Impact cratering plays a major role in shaping the Moon's surface, producing widespread ejecta deposits that archive the sedimentary and morphological imprint of planetary surface processes. Since early 2019, the Chang'e-4 mission has been investigating such deposits within the Von Kármán crater, where materials ejected from the nearby Finsen crater were emplaced across a complex landscape. This setting offers a rare opportunity to study ejecta emplacement directly from the ground. However, despite valuable in situ subsurface exploration, the geomorphic patterns and depositional mechanisms of these ejecta remain unconstrained at the scale of individual landforms. Here, we integrate digital terrain analysis with lunar penetrating radar data to characterize the morphology and internal structure of the landform traversed by the mission's rover. The analysis defines the spatial extent of the landform and reveals its morphology, which is configured as a ridge over a sheet-like flow. Internally, we identify two stacked sedimentary sequences overlying mare basalt: a basal paleoregolith marked by a hummocky structure overlain by Finsen ejecta. Ejecta morphology reflects interactions between local topography and deposition volume, with ridge areas reaching ∼30 m in thickness, including ∼10 m imaged by radar. The landform's shape and subsurface architecture support emplacement triggered a syn-depositional dry debris flow that remobilized the underlying paleoregolith. These findings provide an example of medial-to-distal ejecta emplacement shaped by dynamic processes, contrasting with more static classical models. They demonstrate how integrating surface, and subsurface data supports reproducible ejecta models, offering a framework for investigations on the Moon and other planetary surfaces.
