塔里木盆地北部下寒武统肖尔布拉克组海进-海退转换背景下的微生物礁滩发育模式  

Development Model of Microbial Reef-shoal in the Lower Cambrian Xiaoerbulak Formation Under Transgression-Regression Transition in the Northern Tarim Basin

作　　者：陈格格 高志前[1] 焦存礼[2] 胡宗全[2] 袁钰轩 卫端 翟昕箐 畅哲 CHEN Gege;GAO Zhiqian;JIAO Cunli;HU Zongquan;YUAN Yuxuan;WEI Duan;ZHAI Xinqing;CHANG Zhe(School of Energy,China University of Geosciences(Beijing),Beijing 100083,China;Petroleum Exploration and Development Research Institute,SINOPEC,Beijing 100089,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中国石油化工股份有限公司石油勘探开发研究院,北京100089

出　　处：《现代地质》2023年第5期1169-1181,共13页Geoscience

基　　金：中国石油化工股份有限公司科技部项目(P22122);中石化西北勘探开发研究院项目(33550000-22-ZC0611-0007);国家自然科学基金项目(41972130)。

摘　　要：基于塔里木盆地西北缘阿克苏地区的野外露头观察和北部地区重点探井的测井资料分析和薄片鉴定工作,建立塔里木盆地塔北地区的高精度层序地层格架,分析肖尔布拉克组碳酸盐岩台地的演化过程及微生物礁滩发育模式。研究认为肖尔布拉克组可分为2个三级层序(SQ1和SQ2)和5个四级层序(sq1、sq2、sq3、sq4和sq5),其中sq1和sq2发育层状微生物席,为中-内缓坡沉积,对应缓坡型台地;sq3时期相对海平面先上升后下降,缓坡型台地转变为弱镶边台地,在古地貌高地微生物开始建礁,古地貌较低的斜坡区微生物岩基本不发育;sq4和sq5时期海平面持续下降,弱镶边台地发育,sq4发育藻粒滩和微生物礁沉积,sq5发育砂屑滩、砾屑滩和微生物礁沉积。高精度层序地层对比结果显示海平面的变化在垂向上控制着微生物礁滩的演化特征,古地貌在平面上控制着微生物礁滩的分布。Based on the outcrop observation in Aksu area in the northwestern Tarim Basin,and the analysis of logging data and thin section identification of key exploration wells there,the high-precision sequence stratigraphic framework at north Tarim Basin is established.We analyzed the development model of microbial reefshoal and carbonate platform evolution in the Xiaoerbulak period,and suggested that the Xiaoerbulak Formation can be subdivided into two third-order sequences(SQ1 and SQ2)and five fourth-order sequences(sq1,sq2,sq3,sq4 and sq5):sq1 and sq2 developed layered microbial mats,which were middle-inner ramp deposition,corresponding to the ramp carbonate platform stage;sq3 is a transition period from ramp carbonate platform to slightly rimmed shelf carbonate platform,and the relative sea-level likely rose first and then fell,and microorganisms began to build reefs in the paleo-geomorphic highlands,and the microbiolites were basically undeveloped in the slope area of low paleo-geomorphic terrain;sq4 and sq5 represent the stage of slightly rimmed shelf carbonate platform with continuous sea-level decline;sq4 developed algal grain shoal and microbial reef deposits,whilst sq5 developed sand shoal,gravel shoal and microbial reef deposits.The high-precision sequence stratigraphic correlation shows that the sea-level change controlled the vertical development of microbial reef shoal,and the paleo-geomorphology controlled the planar microbial reef shoal distribution.

关 键 词：高精度层序划分 层序地层格架 微生物礁滩 沉积相 发育模式 

分 类 号：P618.13[天文地球—矿床学]