نتایج جستجو برای: geochemical method

تعداد نتایج: 1641388  

2007
N. Nelms A. Holland D. Talboys I. Hutchinson D. Simpson G. Cressey P. Bland

Geochemical analysis of the surface material of terrestrial type planets is of fundamental importance in understanding the geological context of the planetary environment. Consequently this analysis should be performed whenever possible and indeed this has occurred on a number of previous landers. Current techniques include X-ray fluorescence (XRF) and Rutherford back-scattering of alpha partic...

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...

2017
Xiaoli Zhang Jinxian He Yande Zhao Hongchen Wu Zeqiang Ren

Biomarker compounds that derived from early living organisms play an important role in oil and gas geochemistry and exploration since they can record the diagenetic evolution of the parent materials of crude oil and reflect the organic geochemical characteristics of crude oil and source rocks. To offer scientific basis for oil exploration and exploitation for study area, gas chromatography-mass...

Journal: :Environmental microbiology 2011
Jason W Sahl Marcus O Gary J Kirk Harris John R Spear

Sistema Zacatón in north-eastern Mexico is host to several deep, water-filled, anoxic, karstic sinkholes (cenotes). These cenotes were explored, mapped, and geochemically and microbiologically sampled by the autonomous underwater vehicle deep phreatic thermal explorer (DEPTHX). The community structure of the filterable fraction of the water column and extensive microbial mats that coat the ceno...

ژورنال: علوم آب و خاک 2019

Exploring the homogenous regions for site specific management is important, especially in the areas under different anthropogenic activities. This was investigated using multi-way analysis including Factor Analysis, Hierarchical Clustering Analysis and k means in the areas under long-term wastewater irrigation over a period of more than 40 years, in Shahre Rey, south of Tehran. By using Factor ...

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...

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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