Sedimentary characteristics, genetic types and control factors of deep-water sandstones in the western Lijin Sag, China

摘要

This paper contributed three academic results for a deep-water fan-related sedimentary system formed in the Lijin Sag, China: First, the sedimentary characteristics of the sublacustrine fan and the lobe were reported. The shape and internal architecture of sublcustrine fan and lobe complexes were interpreted by the seismic data. The reasoning for the mound-shaped lobe complexes in the seismic profile was explained. The relationship between the sublacustrine fan and the lobe complexes and their sedimentary processes were discussed. Second, the sublacustrine fan was formed by sandy debris flow, and the lobes were reworked sands formed by wind-driven bottom flow. According to the characteristic and the principle of the hypopycnal plume, the academic view that the extrabasin sandy turbidity flow can't be formed in the saltwater lake was discussed. The deep-water sandstone characterized by the sedimentary structure related to traction flow was explained to be formed by the wind-driven bottom current in the continental saltwater basin. Third, three factors controlling the distribution of deep-water sandstones were analyzed: provenance, basin topography and strong wind stress.