莺歌海盆地构造演化动力学机制探讨

Study on the dynamic mechanism of tectonic evolution in Yinggehai Basin

莺歌海盆地是在印支地块与华南地块缝合线上发展起来的新生代沉积盆地,其奇特的地质现象与复杂的动力学背景是国内外学者研究的热点。关于其形成机制,目前主要有四种观点:"中国东部裂陷式"观点、"左旋走滑"观点、"右旋走滑"观点、"先左旋后右旋"观点。通过对该盆地区域地质背景、盆地构造几何学、运动学及沉积学综合分析,认为莺歌海盆地形成演化受印-藏碰撞、太平洋板块俯冲以及地幔上涌的影响,主要经历了古新世—早渐新世左旋拉分、晚渐新世—中新世热沉降、上新世—第四纪右旋拉分三个阶段。

Yinggehai Basin belongs to the Cenozoic sedimentary basin developed in the Indo-China block and South China block suture line.Its peculiar geological phenomena and the complex dynamics setting are studied as hot spots by domestic and foreign academics.There are four perspectives of its formation mechanism at present：＂Chinese Eastern rift-style＂,＂left-lateral strike-slip＂,＂right-lateral strike-slip＂,＂after the first left-lateral strike-slip right-lateral strike-slip＂.Through the regional geological background,basin geometry,kinematics and sedimentology comprehensive analysis,it is figured out that the formation and evolution of Yinggehai basin are influenced by India-Tibet collision,Pacific plate subduction and mantle upwelling.There are three tectonic evolution stages which are the Paleogene-Early Oligocene sinistral pull-apart,Late Oligocene-Miocene thermal subsidence,the Pliocene-Quaternary dextral pull-apart.