Provenance Constraints on Fan-Delta–Submarine-Fan Linkages in the Late Miocene Upper Huangliu Formation, Yinggehai Basin, South China Sea

Reconstructing links between basin-margin fan deltas and submarine fans requires evaluating compositional similarities within a depositional framework. This study integrates 3D seismic data, drilling records from 31 wells, and core observations with heavy-mineral data from 89 samples in 17 wells, lithic-fragment counts from 30 samples in 10 wells, and published detrital zircon age spectra from eight wells in the Upper Huangliu Formation, Yinggehai Basin. Three basin-margin belts exhibit spatial differences in heavy-mineral assemblages, heavy-mineral indices, lithic compositions, and zircon age spectra. Several margin-proximal submarine fans retain affinities with adjacent fan deltas, whereas basin-interior samples show both overlap with and departures from these references. Proximity alone therefore cannot explain all preserved compositions. The western gentle-slope configuration involves sediment transfer toward the depression, whereas the eastern slope-break configuration includes slope and slope-foot accumulation. Core and seismic observations support gravity flows as the primary depositional mechanism and suggest possible local bottom-current reworking. However, traction structures and erosional geometries also permit gravity-flow interpretations and do not establish regional sediment redistribution. The resulting qualitative source-to-sink model links basin-margin supply, paleotopographically constrained transport, and intrabasinal accumulation, providing a framework for interpreting submarine-fan composition and sand-body distribution.