干旱区生态环境知识资源中心(Arid): Geochemistry and palynology of the upper Albian at the Abu Gharadig Basin, southern Tethys: Constraints on the oceanic anoxic event 1d

Arid

DOI	10.1002/gj.3810
	Geochemistry and palynology of the upper Albian at the Abu Gharadig Basin, southern Tethys: Constraints on the oceanic anoxic event 1d
	Mansour, Ahmed; Gentzis, Thomas; Carvajal-Ortiz, Humberto; Tahoun, Sameh S.; Wagreich, Michael
通讯作者	Mansour, A
来源期刊	GEOLOGICAL JOURNAL
ISSN	0072-1050
EISSN	1099-1034
出版年	2020
卷号	55 期号:9 页码:6338-6360
英文摘要	The mid-Cretaceous period was a time of abnormal polar temperature warming and consequent global oceanic anoxia that enhanced the widespread accumulation of organic matter-rich marine sediments. The current contribution focuses on the late Albian oceanic anoxic subevent 1d (OAE 1d) that represents a period of increased perturbation of the global carbon cycle. Palynological and geochemical investigations, including TOC/Rock-Eval pyrolysis and stable carbon isotope of organic matter (delta C-13(TOC)), were conducted for the upper part of the Kharita Formation from the Abu Gharadig Basin, north Western Desert, Egypt, to (a) confirm the age of this unit, (b) assess the depositional environments and prevalent redox conditions, and (c) confirm the occurrence of the OAE 1d within the sedimentary record in this part of the southern Tethys. Based on the TOC content and Rock-Eval pyrolysis parameters, the organic matter in the upper Kharita Formation is expected to have a limited hydrocarbon generation potential consisting of gas only. The sedimentation patterns and role of continental weathering and runoff influx were assessed through trace element ratios and relationships. Redox conditions were interpreted based on S-total-TOC relationship, S-total-TOC-Fe(total)ternary plot, Rock-Eval S-2, trace element proxies and relationships (including Cr vs. V + Ni, V/Cr vs. S-total, and S-total/Fe vs. Mn/S-total). The ratio of TOC/P(total)was implemented to assess both marine primary productivity and oceanic anoxia during this period. Biostratigraphic constraints showed that the upper part of the Kharita Formation spanned a late Albian age (Cretacaeiporites densimurusInterval Zone). Results showed that the OAE 1d was characterized by organic matter deposition during dysoxic-suboxic to anoxic redox conditions in a fluvio-deltaic to shallow marine depositional environment in this part of the Tethys. A low to moderate primary productivity was also prevalent during a fairly high rate of sediment accumulation. Regional correlation of positive delta(13)C(TOC)excursion during the OAE 1d throughout the Tethys and Atlantic oceans matched well, in several parts, with the current study interval that confirm the global distribution of the OAE 1d. In this region of the southern Tethys, an overall collapse of water column stratification during the OAE 1d principally related to decreased terrestrial input at low relative sea level, as evidenced from freshwater algaePediastrumand pteridophyte sporeCrybelosporites pannuceus; however, orbital forcing likely induced monsoonal activity at low-latitudes in the SE, N, and W Tethys.
英文关键词	Abu Gharadig carbon-isotope chemostratigraphy Egypt late Albian OAE 1d palynology southern Tethys
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000563540800001
WOS关键词	NORTHERN WESTERN DESERT ; MARINE BLACK SHALES ; ORGANIC-MATTER ; HEMIPELAGIC CARBONATES ; SEDIMENTARY-ROCKS ; PHOSPHORUS ; PRESERVATION ; ACCUMULATION ; STRATIGRAPHY ; ATLANTIC
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/325868
作者单位	[Mansour, Ahmed] Menia Univ, Fac Sci, Geol Dept, Al Minya 61519, Egypt; [Gentzis, Thomas; Carvajal-Ortiz, Humberto] Core Labs LP, Houston, TX USA; [Tahoun, Sameh S.] Cairo Univ, Fac Sci, Geol Dept, Giza, Egypt; [Wagreich, Michael] Univ Vienna, Fac Earth Sci Geog & Astron, Dept Geodynam & Sedimentol, Vienna, Austria
推荐引用方式 GB/T 7714	Mansour, Ahmed,Gentzis, Thomas,Carvajal-Ortiz, Humberto,et al. Geochemistry and palynology of the upper Albian at the Abu Gharadig Basin, southern Tethys: Constraints on the oceanic anoxic event 1d[J],2020,55(9):6338-6360.
APA	Mansour, Ahmed,Gentzis, Thomas,Carvajal-Ortiz, Humberto,Tahoun, Sameh S.,&Wagreich, Michael.(2020).Geochemistry and palynology of the upper Albian at the Abu Gharadig Basin, southern Tethys: Constraints on the oceanic anoxic event 1d.GEOLOGICAL JOURNAL,55(9),6338-6360.
MLA	Mansour, Ahmed,et al."Geochemistry and palynology of the upper Albian at the Abu Gharadig Basin, southern Tethys: Constraints on the oceanic anoxic event 1d".GEOLOGICAL JOURNAL 55.9(2020):6338-6360.