Holocene Sequence of Sea-Level Fluctuations in Relation to Climatic Trends in the Atlantic-Mediterranean Linkage Coast

Abstract

The systems of spit bars that crop out in the area of linkage Atlantic-Mediterranean began to accumulate around 6,900 yr BP during the maximum of the Present Interglacial. From the morpho-sedimentological study of these spit bar systems, the study of littoral dynamics (particularly the littoral drift and interchange of "superficial Atlantic water" (SAW) and Mediterranean water), and the results of ¹⁴C measurements, we have deduced that (a) the maximum of the Present Interglacial took place ca. 6.500 yr BP, (b) the progradation of spit bar systems relates to climate; anticyclonic conditions increase the entrance of "superficial Atlantic Water" into the Mediterranean, and enhance littoral drift favouring progradation. In contrast, the entrance of SAW decreases under low-pressure conditions causing reduced littoral drift, no progradation and, as a consequence, generation of the very large swales or erosional surfaces separating successive spits. (c) In the most complete case, four large prograding bodies called H_1, H₂, H₃ and H₄, can be distinguished, but more ¹⁴C measurements are required to deduce more precise periodicities.