琼东南盆地南部坳陷带12号断层性质及成因  

FEATURES OF NO.12 FAULT AND ITS FORMING MECHANISM IN THE SOUTHERN DEPRESSION OF QIONGDONGNAN BASIN

作　　者：龙根元[1] 吴世敏[2] 刘兵[3] 贺超[1] 

机构地区：[1]海南省海洋地质调查研究院,海口570206 [2]中山大学地球科学与地质工程学院,广州510275 [3]海南省地质调查院,海口570206

出　　处：《海洋地质与第四纪地质》2016年第2期93-99,共7页Marine Geology & Quaternary Geology

基　　金：国家重点基础研究发展计划项目(2007CB411706);国家自然科学基金项目(41276048;91328205;41476039)

摘　　要：利用琼东南盆地的反射地震剖面等资料,重点分析了盆地南部坳陷带内12号断层平面、剖面及断层附近地层沉积特征,指出该断层为玉琢礁凹陷和华光礁凹陷内部控凹断层之间的转换断层。结合盆地构造演化特征,进一步将该断层演化划分出以下几个阶段:从始新世—渐新世,12号转换断层活动强烈,它的产生与发展主要受其两侧凹陷的伸展断层所制约,如华光2号、11号等控凹断层;中新世后,盆地处于裂后沉降期,随着盆地控凹断裂活动停止,12号断层活动亦停止;晚中新世之后,可能受吕宋岛弧向西聚合影响,此转换断层表现为走滑性质;进入第四纪断层完全停止活动。Based on the seismic profiles through the Qiongdongnan Basin,the authors found that the No.12 fault in the Southern depression is a transfer fault,after analysis of the spatial extension and 2-D section of the fault as well as the associated stratigraphic framework.The No.12 fault is the accommodation structure between the Huaguangjiao Sag and Yuzhuojiao Sag.The fault has experienced three stages of evolution.It began with the rift extension from Eocene to Oligocene.In this stage,the No.12 fault made an intense move under the control of the NE—NNE trend fault between the Huanguangjiao Sag and the Yuzhuojiao Sag,such as Huaguang No.2fault and No.11 fault.In the post-rifting subsidence stage of Miocene,the No.12 fault stopped movement due to the inactivity of the main faults of the sags in southern depression.Finally,in Late Miocene,the No.12 fault remained active as a strike-slip fault resulting from the convergence of the Luzon Arc westward.

关 键 词：南部坳陷带 12号断层 转换断层 琼东南盆地 

分 类 号：P736.1[天文地球—海洋地质]