HYDROCARBON ACCUMULATION OF FOUR ASSOCIATION TYPES OF FORELAND BASINS IN CENTRAL AND WESTERN CHINA:PART I.GEOLOGICAL CONDITIONS

Foreland basins are important areas of exploration for petroleum in China.According to the basin construction and evolution,the foreland basins in central and western China can be divided into four types of assemblages including the presenile,the reconstructed,the regenerated and the superimposed.This paper discusses the geological conditions of accumulation,such as the assemblages of source rock,reservoir and seal,in different foreland basins based on the examples of northwestern Junggar foreland basin(the presenile),western Sichuan foreland basin(the reconstructed),northern Chaidamu foreland thrust(the regenerated) and southern Junggar foreland basin(the superimposed).The thermal evolutions of main source rocks are stated in the four types of foreland basins.The foreland development in the late period of Himalayan movement has an obvious control on the thermal evolution of source rocks in the Chaidamu foreland thrust(the regenerated) and southern Junggar foreland basin(the superimposed).