According to the study made on saturated hydrocarbon fractions of Tertiary browncoals that collected from Baize

Nanning and Hepu of Guangxi Province

the hydrocarbonsin the brown coals are immatured. It is proposed that the resin and wax of higher plant

especially bacteria

could form large amounts of immatured hydrocarbon in immaturesarge. This is considerably important for immature or lower mature hydrocarbon exploration in Tertiary coal measures in China’s coast areas and continental shelf.