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Showing 1 to 20 of 31 for “"siderite"”.
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Geochemical Analysis of Ironstone Preserved Molluscan Fossils of the Hell Creek Formation (Cretaceous) and Ludlow Member of the Fort Union Formation (Paleogene) of Southwestern North Dakota
… of the ironstone nodules and fossils as siderite (FeCO3), quartz (SiO2), and goethite (FeOOH). The original nodule-forming iron mineral was identified as siderite. Analysis of thermodynamic relationships and stability diagrams indicates that siderite formation occurs within a fairly …
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Reactivity of Iron-Bearing Minerals Under Carbon Sequestration Conditions
… sequester carbon as a ferrous carbonate mineral (siderite). The formation of siderite requires the reduction of ferric ions which may be achieved by the co-injection of H2S or SO2 contaminants with CO2. Both ferrihydrite and hematite nanoparticles were exposed to an aqueous Na2S solution in the …
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Stratigraphic setting of some new and rare phosphate minerals in the Yukon Territory
… detrital quartz grains, skeletal fragments, and siderite matrix. Mixed phosphate-siderite pellets (as well as granules) and matrix constitute a spectrum from sandstone to mudstone and comprise the major part of the formation. The rocks were originally composed of detrital quartz and clay minerals …
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Using oxygen and carbon stable isotopes, 53Mn-53Cr isotope systematics, and petrology to constrain the history of carbonates and water in the CR and CM chondrite parent bodies
… the CR1 chondrite GRO 95577 and determined that siderite is the youngest secondary mineral yet observed in carbonaceous chondrites. This has implications for the CR parent body as it either was large enough to retain heat for long periods of time or was heated by impact after most aqueous …
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The formation of carbonate minerals in laboratory and environmental settings
… pore fluid chemistry and thus the stability of siderite in conditions that mimic the saltmarsh. My incubation results suggest that the formation of siderite nodule can be very rapid (within weeks) after burial when there is a substantial iron source. My research thus explores the mineralisation …
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Thermal and Diagenetic Evolution of Carboniferous Sandstones, Central Appalachian Basin
… by stratigraphic position. The distribution of siderite and iron-oxide/oxyhydroxide may reflect the second order paleoclimatic signature recognized throughout the Carboniferous, where siderite formed during everwet periods and iron-oxide/oxyhydroxide during semi-arid conditions, reflecting …
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Sulfide immobilization with taconite tailings: products, capacity, and stability
… beneficiated tailings product made of primarily siderite and quartz, as well as Fe-rich clay minerals. Chapter 2 contains a study of the reaction of aqueous sulfide with siderite and emphasizes the nature of the reaction product and the determinants of overall sulfide immobilization capacity. In …
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Detailed paleoclimatic records from late Pennsylvanian polygenetic paleosols : north-central Texas, USA.
… conditions (gley matrix colors, pedogenic siderite), however overprinting occurred through rapid transgression in one paleosol and gradual sea-level rise in the other. Reconstructed physical and wet chemical soil properties indicate these paleosols were finely textured, fertile, and void of …
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Ichnotaxonomic assessment of Mazon Creek area trace fossils, Illinois, USA
… known for soft-bodied organisms preserved within siderite concretions. Trace fossils, though less well known, also occur in concretions. Several hundred trace-fossil-bearing concretions were examined from collections at The Field Museum, Chicago, and The University of Kansas Natural History …
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Concretions and nodules in the Hell Creek Formation, southwestern North Dakota
… cone-in-cone masses. The nodular types include siderite masses and lenses and iron oxide spheres. Moving groundwater solutions, in many cases acccmpanied by locally reducing conditions resulting from the accumulation of organic materials, have apparently been important factors in the formation …
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Mineralogy and geochemistry of the carbonaceous mudstones and coal petrogenesis of the Grootgeluk formation in the Waterberg coalfield, South Africa
… by kaolinite, organic matter (-40 weight %), siderite, calcite and minor proportions of apatite. The carbo- tonstein has mineralogical, maceral and chemical characteristics distinctive from the other mudstones. Syn-depositional calcite lenses occur predominantly in the upper-half of the …
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Characterization of Residual Mineral Content of Bauxite Stockpiles in Saline County, Arkansas: An XRD Analysis Approach
… zirconium (r = 0.76) and niobium (r = 0.72). Siderite, a minor mineral phase, appears associated with niobium, zirconium, and titanium, suggesting trace metal affinity. A strong inverse relationship between gibbsite and kaolinite (r = -0.96) indicates differing formation pathways. Anatase and …
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Magnetic Characteristics of Carboniferous Continental Depositional Systems: Implications for the Recognition of Depositional Hiatuses
… lower Pennsylvanian quartz arenite facies, early siderite cementation zones as well as conglomerate lags with distinctive magnetic characteristics are thought to reflect periods of prolonged exposure and to define unconformities within compound valley fills.
