Pleistocene raised marine deposits of the Cap Bon peninsula (N-E Tunisia): Records of sea-level highstands, climatic changes and coastal uplift

Morphostratigraphic and sedimentological studies were undertaken in the Cap Bon peninsula, north-eastern Tunisia. These studies have identified a series of middle to late Pleistocene-age marine deposits discontinuously cropping out on three raised platforms (Pf I, Pf II and Pf III). These stepped marine platforms (terraces) were related to the interplay between Pleistocene sea-level changes and progressive uplift movement during Quaternary period. We present here a description of facies organization and stratigraphic characteristics of the platform deposits, and their relation with eustatic and climatic variations. All the marine platforms unconformably overlie a Mio-Pliocene and Quaternary slope succession. The sedimentary sequences represented by mixed carbonate and siliciclastic bodies are related to the succession of highstand shorelines and contrasting climate conditions. The intercalated soils and calcretization occurred during episodes of relative sea-level fall. The oldest platforms (Pf I and Pf II), found at an elevation of about + 100 m and + 60 m respectively, have so far no equivalent in the northern, in the eastern or in the southern coasts of Tunisia. They are correspondingly attributed to MIS 11/13 and MIS 9/11. The youngest and lowest platform (Pf III) attains an altitude of + 40 m and shows three high-frequency cycles of sea-level rise and fall, probably associated with Marine Isotope Stage (MIS) 5e and MIS 7.