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Element Geochemical Characteristics and Geological Significance of Mudstones from the Middle Jurassic Shaximiao Formation in Sichuan Basin, Southwest China

[Image: see text] Thick sequences of terrestrial multicolored mudstones of the Middle Jurassic Shaximiao Formation in the Sichuan Basin, Southwest China, effectively recorded paleoclimate and paleoenvironment changes. The paleoenvironment of the Shaximiao Formation is reconstructed by using detailed...

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Autores principales: Ma, Di, Zhang, Zhijie, Zhou, Chuanmin, Cheng, Dawei, Hong, Haitao, Meng, Hao, Yu, Xinghe, Peng, Zixiao
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2023
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10448696/
https://www.ncbi.nlm.nih.gov/pubmed/37636928
http://dx.doi.org/10.1021/acsomega.3c01496
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author Ma, Di
Zhang, Zhijie
Zhou, Chuanmin
Cheng, Dawei
Hong, Haitao
Meng, Hao
Yu, Xinghe
Peng, Zixiao
author_facet Ma, Di
Zhang, Zhijie
Zhou, Chuanmin
Cheng, Dawei
Hong, Haitao
Meng, Hao
Yu, Xinghe
Peng, Zixiao
author_sort Ma, Di
collection PubMed
description [Image: see text] Thick sequences of terrestrial multicolored mudstones of the Middle Jurassic Shaximiao Formation in the Sichuan Basin, Southwest China, effectively recorded paleoclimate and paleoenvironment changes. The paleoenvironment of the Shaximiao Formation is reconstructed by using detailed sedimentological and elemental geochemical analysis of the multicolored mudstones. The provenance, paleoclimate, paleosalinity, and paleoredox conditions are distinguished by using the discriminant indicators of CIA, C-value, Sr/Cu, Rb/Sr, Th/U, V/Cr, and V/(V + Ni). The results show that all samples derive primarily from felsic igneous rocks and intermediate rocks rather than recycled sediments. The mudstone sequences were deposited under semiarid and semihumid regions with paleoclimate evolved to drier and cooler conditions from lower to upper Shaximiao Formation. Such a paleoclimate coincided with the records of several basins in the lower paleolatitudes of the Northern Hemisphere and were possibly affected by the Middle Jurassic global geological events such as wildfire, paleogeographic reorganizations, and seaway dynamics change. The paleowater body belongs to a typical terrestrial freshwater environment, although the paleosalinity increased significantly during arid periods. The multicolored mudstones were deposited in oxidation and weak-oxidation to weak-anoxic conditions. We also propose a detailed conceptual paleoenvironment model for Shaximiao Formation, with a large perennial lake surrounded by limited alluvial plain during a period of high lake level and small ephemeral lakes scattering extensive alluvial plain during a phase of low lake level.
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spelling pubmed-104486962023-08-25 Element Geochemical Characteristics and Geological Significance of Mudstones from the Middle Jurassic Shaximiao Formation in Sichuan Basin, Southwest China Ma, Di Zhang, Zhijie Zhou, Chuanmin Cheng, Dawei Hong, Haitao Meng, Hao Yu, Xinghe Peng, Zixiao ACS Omega [Image: see text] Thick sequences of terrestrial multicolored mudstones of the Middle Jurassic Shaximiao Formation in the Sichuan Basin, Southwest China, effectively recorded paleoclimate and paleoenvironment changes. The paleoenvironment of the Shaximiao Formation is reconstructed by using detailed sedimentological and elemental geochemical analysis of the multicolored mudstones. The provenance, paleoclimate, paleosalinity, and paleoredox conditions are distinguished by using the discriminant indicators of CIA, C-value, Sr/Cu, Rb/Sr, Th/U, V/Cr, and V/(V + Ni). The results show that all samples derive primarily from felsic igneous rocks and intermediate rocks rather than recycled sediments. The mudstone sequences were deposited under semiarid and semihumid regions with paleoclimate evolved to drier and cooler conditions from lower to upper Shaximiao Formation. Such a paleoclimate coincided with the records of several basins in the lower paleolatitudes of the Northern Hemisphere and were possibly affected by the Middle Jurassic global geological events such as wildfire, paleogeographic reorganizations, and seaway dynamics change. The paleowater body belongs to a typical terrestrial freshwater environment, although the paleosalinity increased significantly during arid periods. The multicolored mudstones were deposited in oxidation and weak-oxidation to weak-anoxic conditions. We also propose a detailed conceptual paleoenvironment model for Shaximiao Formation, with a large perennial lake surrounded by limited alluvial plain during a period of high lake level and small ephemeral lakes scattering extensive alluvial plain during a phase of low lake level. American Chemical Society 2023-08-10 /pmc/articles/PMC10448696/ /pubmed/37636928 http://dx.doi.org/10.1021/acsomega.3c01496 Text en © 2023 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Ma, Di
Zhang, Zhijie
Zhou, Chuanmin
Cheng, Dawei
Hong, Haitao
Meng, Hao
Yu, Xinghe
Peng, Zixiao
Element Geochemical Characteristics and Geological Significance of Mudstones from the Middle Jurassic Shaximiao Formation in Sichuan Basin, Southwest China
title Element Geochemical Characteristics and Geological Significance of Mudstones from the Middle Jurassic Shaximiao Formation in Sichuan Basin, Southwest China
title_full Element Geochemical Characteristics and Geological Significance of Mudstones from the Middle Jurassic Shaximiao Formation in Sichuan Basin, Southwest China
title_fullStr Element Geochemical Characteristics and Geological Significance of Mudstones from the Middle Jurassic Shaximiao Formation in Sichuan Basin, Southwest China
title_full_unstemmed Element Geochemical Characteristics and Geological Significance of Mudstones from the Middle Jurassic Shaximiao Formation in Sichuan Basin, Southwest China
title_short Element Geochemical Characteristics and Geological Significance of Mudstones from the Middle Jurassic Shaximiao Formation in Sichuan Basin, Southwest China
title_sort element geochemical characteristics and geological significance of mudstones from the middle jurassic shaximiao formation in sichuan basin, southwest china
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10448696/
https://www.ncbi.nlm.nih.gov/pubmed/37636928
http://dx.doi.org/10.1021/acsomega.3c01496
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