文献类型：期刊文献

英文题名：Influence of hydrothermal and upwelling events on organic matter accumulation in the gas-bearing lower Cambrian shales of the middle Yangtze Block, South China

作者：Cao, Hansheng[1,2,3];Wang, Zaiyun[1,2,3];Dong, Lanfang[1,2,3];Xiao, Yuchen[1,2,3];Hu, Liumei[1,2,3];Chen, Fajin[1,2,3];Wei, Kai[4,5];Chen, Chunqing[1,2,3];Song, Zhiguang[1,2,3];Wu, Li[1,2,3]

机构：[1]Guangdong Ocean Univ, Coll Ocean & Meterol, Lab Coastal Ocean Variat & Disaster Predict, Zhanjiang 524088, Peoples R China;[2]Guangdong Ocean Univ, Coll Ocean & Meteorol, Dept Educ Guangdong Prov, Key Lab Climate Resources & Environm Continental S, Zhanjiang 524088, Peoples R China;[3]Minist Nat Resources, Key Lab Space Ocean Remote Sensing & Applicat, Beijing 100081, Peoples R China;[4]China Geol Survey, Geosci Innovat Ctr Cent South China, Wuhan Ctr, Wuhan 430205, Peoples R China;[5]China Geol Survey, Wuhan Ctr, Hubei Key Lab Paleontol & Geol Environm Evolut, Wuhan 430205, Peoples R China

年份：2023

卷号：155

外文期刊名：MARINE AND PETROLEUM GEOLOGY

收录：SCI-EXPANDED(收录号：WOS:001024647000001)、、EI(收录号：20232414250186)、Scopus(收录号：2-s2.0-85161662485)、WOS

基金：This research is supported by the Guangdong Natural Science Foundation of China (2022A1515012100) , South China Sea Scholar Project of Guangdong Ocean University (002029002007) , Guangdong Provincial College Innovation Team Project (2019KCXTF021) , First- class Discipline Plan of Guangdong Province (080503032101, 231420003) , Project of Enhancing School with Innovation of Guang- dong Ocean University (GDOUQ18301) , First-class special Funds of Guangdong Ocean University (231419029) .

语种：英文

外文关键词：Shale gas potential; Shuijingtuo formation; Depositional environment; Element geochemistry; Paleoredox conditions; Paleoproductivity

外文摘要：With onoing studies on the diversification of animals during the early Cambrian in the Yangtze Block, resource effects associated with environmental changes have started to be elucidated, in which regional sedimentary events might have played an important role. The gas-rich Yichang area in the southern Huangling anticline is a potential area for shale gas development and provides a more suitable target for unravelling the debates on organic matter (OM) accumulation in the Low Cambrian marine black shales. This study integrated elemental geochemical and mineralogy time-series analyses based on core samples drilled in Yichang area on the shallow-water platform to constrain the evolution of the depositional environments and consider the forcing function behind OM enrichment in the Shuijinguo Formation. Distinctive TOC and Cu/Al peaks within the black shale deposited in the Shuijingtuo Member I suggest intensification of bioproductivity level. The chemical index of alteration (CIA), regarded as an indicator of paleoclimatic variation, increased in the upsection, and together with increasing Sr/Cu and quartz/feldspar ratio values, suggest a trend toward warming conditions and a moderate degree of chemical weathering. The geochemical proxies for the degree of water mass restriction (Mo/ TOC and Co x Mn) and paleoredox (MoEF, UEF, U/Th and Corg/P) indicate that the shallow-water shelf expe-rienced weakly-to moderately-restricted water conditions under an anoxic/euxinic environment in the Shui-jingtuo Member I and transited to a moderately-restricted water mass with suboxic conditions during the late Shuijingtuo and Shipai periods. A positive Eu anomaly within the Shuijingtuo Member I provided robust evi-dence of hydrothermal activity. We propose here for an opening of deposition conditions on the shallow-water platform which results in enhanced upwelling and hydrothermal activity (Si, Ba, et.), thereby ultimately dis-rupting the original nutrient cycling for the metabolism and prompting the OM accumulation in the epiconti-nental sea during the early Cambrian.