摘要
中国东-南部裂陷系列盆地油气资源十分丰富,而断层的分布演化十分复杂,是油气进一步勘探开发需要解决的关键问题。本文应用广义断层模式,在大量三维地震资料构造解析的基础上,以渤海湾盆地的南堡凹陷和北部湾盆地的涠西南凹陷为例,对中国东-南部盆地复杂的断裂系统进行了解剖和归纳,并提出了伸展变形区预测断层性质的伸展应变椭圆。结果表明,中国东-南部裂陷盆地断裂系统的复杂性存在9种表现方式,从成因上进一步归纳为3个方面:(1)断层的走向和性质多样;(2)断层在平、剖面上存在复杂多变的组合形式;(3)断层形成和演化存在复杂的时-空关系。造成复杂性的根本原因是先存断裂分布的复杂性和不同方向(北西-南东向和近南北向)伸展变形的叠加。不同盆地、同一盆地不同区域应力场演化具有很大的相似性:40Ma以前,北西-南东向伸展;38Ma以来,近南北向伸展。断层分布和演化差异主要是由先存构造分布差异造成的。
Rift basins in eastern and southern China host abundant oil and gas resources.But the complicated evolution and distribution of the faults are the key issues to be solved in future oil and gas exploration and development.Based on the structure interpretation of a large number of 3D seismic data and the generalized faulting model,this study selected the Nanpu Sag in the Bohai Bay Basin and the Weixinan Sag in the Beibuwan Basin as study examples so as to analyze and summarize the complicated fault system of basins in eastern and southern China.An extension strain ellipse was proposed to predict fault nature in extensional deformation zone.The results show that there are nine ways by which fault system complexity of rift basins in the east-south China are presented.They can be further summarized into three aspects,（1）variety of the fault strike and nature,（2）variable assemblages in the plane and profile,（3）complicated spatiotemporal relation of fault distribution and evolution.The fundamental reasons for complexity of the fault system are the distribution complexity of the pre-existing faults and the superposition of extensional deformation in different directions（NW-SE and near N-S）.The evolution of tectonic stress field in different basins and even in different parts of a basin shows great similarities,NW-SE extension before 40Ma and north-south extension since 38Ma.Therefore,the distribution and evolution of faults are mainly affected by the differences in the distribution of pre-existing faults.
作者
童亨茂
范彩伟
孟令箭
赵宝银
范晋煜
TONG Hengmao;FAN Caiwei;MENG Lingjian;ZHAO Baoyin;FAN Jinyu(State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum,Beijing,102249;Zhanjiang Branch of CNOOC,Zhanjiang,Guangdong,524057;Eacploration and Development Research Institute,PetroChina Jidong Oilfield Company,Tangshan,Hebei,063004)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2018年第9期1753-1765,共13页
Acta Geologica Sinica
基金
国家油气重大专项(编号2016ZX05024-005-004)
国家自然科学基金项目(编号41272160)资助成果
关键词
裂陷盆地
断层
复杂性
伸展
成因机制
广义断层模式
rift basin
fault
complexity
extension
origin mechanism
generalized fault model
作者简介
童亨茂，男，1967年生。教授，博士生导师，从事盆地构造分析研究和教学工作。Email：tonghm@cup．edu．cn。
