe 0.2 SiO 4 ), goethite, smectite and pyrite as Fe sources for a Chloromonas brevispina - bacteria co-culture through laboratory-based experimentation. Fo 90 was capable of stimulating snow algal growth and increased the algal growth rate in otherwise Fe-depleted co-cultures. Fo 90 -bearing systems also exhibited a decrease in bacteria:algae ratios compared to Fe-depleted conditions, suggesting a shift in microbial community structure. The C. brevispina co-culture also increased the rate of Fo 90 dissolution relative to an abiotic control. Analysis of 16S rRNA genes in the co-culture identified Gammaproteobacteria , Betaprotoeobacteria and Sphingobacteria , all of which are commonly found in snow and ice environments. Archaea were not detected. Collimonas and Pseudomonas , which are known to enhance mineral weathering rates, comprised two of the top eight (> 1 %) OTUs. These data provide unequivocal evidence that mineral dust can support elevated snow algae growth under otherwise Fe-depleted growth conditions, and that snow algae can enhance mineral dissolution under these conditions. IMPORTANCE Fe, a key micronutrient for photosynthetic growth, is necessary to support the formation of high-density snow algae blooms. The laboratory experiments described herein allow for a systematic investigation of snow algae-bacteria-mineral interactions and their ability to mobilize and uptake mineral-bound Fe. Results provide unequivocal and

[Iron from soil to plant products].

PubMed

Briat, Jean-François

2005-11-01

As an essential mineral, iron plays an important role in fundamental biological processes such as photosynthesis, respiration, nitrogen fixation and assimilation, and DNA synthesis. Iron is also a co-factor of many enzymes involved in the synthesis of plant hormones. The latter are involved in many pathways controling plant development or adaptative responses to environmental conditions. Iron reactivity with oxygen leads to its insolubility (responsible for deficiency) and potential toxicity, and complicates iron use by aerobic organisms. If plants lacked an active root system with which to acquire iron from the soil, most would experience iron deficiency and show physiological changes. In contrast, an excess of soluble iron, which can occur in flooded acidic soils, can lead to ferrous iron toxicity due to iron reactivity with reduced forms of oxygen and subsequent free radical production. An optimal iron concentration is thus required for a plant to grow and develop normally. This concentration depends on multiple regulatory mechanisms controlling iron uptake from soil by the roots, as well as iron transport and distribution to the various plant organs. Optimized seed iron content is a major biotechnological challenge identified by the World Health Organization, and it is therefore crucial to understand the underlying mechanisms. Iron delivery to seeds is tightly controlled, and depends on the nature of iron speciation in specific chelates, and their transport.

Mineral trioxide aggregate enriched with iron disulfide nanostructures: an evaluation of their physical and biological properties.

PubMed

Argueta-Figueroa, Liliana; Delgado-García, José J; García-Contreras, René; Martínez-Alvarez, Omar; Santos-Cruz, José; Oliva-Martínez, Carlos; Acosta-Torres, Laura S; de la Fuente-Hernández, Javier; Arenas-Arrocena, Ma C

2018-06-01

The purpose of this study was to characterize mineral trioxide aggregates (MTA) enriched with iron disulfide (FeS 2 ) nanostructures at different concentrations, and to investigate their storage modulus, radiopacity, setting time, pH, cytotoxicity, and antimicrobial activity. Iron disulfide nanostructures [with particle size of 0.357 ± 0.156 μm (mean ± SD)] at weight ratios of 0.2, 0.4, 0.6, 0.8, and 1.0 wt% were added to white MTA (wMTA). The radiopacity, rheological properties, setting time, and pH, as well as the cytotoxicity (assessed using the MTT assay) and antibacterial activity (assessed using the broth microdilution test) were determined for MTA/FeS 2 nanostructures. The nanostructures did not modify the radiopacity values of wMTA (~6 mm of aluminium); however, they reduced the setting time from 18.2 ± 3.20 min to 13.7 ± 1.8 min, and the storage modulus was indicative of a good stiffness. Whereas the wMTA/FeS 2 nanostructures did not induce cytotoxicity when in contact with human pulp cells (HPCs) and human gingival fibroblasts (HGFs), they showed bacteriostatic activity against Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis. Adding FeS 2 nanostructures to MTA might be an option for improving the root canal sealing and antibacterial effects of wMTA in endodontic treatments. © 2018 Eur J Oral Sci.

The fate of iron on Mars: Mechanism of oxidation of basaltic minerals to ferric-bearing assemblages

NASA Technical Reports Server (NTRS)

Burns, Roger G.

1992-01-01

Perhaps the most conspicuous indication that chemical weathering has occurred on the surface of Mars is the overall color of the red planet and the spectroscopic features that identify ferric-bearing assemblages in the martian regolith. Apparently, Fe(2+) ions in primary minerals in parent igneous rocks on the martian surface have been oxidized to ferric iron, which occurs in degradation products that now constitute the regolith. The mineralogy of the unweathered igneous rocks prior to weathering on the martian surface is reasonably well constrained, mainly as a result of petrographic studies of the SNC meteorites. However, the alteration products resulting from oxidative weathering of these rocks are less well-constrained. The topics covered include the following: primary rocks subjected to chemical weathering; dissolution processes; oxidation of dissolved Fe(2+); mechanism of polymerization of hydrous ferric oxides; terrestrial occurrences of ferromagnesian smectites; and dehydroxylated Mg-Fe smectites on Mars.

Wollastonite : a versatile industrial mineral

USGS Publications Warehouse

,

2001-01-01

Wollastonite is a chemically simple mineral named in honor of English mineralogist and chemist Sir W.H. Wollaston (1766–1828). It is composed of calcium (Ca) and silicon and oxygen (SiO2, silica) with the chemical formula CaSiO3. Although much wollastonite is relatively pure CaSiO3, it can contain some iron, magnesium, manganese, aluminum, potassium, sodium, or strontium substituting for calcium in the mineral structure. Pure wollastonite is bright white; the type and amount of impurities can produce gray, cream, brown, palegreen, or red colors.

Modelling of Soluble Iron Formation, Transport and Deposition to the North Pacific Ocean, Role of Anthropogenic Pollutants.

NASA Astrophysics Data System (ADS)

Solmon, F.; Chuang, P.; Meskhidze, N.

2006-12-01

Soluble iron deposited via atmospheric processes represents an important nutrient for open ocean ecosystems, which might influence phytoplancton productivity and atmospheric carbon uptake. Atmospheric deposition of mineral dust is known to be the essential supply of iron to the ocean. However, most of the iron contained in mineral particles is unsoluble, whereas only the soluble fraction of the iron is thought to be effectively bio-available. There is still a great deal of uncertainties in the estimation of this fraction and the representation of iron solubilisation processes in the atmosphere. In this scope, we present a modeling study aiming at better representing such processes. In particular, we focus on the different roles of anthropogenic chemical compounds in the atmospheric iron cycle and deposition. These roles are of two orders : (i) the acidification of mineral particles by anthropogenic compounds influencing the solubilisation of the iron transported and (ii) the direct emission, transport and deposition of iron emitted by anthropogenic activities. For this study, we implement a set of specific mechanisms in the global chemistry transport model GEOS- CHEM. Our study focuses on the East Asia - North pacific outflow, a region where interactions between dust and pollution are particularly likely to occur and where the ocean ecosystem is known to be iron limited.

Iron Oxidation and Core Formation in Recombinant Heteropolymeric Human Ferritins.

