南海北部莺歌海盆地成因机制：与渭河盆地构造对比分析的启示  

GENETIC MECHANISM OF THE YINGGEHAI BASIN,NORTHERN SOUTH CHINA SEA:A COMPARATIVE STUDY TO THE WEIHE BASIN

作　　者：杨鹏 夏斌 蔡周荣 万志峰 黄强太 张勇 

机构地区：[1]中山大学海洋科学学院,海洋石油勘探与开发广东高校重点实验室,中山大学海洋石油勘探开发研究中心,广州510006 [2]矿床地球化学国家重点实验室,贵阳550002

出　　处：《海洋地质与第四纪地质》2017年第6期65-75,共11页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金(41372208,40534019);中国科学院地球化学研究所矿床地球化学国家重点实验室开放基金(201304);广东省自然科学基金(2015A030313157)

摘　　要：南海北部莺歌海盆地为新生代沉积盆地,地处欧亚板块、太平洋板块和印度-澳大利亚板块交汇处,构造位置独特,复杂的地质构造现象使其形成演化的动力学机制成为国内外研究的热点。同一类型盆地具有相似的构造、沉降、沉积演化历史与成因机制。莺歌海盆地与渭河盆地均位于多板块交汇处,存在长期相对快速沉积、沉降及构造演化迁移等典型走滑型盆地特征。在明确渭河盆地成因机制的基础上,对比两盆地构造、沉降及沉积演化历史,结合莺歌海盆地特殊的构造位置及南海扩张的构造背景,分析得出:莺歌海盆地形成演化和印度-澳大利亚板块与青藏板块碰撞、印支板块逃逸及自身旋转、华南板块向东挤出及太平洋板块俯冲关系密切,受多板块构造活动影响较大,新生代以来先后依次经历左旋走滑、伸展—热沉降—右旋走滑、伸展三大成盆演化期。另外,与渭河盆地相比,莺歌海盆地发育有高温、高压及泥底辟等特殊地质现象,主要受控于热沉降阶段,与渐新世以来(33~15Ma)南海扩张事件具有重要关系。The Yinggehai Basin is a Cenozoic depositional basin located on the Northern Continental Margin of the South China Sea,a unique and important tectonic position at the convergent hinge among the Eurasian,Pacific and Indo-Australian plates.The complicated geotectonics of the basin has made the genetic mechanism of the basin a hotspot.In this paper,the Weihe Basin,a basin with similar tectonic subsidence and sedimentary evolution history and genetic mechanism,is selected for purpose of comparative study.The Yinggehai Basin and the Weihe Basin are on the Southern and Northern margins of the South China plate respectively.Both of them are located at a juncture of plates as typical strike slip basins with long terms of rapid subsidence and sedimentation histories.Taking the Weihe Basin as an example,a comparative study is carried out on the history of tectonic subsidence and sedimentation,upon the consideration of specific tectonic location of the Yinggehai Basin and the tectonic background of the expanding South China Sea.The comparison reveals that the formation and evolution of the Yinggehai Basin is closely related with the collision between the India plate and the Qinghai-Xizang plate,escape and the self rotation of Indo-China block,eastward extrusion of the Southern China block and the subduction of the Pacific plate.Affected by the multi-stage plate tectonic activities,the basin has experienced several evolutionary stages.Since Cenozoic,it has suffered a sinistral strike stage,a slip stretch-thermal subsidence stage and an extral strike slip extension stage.In addition,high temperature and pressure geological records,mud diapir and other special geological phenomena are observed in the Yinggehai Basin under the control of thermal subsidence related to the expansion of the South China Sea since Oligocene（33~15 Ma）.

关 键 词：构造沉降 沉积演化 成因机制 盆地分析 板块构造 渭河盆地 莺歌海盆地 南海 

分 类 号：P736.1[天文地球—海洋地质]