Offshore remobilization processes and deposits in low-energy temperate-water carbonate-ramp systems: Examples from the Neogene basins of the Betic Cordillera (SE Spain)

General facies models developed for modern and ancient Mediterranean temperate-water carbonates in the last two decades have shown that the style of deposition on outer-ramp, slope, and basin environments in low-energy areas such as the Mediterranean Sea differs overall from that of high-energy open-ocean areas, given the wider variety of smaller-scale topographic and hydrodynamic conditions in the former setting. However, these depositional models generally lack relevant information about sedimentary processes, transport mechanisms and controlling factors on offshore sediment redeposition, which are potential sources of information for sequence stratigraphic, palaeoclimate and exploration studies. Several examples from the Neogene Betic basins of the western Mediterranean region have been selected to integrate the processes and controlling factors on the offshore sediment transport and the resulting deposits. Additional published data from other Mediterranean localities have also been considered.An idealized model of temperate-water carbonate deposition in the study examples comprises a shallow-water coastal belt and a shoal area developed landwards of a carbonate-factory zone, and deeper-water outer-ramp, slope, and basin settings below the storm wave base. The environments off the factory bear a variety of remobilized deposits characterized by distinctive features. These deposits include storm shell beds, sediment gravity flows (debrites and turbidites), bed packages with hummocky and swaley cross-stratification (HCS and SCS), slope sandwaves, and channel as well as lobe deposits.The different types of redeposited facies resulted from various offshore sediment-transport processes interacting with the local conditions. Storm shell beds developed in low-energy protected basins, regardless of the ramp profile. Debrites and turbidites formed in the distal parts of moderately-steep ramps within moderately energetic hydrodynamic contexts. Similar gradients but with higher hydrodynamic energy and appropriate sediment grain size favoured the formation of deposits with HCS and SCS in relatively deep-water settings. The circulation pattern of currents within the basin was the main factor controlling the formation of downslope migrating sandwaves. In the case of channel and lobe deposits, hydrodynamic-flow behaviour through the channels and at the transition point conditioned the features of the resulting deposits.Offshore resedimentation is consistent with a highstand shedding model in the case of storm-driven event deposits (storm beds, sediment gravity flows and deposits with HCS–SCS) while offshore directed and persistent unidirectional currents generated prograding margin clinoforms during falling and low sea levels.This review provides a concise depositional framework to understand the different redeposition processes operating in low-energy, temperate-water carbonate ramps and to interpret remobilized deposits in low-energy regions such as the Mediterranean Sea.