Geochemical characteristics of aromatic hydrocarbons of coal-bearing gas source rocks from Upper Triassic Xujiahe Formation in Sichuan Basin

Thirty three coal-bearing gas source rock samples from the Upper Triassic Xujiahe Formation in the Sichuan Basin were analyzed by GC-MS.The results show that the concentration of cadalene,retene,1,2,5-tri-methylnaphthalene and 1,2,5,6-tetramethylnaphthalene derived from terrigenous higher plant organic matter of the coal-bearing gas source rocks are extremely lower than those of the typical coal-bearing source rocks.The relative contents of dibenzothiophenes and fluorenes are higher while the relative content of dibenzofurans is lower compared to the high content of dibenzofurans in typical coal-bearing source rocks.The particular distribution may be explained by transgression effect and high maturity.