聚煤盆地中的水下重力流沉积

THE SUBAQUEOUS GRAVITY FLOW DEPOSITS IN COALFORMING BASINS

Some characteristic coarse-grained clastic sedimentary sequences in Mesozoic coal- forming basins of northern China, not only, consist of multyple genetic units and each unit can be compared with Bouma sequence, but also they have typical characters of the geometry solid, spatial scale, internal depositional architecture and paleocurrent direction of the sedimentary association. The genetic unit reflects a depositional evolution process of subaqueous gravity flow event. But, their associated finegrained sediments are recognized as being formed in The shallow lake. Consequently, these sequences may be interpreted as products of shallow water subaqueous gravity flow.They may constitute special depositional system,for example, subaqueous fan of the gravity flow, fan-delta system.