THE DEVELOPMENT OF MELAMUDSTONE AND THE JURASSIC FILLING SEQUENCE IN TUQUAN BASIN, DAXINGANLING REGION

According to the evolvement features, the filling sequence of the Jurassic volcanic-sedimentary strata in the Tuquan Basin, Daxinganling region can be assigned to three grades of volcanic-sedimentary cycles, including 2 cycles of Grade Ⅰ, 5 cycles of Grade Ⅱ and several cycles of Grade Ⅲ. The organic geochemical characteristics show that the melamudstone in Jurassic Hongqi formation is medium to good grade of source rock for hydrocarbon, while that in the Wanbao formation is relatively poor. The high maturity of the Permian melamudstone is favorable to the formation of Permian hydrocarbon source rocks, indicating that the Paleozoic strata should be the focal point for the future investigation.