四川盆地及邻区晚震旦世古地理与构造—沉积环境演化  

Palaeogeography and tectonic-depositional environment evolution of the Late Sinian in Sichuan Basin and adjacent areas

作　　者：李英强[1] 何登发[1] 文竹[1] 

机构地区：[1]中国地质大学(北京)能源学院

出　　处：《古地理学报》2013年第2期231-245,共15页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金重点项目(编号:40739906);国家科技重大专项(编号:2011ZX05008001)联合资助

摘　　要：利用最新的地震资料、探井资料及区域地质资料等,结合前人的研究成果,建立四川盆地及邻区晚震旦世区域地层格架,编制晚震旦世各沉积时期构造—沉积环境图,并探讨构造—沉积演化过程。研究认为,四川盆地及邻区晚震旦世构造—沉积环境展布受基底构造限制,并具一定继承性。晚震旦世开始大规模的碳酸盐岩台地沉积,整体来看自西向东海域环境由浅变深,由古陆过渡至碳酸盐岩台地、向东至台地边缘—斜坡沉积泥质岩,至深水盆地相沉积硅质岩,各相带总体呈南西—北东走向。上震旦统灯影组一段 ( 简称灯一段) 沉积时期—灯二段沉积中期为填平补齐沉积充填过程; 灯二段沉积时期末—灯三段沉积期在克拉通内拗陷盆地基础上初步形成了平缓的克拉通内部隆起; 灯四段沉积时期伴随着海平面的下降,碳酸盐岩台地边界整体向东迁移。灯二、灯四段沉积时期末受桐湾运动两期抬升的影响,川中部分地区形成岩溶不整合面,盆地西部灯三、灯四段遭受强烈剥蚀。灯影组是四川盆地及邻区重要的油气储集层。With the newly seismic data,drilling,regional geological data and the basis of previous studies,this paper establishes a district sequence stratigraphic framework of the Sichuan Basin and adjacent areas.The tectonic-depositional environment maps of the Late Sinian are compiled and the tectonic-depositional evolution history is studied.The tectonic-depositional environment is controlled by the structure of basement with inheritance.A large-scale carbonate platform deposition started at the Late Sinian.From west to east,the sea level changed from shallow to deep,with the sediments changing from mudstones of residual land, carbonate platform and platform margin-slope eastwards, to sedimentary siliceous rock of deep water basin.The strike of each facies belt is generally from southwest to northeast.During the depositional stage between the sedimentary periods of the Member 1 and the middle of Member 2 of Dengying Formation of Upper Sinian,this area was filled up by sediments.The flattened intracratonic uplift was forming on the intracrationic basin during the depositional periods between the end of Member 2 and the Member 3 of Dengying Formation.And during the Member 4 of Dengying Formation,the platform boundary moved eastward with the decline of the sea level.Affected by two periods of Tongwan tectonic movement,some areas of central basin formed palaeokarst unconformity during the depositional periods of the Members 2 and 4 of Dengying Formation,and the Members 3 and 4 of Dengying Formation suffered a strong denudation in the western basin.The Dengying Formation is an important oil reservoir in Sichuan Basin and adjacent areas.

关 键 词：古地理 构造—沉积环境 灯影组 晚震旦世 四川盆地 

分 类 号：P512[天文地球—地质学]