PubMed

Mehlenbacher, Matthew; Poli, Maura; Arosio, Paolo; Santambrogio, Paolo; Levi, Sonia; Chasteen, N Dennis; Bou-Abdallah, Fadi

2017-08-01

In animals, the iron storage and detoxification protein, ferritin, is composed of two functionally and genetically distinct subunit types, H (heavy) and L (light), which co-assemble in various ratios with tissue specific distributions to form shell-like protein structures of 24 subunits within which a mineralized iron core is stored. The H-subunit possesses a ferroxidase center (FC) that catalyzes Fe(II) oxidation, whereas the L-subunit does not. To assess the role of the L-subunit in iron oxidation and core formation, two human recombinant heteropolymeric ferritins, designated H-rich and L-rich with ratios of ∼20H:4L and ∼22L:2H, respectively, were employed and compared to the human homopolymeric H-subunit ferritin (HuHF). These heteropolymeric ferritins have a composition similar to the composition of those found in hearts and brains (i.e., H-rich) and in livers and spleens (i.e., L-rich). As for HuHF, iron oxidation in H-rich ferritin was found to proceed with a 2:1 Fe(II):O 2 stoichiometry at an iron level of 2 Fe(II) atoms/H-subunit with the generation of H 2 O 2 . The H 2 O 2 reacted with additional Fe(II) in a 2:1 Fe(II):H 2 O 2 ratio, thus avoiding the production of hydroxyl radical. A μ-1,2-peroxo-diFe(III) intermediate was observed at the FC of H-rich ferritin as for HuHF. Importantly, the H-rich protein regenerated full ferroxidase activity more rapidly than HuHF did and additionally formed larger iron cores, indicating dual roles for the L-subunit in facilitating iron turnover at the FC and in mineralization of the core. The L-rich ferritin, while also facilitating iron oxidation at the FC, additionally promoted oxidation at the mineral surface once the iron binding capacity of the FC was exceeded.

Mineral Precipitation in Porous Media: Laboratory Diffusion Experiments as Analogues for Concretion Formation in Utah and on Mars

NASA Astrophysics Data System (ADS)

Barge, L. M.; Petruska, J.; Potter, S.; Cho, J.; Chan, M.; Nealson, K.

2007-12-01

We present results of laboratory gel diffusion experiments designed to simulate the precipitation of iron minerals in natural systems. Liesegang bands and crystals of various iron minerals were formed in aqueous gels, "mini- concretions" of mineral precipitate were formed in both sand and a sand/agarose mixture, and the formation of hollow mineral spheres was observed in gel precipitation experiments where organics were introduced. These mineral structures are analogous to concretion forms observed in the Navajo Sandstone region of Utah, which have been suggested as terrestrial analogs for the "blueberry" hematite concretions on Mars. Iron mineral precipitates (perhaps with a gel precursor) occur in many forms in the Navajo Sandstone, including "mini- concretions" (solid concretions 1-2 mm in diameter), "rind-like" concretions (hollow spheres of hematite several cm in diameter, surrounding a region of sandstone), and Liesegang banding (banded patterns that form at reaction fronts through diffusion of ions from one reservoir to another). On Mars only small (4-5mm) and mini-concretions (~ 1mm) have been observed; Liesegang bands or large rind-like concretions have not yet been discovered. The varying conditions that give rise to each of these mineral structures in the laboratory indicate that the small, spheroidal types of iron precipitates found in the Utah and Martian environments may be diagnostic of the diffusion medium, presence of organics, and characteristics of fluid in that region.

Mineral Dissolution and Precipitation due to Carbon Dioxide-Water-Rock Interactions: The Significance of Accessory Minerals in Carbonate Reservoirs (Invited)

NASA Astrophysics Data System (ADS)

Kaszuba, J. P.; Marcon, V.; Chopping, C.

2013-12-01

Accessory minerals in carbonate reservoirs, and in the caprocks that seal these reservoirs, can provide insight into multiphase fluid (CO2 + H2O)-rock interactions and the behavior of CO2 that resides in these water-rock systems. Our program integrates field data, hydrothermal experiments, and geochemical modeling to evaluate CO2-water-rock reactions and processes in a variety of carbonate reservoirs in the Rocky Mountain region of the US. These studies provide insights into a wide range of geologic environments, including natural CO2 reservoirs, geologic carbon sequestration, engineered geothermal systems, enhanced oil and gas recovery, and unconventional hydrocarbon resources. One suite of experiments evaluates the Madison Limestone on the Moxa Arch, Southwest Wyoming, a sulfur-rich natural CO2 reservoir. Mineral textures and geochemical features developed in the experiments suggest that carbonate minerals which constitute the natural reservoir will initially dissolve in response to emplacement of CO2. Euhedral, bladed anhydrite concomitantly precipitates in response to injected CO2. Analogous anhydrite is observed in drill core, suggesting that secondary anhydrite in the natural reservoir may be related to emplacement of CO2 into the Madison Limestone. Carbonate minerals ultimately re-precipitate, and anhydrite dissolves, as the rock buffers the acidity and reasserts geochemical control. Another suite of experiments emulates injection of CO2 for enhanced oil recovery in the Desert Creek Limestone (Paradox Formation), Paradox Basin, Southeast Utah. Euhedral iron oxyhydroxides (hematite) precipitate at pH 4.5 to 5 and low Eh (approximately -0.1 V) as a consequence of water-rock reaction. Injection of CO2 decreases pH to approximately 3.5 and increases Eh by approximately 0.1 V, yielding secondary mineralization of euhedral pyrite instead of iron oxyhydroxides. Carbonate minerals also dissolve and ultimately re-precipitate, as determined by experiments in the

Structural characterization of encapsulated ferritin provides insight into iron storage in bacterial nanocompartments

PubMed Central

He, Didi; Hughes, Sam; Vanden-Hehir, Sally; Georgiev, Atanas; Altenbach, Kirsten; Tarrant, Emma; Mackay, C Logan; Waldron, Kevin J; Clarke, David J; Marles-Wright, Jon

2016-01-01

Ferritins are ubiquitous proteins that oxidise and store iron within a protein shell to protect cells from oxidative damage. We have characterized the structure and function of a new member of the ferritin superfamily that is sequestered within an encapsulin capsid. We show that this encapsulated ferritin (EncFtn) has two main alpha helices, which assemble in a metal dependent manner to form a ferroxidase center at a dimer interface. EncFtn adopts an open decameric structure that is topologically distinct from other ferritins. While EncFtn acts as a ferroxidase, it cannot mineralize iron. Conversely, the encapsulin shell associates with iron, but is not enzymatically active, and we demonstrate that EncFtn must be housed within the encapsulin for iron storage. This encapsulin nanocompartment is widely distributed in bacteria and archaea and represents a distinct class of iron storage system, where the oxidation and mineralization of iron are distributed between two proteins. DOI: http://dx.doi.org/10.7554/eLife.18972.001 PMID:27529188

Mineral resource of the month: Arsenic

USGS Publications Warehouse

Bedinger, George M.

2014-01-01

Arsenic is a gray metal rarely encountered as a free element, but is widely distributed in minerals and ores that contain copper, iron and lead. Arsenic is often found in groundwater as a result of the natural weathering of rock and soil.

Composition, speciation and distribution of iron minerals in Imperata cylindrica.

PubMed

Amils, Ricardo; de la Fuente, Vicenta; Rodríguez, Nuria; Zuluaga, Javier; Menéndez, Nieves; Tornero, Jesús

2007-05-01

A comparative study of the roots, rhizomes and leaves of an iron hyperaccumulator plant, Imperata cylindrica, isolated from the banks of an extreme acidic environment, using complementary techniques: Mösbauer spectroscopy (MS), X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled to energy-dispersive X-ray microanalysis (EDAX) and transmission electron microscopy (TEM), has shown that two main biominerals, jarosite and ferrihydrate-ferritin, accumulate in the different tissues. Jarosite accumulates mainly in roots and rhizomes, while ferritin has been detected in all the structures. A model of iron management in I. cylindrica is presented.

Hyperspectral surface materials map of quadrangle 3568, Pul-e Khumri (503) and Charikar (504) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3364, Pasaband (417) and Markaz-e Kajiran (418) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3566, Sangcharak (501) and Sayghan-o-Kamard (502) quadrangles, Afghanistan, showing iron-bearing minerals and other material

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Chromium-removal processes during groundwater remediation by a zerovalent iron permeable reactive barrier.

PubMed

Wilkin, Richard T; Su, Chunming; Ford, Robert G; Paul, Cynthia J

2005-06-15

Solid-phase associations of chromium were examined in core materials collected from a full-scale, zerovalent iron permeable reactive barrier (PRB) at the U.S. Coast Guard Support Center located near Elizabeth City, NC. The PRB was installed in 1996 to treat groundwater contaminated with hexavalent chromium. After eight years of operation, the PRB remains effective at reducing concentrations of Cr from average values >1500 microg L(-1) in groundwater hydraulically upgradient of the PRB to values <1 microg L(-1) in groundwater within and hydraulically downgradient of the PRB. Chromium removal from groundwater occurs at the leading edge of the PRB and also within the aquifer immediately upgradient of the PRB. These regions also witness the greatest amount of secondary mineral formation due to steep geochemical gradients that result from the corrosion of zerovalent iron. X-ray absorption near-edge structure (XANES) spectroscopy indicated that chromium is predominantly in the trivalent oxidation state, confirming that reductive processes are responsible for Cr sequestration. XANES spectra and microscopy results suggest that Cr is, in part, associated with iron sulfide grains formed as a consequence of microbially mediated sulfate reduction in and around the PRB. Results of this study provide evidence that secondary iron-bearing mineral products may enhance the capacity of zerovalent iron systems to remediate Cr in groundwater, either through redox reactions at the mineral-water interface or by the release of Fe(II) to solution via mineral dissolution and/or metal corrosion.

