Thermal Evolution History Analysis of Source Rocks of Hefei Basin

Key words: 
• vitrinite reflectivity /
• Hefei basin /
• illite /
• crystallinity /
• paleogeotemperature /
• thermal evolution /
• source rock

Abstract: Based on vitrinite reflectivity analysis, paleogeotemperature inversion and X ray diffraction series of the smallest granule illite crystallinity, this paper has analyzed thermal evolution of source rock since CarboniferousPermian. The result indicates that 1:CarboniferousPermian source rock was in high maturity, entered threshold of oil generation after the lower Jurassic deposition. After the upper Jurassic, paleogeotemperature was up to 245℃. 2: Fanghushan Formation of the lower Jurassic was also in higher maturity, entered threshold of oil generation after the middle Jurassic, maximal paleogeotemperature up to 260℃ after the middle Cretaceous. 3: Middleupper Jurassic enter threshold of oil generation at lower Cretaceous. Its maximal paleogeotemperature up to 225℃ and 230℃ after Zhuxiang Formation.4: Maximal paleogeotemperature of Zhuxiang Formation up to 110120℃ at the end of the early Cretaceous 5:. Dingyuan Formation of paleogene is immature, maximal paleogeotemperature less than 50℃ after Dingyuan Formation deposition.