Temporal Variation in the Chemical Index of Alteration in Early Cretaceous Black Shale as a Proxy for Paleoclimate

doi:10.1086/722337

	Temporal Variation in the Chemical Index of Alteration in Early Cretaceous Black Shale as a Proxy for Paleoclimate
	Wang, Wenxia 5; Gan, Zuobin 5; Zhang, Xiangyu 3,4,5; Li, Shoujun 2,4; Xu, Yanming 1
刊名	JOURNAL OF GEOLOGY
	2022-09-01
页码	19
ISSN号	0022-1376
DOI	10.1086/722337
通讯作者	Zhang, Xiangyu(xiangyu_159@126.com)
英文摘要	To better understand Early Cretaceous climate variation in inland East Asia, the temporal variation in the chemical index of alteration (CIA) was reconstructed in black shale from an outcrop of the Fajiaying Formation in the Lower Cretaceous Laiyang Group at Lingshan Island, East China. As the formation height increased, the corresponding CIA increased. The obtained index of compositional variability values and an (Al2O3)-(CaO* + Na2O)-K2O ternary diagram demonstrate that the gathered samples had not evolved into K-metasomatism during diagenesis. Moreover, low Zr concentrations parallel to the magmatic trend in the Th/Sc-versus-Zr/Sc diagram reveal that the sediment sorting and recycling did not affect the paleoweathering proxies. The lack of correlation between the CIA and Al/Si or K/Si further suggests that the paleoweathering proxies were not affected by the sediment sorting. Accordingly, as the CIA and the chemical index of weathering increased, the corresponding chemical weathering increased slightly. This is consistent with the transition from a dry-hot climate to a warm-humid one proposed by paleoclimatic proxies such as Rb/Sr, Sr/Cu, Al2O3/MgO, and clay minerals. In this study, a near-ubiquitous correlation is proposed between the variations of paleoclimate and the CIA of shale, in which a rise in humidity significantly increased the chemical weathering. Meanwhile, it was found that under the dry-hot conditions of the Early Cretaceous, chemical weathering in inland areas far from the ocean was relatively weak and dependent on atmospheric humidity. This analysis validates the CIA, as part of the stratigraphic record, to be a robust proxy for terrestrial paleoclimatic variation during the Early Cretaceous.
资助项目	Key Laboratory of Stratigraphy and Palaeontology, Ministry of Natural Resources[KLSP1904] ; Shandong University of Science and Technology[SDKDYC190104] ; State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences)[123104]
WOS关键词	OCEANIC ANOXIC EVENT ; SEA-SURFACE TEMPERATURES ; LINGSHAN ISLAND ; SEDIMENTARY-ROCKS ; WEATHERING TRENDS ; CARBON-ISOTOPE ; VOLCANIC-ROCKS ; EVOLUTION ; STRATIGRAPHY ; PROVENANCE
WOS研究方向	Geology
语种	英语
出版者	UNIV CHICAGO PRESS
WOS记录号	WOS:000899603900001
资助机构	Key Laboratory of Stratigraphy and Palaeontology, Ministry of Natural Resources ; Shandong University of Science and Technology ; State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences)
内容类型	期刊论文
源URL	[http://ir.nigpas.ac.cn/handle/332004/41585]
专题	中国科学院南京地质古生物研究所
通讯作者	Zhang, Xiangyu
作者单位	1.7 Explorat Inst Geol & Mineral Resources, Linyi 276006, Shandong, Peoples R China 2.Chinese Acad Sci, Nanjing Inst Geol & Palaeontol, State Key Lab Palaeobiol & Stratig, Nanjing 210008, Jiangsu, Peoples R China 3.Minist Nat Resources, Key Lab Stratig & Palaeontol, Beijing 100037, Peoples R China 4.Shandong Univ Sci & Technol, Coll Earth Sci & Engn, Qingdao 266590, Shandong, Peoples R China 5.Linyi Univ, Coll Life Sci, Linyi 276000, Shandong, Peoples R China
推荐引用方式 GB/T 7714	Wang, Wenxia,Gan, Zuobin,Zhang, Xiangyu,et al. Temporal Variation in the Chemical Index of Alteration in Early Cretaceous Black Shale as a Proxy for Paleoclimate[J]. JOURNAL OF GEOLOGY,2022:19.
APA	Wang, Wenxia,Gan, Zuobin,Zhang, Xiangyu,Li, Shoujun,&Xu, Yanming.(2022).Temporal Variation in the Chemical Index of Alteration in Early Cretaceous Black Shale as a Proxy for Paleoclimate.JOURNAL OF GEOLOGY,19.
MLA	Wang, Wenxia,et al."Temporal Variation in the Chemical Index of Alteration in Early Cretaceous Black Shale as a Proxy for Paleoclimate".JOURNAL OF GEOLOGY (2022):19.