Predicting the mineral composition of dust aerosols – Part 1: Representing key processes

DOE PAGES

Perlwitz, J. P.; Perez Garcia-Pando, C.; Miller, R. L.

2015-10-21

Soil dust aerosols created by wind erosion are typically assigned globally uniform physical and chemical properties within Earth system models, despite known regional variations in the mineral content of the parent soil. Mineral composition of the aerosol particles is important to their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, heterogeneous formation of sulfates and nitrates, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Here, aerosol mineral composition is derived by extending a method that provides the composition of a wet-sieved soil. The extension accountsmore » for measurements showing significant differences between the mineral fractions of the wet-sieved soil and the emitted aerosol concentration. For example, some phyllosilicate aerosols are more prevalent at silt sizes, even though they are nearly absent at these diameters in a soil whose aggregates are dispersed by wet sieving. We calculate the emitted mass of each mineral with respect to size by accounting for the disintegration of soil aggregates during wet sieving. These aggregates are emitted during mobilization and fragmentation of the original undispersed soil that is subject to wind erosion. The emitted aggregates are carried far downwind from their parent soil. The soil mineral fractions used to calculate the aggregates also include larger particles that are suspended only in the vicinity of the source. We calculate the emitted size distribution of these particles using a normalized distribution derived from aerosol measurements. In addition, a method is proposed for mixing minerals with small impurities composed of iron oxides. These mixtures are important for transporting iron far from the dust source, because pure iron oxides are more dense and vulnerable to gravitational removal than most minerals comprising dust aerosols. Finally, a

Inheritance of seed iron and zinc concentrations in common bean (Phaseolus vulgaris L.)

USDA-ARS?s Scientific Manuscript database

Micronutrients are essential elements needed in small amounts for adequate human nutrition and include the elements iron and zinc. Both of these minerals are essential to human well-being, and an adequate supply of iron and zinc helps to prevent iron deficiency anemia and zinc deficiency, two preva...

Activation of Peroxymonosulfate by Subsurface Minerals.

PubMed

Yu, Miao; Teel, Amy L; Watts, Richard J

2016-08-01

In situ chemical oxidation (ISCO) has become a widely used technology for the remediation of soil and groundwater. Although peroxymonosulfate is not a common oxidant source for ISCO, its chemical structure is similar to the ISCO reagents hydrogen peroxide and persulfate, suggesting that peroxymonosulfate may have the beneficial properties of each of these oxidants. Peroxymonosulfate activation in the presence of subsurface minerals was examined as a basis for ISCO, and possible reactive species (hydroxyl radical, sulfate radical, and reductants+nucleophiles) generated in the mineral-activated peroxymonosulfate systems were investigated. Rates of peroxymonosulfate decomposition and generation rates of reactive species were studied in the presence of three iron oxides, one manganese oxide, and three soil fractions. The iron oxide hematite-activated peroxymonosulfate system most effectively degraded the hydroxyl radical probe nitrobenzene. Reductants+nucleophiles were not generated in mineral-activated peroxymonosulfate systems. Use of the probe compound anisole in conjunction with scavengers demonstrated that both sulfate radical and hydroxyl radical are generated in mineral-activated peroxymonosulfate systems. In order to confirm the activation of peroxymonosulfate by subsurface minerals, one natural soil and associated two soil fractions were evaluated as peroxymonosulfate catalysts. The natural soil did not effectively promote the generation of oxidants; however, the soil organic matter was found to promote the generation of reductants + nucleophiles. The results of this research show that peroxymonosulfate has potential as an oxidant source for ISCO applications, and would be most effective in treating halogenated contaminants when soil organic matter is present in the subsurface. Copyright © 2016. Published by Elsevier B.V.

Potential function of added minerals as nucleation sites and effect of humic substances on mineral formation by the nitrate-reducing Fe(II)-oxidizer Acidovorax sp. BoFeN1.

PubMed

Dippon, Urs; Pantke, Claudia; Porsch, Katharina; Larese-Casanova, Phil; Kappler, Andreas

2012-06-19

The mobility of toxic metals and the transformation of organic pollutants in the environment are influenced and in many cases even controlled by iron minerals. Therefore knowing the factors influencing iron mineral formation and transformation by Fe(II)-oxidizing and Fe(III)-reducing bacteria is crucial for understanding the fate of contaminants and for the development of remediation technologies. In this study we followed mineral formation by the nitrate-reducing Fe(II)-oxidizing strain Acidovorax sp. BoFeN1 in the presence of the crystalline Fe(III) (oxyhydr)oxides goethite, magnetite and hematite added as potential nucleation sites. Mössbauer spectroscopy analysis of minerals precipitated by BoFeN1 in (57)Fe(II)-spiked microbial growth medium showed that goethite was formed in the absence of mineral additions as well as in the presence of goethite or hematite. The presence of magnetite minerals during Fe(II) oxidation induced the formation of magnetite in addition to goethite, while the addition of humic substances along with magnetite also led to goethite but no magnetite. This study showed that mineral formation not only depends on the aqueous geochemical conditions but can also be affected by the presence of mineral nucleation sites that initiate precipitation of the same underlying mineral phases.

Geogenic Groundwater Contamination: A Case Study Of Canakkale - Western Turkey

NASA Astrophysics Data System (ADS)

Deniz, Ozan; Çalık, Ayten

2016-04-01

Study area is located NW of Turkey. Total area of the drainage basin is 465 square kilometers and mostly covered by volcanic rocks. Majority of these rocks have highly altered and lost their primary properties because of alteration processes. Especially argillic alteration is common. Tectonic movements and cooling fractures were created suitable circulation environment of groundwater in the rocks (secondary porosity). Alteration affects the composition of groundwater and some rock elements pass into groundwater during the movement of water in the cavities of rocks. High concentration of natural contaminants related to water-rock interaction in spring water has been studied in this research. Field measurements such as pH, electrical conductivity, temperature, oxidation-reduction potential and salinity carried out in 500 water points (spring, drilling, well and stream). 150 water samples taken from the water points and 50 rock samples taken from the source of springs has been investigated in point of major anion-cations, heavy metals and trace elements. Some components in the water such as pH (3.5-9.1), specific electrical conductivity (84-6400 microS/cm), aluminum (27-44902 ppb), iron (10-8048 ppb), manganese (0.13-8740 ppb), nickel (0.2-627 ppb), lead (0.1-42.5 ppb) and sulphate (10 to 1940 ppm) extremely high or low in the springs sourced from especially highly altered Miocene aged volcanic rocks. Some measured parameters highly above according to European Communities Drinking Water Regulations (2007) and TS266 (2015-Intended for Human Consumption Water Regulations of Turkey) drinking water standards. The most common element which is found in the groundwater is aluminum that is higher than to the drinking water standards (200 microg/L). The highest levels of the Al values measured in acidic waters with very low pH (3.4) emerging from altered volcanic rocks because of acid mine drainage in Obakoy district, north of the study area. The abundance of this element in

The life cycle of iron Fe(III) oxide: impact of fungi and bacteria

NASA Astrophysics Data System (ADS)

