Abstract:

The measurement and computer modelling of apatite fission tracks in Western Sichuanforeland basin and Longmenshan Region offer new information for the recognition of "Sichuan Movement". The "Sichuan Movement" has four episodes. The first one took place in60 Ma (Early Paleocene-Late Paleocene),the second one took place in 35-36 Ma (EoceneOligocene),the third episode happened in 10 Ma (Middle-Late Miocene),and the fourth onein Early-Late Pleistocene. It could be seen from the above mentioned that the so-called"Sichuan Movement"is acturally the Himalayan movement. This movement provided available condition for hydrocarbon migration and accumulation,and it is also the main cause resulting in effective fractures in the basin. Most of the gas pools in the basin were formed during this period.