泛扬子克拉通西部地区灯影期构造—沉积格局  

Tectono-sedimentary response in the western Pan-Yangtze Craton during Dengying period

作　　者：李楠 李国辉 苑保国 王文之 钱红杉 黄茂轩 陈曦 李成龙 LI Nan;LI Guohui;YUAN Baoguo;WANG Wenzhi;QIAN Hongshan;HUANG Maoxuan;CHEN Xi;LI Chengong(Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sich-uan 610041,China)

机构地区：[1]中国石油西南油气田公司勘探开发研究院,四川成都610041

出　　处：《天然气勘探与开发》2024年第4期1-14,共14页Natural Gas Exploration and Development

基　　金：中国石油集团公司攻关性应用性科技专项(编号:2023ZZ16)。

摘　　要：勘探实践表明,四川盆地新元古界上震旦统灯影组具有丰富的油气资源,为了科学认识古构造对沉积、储层及油气成藏的控制作用,进一步夯实灯影组下一步勘探理论依据,需要针对灯影期构造—沉积格局进行研究。基于重磁、构造、沉积等资料分析,开展克拉通西部边界的探讨,研究古裂陷的分布与成因;基于构造控制沉积建造的思路,探究晚震旦世灯影期上扬子克拉通沉积格局。研究结果表明:(1)扬子克拉通西界由龙门山—安宁河断裂带向西推延至金沙江—红河断裂带,称为泛扬子克拉通;(2)泛扬子克拉通内发育3支克拉通内裂陷,将泛扬子克拉通西部地区分割成东部和西部两个次级克拉通盆地;(3)东部次级克拉通盆地以白云岩类为主,沉积环境相对局限,西部次级克拉通盆地石灰岩类厚度较大,沉积环境相对开放;(4)克拉通内裂陷及其两侧台缘带的沉积建造构建了优越的侧向对接源—储成藏组合,是目前灯影组重点勘探对象,万源—达州裂陷带是值得关注的勘探区。Exploration practices have revealed abundant oil and gas resources in the Neoproterozoic Upper Sinian Dengying Forma-tion,Sichuan Basin.To ascertain paleostructure controls on reservoir and its forming together with sedimentation,and to theoretically support the subsequent exploration in this formation,it is essential to study the tectono-sedimentary response during Dengying period.Thus,the western boundary of craton was discussed according to gravity and magnetic,tectonic and sedimentary data to make clear both distribution and genesis of paleo-rift.Moreover,sedimentary patterns were explored for the Upper Yangtze Craton during the Late Sinian Dengying period in line with the train of thought on structure-controlled depositional architecture.Results show that(i)for the Yangtze Craton,its west side extends westward to Jinshajiang-Honghe fault zone from Longmenshan-Anninghe fault zone,creating the so-called Pan-Yangtze Craton where is developed with three intra-cratonic rifts;(ii)the western Pan-Yangtze Craton is divided into two sub-cratonic basins of the east and the west through these rifts;(iii)the east sub-cratonic basin is dominated by dolomite in rela-tively restricted depositional setting,while the west of thicker limestone in relatively open setting;and(iv)with lateral connection,a superior source-reservoir assemblage which serves as the key exploration target in the Dengying Formation is built due to sedimentary buildup in the rifts or platform marginal zones on both sides of the craton.It is worth to note Wanyuan-Dazhou rift as an exploration prospect.

关 键 词：构造—沉积格局 克拉通内裂陷 晚震旦世灯影期 泛扬子克拉通西部 

分 类 号：P618.13[天文地球—矿床学]