scholarly journals Geochemical characteristics and sedimentary environment of the Middle Devonian organic-rich shales in the Northwest of Guizhong Depression, Southwest China

China Geology ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 567-574
Author(s):  
Kun Yuan ◽  
◽  
Wen-hui Huang ◽  
Xin-xin Fang ◽  
Shi-zhen Li ◽  
...  
Keyword(s):  
Middle Devonian ◽  
Southwest China ◽  
Sedimentary Environment ◽  
Geochemical Characteristics

scholarly journals Geochemical Characteristics of the Middle Devonian Dacaozi-Tanshanping Shale Strata in the Yanyuan Basin, Southwest China: Implications for Organic Matter Accumulation and Preservation

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Ziya Zhang ◽  
Wei Yang ◽  
Xingyu Li ◽  
Yan Song ◽  
Zhenxue Jiang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sea Level ◽  
Middle Devonian ◽  
Chemical Weathering ◽  
Southwest China ◽  
Carbonate Platform ◽  
Geochemical Characteristics ◽  
Organic Matter Accumulation ◽  
Terrigenous Input ◽  
Preservation Condition

How the geochemical characteristics of organic matter shale for the carbonate platform facies remain uncertain, which restricts an integrated reconstruction of the model of organic matter accumulation and preservation. Here, we present new results from element geochemical fingerprinting and integrated analyses of paleoclimate, paleoproductivity, paleoredox environment, and terrigenous input of the targeted Middle Devonian Tanshanping and Dacaozi Formations in the Ninglang-Yanyuan Basin, Southwest China. It is worth noting that although the carbonate platform connects with the open sea partially, the redox environment will not be completely controlled by relative sea level variations. Specially, the paleoclimate, paleoproductivity, and paleoredox conditions are the main controlling factors of the accumulation and preservation of organic matter. In view of the paleoclimate indexes, we suggest that both a relatively warm-humid climate characterized by intensified chemical weathering conditions and a higher terrigenous input are identified as two major drivers forcing the reductive environment in the sedimentary waterbody. Finally, a comprehensive model is established for providing new insights into the mechanism of organic matter accumulation and preservation for the carbonate platform facies. The paleoredox environment, paleoproductivity, paleoclimate, and terrigenous input are believed to have exerted a very considerable force on reconstructing the model of organic matter accumulation and preservation for the carbonate platform facies. Specially, the coupling interactions between the paleoproductivity and redox condition are thus also stressed. We found that the preservation condition is much more important than the paleoproductivity, resulting in the degree of organic matter enrichment. Even if the paleoproductivity of a sedimentary waterbody of a depositional period of the Dacaozi Formation was higher, the TOC concentrations were relatively low due to the poor preservation condition by fall of the sea level and increase of the terrigenous input. In another aspect, the better preservation condition of the Tanshanping Formation makes the TOC concentrations higher in the case of lower paleoproductivity in the sedimentary waterbody.

Geochemical Characteristics of Ore-Bearing Strata of Pb-Zn Deposits in the Sichuan-Yunnan-Guizhou Border Area in Southwest China

2013 ◽  
Vol 868 ◽  
pp. 113-116
Author(s):  
Long Jian ◽  
Fu Ju Jia ◽  
Yan Dao
Keyword(s):  
Comparative Study ◽  
Southwest China ◽  
Geochemical Characteristics ◽  
Border Area ◽  
Zinc Deposit ◽  
Element Abundances ◽  
Elemental Geochemistry ◽  
Different Ages ◽  
Lead Zinc ◽  
The Comparative Study

The Pb-Zn deposits (or points) with different ages of ore-bearing strata are counted in in the paper. Through discussing the lithology and elemental geochemistry in ore-bearing strata to explain the lead element and zinc element relate to strata and lithology, the author suggested the lead-zinc deposit mainly were exposed in specific stratum, considering the deposits was obviously was controlled by stratum and was greatly influenced by lithology. For this reason, combining with the comparative study of element abundances in rock, it has maily demonstrated the relevance of ore-forming elements.

scholarly journals Geological and Geochemical Characteristics of Low-Arsenic Groundwater in The Karamay Area Between Two High Arsenic Areas of Xinjiang, China

2021 ◽  
Author(s):  
Qiao Li ◽  
Hongfei Tao ◽  
Mahemujiang Aihemaiti ◽  
Youwei Jiang ◽  
Wenxin Yang ◽  
...  
Keyword(s):  
River Basin ◽  
Sedimentary Environment ◽  
Water Injection ◽  
Arsenic Concentration ◽  
Junggar Basin ◽  
High Energy ◽  
Geochemical Characteristics ◽  
Upper Permian ◽  
Arsenic Content ◽  
River Diversion