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Linkage Between Lower Pennsylvanian Sandstone Diagenesis and Carbon Sequestration Reservoir Quality in Russell County, Virginia
… with a diagenetic mineral assemblage including siderite, chlorite, kaolinite, albite, illite, silica and calcite. Primary porosity is not preserved, but secondary porosity (5 ± 3.1 %) has developed at the expense of feldspars and unstable lithic fragments. Permeability assessments collected in …
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Kinetics of the release and precipitation of phosphorus in anaerobic digesters sequencing biological phosphorus removal systems
… is limited by the competitive precipitation of siderite (FeCO₃ ). The extent to which the compounds are precipitated depends on the solids retention times, ionic strengths, size and amorphous nature of the precipitates and the substitution of foreign ions in the crystal lattice. The effective …
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Stratigraphic control and distal hydrothermal footprint of the Ursa Zn-Pb-Ag prospect, Selwyn Basin, Yukon Territory, Canada
… earlier barite. The weakly altered rocks contain siderite and witherite. The results of this study provide new guidelines on how the distal signature of clastic-dominated deposits in the Selwyn Basin can be identified and used as potential vectors to mineralization.
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The Aptian-Albian ironstone of the Rapid Creek formation, Little Fish Creek, NWT: implications for Cretaceous Ocean Anoxic Events and critical mineral deposits
… hummocky cross-stratified ironstone dominated by siderite and apatite. The thickness of these ironstone tops increases in each parasequence, suggesting increased progradation during early highstand conditions. As in many Paleozoic ironstones, Fe is interpreted to have been supplied via upwelling, …
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Authigenic kaolinite in the Bear Den Member (Paleocene) of the Golden Valley Formation, in southwestern North Dakota
… <p>3. Plagioclase, amphibole, pyrite, and siderite are present but would not have been able to withstand weathering.</p> <p>4. Kaolinite and muscovite show parallel alignment.</p> <p>This study reviews these ideas and more recent work that suggests that the kaolinite of the Bear Den Member …
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EFFECTS OF GROUND-WATER FLOW ON SOIL CHEMISTRY, NUTRIENT AVAILABILITY AND PLANT SPECIES DISTRIBUTIONS IN FOUR NEW YORK STATE FENS
… predominated. Iron minerals, including siderite and iron-sulfides, also strongly influenced pore-water chemistry. Sulfur content and bicarbonate-dithionite extractable P increased in areas with elevated alkalinity and evidence of SO42- reduction, suggesting that iron-sulfur reactions …
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Isotopic fractionation of chromium and uranium during abiotic and microbial Cr(VI) reduction and microbial U(VI) reduction
… phases (Fe(II-doped goethite, FeS, green rust, siderite and sediments from an active barrier) occurring at Permeable Reactive Barriers and by a group of metabolically diverse bacteria (G. sulfurreducens, Shewanella sp. (Neckar River), P stutzeri DCP-Ps1 and D. vulgaris). The results can be used …
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