Oil-gas characteristics controlled by coalifications in upper triassic sedimentary organic matters in Chuxiong basin

The coal seams of Late Triassic in Chuxiong Mesozoic Basin had experienced two periods of coalification, one occurring at the foreland basin stage, another at the inland rift stage. The two stages were all mainly coalificated by the plutonic metamorphism. The results show that the same trend as high level in the west and north, low in the east and south. Through analyzing the oil-gas characteristics controlled by coalification, we consider the coalification of the later stage had an important significance to oil-gas exploration because of its later hydrocarbon-generation, greater evolutionary amplitude and deeper hydrocarbon-generation intensity.