The carbonate rocks of shallow platform factes is the primary sedimentation type in China's marine carbonate rocks. Its sedimental environment favoured the propagation of organisms but did not favour for the preservation of organic matter. Since sedimental boundary surface was near oxidizing milieu

large amount of organic matter was resolved during deposition and shallow burying process. This resulted in lower abundance and poor types of organic matter. Though the organic matter come from lower grade aquatic lives

hydrocarbon generation potential

especially liquid hydrocarbon generation potential is quite low. So it is suggested that

shallow platform carbonate rocks could not be considered as important oil source rocks but could be taken as gas source rocks.