Formation, evolution and present-day activity of offshore sand ridges on a narrow, tideless continental shelf with limited sediment supply

The morphology, architecture and distribution of the Murcia sand ridges suggest that they were formed in a shallow-water environment during the Holocene transgression and were later detached from the coast due to the subsequent sea level rise. The shallow architecture of the sand ridges reveals the presence of small, mound-like features within the sand ridges, most probably associated with coastal deposits, which could have served as a precursor for the development of the sand ridges. The preservation of these deposits within the sand ridges evidences limited offshore ridge migration. At present, active subaqueous dunes superimposed on the sand ridges suggest that they may play a significant role in the ridge evolution. At a regional scale, the comparison of the Murcia sand ridges with those described in the western Mediterranean allows us to propose a gradation from partially evolved to fully evolved sand ridges with increasing water depth.