Chen W B, Fu X G, Tan F W, Feng X L. The discovery of the Carboniferous source rock in Qiangtang Basin of Tibet and its geological significance

The Jurassic source rocks have long been regarded as the research priority because most oil and gas shows in Qiangtang basin were found from the Jurassic source rocks. The Carboniferous source rocks's capability of hydrocarbon generation has not been given sufficient consideration because its strata assume scattered distribution in Qiangtang basin. According to the data obtained from the surface samples, the authors used analytical methods of Rock-Eval, microscope observation, vitrinite reflectance and biomarkers to analyze the organic geochemical characteristics of the Carboniferous source rocks in Qiangtang basin. The results reveal that the organic matter abundance of source rocks is higher in Carboniferous, and organic matter is mainly of Ⅱ1 type, and the overall thermal evolution has reached the high degree of the over-mature stage. The discovery of Carboniferous source rocks has filled for the first time the gap in the study of Paleozoic source rocks in Qiangtang basin, and indicated the new formation and new areas of oil and gas exploration，thus having great significance for the assessment of oil and gas resources in the whole Qiangtang basin.