Abstract:

Through the analysis of vitrinite reflectance,inclusion and apatite fission track,paleogeotemperature and paleogeothermal gradient obtained in Late Mesozoic of Qinshui Basin show well coincidence with each other.The paleogeothermal gradient of Qincan-1 well is between 4.73℃/100 m～6.10℃/100 m,its paleoheat flow is 82 mW/m²～106 mW/m².This is evidently related to tectonic thermal event.In horizental,the distribution of R_o value coincides with the configuration of the basin in Late Mesozoic,and the high R_o value distribution region was related to magmatic activity.The isotopic age of the rock bodies is between 95.34 Ma～166.45 Ma, and the highest abundent of that in the peripheral magmatic active zones is 124 Ma～153 Ma.It suggests that the tectonic thermal event happened in Late Jurassic-Early Cretaceous,and that the event was the reflection of mid Yenshan movement.

Key words: Qinshui Basin, paleogeothermal gradient, fission track, tectonic thermal event