Abstract The groundwater of several regions in Xinjiang, China, including the Kuitun and the Manas River Basins in the Junggar Basin, is heavily polluted with arsenic. However, the arsenic content of the groundwater of the Karamay area located within the Junggar Basin is relatively low and below the recommended drinking water limit. In our study, we analyze the factors that result in this anomaly. The geological and geochemical characteristics of the water-bearing system in this area were investigated by analyzing water samples, carrying out hydrogeological surveys, and statistical techniques. Since the Carboniferous, the geological development and subsequent structural evolution resulted in a lower arsenic concentration in groundwater of the Karamay region than that of the Kuitun River Basin and the Manasi River Basin. The missing high-energy sedimentary environment in the Middle-Upper Permian and the composition of sediments controlled the characteristics of the multi-layer aquifer in this area. We find that the lack of arsenic sources, neutral and slightly alkaline environment, water injection to extract oil, and the Irtysh River Diversion to Urumqi Project, result in better groundwater quality and lower arsenic pollution in this area.

Sedimentary Environment and Geochemical Characteristics of Surface Sediments in Boseong River

2017 ◽  
Vol 29 (3) ◽  
pp. 151-167
Author(s):  
Kangho Oh ◽  
Hyungbin Yoo ◽  
Yeongkoo Koh ◽  
Seoktai Youn
Keyword(s):  
Surface Sediments ◽  
Sedimentary Environment ◽  
Geochemical Characteristics

Geochemical characteristics and resource potential analysis of Chang 7 organic-rich black shale in the Ordos Basin

2018 ◽  
Vol 156 (07) ◽  
pp. 1131-1140 ◽  
Author(s):  
JIANGMIN DU ◽  
YANDE ZHAO ◽  
QINGCHUN WANG ◽  
YANQIU YU ◽  
HUI XIAO ◽  
...  
Keyword(s):  
Trace Elements ◽  
Large Scale ◽  
Sedimentary Environment ◽  
Ordos Basin ◽  
Biological Marker ◽  
Geochemical Characteristics ◽  
Gas Chromatography Mass Spectrometry ◽  
Hydrocarbon Generation ◽  
Resource Potential ◽  
The Ordos Basin

AbstractThe Ordos Basin is the largest and most important intracontinental sedimentary depression in China, and a significant amount of crude oil resources has developed within this Mesozoic formation. High-grade organic-rich shale is prevalent in the large-scale areas of the Chang 7 sedimentary stage and provides essential hydrocarbon resources for abundant oil enrichment in the Mesozoic. This research investigated the geochemical characteristics of Chang 7 shale using core samples and well logs and via laboratory tests. In addition, the microscopic components of the shale organic matter (OM), biological marker compounds, carbon isotopes, enrichment grade of trace elements, and elemental ratio were analysed systematically. Moreover, the aspects related to the shale OM source, sedimentary environment and resource potential were evaluated. Our results revealed that spherical alginate and calcium spherical alginate were predominant in the micropetrological components of the shale. Many biomarkers, including n-alkanes, steranes and terpanes, were detected in the gas chromatography – mass spectrometry spectra. An analysis of n-alkanes, regular sterane shapes (C21−/C22− and C26+C27/C28+C29), odd–even predominance index (OEP) and carbon preference index (CPI) values and carbon isotope distributions showed that OM was produced from aquatic organisms. The indicators of trace elements, such as Sr/Ba and V/V+Ni, combined with the biomarker compound in Pr/Ph and the gammacerane index showed the presence of a semi-deep – deep lake environment containing fresh–brackish water. In addition, the hydrocarbon conversion rate index and shale rock pyrolysis parameters revealed that Chang 7 has a high hydrocarbon generation ability and hydrocarbon expulsion efficiency.

Research Progress of Bauxite in WZD Area, Northern Guizhou, China

2014 ◽  
Vol 989-994 ◽  
pp. 1392-1395
Author(s):  
Tao Cui
Keyword(s):  
Rare Earth ◽  
Sedimentary Environment ◽  
Comprehensive Analysis ◽  
Geochemical Characteristics ◽  
Parent Rock ◽  
Research Progress ◽  
Mineralization Process ◽  
Migration Mechanism ◽  
Rare Earth Mineral

This paper has a comprehensive analysis on the bauxite in Wuchuan-Zheng, an-Daozhen (WZD) area, northern Guizhou, China through synthesize former research. The understanding of mineralogic, petrologic and geochemical characteristics is deep, and sedimentary environment, parent rock and mineralization process have been defined. Main questions need further research as follow: minerogenetic epoch; migration mechanism of elements; genesis of rare earth mineral.

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