Source-to-sink sediment transport reversals during glacial sea-level lowstands sustain soil formation on pericoastal carbonate terrains

Understanding the processes that drive soil formation is crucial for developing sustainable land-use strategies, as changing land-use practices and climate change exacerbate soil erosion. The formation of substantial arable soils on carbonate bedrock requires substantial dust accretion as the underlying bedrock lacks siliciclastic material. In the Galilee, most fine dust particles are far-travelled from the Sahara and Arabian Deserts. However, the investigation of surface soils along a west–east transect across the Galilee reveals a substantial content of super-coarse, angular quartz silt and heavy minerals, such as zircon, inconsistent with a purely distal origin, calling for additional input from another, currently unrecognised source. Considering the natural setting of the region, we propose that glacial–interglacial cycles have transformed the nearby Haifa Bay from a sediment sink during interglacial high sea-level stands to a source of coarse aeolian sediments during glacial low sea-level stands. This proximal source could provide the coarse siliciclastic fraction identified in soils across the region, which not only improves physical soil properties, such as soil texture, structure and water retention, but could also provide phosphorus-rich apatite, thereby potentially enhancing overall soil fertility. This regional case study outlines how glacial–interglacial sea-level fluctuations resulted in a source-to-sink reversal, activating local sediment reservoirs and reshaping pericoastal soil composition. We postulate that such processes played a key role in maintaining fertile landscapes that supported long-term human settlement on the carbonate bedrock in the eastern Mediterranean.