College of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China

The reported and published research works on fluid deposition in recent years have been reviewed, summarized, concluded and explained in this article from the viewpoint of sedimentary flow. Sedimentary flow can be classified into traction flow, conversional flow and gravity flow based on sedimentology perspective. Among these, traction flow is the foundation of the sedimentary study, which can be further divided into three elementary types (unidirectional flow, bi-directional flow and oscillatory flow) and three compound types (overlay flow, combined flow and superposition flow), which can be further studied using hydromechanics method. The key to the study of conversional flow and gravity flow deposition is the mutual transitions between traction flow and gravity flow, as well as different gravity flow types, such as turbidite current, fluidized sediment flow, grain flow and debris flow. The sedimentary mechanics of flow could be classified into three types which include vertical settling deposition (static water), bed blocking deposition (traction flow) and energy weakening deposition (gravity flow), the interactions of different flow types could finally form the hydrodynamic conditions of hummocky (swaley) cross-bedding. This overview suggests that studying sedimentology from a fluid perspective is feasible in spite of many difficulties, and has an important significance especially in complex hydrodynamic conditions.