DISTRIBUTION AND GEOCHEMICAL CHARACTERISTICS OF PERMIAN SOURCE ROCKS IN THE SOUTHERN NORTH-CHINA

The coal prone source rocks are well developed in Southern North China in the Permian deposits of Taiyuan Formation,Shanxi Formation,and Lower and Upper Shihezi Formations.The abundance,type and maturity of source rocks indicate that coal measure bearing mudstone is the main effective source rock.The Taiyuan Formation,Shanxi Formation,and Lower Shihezi Formation are all high in the abundance of organic matters,of which the matrix belongs to the type III(humic type) with little of typeⅡ2(sapropelic-humic type).The Lower Permian organic matters are matured or even over matured,but Upper Permian ones non-matured or just matured.Therefore,the Upper Permian in this region is high in hydrocarbon generation potential.