Sedimentary Configuration Evolution and Controlling Factors of Channel-Levee Systems in the Offshore Indus Basin

Recent advances in earth science and exploration have made deepwater channel-levee systems a research focus. We collected and analyzed over 10000 km of two-dimensional multichannel seismic data from the offshore Indus Basin to identify channel-levee systems at various hierarchical levels depending on their seismic reflection characteristics. Seismic facies analysis was integrated with well data to map the spatial distribution of channel-levee systems in the offshore Indus Basin across various geological periods, and the factors influencing their development were discussed. These systems within the basin were identified using a developed, refined three-tier classification method. The first-order system consists of multiple spatially stacked complexes, the second-order system continuously developed multistage channel-levee bodies, and the third-order system represents the smallest identifiable sedimentary units on seismic profiles. Our findings demonstrate the evolution of the offshore Indus Basin from a single-stage channel with lateral migration to multistage vertical channel stacking from the Miocene to the Pleistocene. Tectonic activities exert their effect on channel-levee systems through their influence on the relative sea level. They also trigger volcanic or seismic events and affect siliciclastic supply. Warm and humid climate conditions form large river systems, which aid in the transport of terrestrial debris to the basin margin. Most channel-levee systems are assumed to have formed during low sea-level periods. This study offers new insights into the formation and evolution of turbidite sedimentary systems in the offshore Indus Basin and presents a practical classification method for comprehending gravity-flow sedimentary configurations and deepwater hydrocarbon exploration.