干旱区生态环境知识资源中心(Arid): Paleoclimatic variability in the southern Tethys, Egypt: Insights from the mineralogy and geochemistry of Upper Cretaceous lacustrine organic-rich deposits

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DOI	10.1016/j.cretres.2021.104880
	Paleoclimatic variability in the southern Tethys, Egypt: Insights from the mineralogy and geochemistry of Upper Cretaceous lacustrine organic-rich deposits
	Fathy, Douaa; Wagreich, Michael; Ntaflos, Theodoros; Sami, Mabrouk
通讯作者	Fathy, D (corresponding author), Minia Univ, Fac Sci, Geol Dept, El Minia 61519, Egypt.
来源期刊	CRETACEOUS RESEARCH
ISSN	0195-6671
EISSN	1095-998X
出版年	2021
卷号	126
英文摘要	The effect of paleoclimate during global warming periods on Upper Cretaceous lacustrine deposits is not fully understood. In this study, comprehensive sedimentological, mineralogical, and geochemical data were used to unravel the past climatic changes and their influence on the accumulation of Campanian lacustrine organic-rich deposits in Egypt. Three sedimentary lithofacies associations are recorded within the uppermost part of the Quseir Formation. The laminated clay-rich mudstone lithofacies has the highest organic matter (TOC up to 1.2 wt.%). Sedimentological observations indicate that the bulk lithologic assemblage was originated in a shallow lacustrine setting. The studied samples consist of clay minerals, quartz, pyrite, carbonate, fluorapatite, and halite. The siliciclastic content reaches up to 78wt.%, whilst the carbonate content ranges from 3 to 22 wt.%. Compared to Post-Archean Australian shales (PAAS), the studied samples are significantly rich in Mg, Ca, P, Al, V, Ga, and Cr contents. The mudstone samples are characterized by high ratios (C-value, CIA, CIW, Mg/Ca, Fe/Mn, Ga/Rb) and low values (K2O/Al2O3), reflecting relatively warm and humid conditions during deposition of these sediments. The prevalence of smectite, as well as the sedimentary features, support that the lacustrine organic-rich mudstones are mainly deposited under warm seasonal climate (arid/humid). Additionally, the presence of dolomite and halite along with the Sr/Ba ratios (1.30-2.13), strongly suggest a saline water setting. The changes between aridity and humidity periods are probably the main reason for the significant variation in water chemistry, especially salinity. Therefore, the paleoclimatic variations largely controlled the depositional process during the formation of the Upper Cretaceous lacustrine organic-rich mudstones in the southern Tethys. (C) 2021 Elsevier Ltd. All rights reserved.
英文关键词	Greenhouse climate Salinity Lithofacies Clay minerals Depositional environment Clastic rocks
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000685072600002
WOS关键词	MAJOR-ELEMENT CHEMISTRY ; NORTHWESTERN RED-SEA ; OIL-SHALE DEPOSITION ; BOHAI BAY BASIN ; WESTERN DESERT ; CHINA IMPLICATIONS ; QUSEIR FORMATION ; PALEOENVIRONMENTAL RECONSTRUCTION ; SEQUENCE STRATIGRAPHY ; TIBETAN PLATEAU
WOS类目	Geology ; Paleontology
WOS研究方向	Geology ; Paleontology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/362910
作者单位	[Fathy, Douaa; Sami, Mabrouk] Minia Univ, Fac Sci, Geol Dept, El Minia 61519, Egypt; [Wagreich, Michael] Univ Vienna, Dept Geol, Vienna, Austria; [Ntaflos, Theodoros] Univ Vienna, Dept Lithospher Res, Althanstr 14, A-1090 Vienna, Austria
推荐引用方式 GB/T 7714	Fathy, Douaa,Wagreich, Michael,Ntaflos, Theodoros,et al. Paleoclimatic variability in the southern Tethys, Egypt: Insights from the mineralogy and geochemistry of Upper Cretaceous lacustrine organic-rich deposits[J],2021,126.
APA	Fathy, Douaa,Wagreich, Michael,Ntaflos, Theodoros,&Sami, Mabrouk.(2021).Paleoclimatic variability in the southern Tethys, Egypt: Insights from the mineralogy and geochemistry of Upper Cretaceous lacustrine organic-rich deposits.CRETACEOUS RESEARCH,126.
MLA	Fathy, Douaa,et al."Paleoclimatic variability in the southern Tethys, Egypt: Insights from the mineralogy and geochemistry of Upper Cretaceous lacustrine organic-rich deposits".CRETACEOUS RESEARCH 126(2021).