Bonneville, Steeve

2014-05-01

Iron oxides are ubiquitous reactive constituents of soils, sediments and aquifers. They exhibit vast surface areas which bind a large array of trace metals, nutrients and organic molecules hence controlling their mobility/reactivity in the subsurface. In this context, understanding the "life cycle" of iron oxide in soils is paramount to many biogeochemical processes. Soils environments are notorious for their extreme heterogeneity and variability of chemical, physical conditions and biological agents at play. Here, we present studies investigating the role of two biological agents driving iron oxide dynamics in soils, root-associated fungi (mycorrhiza) and bacteria. Mycorrhiza filaments (hypha) grow preferentially around, and on the surface of nutrient-rich minerals, making mineral-fungi contact zones, hot-spots of chemical alteration in soils. However, because of the microscopic nature of hyphae (only ~ 5 µm wide for up to 1 mm long) and their tendency to strongly adhere to mineral surface, in situ observations of this interfacial micro-environment are scarce. In a microcosm, ectomycorrhiza (Paxillus involutus) was grown symbiotically with a pine tree (Pinus sylvestris) in the presence of freshly-cleaved biotite under humid, yet undersaturated, conditions typical of soils. Using spatially-resolved ion milling technique (FIB), transmission electron microscopy and spectroscopy (TEM/STEM-EDS), synchrotron based X-ray microscopy (STXM), we were able to quantify the speciation of Fe at the biotite-hypha interface. The results shows that substantial oxidation of biotite structural-Fe(II) into Fe(III) subdomains occurs at the contact zone between mycorrhiza and biotite. Once formed, iron(III) oxides can reductively dissolve under suboxic conditions via several abiotic and microbial pathways. In particular, they serve as terminal electron acceptors for the oxidation of organic matter by iron reducing bacteria. We aimed here to understand the role of Fe(III) mineral

Comprehensive Utilization of Iron and Phosphorus from High-Phosphorus Refractory Iron Ore

NASA Astrophysics Data System (ADS)

Sun, Yongsheng; Zhang, Qi; Han, Yuexin; Gao, Peng; Li, Guofeng

2018-02-01

An innovative process of coal-based reduction followed by magnetic separation and dephosphorization was developed to simultaneously recover iron and phosphorus from one typical high-phosphorus refractory iron ore. The experimental results showed that the iron minerals in iron ore were reduced to metallic iron during the coal-based reduction and the phosphorus was enriched in the metallic iron phase. The CaO-SiO2-FeO-Al2O3 slag system was used in the dephosphorization of metallic iron. A hot metal of 99.17% Fe and 0.10% P was produced with Fe recovery of 84.41%. Meanwhile, a dephosphorization slag of 5.72% P was obtained with P recovery of 67.23%. The contents of impurities in hot metal were very low, and it could be used as feedstock for steelmaking after a secondary refining. Phosphorus in the dephosphorization slag mainly existed in the form of a 5CaO·P2O5·SiO2 solid solution where the P2O5 content is 13.10%. At a slag particle size of 20.7 μm (90% passing), 94.54% of the P2O5 could be solubilized in citric acid, indicating the slag met the feedstock requirements in phosphate fertilizer production. Consequently, the proposed process achieved simultaneous Fe and P recovery, paving the way to comprehensive utilization of high-phosphorus refractory iron ore.

Development of Atmospheric Chemistry-Aerosol Transport Model for Bioavailable Iron From Dust and Combustion Source

NASA Astrophysics Data System (ADS)

Ito, A.; Feng, Y.

2009-12-01

An accurate prediction of bioavailable iron fraction for ocean biota is hampered by uncertainties in modeling soluble iron fractions in atmospheric aerosols. It has been proposed that atmospheric processing of mineral aerosols by anthropogenic pollutants may be a key pathway to transform insoluble iron into soluble forms. The dissolution of dust minerals strongly depends on solution pH, which is sensitive to the heterogeneous uptake of soluble gases by the dust particle. Due to the complexity, previous model assessments generally use a common assumption in thermodynamical equilibrium between gas and aerosol phases. Here, we compiled an emission inventory of iron from combustion and dust source, and incorporated a dust iron dissolution scheme in a global chemistry-aerosol transport model (IMPACT). We will examine and discuss the uncertainties in estimation of dissolved iron as well as comparisons of the model results with available observations.

Feasibility Studies for Production of Pellet Grade Concentrate from Sub Grade Iron Ore Using Multi Gravity Separator

NASA Astrophysics Data System (ADS)

Rao, Gottumukkala Venkateswara; Markandeya, R.; Kumar, Rajan

2018-04-01

An attempt has been made to utilise Sub Grade Iron Ore by producing pellet grade concentrate from Deposit 5, Bacheli Complex, Bailadila, Chhattisgarh, India. The `as received' Run of Mine (ROM) sample assayed 40.80% Fe, 40.90% SiO2. Mineralogical studies indicated that the main ore mineral is Hematite and lone gangue mineral is Quartz. Mineral liberation studies indicated that, the ore mineral Hematite and gangue mineral Quartz are getting liberated below 100 microns. The stage crushed and ground sample was subjected to concentration by using a Multi Gravity Separator (MGS). Rougher Multi Gravity Separation (MGS) experimental results were optimised to recover highest possible iron values. A concentrate of 55.80% Fe with a yield of 61.73% by weight with a recovery of 84.42% Iron values was obtained in rougher MGS concentrate. Further experiments were carried out with rougher MGS concentrate to produce a concentrate suitable for commercial grade pellet concentrate. It was proved that a concentrate assaying 66.67% Fe, 3.12% SiO2 with an yield of 45.08% by weight and with a recovery of 73.67% iron values in the concentrate.

Mineralogy and geochemistry of Eocene Helete formation , Adiyaman, Turkey

NASA Astrophysics Data System (ADS)

Choi, J.; Lee, I.; Yildirim, E.

2013-12-01

Helete formation is located at Adiyaman, Turkey which is in the Alpine-Himalayan orogeny belt. Helete formation is represented by andesitic, basaltic and gabbroic rocks cut by localized felsic intrusions and overlain by open-marine Nummulitic carbonate sediments. Electron microprobe analyses were conducted for 15 rocks samples of Helete formation. These rock samples are named as basalt, andesite, gabbro, diorite, dacite, and granite. Basalt and andesite samples are composed of clinopyroxene(augite), plagioclase(Ab98-96), carbonate, and hyaline. Gabbro samples have wide range of plagioclase composition from anorthite to albite(Ab92-16), and other minerals like clinopyroxene(augite) and amphibole(hornblende and actinolite). Diabase samples consist of epidote group minerals and sphene with plagioclase(Ab80), pyroxene and hornblende. Dacite samples are composed of dolomite and quartz. Granite samples are composed of quartz, chlorite, and plagioclase which range from albite to oligoclase in composition (Ab98-89).

A comparison of iron extraction methods for the determination of degree of pyritisation and the recognition of iron-limited pyrite formation

NASA Technical Reports Server (NTRS)

Raiswell, R.; Canfield, D. E.; Berner, R. A.

1994-01-01

Measurements of degree of pyritisation require an estimate of sediment iron which is capable of reaction with dissolved sulphide to form pyrite, either directly or indirectly via iron monosulphide precursors. Three dissolution techniques (buffered dithionite, cold 1 M HCl, boiling 12 M HCl) were examined for their capacity to extract iron from a variety of iron minerals, and iron-bearing sediments, as a function of different extraction times and different grain sizes. All the iron oxides studied are quantitatively extracted by dithionite and boiling HCl (but not by cold HCl). Both HCl techniques extract more iron from silicates than does dithionite but probably about the same amounts as are potentially capable of sulphidation. Modern sediment studies indicate that most sedimentary pyrite is formed rapidly from iron oxides, with smaller amounts formed more slowly from iron silicates (if sufficient geologic time is available). It is therefore recommended that the degree of pyritisation be defined with respect to the dithionite-extractable (mainly iron oxide) pool and/or the boiling HCl-extractable pool (which includes some silicate iron) for the recognition of iron-limited pyritisation.

Osmotically driven tensile stress in collagen-based mineralized tissues.

PubMed

Bertinetti, Luca; Masic, Admir; Schuetz, Roman; Barbetta, Aurelio; Seidt, Britta; Wagermaier, Wolfgang; Fratzl, Peter

2015-12-01

Collagen is the most abundant protein in mammals and its primary role is to serve as mechanical support in many extracellular matrices such as those of bones, tendons, skin or blood vessels. Water is an integral part of the collagen structure, but its role is still poorly understood, though it is well-known that the mechanical properties of collagen depend on hydration. Recently, it was shown that the conformation of the collagen triple helix changes upon water removal, leading to a contraction of the molecule with considerable forces. Here we investigate the influence of mineralization on this effect by studying bone and turkey leg tendon (TLT) as model systems. Indeed, TLT partially mineralizes so that well-aligned collagen with various mineral contents can be found in the same tendon. We show that water removal leads to collagen contraction in all cases generating tensile stresses up to 80MPa. Moreover, this contraction of collagen puts mineral particles under compression leading to strains of around 1%, which implies localized compressive loads in mineral of up to 800MPa. This suggests that collagen dehydration upon mineralization is at the origin of the compressive pre-strains commonly observed in bone mineral. Copyright © 2015 Elsevier Ltd. All rights reserved.

