Abstract:

The authors deals with the sedimentary characteristics of the Late Jurassic Mohe basin, and studies its tectonic type and genetic mechanism. Detailed sedimentary research indicates that Late Jurassic Mohe basin contains the alluvial fan, fan-delta and lacustrine facies,  belonging to continental molasse deposits of the foreland basin. The provenances of the Late Jurassic Mohe basin came both from the southern and northern direction and is characterized by bidirectional provenance of typical foreland basin. The northern provenance was the Mongolia-Okhotsk orogenic belt, lied at the southern margin of the Siberian plate; the southern provenance was the basement of underlying plate, lied at the northern part of the Daxing’anling Mountains. According to sedimentary characteristics, regional tectonic setting and materials of the Upper Amur basin in Russian, the Late Jurassic Mohe basin is considered to be the southern half part of the Mohe-Upper Amur foreland basin, whose formation and evolution were controlled by the Mongolia-Okhotsk orogenic belt. The Er’shi’erzhan and Emuerhe periods were the main basin forming periods for the Mohe basin. Dark mudstones had developed in a wide area during this period, and are good source rocks.

Key words: Mohe basin, Upper Jurassic, sedimentary characteristics, foreland basin, Upper Amur basin, sedimentology