Newly proposed methyltricyclic and methyltetracyclic terpane series in the Shuicheng boghead coal, China

Two newly proposed series of methyltricyclic and methyltetracyclic terpanes have been detected and tentatively identified from an Upper Permian boghead coal in the Dahebian mine, Shuicheng mining district, Guizhou province, southwest China, based on GC-MS analyses and mass spectrum interpretation. The boghead coal is characterized by microbial biomarkers, which account for 52.4% of the aliphatic hydrocarbon fraction in the coal sample, with higher plant biomarkers amounting to 32.2% of the same fraction. On this basis, a microbial source is considered to be the most likely source of both the methyltricyclic and methyltetracyclic terpane series