GEOLOGICAL APPROACH TO THE STUDY OF PALAEOLITHIC ANTHROPOGENIC SEDIMENTS AT THE LAKONIS BEACH, GYTHION, PELOPONNESE

• E. Chiotis (Institute of Geology and Mineral Exploration, 70 Messoghion str., 115 27 Athens, Greece)

The stratigraphy of anthropogenic sediments is studied in geological terms at the Palaeolithic cave settlements at Lakonis beach. The paper aims at the differentiation of stratigraphic unities based on sedimentological criteria and at the correlation of them over the neighbouring settlement sites. Additionally, the petrography of the stone artifacts is studied and the abundance of the rocks used as raw materials.

It is underlined that the preserved sediments represent only a small portion of the primarily deposited sediments due to drastic erosion at certain intervals during which the settlement was impossible or at least interrupted. The first erosional phase was caused by marine transgression that deposited a conglomerate layer only locally preserved today, still though very useful as a stratigraphic reference level. In the intervals of settlement, following the marine transgression, at least two episodes of terrestrial erosion by sometimes, violent water flow can be observed. The latest episode is very clear from the deposition at the Kavos site of a blanket of porous carbonaceous sediment, a few centimeters thick that covered the underlined sediments. Water circulation led also to the fossilization of the roots of bushes. During the deposition of this travertine-like crust the settlement was again interrupted. At Kavos site, where the most complete stratigraphic section is available, the falling down of the roof of the cave after this erosional episode might be associated with the erosion of cave pillars that put an end to the settlement.

Three main stratigraphic unities are distinguished: the oldest one below the marine conglomerate, the latest one above the crust of travertine and the intermediate one in between, which might correspond to two successive periods of inhabitation separated by a minor interval of erosion. The periods of erosion correspond to warm climate intervals while the sediments subjected to erosion had originally been deposited in periods of colder climate. The fact that some anthropogenic sediments escaped from marine erosion under circumstances of high agitation, as evidenced from the deposition of conglomerate, indicates an early lithification of the anthropogenic sediments that survived. Apart from the strong cementing action of the calcite, the role of bones is examined, especially because apatite derived from bones is observed, surrounding pieces of marble.

The geological evidence is not sufficient for the dating of the sediments, it provides however both an orientation frame for dating and suggestions for effective sampling as explained in detail.

The artifacts are made of a variety of rocks including andesite, tuffite, quartz and chert. All these rocks are presently available in short distance from the caves in the form of pebbles in steams and along the beach. Only one artifact is made of a rock so far not identified in the broader area, i.e. a pink chert, which might come from nodules in Neogene sediments.