南昆嵩地区断裂−构造演化特征及其控制因素  

Characteristics of fault-tectonic evolution and its controlling factors in the South Kunsong area

作　　者：贺华瑞 栾锡武 魏新元 乔江浩 He Huarui;Luan Xiwu;Wei Xinyuan;Qiao Jianghao(School of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China;College of Marine Geosciences,Ocean University of China,Qingdao 266100,China)

机构地区：[1]山东科技大学地球科学与工程学院,山东青岛266590 [2]中国海洋大学海洋地球科学学院,山东青岛266100

出　　处：《海洋学报》2022年第12期95-108,共14页

基　　金：国家自然科学基金(92055211);中国−东盟海洋地震数据平台与研究中心建设项目(12120100500017001)。

摘　　要：南昆嵩地区是万安盆地西部负向构造单元,其中部N–S向断裂贯穿南北,独特的构造特征使其成为研究万安盆地西部构造演化与区域断裂走滑活动的窗口。将研究区沉积地层划分为3套构造层,通过回剥法绘制南昆嵩地区构造–沉积充填剖面,并计算南昆嵩地区构造沉降量以及构造沉降速率,论述南昆嵩地区构造演化史与沉降过程以及控制因素。研究结果表明:下部构造层和中部构造层中断裂组合样式主要为卷心型断层、“Y”型断层、阶梯状断层和高角度花状构造等,断裂延伸方向大致可分为:N–S向、W–E向和NE–SW向3种;上部构造层断裂不发育,为稳定沉积;在区域走滑断裂以及南海扩张运动的控制下,南昆嵩地区始新世以来构造演化经历4个阶段:初始裂谷期、伸展断拗期、走滑改造期和热沉降期,新生代地层构造性质也表现为以伸展与走滑作用为主–走滑断裂控制–热沉降的三段式转变。The South Kunsong area is a negative tectonic unit in the western part of the Wan’an Basin,in which the N−S trending faults run through the north and the south.The unique tectonic characteristics make it a window for studying the tectonic evolution and regional fault strike-slip activities in the western part of the Wan’an Basin.The sedimentary strata in the study area are divided into three sets of structural layers,the structure-sedimentary filling section in the South Kunsong area is drawn by the back stripping method,and the tectonic subsidence and tectonic subsidence rate in the South Kunsong area are calculated.Settlement process and controlling factors.The research results show that the fault combination styles in the lower and middle structural layers are mainly core-type faults,"Y"-type faults,stepped faults and high-angle flower-shaped structures.W−E trending and NE−SW trending;the upper tectonic layer is not developed with faults and is stable deposition;under the control of regional strike-slip faults and the South China Sea spreading movement,the tectonic evolution of the South Kunsong area has experienced four stages since the Eocene:the initial stage.During the rifting period,extensional fault-deflection period,strike-slip reformation period and thermal subsidence period,the stratigraphic structure properties of the Cenozoic also showed a three-stage transformation of extension and strike-slip,control of strike-slip faults,and thermal subsidence.

关 键 词：南海万安盆地 南昆嵩地区 走滑断裂 构造演化 构造层 

分 类 号：P736.2[天文地球—海洋地质]