Abstract:

The southern North China is considered one of the areas with great hydrocarbon potentials. The Upper Paleozoic coalbearing strata are major exploration targets in the area. An analysis of more than 600 sets of vitrinite reflectance (Ro) data and other geothermometer data such as Tmax and spore color index indicates that the thermal evolution of the Upper Paleozoic is uneven, showing a general trend of higher in the north and west but lower in the south and east. By combining a reconstruction of the eroded strata with an analysis of the paleostructure evolution, fission track dating and magmatic rocks dating, we concluded that the Upper Paleozoic strata experienced complex thermal evolution history and hydrocarbon generation history, and identified three hydrocarbon generation types including the early, the earlylate and the continuous types. The organic matter in the Upper Paleozoic strata mainly experienced hypozonal metamorphism in early stage. Magmatic thermal metamorphism and dynamic metamorphism were the major causes of local abnormal high thermal evolution. The regional tectonicthermal events in the MidLate Mesozoic were the crucial factors controlling the regional high thermal evolution of the Paleozoic in TaikangJiyuan area. The Upper Paleozoic with favorable conditions for secondary hydrocarbon generation, accumulation and preservation are the realistic exploration targets. They mainly occur in deep of MesoCenozoic depression, such as the middle part of the Niqiuji sag and the middle part of the TanzhuangShenqiu sags.