ON PETROLEUM SOURCE AND MATURATION CHARACTERISTICS OF THE ORGANIC MATTER OF CAMBRIAN AND MIDDLE-UPPER PROTEROZOIC IN KUANCHENG REGION OF NORTHERN HEBEI PROVINCE

The Middle-Upper Proterozoic and Cambrian sediments are well developed in Yanliao Subsidence Belt of North China and the thickness of the sedimentary strata is almost 10 Km in which oil/gas shows are widespreaded. Based on the outcropped stratigraphic profile of the area, the oil generation conditions, geochemical characteristics, and oil source of the Middle-Upper Proterozoic and Cambrian systems are studied using many analytical data. It is suggested that the dark grey-limestones and shales of Zit, Zih, Zcg, Zcch and Zqx are the good source rooks. The oil/gas shows in the area are mainly derived from the limestone of the Tielng Formation and the shales of the Hongshuizhuang Formation. The maturity of the organic matter in Jixian System of Middle-Upper Proterozoic is rather low and still remains in the oil generation stage,while those of the overlying and underlying Qing-beikou, Cambrian systems and Changcheng System have already entered the overmature stage.