下扬子陆域东部北西向断裂特征及其形成机制  

Characteristics and formation mechanism of NW faults in the eastern part of the lower Yangtze continental region

作　　者：王超 唐贤君 钟荣全 WANG Chao;TANG Xianjun;ZHONG Rongquan(China National Offshore Oil Corporation(China)Limited,Shanghai Branch,Shanghai 200335)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《上海国土资源》2023年第2期107-112,共6页Shanghai Land & Resources

基　　金：国家科技重大专项“东海深层大型气田勘探评价技术”(2016ZX05027-002)。

摘　　要：下扬子陆域东部断裂走向主要为NNE-NE向,NW向断裂零星可见,关于NW向断裂分布规律及形成机制一直是研究的难点。本文通过区域重力、磁力资料分析,结合NW向断裂野外及卫星遥感资料,探索NW向断裂的分布规律及成因。研究结果表明:在区域特征上,下扬子陆域东部自西向东,NE向断裂体系存在明显分带差异,且区域重力、磁力异常等资料上有响应,这些差异性也反映了潜在NW向断裂带的存在;在断裂分布上,NW向断裂规模总体较小,但是具有成带发育特点,平面分布呈右阶排列形成区域NW向断裂带,控制两侧构造变形的差异;在断裂成因上,NW向断裂主要形成于中生代,在燕山期挤压背景下,受区域不均衡作用影响,东西部差异挤压控制下扬子西窄东宽的构造格局,此时,区域NW向断裂带开始发育,主要起区域应力调节作用。The strikes-slip faults in the eastern part of the Yangtze continental domain are mainly directed NE.The NW faults are sporadically distributed,and some are hidden.Currently,it is difficult to study the distribution and formation mechanisms of NW faults.Based on the analysis of regional gravity and magnetic data combined with field and satellite remote sensing data of NW faults,this study established a regional fault system and explored the distribution rules and genesis of NW faults.The results show that,in terms of regional characteristics,the NE fault system in the eastern part of the lower Yangtze continental domain has clear zoning differences from west to east,and the regional gravity and magnetic anomaly data have obvious zoning.These differences also show the existence of a potential NW fault zone.With respect to fault distribution,the development scale of NW-dominant faults is small,but they have the characteristics of zonal development.The plane distribution is arranged in the right steps to form a fault zone,which controls the difference in structural deformation on both sides.NW faults were mainly formed in the Mesozoic era.Under the Yanshanian compression background,affected by regional imbalance,differential compression in the east and west controlled the narrow structural pattern in the west and the wide pattern in the east,and NW fault zones began to develop,mainly playing a role in stress adjustment.

关 键 词：构造断裂 分布特征 成因机制 下扬子地区 

分 类 号：P315[天文地球—地震学] P318[天文地球—固体地球物理学]