The Middle and Late Holocene Geology and Landscape Evolution of the Lower Acheron River Valley, Epirus, Greece

Abstract

The lower Acheron River Valley, Epirus, Greece, hosts a rich, archaeological heritage dating back to the Lower Palaeolithic (Dakaris, 1971). Beginning with the Odyssey of Homer in the eighth century BC, numerous ancient authors make reference to the valley and describe a landscape configuration that is significantly different from that of the present. Three notable discrepancies concern: 1.) the size of the Glykys Limen (modern Phanari Bay), 2.) the nature, geometry, and evolution of the Acherousian lake, and 3.) the course of the Acheron River with respect to Kastri during the Classical Period. Are these ancient authors incorrect in their descriptions of the valley, or can a natural sequence of geomorphic evolution account for such discrepancies? To answer this question, an examination of the changing paleogeography and paleoenvironmental configuration of the valley during the past 4000 years was undertaken. Twenty-eight gouge auger sediment cores were taken from various locations in the valley between 1992 and 1994. Selected sediment samples underwent analyses of microfossil assemblages, organic carbon content, grain-size, magnetic susceptibility, and anhysteretic magnetization. Results from these analyses were used along with stratigraphic data and eight radiocarbon dates to reconstruct the middle and late Holocene paleogeography of the valley. The reconstructions suggest that the accounts given by ancient authors are correct, and that the discrepancies are the result of natural landscape evolution. In fact, the picture that emerges shows that recent geomorphic change in the valley has been quite significant with nearly six kilometers of shoreline progradation having occurred during the last 4,000 years.