Clustered carbonate mounds in the upper continental slope of the Alboran Sea

High-resolution multibeam bathymetry, seismic reflection data and underwater imagery were used to characterize the morphostructure as well as the ancient and contemporary habitat-forming species in three fields of clustered mounds that were recently discovered in the northern Alboran Sea. A total of 150 small mounds were detected between 140 to 300 m water depth. They display reliefs ranging from 2 to 17 m and circular or mainly NW-SE elongated shapes. The seismic reflection data highlight the presence of stacked buried and exposed mounds that exhibit acoustically transparent facies. They have an heterogeneous composition, mainly consisting of bioclasts of solitary scleractinians, bivalves and rhodoliths that are covered with soft sediments. These mounds may have gone through a complex mound development with a further geological and biological evolution in interaction with bottom currents. The analysis of these carbonate mounds may shed new light on the enormous scale of carbonate deposition along the Iberian Mediterranean margin