转换—伸展盆地──莺歌海的演化

EVOLUTION OF TRANSFORM-EXTENSION YINGGEHAI BASIN

在系统研究莺歌海盆地沉降史、变形史、充填史和埋藏史的基础上，确定了莺歌海盆地的演化阶段和盆地类型，并建立了转换－伸展盆地的演化模式．莺歌海盆地演化可分为４个主要发展阶段：（１）初始断陷；（２）裂陷；（３）拗陷；（４）再次裂陷，盆地的沉降机理是：初始断陷为岩石圈刚性体的简单伸展；裂陷为与先期剪切断裂带重新活动有关的走滑－伸展；拗陷走滑－伸展相对较弱，叠加热沉降；再次裂陷以走滑－伸展为主，叠加重力沉降和压实作用．

Based on the systematic researches of histories of the subsidence,deformation,infilling and bury, the paper has determined the type and evolution stages of Yinggehai basin, and established the model of transform-extension basin, Evolution of Yinggehai basin can be divided into four major stages:(1)initial fault depression;(2)rifting;(3)depression; and(4) rerifting stages.The subsidence mechanism includes:simple extension of initial fault-depression in the lithospheric rigidity body; strike-extension of rifting related to the influence of reactivated pre-existing basement shear zones;slightly strike-extension,surperimposed thermal subsidence of depression;strike-extension, superimposed gravity,subsidence and compaction of rerifting.