The Syrian Coast: A Model of Holocene Coastal Evolution

On the calcareous Syrian coast, rocky but low for the most part, three different processes alternated several times during the Holocene: heavy sedimentation with prograding beaches; mechanical erosion with the receding of the coast and the formation of beach-rock; organogenic construction (vermetids) and biocorrosion. No less than three main aggradational phases occurred (during the 4th millenium BC, the 2nd millenium BC and the medieval period); each of them can be correlated with an important alluvial discharge from the Lebanese and Syrian wadis and rivers, carried by the South-North coastal drift and built into huge beaches. Only the last fluvial terrace (the medieval one) could be C-14 dated so far, but the oldest terrace, rich in Neolithic sherds, cannot be older than the 5th millenium BC, and the second one contains Bronze Age (2nd millenium BC) artifacts. So the aggradation beaches are clearly in phase with fluviatile discharges controlled by climatic oscillations or anthropic factors. When the alluvial discharge diminished, former beach deposits were eroded by the waves and currents, the coast receded and beach-rock formed. The unconsolidated beach sediments were, to a large extent, carried away, and biological and biochemical processes developed on the bedrock and beach-rock (vermetids settled down and corrosion benches developed). Then whenever a new alluvial phase occurred, the vermetids were eroded or disappeared; fossilized under beaches, the biological and biochemical processes stopped, and a new cycle began with an aggradation beach stage. So during the Holocene on the Syrian coast, several geomorphic processes successively occurred, mainly controlled by climatic oscillations but also probably by anthropic factors. According to numerous C-14 datings, the duration of each phase was about a millennium.