Geoarchaeology of Sidon's ancient harbours, Phoenicia

Geoarchaeological data from Sidon's ancient harbour areas elucidate six evolutionary phases since the Bronze Age. (1) At the time of Sidon's foundation, during the third millennium BC, medium sand facies show the city's northern and southern pocket beaches to have served as proto-harbours for Middle to Late Bronze Age societies. (2) Towards the end of the Late Bronze Age and the Early Iron Age, expanding international trade prompted coastal populations into modifying these natural anchorages. In Sidon's northern harbour, transition from shelly to fine-grained sands is the earliest granulometric manifestation of human coastal modification. The lee of Zire island was also exploited as a deep-water anchorage, or outer harbour, at this time. (3) Although localised sediments evoke developed port infrastructure during the Phoenician and Persian periods, high-resolution reconstruction of the northern harbour's Iron Age history is problematic given repeated dredging practices during the Roman and Byzantine periods. (4) Fine-grained silts and sands in the northern harbour are coeval with advanced Roman engineering works, significantly deforming the coastal landscape. Bio- and lithostratigraphical data attest a leaky lagoon type environment, indicative of a well-protected port. (5) The technological apogee of Sidon's northern harbour is recorded during the late Roman and Byzantine periods, translated stratigraphically by a plastic clays unit and brackish lagoon fauna. (6) A final semi-abandonment phase, comprising coarse sand facies, concurs silting up and a 100-150 m progradation of the port coastline after the seventh century AD. We advance three hypotheses to explain these stratigraphic data, namely cultural, tectonic and tsunamogenic. Finally, our results are compared and contrasted with research undertaken in Sidon's sister harbour, Tyre.