Petrographic characteristics and peat environments of Gashun mine (Jurassic), Hoxtolgay coalfield, China

Twenty-two coal samples and eleven parting samples were taken from Gashun Coal Mine, Hoxtolgay coalfield, Xingjiang Autonomous Region, and the samples were analyzed by using optical microscopy. The results indicate that the dominant macerals are vitrinite (av. 76.6%) with minor amounts of inertinite (av. 18.84%) and low liptinite (av. 2.7%), along with low content of mineral matters (av. 1.86%). All GI, TPI, VI, GWI values and two facies diagrams indicate that the main coal facies are in limnic area. Meanwhile, the overall petrographic composition and coal facies types indicate that the coal formed in strong wet reducing peat accumulating conditions which were the lacustrine marshes.