Organic Geochemistry of Triassic Source Rocks in the Southern Qilian Basin

According to the outdoor profile survey,collection of samples in systematic and the organic geochemical analysis technique including rock pyrolysis,residual organic carbon content,kerogen analysis,organic maceral,vitrinite reflectance,gas chromatography of saturated hydrocarbon and transmitted light microscopy,the authors discussed organic matter abundance,type and maturity of T3g carbonate and T2d mudstone outcrop samples in the Southern Qilian Basin,the original sedimentary environment and bio-inputs of organic matter.The results show that T3g carbonate belong to good source rocks,the organic matter is type Ⅰ-Ⅱ and T2d mudstone is type Ⅱ Ⅲ.The organic matter has a high degree of thermal evolution and is at the high and over mature stage.They are deposited in transitional and mainly terrestrial facies.Organic matters are mainly derived from aquatic plant and errestrial life biodegradation.