Geomorphologic reconstruction of an uplift in a continental basin with a source-to-sink balance: an example from the Huizhou-Lufeng uplift, Pearl River Mouth Basin, South China Sea

Abstract For the first time, we have applied the idea of a source-to-sink balance to study the ancient geomorphology of an uplift in a continental basin. By assessing the differential subsidence and denudation in the context of a source-to-sink system's volume balance, we have established a set of methods to restore the uplift geomorphology. We use the latest 3D seismic data over the Huizhou-Lufeng uplift, Pearl River Mouth Basin, South China Sea. By identifying the catchment and sedimentary boundaries, we have divided first-order, second-order, and third-order source-to-sink systems and subordination between them. The results showed that there are three second-order systems and three third-order source-to-sink systems recorded in the unique first-order systems of the eastern Huizhou-Lufeng uplift. The restored geomorphology of the Huizhou-Lufeng uplift in the Lower Wenchang Formation shows that the ancient height (h0) and the dip angle (α0) of each source area are generally much larger than those in the present day in the three third-order source-to-sink systems. These recovered landforms are related to the development of relatively sand-dominated delta systems. The three second-order source-to-sink systems have a larger ancient height (h0), but the ancient dip angle (α0) increment is smaller than today, likely related to the development of interbedded sandstone and mudstone delta systems. Our restoration of the geomorphology in this region may guide the assessment of reservoir properties and scales in the Pearl River Mouth Basin, in large part because our source-to-sink method explains the distribution of various sediment types in the region.