东海陆架盆地西湖凹陷新生代断—拗转换面的厘定  

Delimitation of Cenozoic Rift-Depression Transitional Unconformity in Xihu Depression, East China Sea Shelf Basin

作　　者：杨彩虹[1] 王英民[2] 曾广东[1] 张兰[2] 万丽芬[1] 李昆[2] 周兴海[1] 郭颖[2] 吴嘉鹏[2] 

机构地区：[1]中国石化上海海洋油气分公司研究院 [2]中国石油大学(北京)地球科学学院

出　　处：《海相油气地质》2014年第3期18-26,共9页Marine Origin Petroleum Geology

基　　金：中国石化2012年重大勘探先导项目"东海盆地西湖凹陷深层勘探潜力与区带评价"资助

摘　　要：以近年来东海盆地西湖凹陷新增加的钻井资料和区域连片三维地震资料为基础,通过对区域二维地震大剖面进行重新解释,对主要控凹的同沉积断裂活动史进行了定量分析,并对T30(平湖组顶界面)、T34(宝石组顶界面)和T24(花港组顶界面)三个地震不整合面的规模、不整合面上下断层发育程度和地层厚度横向的变化、以及不整合面上下沉积旋回和沉积相转换的强度进行了比较。指出只有T30界面才是西湖凹陷从伸展断陷盆地转换为拗陷盆地的转换面,此不整合面的规模最大,界面上下的构造样式、沉积相和断层活动指数的转变强度最大;而T34界面仅为两个断陷幕之间的次级不整合面,T24界面仅为两个拗陷幕之间的次级不整合面。On the basis of the recently available drilling data and 3D seismic data from Xihu Depression and the reinterpretation results of 2D regional seismic profiles, the activity history of the major boundary-faults are quantitatively analyzed. In vertical, there are three major seismic unconformities including T30 （ the top of Pinghu Fm.）, T34 （ the top of Baoshi Fm.） and T24 （ the top of Huagang Fm.） . The scale, the fault development density, and the lateral strata thickness variation of the three unconformities are carefully investigated. The faulting activities and lateral change of strata thickness below and above the three unconformities, the depositional cycles and the intensity of sedimentary facies transition are compared. It is concluded that only the unconformity T30 can serve as the transitional unconformity between the syn-rift and the post-rift depressions. This unconformity T30 is the largest in scale, and demonstrates the largest transitional intensity in structural style, sedimentary facies and fault growth indices below and above the unconformity. By contrast, it is considered that the interface T34 is only a second-order unconformity between two rifting episodes and the interface T24 is only a secondary-order unconformity between two depression episodes in the basin.

关 键 词：东海盆地 西湖凹陷 新生代 不整合面 构造转换面 构造演化 

分 类 号：TE121.2[石油与天然气工程—油气勘探] P631.44[天文地球—地质矿产勘探]