莺—琼盆地的演化与构造—热体制

EVOLUTION OF YING QIONG BASIN AND ITS TECTONIC—THERMAL SYSTEM

莺歌海盆地与琼东南盆地是两种不同成因类型的盆地，前者是与红河大断裂有关的转换—伸展盆地，而后者则为伸展盆地。距今５Ｍａ时的又一次新的热事件后使两盆地统一为一个盆地，开始了共同的新的沉降活动。采用地球物理方法，据盆地拉张指数、古今热流值等指标研究了盆地的沉降、构造演化以及热体制。运用ＤＳＴ和ＲＦＴ测压、地震层速度和测井声波时差趋势多项式法换算压力数据，作出了超压剖面图及超压顶面等深图等，据此分析了盆地超压及高温环境形成机制。进而分别阐述了转换—伸展盆地演化与油气的关系，伸展盆地演化与油气的关系。

The Yinggehai Basin and Qiongdongnan Basin are the two basins with different genetic types;the former is a transtensional basin related to the Red River major fault,but the latter a tensional one.Five million years ago,the thermal event happened once more,which caused the two basin to be combined into one,and a new united subsidence was beginning.By use of geophysical method,the subsidence,tectonic evolution and thermal system of the basin were studied in accordance with the basin tensional index,ancient and present thermal flow values,etc.The superpressure cross section and equal depth (to the top of superpressure) map were drawn up through pressure measurement by DST and RFT and pressure calculation by polynomial method according to the seismic interval velocity and acoustic interval transit time logging data.On the basin of this,the mechanism of forming the superpressure and high temperature environment in the basin is analyzed and the relation between the transtensional basin evolution and the petroleum distribution and that between the tensional basin evolution and the petroleum distribution are stated.