Holocene Paleoenvironments and Magna Grecia settlements at the mouth of the River Sele (Campania, Southern Italy).

Abstract«Piana del Sele» is a coastal plain lying on the southern reach of the Tyrrhenian coast and is of great historical and archeological concern in that here are located the Greek town of Poseidon and the sanctuary devote to Hera Argiva nearby the Sele outlet.A geomorphologic survey and a multidisciplinary study on sediment cores from 16 boreholes drilled along 3 transects close to the mouth of the River Sele provided the following characterization of sedimentary suite:a - Lowermost unit: it consists of clay and silty clay sediments enriched in peat and/or dispersed organic matter up to 20 m thick and ranging in radiocarbon age from 10 to 6 kyr B.P. Ostracods point out an environment trending from brackish to freshwater conditions whereas and benthic foraminifers compatible with low salinity prevail. Pollen analysis revealed abundance hygrophilous and hydrophilous plants along with the recurrent occurrence of alder woods. Thus it results that the unitwas deposited in a low salinity/fresh water coastal basin (lagoon/marsh).b- Intermediate unit: it includes up to 10 m of sands and pebbles; based on the overall features the unit is referred to a former beach/dune system. This sediment suite records a marine ingression, 14C dated from 10 through 5 kyr B.P. as well as the subsequent sea retreat.c - Uppermost unit: it is made up of weathered clay or fine, dark red colored sediments, containing both carbonate concretions and vegetal debris. Such features do reflect the subaerial deposition developed at the back of the beach/dune system that, since 5 kyr B:P., commenced to migrate seawards up to the present position in response to a progressive marine regression.Radiocarbon datings point out that the Holocene transgression lasted up to 5 kyr B.P. and according to field evidence the relative sea-level rised ca. 1 m above the present one; since then up to now apart from small fluctuations the relative sea-level decreased. It is just during this phase of sea withdraw, in a paleoenvironmental scenario where the former lagoons and marshes were drying up and a regime of subaerial deposition was in progress, that the sanctuary of Hera Argiva was erected.