Hafnium isotope evidence for enhanced weatherability at high southern latitudes during Oceanic Anoxic Event 2

doi:10.1016/j.epsl.2022.117910

IOCAS-IR > 海洋地质与环境重点实验室

	Hafnium isotope evidence for enhanced weatherability at high southern latitudes during Oceanic Anoxic Event 2
	Chen, Hongjin 1,2,6; Bayon, Germain 2; Xu, Zhaokai 1,3,4,5; Li, Tiegang7
	2023
发表期刊	EARTH AND PLANETARY SCIENCE LETTERS
ISSN	0012-821X
卷号	601 页码:10
通讯作者	Bayon, Germain([email protected]) ; Xu, Zhaokai([email protected])
摘要	The Oceanic Anoxic Event 2 (OAE 2; ca. -94 Ma) represents one of the most extreme carbon cycle perturbations of the Phanerozoic, which coincided with major environmental and climate reorganization in both terrestrial and marine realms. Chemical weathering of continental silicate rocks is thought to have played a crucial role during OAE 2, through enhanced release of bio-essential nutrients to the ocean, promoting high rates of marine primary production and organic carbon burial, but also due to its effect on atmospheric CO2 drawdown, which altogether possibly drove the OAE 2 termination. Yet, the evolution of continental chemical weathering during OAE 2 remains poorly defined, especially in high-latitude regions. In this study, we present a combined hafnium-neodymium isotope investigation of the clay-size detrital fraction (A epsilon Hfclay) of late Cenomanian to early Turonian sediments from the southwest Australian margin, at a site (International Ocean Discovery Program U1516) located in the southern high latitudes (-62 degrees S) during the late Cretaceous. The reliability of A epsilon Hfclay as a proxy for continental chemical weathering in ancient anoxic marine sediments was assessed by analyzing a suite of samples retrieved from methanogenic sediments experiencing marine silicate weathering at ocean margins, suggesting negligible effect of reverse weathering on hafnium-neodymium isotope compositions. At Site U1516, the early stage of OAE 2 was characterized by relatively low A epsilon Hfclay values (-5.9 +/- 2), typical of reduced chemical weathering in nearby continental regions. At the onset of the most prominent carbon isotope excursion, an abrupt decrease in A epsilon Hfclay points towards accelerated export of poorly weathered sediments resulting from the abrupt reactivation of river systems in southwest Australia. This period was followed by a pronounced A epsilon Hfclay shift towards positive values, indicative of intensifying chemical weathering conditions during the OAE 2 interval showing the highest delta 13C anomaly. Based on these results, we posit that enhanced hydrological cycle, most likely caused by a southward shift of the westerlies, led to a large increase in weatherability at southern high latitudes during peak OAE 2 warmth. This finding provides empirical support for the potential role played by high-latitude weathering systems in driving the termination of OAE 2, via weathering-driven consumption of atmospheric CO2 and accelerated riverine fluxes of nutrients leading to enhanced organic carbon burial in marine sediments.(c) 2022 Elsevier B.V. All rights reserved.
关键词	OAE 2 IODP expedition 369 Mentelle Basin hafnium-neodymium isotopes silicate weathering reverse weathering
DOI	10.1016/j.epsl.2022.117910
收录类别	SCI
语种	英语
资助项目	National Key Research and Development Program of China[2022YFF0800503]; National Natural Science Foundation of China[41876034]; National Natural Science Foundation of China[41676038]; National Natural Science Foundation of China[41830539]; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB42000000]; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB40010100]; Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology (Qingdao)[2022QNLM050203]; Taishan Scholars Project; French National Research Agency[ANR-20-CE01-0003]; China Scholarship Council
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000895742800001
出版者	ELSEVIER
引用统计	被引频次：9[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/181044
专题	海洋地质与环境重点实验室
通讯作者	Bayon, Germain; Xu, Zhaokai
作者单位	1.Chinese Acad Sci, Inst Oceanol, CAS Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 2.Univ Brest, CNRS, Ifremer, Geoocean, F-29280 Plouzane, France 3.Pilot Natl Lab Marine Sci & Technol Qingdao, Lab Marine Geol, Qingdao 266061, Peoples R China 4.CAS Ctr Excellence Quaternary Sci & Global Change, Pilot Natl Lab Marine Sci & Technol Qingdao, Xian 710061, Peoples R China 5.Chinese Acad Sci, Ctr Ocean Mega Sci, Qingdao 266071, Peoples R China 6.China Geol Survey, Minist Nat Resources, Key Lab Marine Mineral Resources, Guangzhou Marine Geol Survey, Guangzhou 510075, Peoples R China 7.Minist Nat Resources, Inst Oceanog 1, Key Lab Marine Sedimentol & Metallogeny, Qingdao 266061, Peoples R China
第一作者单位	中国科学院海洋研究所
通讯作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	Chen, Hongjin,Bayon, Germain,Xu, Zhaokai,et al. Hafnium isotope evidence for enhanced weatherability at high southern latitudes during Oceanic Anoxic Event 2[J]. EARTH AND PLANETARY SCIENCE LETTERS,2023,601:10.
APA	Chen, Hongjin,Bayon, Germain,Xu, Zhaokai,&Li, Tiegang.(2023).Hafnium isotope evidence for enhanced weatherability at high southern latitudes during Oceanic Anoxic Event 2.EARTH AND PLANETARY SCIENCE LETTERS,601,10.
MLA	Chen, Hongjin,et al."Hafnium isotope evidence for enhanced weatherability at high southern latitudes during Oceanic Anoxic Event 2".EARTH AND PLANETARY SCIENCE LETTERS 601(2023):10.

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