沉积学报2024，Vol.42Issue(3)：877-891,15.DOI:10.14027/j.issn.1000-0550.2023.074
塔里木盆地西北部震旦系—寒武系不整合面成因
Genesis of the Sinian-Cambrian Unconformity in the Northwestern Tarim Basin:Evidence from sedimentology
摘要
Abstract
[Objective]A Sinian-Cambrian parallel unconformity has been widely developed in the Aksu area of the northwestern Tarim Basin,and controversy remains over its formation mechanism.[Methods]Based on sedimentolog-ical research,the genesis of the above unconformity was studied through detailed field observation and microscopic identification,focusing on the sedimentary facies and karst phenomenon at the top of the Upper Sinian Qigebrak For-mation.[Results]The results show that platform margin and slope facies are developed at the top of the Qigebrak For-mation in the Aksu area.The platform margin includes grain beach and microbial reef,consisting of thick-to massive bedded dolo-oolite,medium-to thick-bedded intraclast dolopackstone and massive dolostromatolite reef.Lithofacies of the slope include:dolobreccia,turbidite,and thin-bedded dolowackestone.In the Late Sinian,the sedimentary water bodies in the eastern Aksu area were deeper,and the degree of karst development was significantly stronger than that in the western areas,which was dominated by horizontal phreatic zone vertically.In addition,in the Early Cambrian,the Yuertusi Formation maintained the same sedimentary trend as the top of the Qigebrak Formation,and both showed stratigraphic sequences of deepening water bodies from west to east.[Conclusions]This unconformity was formed by tilting movement induced by tectonic activity at the platform margin in the Late Sinian,which resulted in the uplift of the western Aksu area.In addition,this movement led to the atmospheric freshwater hydrological sys-tem flowing eastward,resulting in strong karstification in the eastern platform margin zone.This study could provide guidance for oil and gas explorations of the Sinian dolomite reservoirs in the region.关键词
震旦系—寒武系/奇格布拉克组/不整合面/成因机制/阿克苏地区Key words
Sinian-Cambrian/Qigebrak Formation/unconformity/genetic mechanism/Aksu area分类
天文与地球科学引用本文复制引用
唐攀,汪远征,李双建,杨钹,王雅萍,印森林,陈恭洋,陈代钊..塔里木盆地西北部震旦系—寒武系不整合面成因[J].沉积学报,2024,42(3):877-891,15.基金项目
国家自然科学基金项目(U19B6003) （U19B6003）
岩石圈演化国家重点实验室开放课题(SKL-K202103) （SKL-K202103）
北京市科技新星计划(Z2111000021211 36)[Foundation:National Natural Science Foundation of China,No.U19B6003 （Z2111000021211 36）
Open Fund Project of State Key Laboratory of Lithospheric Evolution,No.SKL-K202103 （）
Beijing Nova Program,No.Z211100002121136] （）