The three-dimensional distribution of minerals in potato tubers

PubMed Central

Subramanian, Nithya K.; White, Philip J.; Broadley, Martin R.; Ramsay, Gavin

2011-01-01

Background and Aims The three-dimensional distributions of mineral elements in potato tubers provide insight into their mechanisms of transport and deposition. Many of these minerals are essential to a healthy human diet, and characterizing their distribution within the potato tuber will guide the effective utilization of this staple foodstuff. Methods The variation in mineral composition within the tuber was determined in three dimensions, after determining the orientation of the harvested tuber in the soil. The freeze-dried tuber samples were analysed for minerals using inductively coupled plasma-mass spectrometry (ICP-MS). Minerals measured included those of nutritional significance to the plant and to human consumers, such as iron, zinc, copper, calcium, magnesium, manganese, phosphorus, potassium and sulphur. Key Results The concentrations of most minerals were higher in the skin than in the flesh of tubers. The potato skin contained about 17 % of total tuber zinc, 34 % of calcium and 55 % of iron. On a fresh weight basis, most minerals were higher in tuber flesh at the stem end than the bud end of the tuber. Potassium, however, displayed a gradient in the opposite direction. The concentrations of phosphorus, copper and calcium decreased from the periphery towards the centre of the tuber. Conclusions The distribution of minerals varies greatly within the potato tuber. Low concentrations of some minerals relative to those in leaves may be due to their low mobility in phloem, whereas high concentrations in the skin may reflect direct uptake from the soil across the periderm. In tuber flesh, different minerals show distinct patterns of distribution in the tuber, several being consistent with phloem unloading in the tuber and limited onward movement. These findings have implications both for understanding directed transport of minerals in plants to stem-derived storage organs and for the dietary implications of different food preparation methods for potato tubers

Transient state kinetic investigation of ferritin iron release

NASA Astrophysics Data System (ADS)

Ciasca, G.; Papi, M.; Chiarpotto, M.; Rodio, M.; Campi, G.; Rossi, C.; De Sole, P.; Bianconi, A.

2012-02-01

Increased iron concentration in tissues appears to be a factor in the genesis and development of inflammatory and degenerative diseases. By means of real-time small angle x-ray scattering measurements, we studied the kinetics of iron release from the ferritin inorganic core as a function of time and distance from the iron core centre. Accordingly, the iron release process follows a three step model: (i) a defect nucleation in the outer part of the mineral core, (ii) the diffusion of the reducing agent towards the inner part of the core, and (iii) the erosion of the core from the inner to the outer part.

The fate of turkey #88

Treesearch

Mark A. Rumble; Todd Mills

1993-01-01

On January 9, 1990, 32 turkeys were captured in the Black Hills of South Dakota using the drug alpha-chloralose. One of these turkeys had a unique tag attached to it's wing that indicated it had been trapped previously Let's look back in time and see what made the events in the life of this turkey deviate slightly from "The Events in the Turkey Year...

ID ICPMS Lu-Hf Geochronology of Apatite from Iron-Oxide Apatite (IOA) Deposits, Northern Chilean Iron Belt.

NASA Astrophysics Data System (ADS)

Zhang, C.; Vervoort, J. D.; Barra, F.; Palma, G.

2017-12-01

Determining the age of mineralization of ore deposits is important for understanding the mechanisms and timing of ore formation. In many cases, however, conventional dateable mineral phases (e.g., zircon, monazite) are lacking in the ore mineral assemblages. For example, Iron Oxide Apatite (IOA) and Iron Oxide Gold Copper Gold (IOCG) deposits have the remaining fundamental question as to whether they have formed by hydrothermal or magmatic processes, or some combination of the two. In these deposits, the mineralization of iron oxide is often accompanied by the growth of apatites, which typically have REE concentrations of tens to several thousand ppm and which makes them potentially amenable to dating by the Lu-Hf isochron method. These apatites, however, also have very low concentrations of Hf, which makes determination of precise Hf isotope compositions challenging. In this study, we attempted to date these deposits using the apatite Lu-Hf isochron method, using procedures modified from that of Münker et al., 2001 and Barfod et al., 2003 and report the first Lu-Hf ages for apatites from Carmen, Fresia, and Mariela IOA deposits in northern Chilean Iron Belt. The concentration of Hf in analyzed apatite is 0.001 ppm. To ensure at least 0.5ng of Hf is collected for MS analysis, 0.5g apatite was dissolved for each sample. A single stage of Ln-spec resin chromatographic columns was used to separate Hf from REEs as multi stages of separation columns would decrease the Hf yield considerably. Using these procedures, we determined a Lu-Hf apatite age for the Carmen deposit of 130.0±1.7 Ma, which is in accordance with a previously published U-Pb apatite age of 131.0±1.0 Ma (Gelcich et al., 2005). The apatites from Fresia and Mariela yield Lu-Hf ages of 132.8±5.3 Ma and 117.3±0.4 Ma respectively. The lower points on the isochrons are either a low Lu/Hf phase (actinolite, magnetite) or bulk earth ratios. These are some of the first Lu-Hf ages of directly dating apatite

Association between the gut microbiota and mineral metabolism.

PubMed

Skrypnik, Katarzyna; Suliburska, Joanna

2018-05-01

The aim of this review is to present the most recent scientific evidence of interactions between the intestinal microbiota and minerals, and the effect of this interaction on the health of the host. The Web of Science database from the years 2013-2017 on this topic was reviewed. Numerous in vitro studies have shown that iron significantly affects the intestinal microbiota. However, Bifidobacteriaceae are capable of binding iron in the large intestine, thereby limiting the formation of free radicals synthesized in the presence of iron, and thus reducing the risk of colorectal cancer. Animal studies have revealed that supplementation with probiotics, prebiotics and synbiotics has a significant effect on bone calcium, phosphate and bone metabolism. The dynamic interaction between microbiota and zinc was shown. Human studies have provided evidence of the influence of probiotic bacteria on parathormone, calcium and phosphate levels and thus on bone resorption. Recent studies have produced new information mainly on the impact of the intestinal bacteria on the metabolism of calcium and iron. From a scientific perspective, the most urgent fields that remain to be investigated are the identification of all human gut microbes and new therapies targeting the interaction between intestinal bacteria and minerals. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Characterization of magnetite (Fe3O4) minerals from natural iron sand of Bonto Kanang Village Takalar for ink powder (toner) application

NASA Astrophysics Data System (ADS)

Fahlepy, M. R.; Tiwow, V. A.; Subaer

2018-03-01

This research is about magnetite’s characterization (Fe3O4) from natural iron sands of Bonto Kanang Village, District of Takalar for ink powder (toner) application. This study aims to determine the process parameters to obtain magnetite of high purity degree and to observe its physical characteristics as a supporting toner material which synthesized through co-precipitation method. The iron sand was first separated by the magnetic technique and dissolved into HCl solution before conducting the precipitation process. Precipitation was done by dripping ammonium hydroxide (NH4OH). The precipitated powder was dried at 100°C, and then calcined at 400°C. The purity degree and magnetite mineral grain size were analyzed by XRD and SEM-EDS. The EDS elemental test before and after precipitation shown an increase of iron oxide composition from 66.70% to 87.76%. Diffractogram of XRD before and after precipitation showed Fe3O4 compounds with magnetite phase of 59% and 98%, respectively. The crystal structure iron sand powder structure before and after precipitation is cubic with each lattice parameters a = b = c = 8.384971 Å, V = 589.528423 Å3 and a = b = c = 8.386829 Å and V = 589.920291 Å3 when angle α = β = γ = 90°. SEM images (using SE and HV 20kV) showed inhomogeneous magnetite morphology. The magnetite phase percentage that obtained based on the XRD analysis gives information that magnetite precipitation has been successfully performed with high degree of purity. The material obtained can be applied as a support toner material.

