Abstract:

On the basis of the shifts of continental margin since Mesozoic time and the patterns of stress action during tectonic movements in the areas of the east China and the eastern Asia as a whole,it is suggested that the Neoca-thaysian Systems were generated after Whaiyang movement which took placeat the ead of middle Triassic,and now these Systems occupy a broad terri-tory.east of the north-south tectonic structures,extending from Mt.Helan through Mt.Longmen to central Yunnan.Properties in stages of generation and development of Neocathaysian Sys-tems,principles of their division and controls of oil and gas are the primarypoints required to be discussed in this study.According to data on sedimentation,structures and tectonic movements,the process of development of the Neocathaysian Systems can be divided into three stages,namely:①La-te Trissic-Jurassic,②Cretaceous-Paleogene,and ③Neogene-Quarternary.For the purpose of petroleum geology,it is considered to be necessaryto distinguish the primary sedimentary basins from the later ones in orderto have a good knowledge of the process of generation of different subsidence regions and it is emphasized that of prime importance are controls occur redunder a variety of conditions,such as ordinal or seguencial controls by various degree of tectonic structures,composite controls by the same tectionic stru-ctures aud composite controls by different tectonic structures.Finally,thebasic features of oil and gas controls by stages of Neocathaysian Systems arealso discussed thereafter.