中国东部某些中、新生代含油气盆地与部分北东向正断层成因分析

ARE THE FAULTS CONTROLLING MESO-CENOZOIC BEARING OIL AND GAS BASINS IN EASTERN CHINA TENSILE FRACTURES?

中国东部中、新生代含油气盆地众多 ,为断陷盆地类型 ,断层发育也往往表现为正断层形式。对这些盆地性质、形成机制以及正断层的力学性质的认识众说纷纭 ,但以张、张扭性盆地和张、张扭性断层之说占主导。本文从大地构造体系环境、构造型式特点、区域与局部应力场分析、定向岩心破裂面观察、地震反射信息 ,晚近时期构造形迹 (如天然地震裂隙、断裂 )组合规律的地质分析以及正断层控油特点等方面 ,对盆地及控盆断层性质进行了分析研究 ,认为中国东部某些断陷盆地、NE向控盆正断层和盆内主干NE向正断层为扭性或压扭性 。

Most of Mesozoic and Cenozoic bearing oil and gas basins are rifting ones in eastern China whose development closely is related with normal faults.Based on the research,this paper reveals the rifting basins and the NE trending normal fault are mainly compressive or compresso shear type.They resulted from the combination of tectonic stress with gravity,and the vertical stress is greater than horizontal one in the three dimensional stress fields.