نتایج جستجو برای: geochemical calculations

تعداد نتایج: 123646  

Journal: :Inorganics (Basel) 2022

We performed density functional theory (DFT) calculations on binary and ternary oxo/fluoro crystals of the geochemical twin pair zirconium hafnium to evaluate compare their stabilities. This is first DFT study bulk ZrF4 or HfF4, as well a hypothetical ZrOF2 HfOF2 crystal. For α-MO2, β-MF4 MOF2, we have found significantly higher cohesive energies for respective species. suggests considerable ga...

Journal: :journal of mining and environment 0
h. moeini faculty of mining and metallurgy, university of yazd, yazd, iran a. aryafar department of mining, faculty of engineering, university of birjand, birjand, iran

anomaly recognition has always been a prominent subject in preliminary geochemical explorations. among the regional geochemical data processing, there are a range of statistical and data mining techniques as well as different mapping methods, which serve as presentations of the outputs. the outlier’s values are of interest in the investigations where data are gathered under controlled condition...

Journal: Geopersia 2016

Iranian Cenozoic magmatic belt, known as Urumieh-Dokhtar, is recognized as an important polymetallic mineralization which hosts porphyry, epithermal, and polymetallic skarn deposits. In this regard, multivariate analyses are generally used to extract significant anomalous geochemical signature of the mineral deposits. In this study, stepwise factor analysis, cluster analysis, and concentration–...

2005
Ming-Kuo Lee James A. Saunders

We tracked the changes in water chemistry (major and trace elements, S isotope compositions, pH, Eh) and At the Sanders Lead car-battery recycling plant, near Troy, AL, identified solid “mineral” phases produced by biochemigroundwater is highly acidic (pH varies from 3 to 3.5) and carries cal processes. Theoretical geochemical modeling was high concentrations of Pb, Cd, Zn, Cu, and Fe. Pilot fi...

2017
Tzu-Hsuan Tu Li-Wei Wu Yu-Shih Lin Hiroyuki Imachi Li-Hung Lin Pei-Ling Wang

Terrestrial mud volcanoes (MVs) are an important natural source of methane emission. The role of microbial processes in methane cycling and organic transformation in such environments remains largely unexplored. In this study, we aim to uncover functional potentials and community assemblages across geochemical transitions in a ferruginous, sulfate-depleted MV of eastern Taiwan. Geochemical prof...

2015
Gerald D. Pollack GERALD D. POLLACK Eirik J. Krogstad Andrey Bekker Gerald Daniel Pollack

The redox-sensitive geochemical behavior of uranium permits the use of Th/U ratios as a geochemical proxy for the oxidation state of the atmosphere and oceans during sedimentary processes. Due to the effects of post-depositional uranium mobility on Th/U ratios during events involving oxygenated fluids, direct measurements of Th/U ratios are often misleading, but the whole rock Pb isotope compos...

2006
G. H. Jarrar R. J. Stern D. Zachmann

Geochemical, isotopic and age constraints support a comagmatic origin for Ghuweir Mafics and the Feinan A-type granites. The two rocks types, named collectively in this paper as the Feinan Ghuweir Magmatic Suite (FGMS), formed between 556 and 572Ma ago according to Rb–Sr whole-rock dating. FGMS has low Sr initial ratios, which preclude a significant contribution of much older crust in the magma...

2017
Marzena Rachwał Małgorzata Wawer Tadeusz Magiera Eiliv Steinnes

The main objective of the study was an assessment of the pollution level of agricultural land located close to dumps of industrial waste remaining after former Zn and Pb ore processing in Poland. The integrated geophysical-geochemical methods were applied for assessment of soil quality with respect to trace element pollution. Additionally, human health risk induced by the contaminated arable so...

2012
C. Magnier

Surface and Subsurface Geochemical Monitoring of an EOR-CO2 Field: Buracica, Brazil — This paper presents a surface and subsurface geochemical survey of the Buracica EOR-CO2 field onshore Brazil. We adopted a methodology coupling the stable isotopes of carbon with noble gases to investigate the adequacy of geochemical monitoring to track deep fluid leakage at the surface. Three campaigns of CO2...

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