气候变化领域集成服务门户(CCPortal): Tectonic control of Guadalupian-Lopingian cherts in northwestern Sichuan Basin; South China

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DOI	10.1016/j.palaeo.2020.109915
	Tectonic control of Guadalupian-Lopingian cherts in northwestern Sichuan Basin; South China
	Dong Y.; Xu S.; Wen L.; Chen H.; Fu S.; Zhong Y.; Wang J.; Zhu P.; Cui Y.
发表日期	2020
ISSN	0031-0182
卷号	557
英文摘要	Cherts have been considered to be formed mainly through processes involving biosilicification, riverine inputs and hydrothermal activities. In the Permian, massive cherts are widely distributed in South China, bearing significant implications for the reconstruction of paleogeography and paleoceanography of the eastern Paleo-Tethys Ocean. The origin of the Permian cherts in South China, however, remains inconclusive due to a lack of systematic petrographic and geochemical study. In this article, we analyze the petrologic and geochemical characteristics of the cherts collected from five outcrops in the northwestern Sichuan Basin, South China. These cherts are found from the Upper Guadalupian Maokou Formation (ca. 268–259 Ma) and Upper Lopingian Dalong Formation (ca. 254–252 Ma). Field and microscopic observations suggest that cherts from the Maokou Formation occur mainly in nodular forms, and consist of microcrystalline quartz, silicified bioclasts and siliceous fossil debris. Both petrographic observation and geochemical analysis suggest that the Maokou cherts are mainly of hydrothermal origin near deep faults in the southwest and of biogenetic origin with less hydrothermal influence in the northeast of the studied area. The Dalong cherts occur in both nodular and bedded forms, with more abundant siliceous fossil debris than the Maokou cherts. Major, trace and rare earth element data support that the Dalong cherts are influenced by both biosilicification and hydrothermal activities. The spatial heterogeneity of the cherts origin in South China is largely controlled by tectonic activities associated with the Emeishan large igneous province (ELIP) event and the closure of the Paleo-Tethys Ocean. The troughs formed by the extensional tectonic activity linked to the ELIP could provide accommodation space and activate deep faults allowing the rise of silicon-rich hydrothermal fluids from the deep and nutrient-rich water from volcanogenic upwellings. Subsequent cooling may have facilitated the precipitation of large amounts of silica and the formation of cherts in the study region. This work demonstrates that the origin of the Guadalupian-Lopingian cherts in South China is predominantly controlled by tectonic and biological activities, which sheds light on the global “Permian Chert Event”. © 2020 Elsevier B.V.
英文关键词	Cherts; ELIP; Geochemical analysis; Hydrothermal activity; Permian; Troughs
语种	英语
scopus关键词	Guadalupian; heterogeneity; large igneous province; paleoceanography; paleogeography; rare earth element; silica; tectonic evolution; upwelling; China; Sichuan Basin
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150361
作者单位	Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, 610059, China; Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ 07403, United States; State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, 610059, China; Natural History Museum, University of Oslo, Pb.1172 Blinder, Oslo, 0318, Norway; Exploration and Development Research Institute, PetroChina Southwest Oil & Gas Field CompanySichuan Chengdu 610041, China; Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL 60208, United States; College of energy, Chengdu University of Technology, Chengdu, 610059, China
推荐引用方式 GB/T 7714	Dong Y.,Xu S.,Wen L.,et al. Tectonic control of Guadalupian-Lopingian cherts in northwestern Sichuan Basin; South China[J],2020,557.
APA	Dong Y..,Xu S..,Wen L..,Chen H..,Fu S..,...&Cui Y..(2020).Tectonic control of Guadalupian-Lopingian cherts in northwestern Sichuan Basin; South China.Palaeogeography, Palaeoclimatology, Palaeoecology,557.
MLA	Dong Y.,et al."Tectonic control of Guadalupian-Lopingian cherts in northwestern Sichuan Basin; South China".Palaeogeography, Palaeoclimatology, Palaeoecology 557(2020).