Apatite Fission Track Evidences for the Thermal History of Northeast Sichuan Foreland Basin, Southwest China

摘要

Based on Interpretations of the apatite fission track analysis for 6 sample collected from Jurassic sandstone and modeling of confined fission track length distributions, the thermal history of Northeast Sichuan foreland basin has been quantitatively studied. The results indicate that since 150 Ma, the thermal history of Northeast Sichuan foreland basin can be divided into four stages. A rapid sediment during 150-105 Ma, following a comparative cooling occurred from 105-80 Ma, following a quiet phase and then a rapid cooling started at 12 Ma until now. Based on these results, it is believed that tectonic deformation of Northeast Sichuan basin began at 105-80 Ma. With good match of tectonic-developing stage and hydrocarbon generation stage, the structure-lithologic pore gas reservoir came into being. The late Himalaya (12 Ma) tectonic movement controlled late stage accumulation of hydrocarbon, and structure traps developed in this stage.