Authigenic Clay Minerals from North China Reveal Spatiotemporal Variations in Shallow Seawater Redox Conditions during the Terminal Mesoproterozoic
Xie Baozeng
Tang Dongjie
Liu Yajie
Yang Xinnan
Ke Zhutong
Sun Longfei
Li Chao
Wang Xinqiang
Shi Xiaoying
Abstract：This study investigates the environmental context for the rapid evolution of crown-group eukaryotes during the Late Mesoproterozoic,focusing on sedimentological and mineralogical analyses of clastic rocks from the Changlongshan Formation across four sections of the North China Craton.In the Huailai section,fine-to-coarse sandstones from the deep-to-shallow subtidal zones are dominated by chamosite,indicating an anoxic,ferruginous marine environment.Conversely,glauconite dominates silty mudstone and muddy siltstone in the deep subtidal zone,reflecting suboxic conditions.In the Mentougou section,medium-to-coarse sandstones from the shallow subtidal zone are rich in chamosite,suggesting persistent anoxic,ferruginous conditions.In the Jixian and Lulong sections,deep subtidal zone sandstones are dominated by glauconite,indicative of suboxic environments.These results reveal pronounced spatiotemporal variations in redox conditions across the shallow seas of North China during the deposition of the Changlongshan Formation.While oxygenation facilitated the emergence of Longfengshania algae,the spatiotemporal discontinuity in the distribution of oxic water bodies may have limited the sustained evolution and widespread distribution of eukaryotes.
Keywords：Changlongshan Formationglauconitechamositeredox conditionspatial heterogeneitycrown-group eukaryotesedimentologymineralogy
Publication Date：2025-03-14
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：16( 1066-1081 )