Petrographic Characteristics and Peat Environments of No.5 and No.6 Coal Seams in Danhou Mine

Twenty-five coal samples were taken from Danhou Coal Mine, Yuxian coalfield, including twelve samples from No.5 Coal Seam and thirteen samples from No.6 Coal Seam, and the samples were analyzed by using optical microscopy.The results showed that the dominant macerals were vitrinite(av. 48.85%) and inertinite(av. 48.5%), low liptinite and mineral matters(both less than av. 1%) in No.5 Coal Seam; the dominant macerals were vitrinite(av. 59.22%) with minor amounts of inertinite(av. 34.6%) and low mineral matters(av. 5.077%), along with low content of liptinite(less than av.1.86%). All GI, TPI, VI, GWI values and two facies diagrams indicate that the main coal facies were in No.5 and No.6 Coal Seams, the No.5 Coal Seam was the transition between dry forest swamp and extensive water swamp and the No.6 Coal Seam was in extensive water swamp, coal-forming plants were mainly woody plants in both coal seams.