气候变化领域集成服务门户(CCPortal): Water-level and redox fluctuations in a Sichuan Basin lacustrine system coincident with the Toarcian OAE

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DOI	10.1016/j.palaeo.2020.109942
	Water-level and redox fluctuations in a Sichuan Basin lacustrine system coincident with the Toarcian OAE
	Liu J.; Cao J.; Hu G.; Wang Y.; Yang R.; Liao Z.
发表日期	2020
ISSN	0031-0182
卷号	558
英文摘要	Increasing cases have indicated that oceanic anoxic events (OAEs) appear to have records in terrestrial sediments, which provide valuably high-resolution materials for the debated and challenging issues of OAEs. However, the current works are preliminary and need more geological analyses to test. Here we present a case study in the Lower Jurassic Da'anzhai Member of the Toarcian (ca. 180 Ma) Sichuan Basin, SW China. The petrology and sedimentary facies of the Da'anzhai Member were used to reconstruct the relative water-level fluctuations in the Sichuan Basin, which are revealed to be consistent with coeval changes in global sea levels. The Da'anzhai Member was deposited during a period of lake shallowing with enhanced salinities corroborated by the Sr/Ba and S/TOC ratios, when sea level was generally high after global transgression. During the lake shallowing, there were four complete secondary lacustrine deepening–shallowing cycles over shorter time-scales. The total organic carbon contents and organic carbon isotopic stratigraphy show there was a basin wide terrestrial response to the T-OAE as recorded by the Da'anzhai Member. The enrichment factors of Mo relative to PAAS (MoEF) and Corg/P values imply a dysoxic redox condition. The terrestrial response of OAEs is likely caused by changes in hydrological conditions, which were related to the global warming triggered by the Karoo–Ferrar Large Igneous Province. The associated organic carbon accumulation mechanism is a combined effect of elevated primary productivity and oxygen-depleted preservation conditions. Our data suggest that OAEs do have terrestrial response and induce organic carbon accumulation, but the mechanisms are still not much clear and need further studies. © 2020 Elsevier B.V.
英文关键词	Karoo–Ferrar; Mudstone; Organic matter; Primary productivity; Redox condition; Toarcian
语种	英语
scopus关键词	anoxic conditions; carbon isotope; global warming; igneous province; lacustrine environment; lithostratigraphy; organic carbon; paleoceanography; redox conditions; Toarcian; water level; China; Karoo; Sichuan Basin; South Africa
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150350
作者单位	MOE Key Laboratory of Surficial Geochemistry, School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China; State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, PetroChina Key Laboratory of Carbonate Reservoirs, Southwest Petroleum University, Chengdu, Sichuan 610500, China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, College of Resources and Environmental Science, Chongqing University, Chongqing, 400044, China
推荐引用方式 GB/T 7714	Liu J.,Cao J.,Hu G.,et al. Water-level and redox fluctuations in a Sichuan Basin lacustrine system coincident with the Toarcian OAE[J],2020,558.
APA	Liu J.,Cao J.,Hu G.,Wang Y.,Yang R.,&Liao Z..(2020).Water-level and redox fluctuations in a Sichuan Basin lacustrine system coincident with the Toarcian OAE.Palaeogeography, Palaeoclimatology, Palaeoecology,558.
MLA	Liu J.,et al."Water-level and redox fluctuations in a Sichuan Basin lacustrine system coincident with the Toarcian OAE".Palaeogeography, Palaeoclimatology, Palaeoecology 558(2020).