干旱区生态环境知识资源中心(Arid): Arid climate disturbance and the development of salinized lacustrine oil shale in the Middle Jurassic Dameigou Formation, Qaidam Basin, northwestern China

Arid

DOI	10.1016/j.palaeo.2021.110533
	Arid climate disturbance and the development of salinized lacustrine oil shale in the Middle Jurassic Dameigou Formation, Qaidam Basin, northwestern China
	Wang, Yuxuan; Xu, Shang; Hao, Fang; Poulton, Simon W.; Zhang, Yuanyin; Guo, Tianxu; Lu, Yangbo; Bai, Nan
通讯作者	Zhang, YY (corresponding author), China Geol Survey, Oil & Gas Survey, Beisihuan Rd 267, Beijing 100083, Peoples R China.
来源期刊	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
ISSN	0031-0182
EISSN	1872-616X
出版年	2021
卷号	577
英文摘要	The lacustrine Dameigou organic-rich shale of the northern Qaidam Basin is a particularly promising play for recent unconventional oil and gas exploration in China. Deposition was associated with arid intervals during the otherwise humid Middle Jurassic, but the depositional mechanism and organic matter enrichment processes are poorly understood. This study integrates high-resolution organic and inorganic geochemical proxies with detailed sedimentary observations for samples from the Chaiye (CY1) borehole, located in the Yuqia Depression, to investigate the depositional environment and development of the Dameigou shales. Four major lithofacies, including sandy mudstones, oil shale, organic-rich mudstone, and argillaceous mudstone, were identified through detailed microscopic observation and mineralogical analyses. Geochemical paleoclimate proxies (CIA, Fe/Mn and Mg/Ca) indicate that humidity fluctuations primarily drove the lithofacies variation. Other geochemical proxies, including terrigenous supply (Al2O3, Ti2O and regular sterane), lake salinity (Sr/Ba, S/TOC and Ga), redox conditions (V/Cr, U/Th and Pr/Ph), and primary productivity (Ba-xs, P-xs) indicate that climatic variability exerted a first-order control on the chemical evolution of the lake and the development of organic-rich shale in the Yuqia area. During arid intervals, fresh water supply through precipitation and river runoff weakened, leading to an increase in salinity and water column stratification. As a result, surface water became brackish and oxygen-rich, promoting growth of algae, but density stratification drove the bottom waters to anoxia, providing favorable conditions for organic matter preservation. Recycling of nutrients such as phosphorus under anoxic conditions further promoted eutrophication and high productivity in the surface water, which ultimately promoted the precipitation of carbonate minerals.
英文关键词	Organic-rich shale Paleoclimate Redox history Saline lake Water column stratification
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000678383100010
WOS关键词	MAJOR-ELEMENT CHEMISTRY ; WUFENG-LONGMAXI SHALES ; TOTAL ORGANIC-CARBON ; DEPOSITIONAL ENVIRONMENT ; PETROLEUM SYSTEMS ; SEDIMENTARY-ROCKS ; MARINE-SEDIMENTS ; PHOSPHORUS REGENERATION ; GEOCHEMICAL INDICATORS ; AUTHIGENIC URANIUM
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology
WOS研究方向	Physical Geography ; Geology ; Paleontology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/368498
作者单位	[Wang, Yuxuan; Lu, Yangbo; Bai, Nan] China Univ Geosci, Key Lab Tecton & Petr Resources, Minist Educ, Lumo Rd 388, Wuhan 430074, Peoples R China; [Xu, Shang; Hao, Fang] China Univ Petr, Sch Geosci, Changjiangxi Rd 66, Qingdao 266580, Peoples R China; [Poulton, Simon W.] Univ Leeds, Sch Earth & Environm, Leeds LS2 9JT, W Yorkshire, England; [Zhang, Yuanyin; Guo, Tianxu] China Geol Survey, Oil & Gas Survey, Beisihuan Rd 267, Beijing 100083, Peoples R China
推荐引用方式 GB/T 7714	Wang, Yuxuan,Xu, Shang,Hao, Fang,et al. Arid climate disturbance and the development of salinized lacustrine oil shale in the Middle Jurassic Dameigou Formation, Qaidam Basin, northwestern China[J],2021,577.
APA	Wang, Yuxuan.,Xu, Shang.,Hao, Fang.,Poulton, Simon W..,Zhang, Yuanyin.,...&Bai, Nan.(2021).Arid climate disturbance and the development of salinized lacustrine oil shale in the Middle Jurassic Dameigou Formation, Qaidam Basin, northwestern China.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,577.
MLA	Wang, Yuxuan,et al."Arid climate disturbance and the development of salinized lacustrine oil shale in the Middle Jurassic Dameigou Formation, Qaidam Basin, northwestern China".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 577(2021).