Mineral resource of the month: ferrous slag

USGS Publications Warehouse

,

2009-01-01

The article offers information on mineral resource ferrous slag. Ferrous slag is produced through the addition of materials such as limestone and dolomite to blast and steel furnaces to remove impurities from iron ore and to lower the heat requirements for processes in iron and steel making. It is stated that the method of cooling is important for the market uses and value of ferrous slag. Some types of slag can be used in construction, glass manufacturing and thermal insulation.

Iron solubility related to particle sulfur content in source emission and ambient fine particles.

PubMed

Oakes, M; Ingall, E D; Lai, B; Shafer, M M; Hays, M D; Liu, Z G; Russell, A G; Weber, R J

2012-06-19

The chemical factors influencing iron solubility (soluble iron/total iron) were investigated in source emission (e.g., biomass burning, coal fly ash, mineral dust, and mobile exhaust) and ambient (Atlanta, GA) fine particles (PM2.5). Chemical properties (speciation and mixing state) of iron-containing particles were characterized using X-ray absorption near edge structure (XANES) spectroscopy and micro-X-ray fluorescence measurements. Bulk iron solubility (soluble iron/total iron) of the samples was quantified by leaching experiments. Major differences were observed in iron solubility in source emission samples, ranging from low solubility (<1%, mineral dust and coal fly ash) up to 75% (mobile exhaust and biomass burning emissions). Differences in iron solubility did not correspond to silicon content or Fe(II) content. However, source emission and ambient samples with high iron solubility corresponded to the sulfur content observed in single particles. A similar correspondence between bulk iron solubility and bulk sulfate content in a series of Atlanta PM2.5 fine particle samples (N = 358) further supported this trend. In addition, results of linear combination fitting experiments show the presence of iron sulfates in several high iron solubility source emission and ambient PM2.5 samples. These results suggest that the sulfate content (related to the presence of iron sulfates and/or acid-processing mechanisms by H(2)SO(4)) of iron-containing particles is an important proxy for iron solubility.

Mineral content of smooth scallop (Flexopecten glaber) caught Canakkale, Turkey and evaluation in terms of food safety.

PubMed

Berik, Nermin; Çankırılıgil, Ekrem Cem; Gül, Güzin

2017-07-01

In this research, one of the most promising scallop species, smooth scallop (Flexopecten glaber) was studied. According to our findings, smooth scallop has beneficial micro and macro minerals, fat and carbohydrate just before the spawning. While the ratios protein, ash and water decreased from autumn to summer, ratio of crude fat increased till reproduction season in late spring and decreased in summer (P<0.05). In digestive glands, aluminum, bromine, cadmium, calcium, chromium, copper, iron, manganese, nickel, and zinc were detected more compared to adductor muscles (P<0.05). However; boron, magnesium and potassium were found more in adductor muscles (P<0.05) and there were no significant statistically differences in cobalt and lead (P>0.05). Most of the elements in the both tissues except K and Mg increased till summer. On the other hand, two of the most toxic metals, cadmium and aluminum were mostly accumulated in the digestive gland of smooth scallop. It is recommended that; digestive gland of scallops should be removed before consuming in terms of food safety. Besides, scallops are convenient to be processed, because of easy removal muscle tissue from internal organs. Copyright © 2017 Elsevier GmbH. All rights reserved.

Vibrational, X-ray absorption, and Mössbauer spectra of sulfate minerals from the weathered massive sulfide deposit at Iron Mountain, California

USGS Publications Warehouse

Majzlan, Juraj; Alpers, Charles N.; Bender Koch, Christian; McCleskey, R. Blaine; Myneni, Satish B.C.; Neil, John M.

2011-01-01

The Iron Mountain Mine Superfund site in California is a prime example of an acid mine drainage (AMD) system with well developed assemblages of sulfate minerals typical for such settings. Here we present and discuss the vibrational (infrared), X-ray absorption, and M??ssbauer spectra of a number of these phases, augmented by spectra of a few synthetic sulfates related to the AMD phases. The minerals and related phases studied in this work are (in order of increasing Fe2O3/FeO): szomolnokite, rozenite, siderotil, halotrichite, r??merite, voltaite, copiapite, monoclinic Fe2(SO4)3, Fe2(SO4)3??5H2O, kornelite, coquimbite, Fe(SO4)(OH), jarosite and rhomboclase. Fourier transform infrared spectra in the region 750-4000cm-1 are presented for all studied phases. Position of the FTIR bands is discussed in terms of the vibrations of sulfate ions, hydroxyl groups, and water molecules. Sulfur K-edge X-ray absorption near-edge structure (XANES) spectra were collected for selected samples. The feature of greatest interest is a series of weak pre-edge peaks whose position is determined by the number of bridging oxygen atoms between Fe3+ octahedra and sulfate tetrahedra. M??ssbauer spectra of selected samples were obtained at room temperature and 80K for ferric minerals jarosite and rhomboclase and mixed ferric-ferrous minerals r??merite, voltaite, and copiapite. Values of Fe2+/[Fe2++Fe3+] determined by M??ssbauer spectroscopy agree well with those determined by wet chemical analysis. The data presented here can be used as standards in spectroscopic work where spectra of well-characterized compounds are required to identify complex mixtures of minerals and related phases. ?? 2011 Elsevier B.V.

Vibrational, X-ray absorption, and Mössbauer spectra of sulfate minerals from the weathered massive sulfide deposit at Iron Mountain, California

USGS Publications Warehouse

Majzlan, Juraj; Alpers, Charles N.; Bender Koch, Christian; McCleskey, R. Blaine; Myneni, Satish B.C.; Neil, John M.

2014-01-01

The Iron Mountain Mine Superfund site in California is a prime example of an acid mine drainage (AMD) system with well developed assemblages of sulfate minerals typical for such settings. Here we present and discuss the vibrational (infrared), X-ray absorption, and Mössbauer spectra of a number of these phases, augmented by spectra of a few synthetic sulfates related to the AMD phases. The minerals and related phases studied in this work are (in order of increasing Fe2O3/FeO): szomolnokite, rozenite, siderotil, halotrichite, römerite, voltaite, copiapite, monoclinic Fe2(SO4)3, Fe2(SO4)3·5H2O, kornelite, coquimbite, Fe(SO4)(OH), jarosite and rhomboclase. Fourier transform infrared spectra in the region 750–4000 cm−1 are presented for all studied phases. Position of the FTIR bands is discussed in terms of the vibrations of sulfate ions, hydroxyl groups, and water molecules. Sulfur K-edge X-ray absorption near-edge structure (XANES) spectra were collected for selected samples. The feature of greatest interest is a series of weak pre-edge peaks whose position is determined by the number of bridging oxygen atoms between Fe3+ octahedra and sulfate tetrahedra. Mössbauer spectra of selected samples were obtained at room temperature and 80 K for ferric minerals jarosite and rhomboclase and mixed ferric–ferrous minerals römerite, voltaite, and copiapite. Values of Fe2+/[Fe2+ + Fe3+] determined by Mössbauer spectroscopy agree well with those determined by wet chemical analysis. The data presented here can be used as standards in spectroscopic work where spectra of well-characterized compounds are required to identify complex mixtures of minerals and related phases.

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

DTIC Science & Technology

2014-03-11

carbon as an essential alloying constituent in amounts up to ~ 1.7 wt%. Wrought iron is an iron alloy with a very low car- bon content (0.1 to 0.25 wt...PbCO3 ( lead carbonate) and PbS (galena) in association with the flakes. The source of the Pb was con- firmed to be from a Pb-based paint. Based on...the mineral - ogical data, Stoffyn-Egli and Buckley (1992) concluded that, despite the presence of minerals indicative of differ- ing redox potentials

Supplemental levels of iron and calcium interfere with repletion of zinc status in zinc-deficient animals.

PubMed

Jayalakshmi, S; Platel, Kalpana

2016-05-18

Negative interactions between minerals interfering with each other's absorption are of concern when iron and calcium supplements are given to pregnant women and children. We have previously reported that supplemental levels of iron and calcium inhibit the bioaccessibility of zinc, and compromise zinc status in rats fed diets with high levels of these two minerals. The present study examined the effect of supplemental levels of iron and calcium on the recovery of zinc status during a zinc repletion period in rats rendered zinc-deficient. Iron and calcium, both individually and in combination, significantly interfered with the recovery of zinc status in zinc deficient rats during repletion with normal levels of zinc in the diet. Rats maintained on diets containing supplemental levels of these two minerals had significantly lower body weight, and the concentration of zinc in serum and organs was significantly lower than in zinc-deficient rats not receiving the supplements. Iron and calcium supplementation also significantly inhibited the activity of zinc-containing enzymes in the serum as well as liver. Both iron and calcium independently exerted this negative effect on zinc status, while their combination seemed to have a more prominent effect, especially on the activities of zinc containing enzymes. This investigation is probably the first systematic study on the effect of these two minerals on the zinc status of zinc deficient animals and their recovery during repletion with normal amounts of zinc.

