Enigmatic buried scours provide new clues for the Middle to Late Pleistocene paleolandscape reconstruction of the outer Belgian Continental Shelf

The breaching of the Weald–Artois Ridge, which once connected the UK to mainland Europe, represents one of the most significant events shaping the paleolandscape of the Belgian, UK, and French sectors of the Southern North Sea from the Middle Pleistocene onwards. The timing and mechanism of its breaching, which led to the formation of the Dover Strait, remain the subject of ongoing debate. This event marks the onset of regular inundation of the Belgian Continental Shelf (BCS) during sea-level highstands, alternating with exposure during sea-level lowstands. In this region, erosion is dominant, resulting in the frequent exposure of Paleogene-Neogene strata. Nevertheless, a discontinuous cover of Pleistocene and Holocene sediments persists. Together with erosional features, this sedimentary record offers valuable evidence of the region’s complex history.

In recent years, new and higher resolution 2D seismic and acoustic datasets have been acquired for both scientific and commercial purposes in the more offshore sections of the BCS, an area where data availability was previously limited. This study integrates these datasets to develop a more comprehensive understanding of the discontinuous Pleistocene deposits. In a first step, the erosional boundary between Paleogene– Neogene strata and overlying Quaternary deposits was mapped and gridded in unprecedented detail. The resulting surface not only refines the position and morphology of previously described escarpments and valleys but also reveals new escarpments and a series of elongated linear and curved scours of uncertain origin. As these scours are possibly related to either tidal, fluvial, glacial or ice berg scouring, understanding the origin and sequence of these features is essential for reconstructing Quaternary palaeolandscapes and may provide further insights in the breaching of the Weald-Artois Ridge.

Finally, this study aims to identify, sample and describe the various Pleistocene units in the area. Supplementary analyses, such as pollen and microfossil studies, as well as radiocarbon and optically stimulated luminescence (OSL) dating will ultimately enable the development of a comprehensive and updated reconstruction of the palaeolandscape evolution of the outer BCS and adjacent regions.