限定性峡谷和非限定性峡谷沉积充填过程模拟OA北大核心CSTPCD

The changes in the sand-mud ratio and sediment-filling rate in underwater canyon directly affect the geomorphic characteristics of the canyon.Taking the Central Canyon in the Area M of the Qiongdongnan Basin as an example,based on 1 000 km2 of three-dimensional seismic data,the canyon types formed in seven periods in the area were recognized and classified.Software Fluent was used to simulate the characteristics of the filling pro-cess under the conditions of different sand-mud ratios in single-and dual-sourced scenarios.Results show that the canyons that formed in the early stage(T50-T30)are confined canyons,and the those formed in the late stage(T29_1-T29)are unconfined canyons.The channels developed in the confined canyons have strong meandering ability,the superposition of multi-stage channels is obvious,and channel complexes are mostly developed;however,in the unconfined canyons,channels developed are mainly transversely migrated,and then slowly dif-fused into an open area and formed lobe complexes.The simulation and study of the canyon-filling processes in-creased the accuracy of identification of sedimentary units in the canyons,and provided a theoretical basis for the efficiency and the optimization of exploration target areas.