红河断裂带在莺歌海盆地的延伸——中央断裂的识别  

Identification of the Central fault:The extension of the Red River fault zone in the Yinggehai basin

作　　者：付永涛[1,2,3] 陈鹳霏 吴涛 王万银 徐涛 王丁丁[6] 周章国 杨安 FU Yongtao;CHEN Guanfei;WU Tao;WANG Wanyin;XU Tao;WANG Dingding;ZHOU Zhangguo;YANG An(Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao,Shandong 266071,China;National Engineering Research Center for Offshore Oil and Gas Exploration,Beijing 100028,China;Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology,Qingdao,Shandong 266237,China;University of Chinese Academy of Sciences,Beijing 100049,China;CNOOC China Ltd._Hainan,Haikou,Hainan 570311,China;College of Geology Engineering and Geomatics,Chang'an University,Xi'an,Shaanxi 710054,China)

机构地区：[1]中国科学院海洋地质与环境重点实验室,中国科学院海洋研究所,山东青岛266071 [2]海洋油气勘探国家工程研究中心,北京100028 [3]青岛海洋科学与技术试点国家海洋实验室海洋地质过程与环境功能实验室,山东青岛266237 [4]中国科学院大学,北京100049 [5]中海石油(中国)有限公司海南分公司,海南海口570311 [6]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《地质学报》2025年第3期704-718,共15页Acta Geologica Sinica

基　　金：中海石油(中国)有限公司海南分公司勘探项目(编号CCL2022HNFN0321);海洋油气勘探国家工程研究中心开放基金项目(编号CCL2022RCPS0794RQN)联合资助的成果。

摘　　要：红河断裂带的早期左行和后期右行走滑剪切作用对莺歌海盆地的构造演化和沉积过程具有重要的控制作用。虽然在莺歌海盆地的中央坳陷北部和南部已识别出红河断裂,但仍不清楚红河断裂带在中央坳陷是如何延伸的,因此对莺歌海盆地的构造演化和沉积过程研究造成了一定影响。目前多基于盆地东侧的1号断裂和西侧的莺西断裂为边界,研究莺歌海盆地的构造演化。本文基于莺歌海盆地卫星测高重力异常,采用重力异常归一化总水平导数垂向导数(NVDR-THDR)方法厘定了中央断裂的分布,且在中央坳陷北部和中部得到了2D地震剖面的证实。中央断裂是红河断裂带在莺歌海盆地的延伸,在东方底辟区以北发育左阶断层,在平面上形成向东的错断;在昌南底辟区以东为数条平行断层组成的断裂带,在乐东底辟区发展为左行左阶断层系,发育了乐东南洼陷(拉分盆地)。地震剖面显示中央断裂在中央坳陷的埋深较大,在双程旅行时长大于6 s的深度以下,依据地层层序判断其主要活动期为早于30 Ma并持续至15.98 Ma。依据双界面模型快速反演方法计算的莺歌海盆地沉积物厚度,在中央坳陷发育5个厚度大于15 km的沉降中心。总体上,中央断裂以西为沉降中心,以东为沉积深度变浅的梯度带。同时,中央坳陷的5个底辟构造带均分布于中央断裂以西,尤其是乐东区的左行左阶断层系对3个平行分布的底辟带有明显的控制作用。中央断裂对莺歌海盆地构造演化和油气勘探具有重要的意义。The early left-lateral and late right-lateral strike-slip shearing of the Red River fault zone performes a crucial function in controlling the tectonic evolution and sedimentation processes of the Yinggehai basin.While the Red River fault has been identified in the northern and southern parts of the Central depression of the Yinggehai basin,it remains unclear how the Red River fault zone extends within the Central depression,impacting the study of the basin's tectonic evolution and sedimentation processes.Current studies on the tectonic evolution of the Yinggehai basin are based on the No.1 fault on the eastern side and the Yingxi fault on the western side as boundaries.In this paper,utilizing satellite altimetry gravity anomaly data in the Yinggehai basin and employing the normalized vertical derivative total horizontal derivative edge recognition(NVDR-THDR)method,we determined the distribution of the Central fault.This recognition is verified by 2D seismic sections in the northern and central parts of the Central depression.The Central fault is the extension of the Red River fault zone in the Yinggehai basin,developing as a left-stepping fault system north of the Dongfang diapir area,forming an eastward dislocation in plan view.In the Changnan diapir area,it consists of several parallel faults.In the Ledong diapir area,a left-stepping sinistral strike-slip fault system is developed,leading to the development of the Ledongnan Subsag(pull-apart basin).Seismic profiles reveal that the buried depth of the Central fault is larger in the Central depression,with a two-way travel time exceeding 6 s.According to the stratigraphic sequences,the main active period of the Central fault predates 30 Ma to 15.98 Ma.The Cenozoic sediment thickness of the Yinggehai basin,calculated using the fast inversion method of the double-interface model of the gravity field,reveals the development of five depocenters with thicknesses exceeding 15 km in the Central depression.Generally,to the west of the Central fault are the depocenters,w

关 键 词：红河断裂带 莺歌海盆地 中央坳陷 中央断裂 卫星测高重力异常 沉积中心 底辟 

分 类 号：P61[天文地球—矿床学]