Effects of initial iron corrosion rate on long-term performance of iron permeable reactive barriers: column experiments and numerical simulation.

PubMed

suk O, Jin; Jeen, Sung-Wook; Gillham, Robert W; Gui, Lai

2009-01-26

Column experiments and numerical simulation were conducted to test the hypothesis that iron material having a high corrosion rate is not beneficial for the long-term performance of iron permeable reactive barriers (PRBs) because of faster passivation of iron and greater porosity loss close to the influent face of the PRBs. Four iron materials (Connelly, Gotthart-Maier, Peerless, and ISPAT) were used for the column experiments, and the changes in reactivity toward cis-dichloroethene (cis-DCE) degradation in the presence of dissolved CaCO3 were evaluated. The experimental results showed that the difference in distribution of the accumulated precipitates, resulting from differences in iron corrosion rate, caused a difference in the migration rate of the cis-DCE profiles and a significant difference in the pattern of passivation, indicating a faster passivation in the region close to the influent end for the material having a higher corrosion rate. For the numerical simulation, the accumulation of secondary minerals and reactivity loss of iron were coupled using an empirically-derived relationship that was incorporated into a multi-component reactive transport model. The simulation results provided a reasonable representation of the evolution of iron reactivity toward cis-DCE treatment and the changes in geochemical conditions for each material, consistent with the observed data. The simulations for long-term performance were also conducted to further test the hypothesis and predict the differences in performance over a period of 40 years under typical groundwater conditions. The predictions showed that the cases of higher iron corrosion rates had earlier cis-DCE breakthrough and more reduction in porosity starting from near the influent face, due to more accumulation of carbonate minerals in that region. Therefore, both the experimental and simulation results appear to support the hypothesis and suggest that reactivity changes of iron materials resulting from

Mineral facilities of Europe

USGS Publications Warehouse

Almanzar, Francisco; Baker, Michael S.; Elias, Nurudeen; Guzman, Eric

2010-01-01

This map displays over 1,700 records of mineral facilities within the countries of Europe and western Eurasia. Each record represents one commodity and one facility type at a single geographic location. Facility types include mines, oil and gas fields, and plants, such as refineries, smelters, and mills. Common commodities of interest include aluminum, cement, coal, copper, gold, iron and steel, lead, nickel, petroleum, salt, silver, and zinc. Records include attributes, such as commodity, country, location, company name, facility type and capacity (if applicable), and latitude and longitude geographical coordinates (in both degrees-minutes-seconds and decimal degrees). The data shown on this map and in table 1 were compiled from multiple sources, including (1) the most recently available data from the U.S. Geological Survey (USGS) Minerals Yearbook (Europe and Central Eurasia volume), (2) mineral statistics and information from the USGS Minerals Information Web site (http://minerals.usgs.gov/minerals/pubs/country/europe.html), and (3) data collected by the USGS minerals information country specialists from sources, such as statistical publications of individual countries, annual reports and press releases of operating companies, and trade journals. Data reflect the most recently published table of industry structure for each country at the time of this publication. Additional information is available from the country specialists listed in table 2.

Hyperspectral surface materials map of quadrangle 3264, Naw Zad-Musa Qala (423) and Dihrawud (424) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3262, Farah (421) and Hokumat-e-pur-Chaman (422) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3570, Tagab-e-Munjan (505) and Asmar-Kamdesh (506) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Johnson, Michaela R.; Giles, Stuart A.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Hyperspectral surface materials map of quadrangle 3468, Chak-e Wardak-Siyahgird (509) and Kabul (510) quadrangles, Afghanistan, showing iron-bearing minerals and other materials

USGS Publications Warehouse

King, Trude V.V.; Hoefen, Todd M.; Kokaly, Raymond F.; Livo, Keith E.; Giles, Stuart A.; Johnson, Michaela R.

2013-01-01

This map shows the spatial distribution of selected iron-bearing minerals and other materials derived from analysis of airborne HyMap™ imaging spectrometer (hyperspectral) data of Afghanistan collected in late 2007. This map is one in a series of U.S. Geological Survey/Afghanistan Geological Survey quadrangle maps covering Afghanistan. Flown at an altitude of 50,000 feet (15,240 meters (m)), the HyMap™ imaging spectrometer measured reflected sunlight in 128 channels, covering wavelengths between 0.4 and 2.5 μm. The data were georeferenced, atmospherically corrected and converted to apparent surface reflectance, empirically adjusted using ground-based reflectance measurements, and combined into a mosaic with 23-m pixel spacing. Variations in water vapor and dust content of the atmosphere, in solar angle, and in surface elevation complicated correction; therefore, some classification differences may be present between adjacent flight lines. The reflectance spectrum of each pixel of HyMap™ imaging spectrometer data was compared to the reference materials in a spectral library of minerals, vegetation, water, and other materials. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated, while minerals having slightly different compositions but similar spectral features were less easily discriminated; thus, some map classes consist of several minerals having similar spectra, such as “Goethite and jarosite.” A designation of “Not classified” was assigned to the pixel when there was no match with reference spectra.

Turkey Country Analysis Brief

EIA Publications

2017-01-01

Turkey is well placed to serve as a hub for oil and natural gas supply headed to Europe and other Atlantic markets from Russia, the Caspian region, and the Middle East. Turkey has been a major transit point for oil and is becoming more important as a transit point for natural gas. Growing volumes of Caspian oil are being sent to Black Sea ports such as Novorossisyk, Russia and Supsa, Georgia and then to Western markets by tanker via the Turkish Straits (Bosporus and Dardanelles waterways). Caspian oil and oil from northern Iraq also cross Turkey by pipeline, through the Ceyhan oil terminal on Turkey's Mediterranean coast.

[Balneotherapy and spa therapy of rheumatic diseases in Turkey: a systematic review].

PubMed

Karagülle, M Z; Karagülle, M

2004-02-01

Turkey has a lot of thermal and mineral springs and is looking back on a still vivid tradition of spa therapy and balneotherapy, applied especially for the treatment of rheumatic diseases. This tradition is predominantly empiric and intuitive, however, it has assumed some important aspects of modern balneotherapeutic methods as well. This article is aimed at presenting the characteristics of traditional and modern balneological and spa therapy forms in Turkey. The studies which have been conducted between 1990 and 2000 in different spas in Turkey on the efficacy and effectiveness of spa therapy and balneotherapy for rheumatic diseases have been searched and analyzed independent of their design. A descriptive evaluation of the studies was carried out. A total of 15 published studies have been found and analyzed. The investigations have been carried out in 8 different spa resorts in Turkey. In these studies the effectiveness and efficacy of different balneological and spa therapies on a variety of rheumatic diseases (from osteoarthritis to fibromyalgia and from rheumatoid arthritis to low back pain) could be shown. Nearly all studied balneotherapeutic modalities were applied as bathing cures. Only in one study peloid therapy was applied. Balneotherapeutic therapy was applied in a modern and traditional way, and both open and stationary spa therapy forms were used at the same time. The review has shown the effectiveness of the investigated spa therapy and balneotherapy forms. It could be concluded that nearly all forms of spa therapy and balneotherapy used for the treatment of rheumatic diseases in Turkey are effective. A definitive conclusion, however, is not possible because of the heterogeneity of the study designs, methodological flaws, and the publication bias. In future good quality randomized controlled trials are needed. Copyright 2004 S. Karger GmbH, Freiburg

From Projectile Points to Microprocessors - The Influence of Some Industrial Minerals

USGS Publications Warehouse

Driscoll, Rhonda

2007-01-01

In the language of economic geology, Earth materials are classified as metallic ores, fuel minerals, gemstones, and industrial minerals. Most people know that metallic ores yield shiny, conductive, ductile elements such as copper, iron, or gold. Most understand that energy-producing coals constitute a fuel mineral. Likewise, dazzling rubies and rare sapphires are universally recognized as gemstones. The fourth group, industrial minerals, is largely unknown to the general public, even though industrial minerals are as essential to daily life as metals and fuel minerals. This report examines the occurrence and practical uses of nine important industrial minerals - constituting just a few of the more than 50 industrial minerals that shape human culture.

