نتایج جستجو برای: geochemical zonality index

تعداد نتایج: 407770  

Journal: :رخساره های رسوبی 0
محمد خانه باد طیبه گل افشانی سید رضا موسوی حرمی اسداله محبوبی

in this study, depositional environment and provenance of sandstones of the surijeh formation (lower cretaceous) in the abgarm section in the kopet-dagh basin are investigated. analysis of sedimentary facies in this section shows that there are two clastic (continental and coastal plain) and two carbonate (coastal plain) facies associations are present. the results of modal analysis and geochem...

Journal: :Journal of Water and Climate Change 2022

Abstract The Haihe River basin is the main grain production base and highland of economic strategic development in China. Based on daily meteorological data during 1960–2020, characteristics drought evolution were analyzed by standardized precipitation evapotranspiration index (SPEI). Pearson correlation method cross-wavelet analysis used to explore between SPEI climate factors (global warming,...

2015
Esteban Gazel Jorden L. Hayes Kaj Hoernle Peter Kelemen Erik Everson W. Steven Holbrook Folkmar Hau Paul van den Bogaard Eric A. Vance Shuyu Chu Andrew J. Calvert Michael J. Carr Gene M. Yogodzinski

Thin oceanic crust is formed by decompression melting of the upper mantle at mid-ocean ridges, but the origin of the thick and buoyant continental crust is enigmatic. Juvenile continental crust may form from magmas erupted above intraoceanic subduction zones, where oceanic lithosphere subducts beneath other oceanic lithosphere. However, it is unclear why the subduction of dominantly basaltic oc...

Journal: :global journal of environmental science and management 2015
a.r. karbassi m. pazoki

in this study, the concentrations of heavy metals (ca, zn, cu, fe, mn, ni) in thesediment of shavoor river in khuzestan province in iran has been investigated. after the library studies and field studies, six samples of water and sediment were taken from the river in order to evaluate heavy metal pollution in sediments. to determine the geochemical phases of metals in sediment samples the 5-ste...

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...

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...

Afshar Zia Zarifi Ahmad Adib Masoumeh Khalajmasoumi Misagh Mirzaei Peyman Afzal

The aim of this study is prospecting of iron and manganese in the Balvard 1:100000 sheet which is situated in Sanandaj - Sirjan structural zone utilizing Index Overlay and Fuzzy Logic methods in the GIS. In this study, the layers for integration, alterations, geological, geophysical, geochemical and structural data based on stream sediments, airborne magnetometeric and remote sensing studies. B...

2016
Wenxiang Zhang Qingzhong Ming Zhengtao Shi Jie Niu Huai Su

Lacustrine deposits at the margin of the southeastern Tibetan Plateau (SETP) are sensitive indicators for the evolution of the southwest Asian monsoon (SWAM) during the Quaternary. Thus, they can provide insight into the Quaternary climatic history and their relationship with global climatic changes. The results of the geochemical analysis of the Xiaozhongdian Basin section at the SETP suggest ...

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