Buried marine-cut terraces and submerged marine-built terraces: The Carchuna-Calahonda coastal area (southeast Iberian Peninsula)

- Marine terraces record recent sea-level changes in the westernmost Mediterranean.
- Gravity prospecting reveals main onshore buried marine-cut terraces.
- Gravity and seismic data establish onshore-offshore marine terraces relations.
- Study of marine terraces evidences a tectonically stable coast.

The Carchuna-Calahonda coastal area is located between the onshore Betic Cordillera and the Alboran Sea. Its onshore sector is formed by detrital sediments that cover a metamorphic basement mostly composed of marbles, contiguous to an offshore shelf setting. New onshore gravity data allow us to characterize the location of flat marine-cut terraces carved into the metamorphic bedrock, which are covered by detrital sediments. In addition, multibeam bathymetry data, 3.5 kHz and sparker reflection seismic profiles, reveal offshore flat features linked to marine terraces that are related with the onshore buried marine-cut terraces. Gravity data are newly used to detect marine-cut terraces covered by sediments, enhancing the integration of onshore and offshore data. The marine terraces are distinguished based on the relative sea-level trend (regressive versus transgressive) and on the dominant sedimentary regime (erosional versus depositional). These data help constrain the ages of the marine terraces younger than 150 ka, using available Late Quaternary sea-level curves. Although previous geodetic research suggests a rapid sinking of the Carchuna-Calahonda coast, the heights of the marine-cut terraces and depositional terraces are mainly driven by sea-level changes, not tectonics.