新生代构造与羌塘盆地油气保存

Effects of the Cenozoic tectonism on the oil and gas preservation in the Qiangtang Basin

羌塘盆地为我国陆上油气资源潜力巨大的一个中生代海相残留盆地,地处青藏高原腹地,但高原的强烈隆升、新构造运动的频繁作用和中上侏罗统的大片裸露,以侏罗系为目的层的油气,能否保存至今令人怀疑。羌塘盆地油气保存条件的问题已成为石油地质条件评价中一个十分突出的焦点问题。笔者就已有的资料,通过对新生代构造活动、断裂活动影响和高原隆升等方面的初步分析,对羌塘盆地油气的保存条件进行初步的探讨。

The Qiangtang Basin in the hinterland of the Qinghai-Xizang Plateau is a largeMesozoic-Cenozoic marine residual basin in China. However, it has been doubtful about its preservation of oil and gas because of intensely uplifting of the Plateau, frequent neotectonic movement and extensive outcropping of the Upper Jurassic strata （ the target strata）. The preservation of oil and gas has thus become a focus of attention in the assessment of oil and gas in the basin. The investigation of the Cenozoic tectonism shows that in spite of the uplifting of the Qiangtang Basin on the whole in response to the rapidly uplifting of the Plateau from the Pleistocene onwards, the geological structures are less deformed and better preserved in the basin than in the other basins on the Plateau.