Main geomorphologic features in the Canary Current Large Marine Ecosystem

Abstract

The Canary Current Large Marine Ecosystem shelf has the typical size and composition, of passive continental margins. In general, it has a mean width between 40-50 km, with exceptions like Bank D´Arguin or Dakar. The maximum age of the sedimentary rocks is 200 Ma. The geomorphological variations are the result of the sedimentary contributions associated to the river basins, which also influence the genesis and presence of canyons in the shelf and slope. These canyons are the main geomorphological features in the region. Seamounts, salt domes, pockmarcks and gravitational processes like debris flows are also observed. The tectonic processes are generally extensive, but have a small influence. It is remarkable the presence of a coral reef with more than 400 km of length in the shallowest Mauritania slope. The geomorphological studies in the intraplate volcanic islands (Canary Islands and Cape Verde), confirm the presence of developed shelves in the older islands, not observed in the younger ones. There are gravitational slides and canyons in all the islands. The region was divided in 4 areas: Morocco–Western Sahara; Mauritania; Canary Islands; and Senegal –Gambia –Guinea–Bissau – Guinea–Cape Verde. Within each of these areas, different geomorphological and geological domains are described.