成都理工大学学报（自然科学版）2025，Vol.52Issue(3)：502-522,21.DOI:10.12474/cdlgzrkx.2025021301
峡东地区陡山沱组三段硅质条带中的微体化石分布特征及其控制因素
The distribution of microfossils in the banded cherts of the Doushantuo Formation,Member Ⅲ,in the eastern Three Gorges area and their controlling factors
摘要
Abstract
In this study,we perform paleontological and sedimentary research of three sections,Tianjiayuanzi,Jiulongwan,and Qinglinkou,located within the carbonate platform of the Huangling Anticline in the eastern Three Gorges area,Yichang City,Hubei Province.The aim is to investigate the spatial distribution patterns of microfossils in silicified bands from the lower Member Ⅲ of the Doushantuo Formation and their potential controlling factors.The results show that silicified bands and nodules in the Tianjiayuanzi section contain abundant acritarch fossils,tubular fossils,and cyanobacteria,along with oolitic grains and intraclasts.The Jiulongwan section contains sparse acritarch fossils and fragmented tubular fossils,with localized accumulations of oolitic sandy clasts,occasional gravel clasts,and minor thrombolites.The Qinglinkou section is dominated by lithified microbial mats and fine sandy grains,with rare thrombolites observed.Based on these findings,it is inferred that during the deposition of the lower Member Ⅲ of the Doushantuo Formation(1)the Tianjiayuanzi section had an intertidal flat environment,(2)the Jiulongwan section occupied an upper subtidal zone,and(3)the Qinglinkou section was situated between a lower subtidal zone and normal wave base.The variations in microfossil assemblage diversity and abundance among these study sections may reflect taphonomic influence;that is,fossils in shallow-water sections are preserved due to the rapid formation of siliceous nodules during early burial.Lower biodiversity in deeper water environments could be attributed to rapid microbial decomposition of planktonic acritarchs in the water column or during early burial in sediments,which is an important source of marine dissolved organic carbon.关键词
埃迪卡拉纪/陡山沱组/沉积环境/化石分布差异Key words
Ediacaran period/Doushantuo Formation/sedimentary environment/fossil distribution difference分类
天文与地球科学引用本文复制引用
吴盈,罗翠,张磊,王夏,张敬轩,段宸章,李飞,常珊,叶炎,刘佳荣..峡东地区陡山沱组三段硅质条带中的微体化石分布特征及其控制因素[J].成都理工大学学报（自然科学版）,2025,52(3):502-522,21.基金项目
四川省自然科学基金项目(2024NSFTD0004). （2024NSFTD0004）
