Characterization of Canyon Wall Slump and Its Impact on Infilling of the Central Canyon in Qiongdongnan Basin

Objectives: Mass transport deposits (MTDs) often have a certain control effect on the development of river channels and the transformation of topography and geomorphology. Methods: In order to explore the influence of MTDs in waterways, this paper, based on three-dimensional seismic data of the west section of the Central canyon in Qiongdongnan Basin, conducted a detailed characterization of the canyon wall collapse phenomenon and block transport sedimentary system in the study area. The geological model of canyon wall collapse was constructed by using fluid dynamics software Fluent to explore the sedimentary distribution and influence of canyon wall collapse. Results and Conclusions: The results show that: 1) The study area is located on the west side of the Central canyon, and large-scale erosion scratches have developed inside the canyon, and compressive ridges and thrust fault structures have been identified; 2) Large-scale erosion scratches occurre in the northern part of the study area, which can be interpreted as the collapse of the canyon wall due to the instability of the target layer. Large-scale bulk transport sediments developed in the target layer eroded the underlying layer and destroyed the original sediments, but the sediments provided a certain provenance basis for the canyon filling; 3) Through the forward modeling of canyon wall collapse, it is found that both sides of the canyon have different erosion degrees, and the steep side of the canyon wall is prone to slide. With the completion of the filling of the canyon, the limit of the channel is weakened, and it is easier to form a migration channel.