松辽盆地古地温恢复

通过多种古地温研究方法恢复了松辽盆地的古地温及古地温梯度 ,研究结果表明松辽盆地古地温高于今地温 ,白垩纪末的地温梯度及大地热流值可达 4 2 6～ 4 80℃ 10 0m和 95～ 10 7mW m2 ,远高于现今地温梯度 3 70℃ 10 0m及大地热流值 69mW m2 。烃源岩热演化程度主要受古地温控制 ,在白垩纪末达到最大古地温 ,以后持续抬升剥蚀和大地热流值衰减、降温使生烃作用减弱或停止。依安组以来的再沉积厚度小 ,不能引起二次生烃

RESTORATION OF THE PALAEOGEOTHERM IN SONGLIAO BASIN

This paper restores the palaeogeotherm and palaeogeothermal gradient in Songliao Basin using several methods. The study shows that the palaeogeotherm is higher than the recent geotherm time. The geothermal gradient and earth heat flow value of Cretaceous reached 4.26- 4.80℃/100m and 95-107mW/m2, which is higher than the recent geothermal gradient 3.70℃/100m and earth heat flow value 69mW/m2. The thermal evolution of hydrocarbon source rock is mainly controlled by palaeogeotherm. The palaeogeotherm reached the highest value in Cretaceous, then it continued to lift degradation and the earth heat flow value decayed and the temperature declined and weakened and stopped the hydrocarbon generation. The re-sedimentation in Yian Member has a little thickness and cannot have secondary hydrocarbon generation.