渤海海域的郯庐扭断裂及含油气盆地的发育

THE TANCHENG -LUJIANG WRENCH FAULT SYSTEM IN BOHAI BAY AREA

本文通过对横切郯庐断裂系统地震剖面的详尽研究,根据该断裂在本区的活动特征,将其划分为3段:北段、南段及中段,并描述了各段的特征:北段为典型的张扭性断裂;南段为强烈平移断裂,且具有拉分性质;中段则以拉张作用为主。在此基础上,指出了该断裂对本区新生代含油气盆地的形成与发展的控制和影响,并讨论了扭性盆地的油气聚集条件。

The Tancheng - Lujiang wrench fault system is one of the most important giant structural zones in Eastern China , which controls or affects the formation of many oil -bearing basins along it .In this article , the structural features and evolution of the Tancheng -Lujiang wrench fault system in Bohai Bay Area during the Cenozoic period , as well as the control of the fault activities on the evolution of sedimentary basin in this area , are discussed upon analyses of seismic expression across the fault system .Main views advanced in the article are as follows : (1 ) Even within the Bohai Bay Area , the structural characteristics of the Tancheng-Lujiang wrench fault system are different in Northern , Southern and Central Bohai ; (2 )The mainly active period of the fault system is the Early Tertiary , it is actually a right -lateral divergent-wrench fault system with a strong synsedimentary characteristic instead of a left-lateral wrench fault system or a purely extensional one ; (3 ) The oil-bearing basin in Bohai Bay Area is not a simply extensional basin as it was thought originally , the distribution of structural traps in the basin is different from those formed in a simply extensional basin , as is its pattern of oil and gas accumulation .