Dietary supplement use is associated with higher intakes of minerals from food sources1234

PubMed Central

Fulgoni, Victor L; Keast, Debra R; Dwyer, Johanna T

2011-01-01

Background: Dietary supplement use is extensive in US adults. Some reports suggested that supplement users had higher nutrient intakes from the diet than did nonusers, but to our knowledge this finding has not been examined in nationally representative survey data. Objective: In this analysis, we examined mineral intakes from the diet by supplement-use categories and how these supplements contributed to meeting or exceeding Dietary Reference Intakes for selected minerals. Design: Data from adults (≥19 y of age; n = 8860) who participated in NHANES 2003–2006, a nationally representative, cross-sectional survey, were examined. Supplement use was defined as the participant's self-reported use of a supplement that contained one or more selected minerals. Results: Dietary intakes of minerals from food sources were higher for magnesium, copper, potassium, and selenium in male supplement users than in nonusers. For women, dietary intakes of minerals from food sources were higher for users than for nonusers for each mineral examined except for selenium. In women, users of calcium-containing dietary supplements were much more likely to meet the Estimated Average Requirement (EAR) than were nonusers. Even after consideration of supplement use, >14% of adults had inadequate intakes for calcium and magnesium on the basis of the percentage of adults with usual intakes less than the EAR. The prevalence of adults who exceeded the tolerable upper intake level (UL) for calcium, zinc, iron, and magnesium was higher in users than in nonusers. Conclusions: Individuals who used mineral-containing dietary supplements had higher mineral intakes from food sources in the diet than did nonusers. For all minerals examined, and particularly for calcium and magnesium in men and women and iron in women, supplement use decreased the prevalence of intake inadequacy for each respective mineral; however, supplements contributed to risk of potentially excessive intakes for calcium, iron, zinc

Interplay between black carbon and minerals contributes to long term carbon stabilization and mineral transformation

NASA Astrophysics Data System (ADS)

Liang, B.; Weng, Y. T.; Wang, C. C.; Chiang, C. C.; Liu, C. C.; Lehmann, J.

2017-12-01

Black carbon receives increasing global wide research attention due to its role in carbon sequestration, soil fertility enhancement and remediation application. Generally considered chemically stable in bulk, the reactive surface of BC can interplays with minerals and form strong chemical bondage, which renders physical protection of BC and contributes to its long term stabilization. Using historical BC-rich Amazonian Dark Earth (ADE), we probe the in-situ organo-mineral association and transformation of BC and minerals over a millennium scale using various synchrotron-based spectroscopic (XANES, FTIR) and microscopic (TXM) methods. Higher content of SRO minerals was found in BC-rich ADE compare to adjacent tropical soils. The iron signature found in BC-rich ADE was mainly ferrihydrite/lepidocrocite, a more reactive form of Fe compared to goethite, which was dominant in adjacent soil. Abundant nano minerals particles were observed in-situ associated with BC surface, in clusters and layers. The organo-mineral interaction lowers BC bioavailability and enhances its long-term stabilization in environment, while at the same time, transforms associated minerals into more reactive forms under rapid redox/weathering environment. The results suggest that mineral physical protection for BC sequestration may be more important than previous understanding. The scale up application of BC/biochar into agricultural systems and natural environments have long lasting impact on the in-situ transformation of associated minerals.

Bioavailability of methyl parathion adsorbed on clay minerals and iron oxide.

PubMed

Cai, Peng; He, Xiaomin; Xue, Aifang; Chen, Hao; Huang, Qiaoyun; Yu, Jun; Rong, Xinming; Liang, Wei

2011-01-30

Adsorption, desorption and degradation by Pseudomonas putida of methyl parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) on montmorillonite, kaolinite and goethite were studied. Metabolic activities of methyl parathion-degrading bacteria P. putida in the presence of minerals were also monitored by microcalorimetry to determine the degradation mechanism of methyl parathion. Montmorillonite presented higher adsorption capacity and affinity for methyl parathion than kaolinite and goethite. The percentage of degradation of methyl parathion adsorbed on minerals by P. putida was in the order of montmorillonite>kaolinite>goethite. The presence of minerals inhibited the exponential growth and the metabolic activity of P. putida. Among the examined minerals, goethite exhibited the greatest inhibitory effect on bacterial activity, while montmorillonite was the least depressing. The biodegradation of adsorbed methyl parathion by P. putida is apparently not controlled by the adsorption affinity of methyl parathion on minerals and may be mainly governed by the activity of the methyl parathion-degrading bacteria. The information obtained in this study is of fundamental significance for the understanding of the behavior of methyl parathion in soil environments. Copyright © 2010 Elsevier B.V. All rights reserved.

Anthropogenic combustion iron as a complex climate forcer

DOE PAGES

Matsui, Hitoshi; Mahowald, Natalie M.; Moteki, Nobuhiro; ...

2018-04-23

Atmospheric iron affects the global carbon cycle by modulating ocean biogeochemistry through the deposition of soluble iron to the ocean. Iron emitted by anthropogenic (fossil fuel) combustion is a source of soluble iron that is currently considered less important than other soluble iron sources, such as mineral dust and biomass burning. Here we show that the atmospheric burden of anthropogenic combustion iron is 8 times greater than previous estimates by incorporating recent measurements of anthropogenic magnetite into a global aerosol model. This new estimation increases the total deposition flux of soluble iron to southern oceans (30–90 °S) by 52%, withmore » a larger contribution of anthropogenic combustion iron than dust and biomass burning sources. The direct radiative forcing of anthropogenic magnetite is estimated to be 0.021 W m –2 globally and 0.22 W m –2 over East Asia. In conclusion, our results demonstrate that anthropogenic combustion iron is a larger and more complex climate forcer than previously thought, and therefore plays a key role in the Earth system.« less

Anthropogenic combustion iron as a complex climate forcer.

PubMed

Matsui, Hitoshi; Mahowald, Natalie M; Moteki, Nobuhiro; Hamilton, Douglas S; Ohata, Sho; Yoshida, Atsushi; Koike, Makoto; Scanza, Rachel A; Flanner, Mark G

2018-04-23

Atmospheric iron affects the global carbon cycle by modulating ocean biogeochemistry through the deposition of soluble iron to the ocean. Iron emitted by anthropogenic (fossil fuel) combustion is a source of soluble iron that is currently considered less important than other soluble iron sources, such as mineral dust and biomass burning. Here we show that the atmospheric burden of anthropogenic combustion iron is 8 times greater than previous estimates by incorporating recent measurements of anthropogenic magnetite into a global aerosol model. This new estimation increases the total deposition flux of soluble iron to southern oceans (30-90 °S) by 52%, with a larger contribution of anthropogenic combustion iron than dust and biomass burning sources. The direct radiative forcing of anthropogenic magnetite is estimated to be 0.021 W m -2 globally and 0.22 W m -2 over East Asia. Our results demonstrate that anthropogenic combustion iron is a larger and more complex climate forcer than previously thought, and therefore plays a key role in the Earth system.

Anthropogenic combustion iron as a complex climate forcer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsui, Hitoshi; Mahowald, Natalie M.; Moteki, Nobuhiro

Atmospheric iron affects the global carbon cycle by modulating ocean biogeochemistry through the deposition of soluble iron to the ocean. Iron emitted by anthropogenic (fossil fuel) combustion is a source of soluble iron that is currently considered less important than other soluble iron sources, such as mineral dust and biomass burning. Here we show that the atmospheric burden of anthropogenic combustion iron is 8 times greater than previous estimates by incorporating recent measurements of anthropogenic magnetite into a global aerosol model. This new estimation increases the total deposition flux of soluble iron to southern oceans (30–90 °S) by 52%, withmore » a larger contribution of anthropogenic combustion iron than dust and biomass burning sources. The direct radiative forcing of anthropogenic magnetite is estimated to be 0.021 W m –2 globally and 0.22 W m –2 over East Asia. In conclusion, our results demonstrate that anthropogenic combustion iron is a larger and more complex climate forcer than previously thought, and therefore plays a key role in the Earth system.« less