地质学报2024，Vol.98Issue(2)：511-529,19.DOI:10.19762/j.cnki.dizhixuebao.2023282
塔里木盆地西北缘埃迪卡拉纪—寒武纪转折期黑色岩系中硅质岩成因及其环境指示意义
Genesis of siliceous rock in the black rock series of Ediacaran-Cambrian transition and its environmental significance in northwestern Tarim basin
摘要
Abstract
The Ediacaran-Cambrian transition is a crucial interval in the geological timeline,marked by the widespread occurrence of various black rock series worldwide,such as siliceous rock,mudstone,and dolomite.In the northwest region of the Tarim basin,specifically within the middle and lower sections of the black series,there is a notable presence of siliceous rocks.These rocks exhibit alternating black and white chert bands,displaying diverse distribution patterns.Determining the origin of these siliceous rocks is essential for understanding the environment conducive to high-quality source rocks within the Yuertusi Formation.In this study,we focus on investigating the siliceous rock within the black rock series of well Xinkedi 1.By employing field observations,petrological analysis,and geochemical techniques,we aim to unravel the origin of these siliceous rocks and their relationship with the organic matter present within the sequence.Additionally,we systematically examine the processes responsible for the formation of the black and white chert bands.The white layers are predominantly composed of pure microquartz,while the black layers contain a mixture of detrital carbonaceous matter,quartz grains,and carbonaceous microlaminae,which are interpreted as remnants of microbial mats.These variations in coloration are believed to be influenced by glacial and interglacial periods.We also establish that the occurrence of organic matter is conducive to the formation of silica.The higher Al2O3/(A12O3+Fe2O3)ratio and lower Lan/Cen valuesuggest a deposition environment dominantly influenced by terrigenous sources in a continental margin.Furthermore,considering paleoclimate and sea level fluctuations,it can be inferred that the deposition of siliceous rock and siliceous shale primarily took place in confined bay or lagoon environments.This study provides valuable insights into understanding the formation environment of siliceous shale and contributes to the evaluation and prediction of source rocks,offering practical implications for resource exploration and development.关键词
新柯地1井/黑白燧石条带/硅质与有机质共生机理/埃迪卡拉纪—寒武纪转折期/沉积环境Key words
well Xinkedi 1/black and white chert bands/siliceous rock and organic matter genetic coupling mechanism/Ediacaran-Cambrian transition/sedimentary environment引用本文复制引用
刘丽红,高永进,朱光有,杨有星,尹成明,孙相灿,李清瑶..塔里木盆地西北缘埃迪卡拉纪—寒武纪转折期黑色岩系中硅质岩成因及其环境指示意义[J].地质学报,2024,98(2):511-529,19.基金项目
本文为国家自然科学基金项目(编号 41802173)和中国地质调查项目(编号 DD20221674,DD20230042,DD20230311)联合资助的成果. （编号 41802173）
