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Showing 1 to 8 of 8 for “"chemical zonation"”.
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Microbial and Chemical Zonation and Mineral Weathering in the Middendorf Aquifer, South Carolina
I consider the nature and origin of the chemical and microbiological zonation of the Cretaceous Middendorf aquifer, in the Coastal Plain of South Carolina, in light of the chemical evolution of groundwater along a flow path there. Some types of microbial activity, most notably aerobic respiration …
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Mineralogy of Eudialyte Group Minerals From the East Hill Suite Of the Mont Saint-Hilaire Alkaline Plutonic Complex, Including an Alternative Site-Assignment Algorithm & A Proposed Classification System
… eudialyte-group compositions and degrees of chemical zonation. These data suggest that late-stage melt heterogeneity in alkaline systems is far more pronounced than previously thought. All analyses exhibited a negative neodymium anomaly in chondrite-normalized data. This supports data from …
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In situ mineral geochemistry as a guide to ore-forming processes
… Cu-Au deposits. These studies revealed complex chemical zonation, providing a detailed record of cryptic fluid chemistry and depositional processes. A distinct isotopic signature and residual metastable silica hydrates in quartz microcrystals from the El Indio deposit, Chile provided the first …
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In situ mineral geochemistry as a guide to ore-forming processes
… Cu-Au deposits. These studies revealed complex chemical zonation, providing a detailed record of cryptic fluid chemistry and depositional processes. A distinct isotopic signature and residual metastable silica hydrates in quartz microcrystals from the El Indio deposit, Chile provided the first …
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Petroleum coke slags: characterization and dissolution
… (2) electron probe microanalysis (EPM) of chemical compositions of individual phases; (3) statistical analysis of the EPM data to eliminate spurious data; (4) estimation of valence states of transition metals using thermodynamic and computational methods; (5) derivation of chemical formulae …
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Cordierite and its retrograde breakdown products as monitors of fluid-rock interaction during retrograde path metamorphism : case studies in the Schwarzwald and the Bayerische Wald (Variscan belt, Germany)
… were distinguished that formed by distinct allochemical processes under different pressure-temperature conditions at different times. They probably represent general features of cordierite breakdown. Border-type (b-type) pinite consists of muscovite and biotite, formed at 350 - 550 °C from a …
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The igneous petrology, thermal history, and genesis of sedimentary rock-hosted Au deposits in the northern Battle Mountain mining district, Nevada
… in Au, As, Ag, Cu, and Sb and show complex chemical zonation. Base metal sulfides show inconclusive paragenetic textural relationships with ore-stage pyrite and may either pre-date or post-date the Au mineralization event. Apatite and zircon (U-Th)/He dates indicate the most recent …
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Pluton Zonation Unveiled by Gamma-ray Spectrometry and Magnetic Susceptibility; A Case Study of the Sheeprock Granite, Western, Utah
… and post-magmatic processes related to its chemical and physical zonation. Uranium ranges from 3.9 to 26.9 ppm (mean 12.7) and thorium from 1.7 to 125.7 ppm (mean 45.5). Similarities in spatial patterns and near normal distributions of U and Th imply minimal remobilization and secondary …