摘要
四川盆地震旦系灯影组微生物岩蕴含巨大资源潜力,从不同尺度描述微生物岩沉积结构有利于明确其分布规律。以露头、岩心和薄片资料为基础,多尺度刻画了微生物岩中观尺度、微观尺度和宏观尺度的结构特征。结果表明:灯影组大量发育微生物岩,根据中观结构特征可分为叠层石与凝块石两大类。此外,还发育内碎屑、核形石、鲕粒及似球粒等颗粒—泥晶白云岩。灯影组在台地上发育11种岩相,这些岩相构成3种岩相组合,分别对应潮间—潮上、浅潮下以及潟湖3种沉积环境。潮间—潮上环境常见窗格状与帐篷状暴露构造,并且发育多期叠置的微生物层宏观建造;浅潮下环境发育透镜状微生物丘建造,以及砂屑颗粒—泥粒碳酸盐岩;潟湖环境以中—厚层状泥晶白云岩为主,上部发育薄层的微生物岩沉积。由此建立四川盆地灯影组微生物岩沉积模式,可形成优质储层的微生物岩主要发育在潮间—潮上带下部和浅潮下带上部。
The Sinian Dengying Formation reveals a great resource potential in the central part of Sichuan Basin.Describing the microbialite depositional fabrics at multi-scale is beneficial for clarifying their distribution.Based on outcrop,core,and thin section data,this study characterizes the fabrics of microbialites at mesoscopic,microscopic,and macroscopic scales.Two types of microbialites,stromatolites and thrombolites,are identified in the Sinian Dengying Formation in Sichuan Basin.In addition,non-skeletal grains such as intraclasts,oncoids,ooids,and peloids have also been observed in the Dengying Formation.Based on these petrological characteristics,eleven lithofacies and three sedimentary cycles have been identified,which correspond to three depositional environments,including supratidalintertidal,shallow subtidal,and lagoon environments.In the supratidal-intertidal environment,the multi-stage microbial biostrome build-ups are observed with the frequently occurrence of the fenestral and teepee structures.The shallow subtidal environment exhibits lens-shaped microbial bioherm build-ups and grain-dominated intraclastic packstone/grainstone.The lagoon cycle is dominated by medium to thick-bedded dolo-mudstone in the lower part.A depositional model for the microbialite of Dengying Formation in Sichuan Basin is established,in which high-quality microbial reservoir are predominantly developed in the lower supratidal-intertidal environment and the upper shallow subtidal environment.
作者
徐哲航
李文正
乔占峰
陈政安
兰才俊
杨岱林
孙晓伟
朱心健
王永骁
蔡君
王泽宇
XU Zhehang;LI Wenzheng;QIAO Zhanfeng;CHEN Zheng'an;LAN Caijun;YANG Dailin;SUN Xiaowei;ZHU Xinjian;WANG Yongxiao;CAI Jun;WANG Zeyu(PetroChina Hangzhou Research Institute of Geology;State Energy Key Laboratory of Oil and Gas in Carbonate Strata;Key Laboratory of Carbonate Reservoir,CNPC;Petrochina Research Institute of Petroleum Exploration&Development;Research Institute of Exploration and Devetopment,PetroChina Southwest Oil&Gas Field Company)
出处
《海相油气地质》
北大核心
2025年第2期133-146,共14页
Marine Origin Petroleum Geology
基金
中国石油天然气集团有限公司基础性前瞻性重大科技专项“叠合盆地中下组合油气成藏与保持机制研究”(编号:2023ZZ02)资助。
关键词
微生物岩
沉积结构
岩相组合
沉积模式
灯影组
四川盆地
microbialite
sedimentary structure
lithofacies association
depositional model
Dengying Formation
Sichuan Basin
