Leonidas Stamatopoulos

Morphological and palaeoenvironmental evolution of the Lagoon of Papas, southwestern Greece, during the Holocene (*)

Geomorphological, stratigraphic and palaeoecological surveys have been carried out along the coastland of the Lagoon of Papas (Kalogria) since 1994, with the aim of depicting its morphodynamic and palaeoenvironmental evolution during the Holocene, until the present. The coast was previously affected by tectonic activity which exerted a morphologic control, interacting with the Quaternary sea-level changes. These processes resulted in subsidence during the MIS 7, followed by the MIS 5 transgression with marine and lagoon sediment deposition. The subsequent regression caused the deposition of alluvial covers and fans, later dislocated by the differential uplift which formed a terrace and a coastal plain at its base, tilted towards the northwest. This plain was dissected and uplifted by recent tectonics which has developed a new terrace, separated from the former by a post-Tyrrhenian fault scarp. Particularly, during the Holocene the coastal plain was characterized by the deposition of alluvial sediments eroded from the southwestern hills, increase of fluvial meanders, westward deviation of watercourses, development of ponds, swamps and finally of a lagoon. Multidisciplinary studies, including examination of historical cartography, bathymetric map, microfossil analysis and geomorphological surveys, have shed light on the gradual genesis of the lagoon. The lagoon developed during the Holocene in a pre-existing wide bay, starting from a sequence of a few littoral spits elongated from southeast to northwest. Palaeoecological analysis confirmed the alternation of brackish to marine environments, through the recognition of different groups of microfossil assemblages. Morphological and sedimentological study of the lagoon bottom showed some hummocks and facies related to buried relict spit and overwash structures. This morphodynamic evolution is analogous to that described for some Tyrrhenian and Adriatic lagoons from Italy, as well as for other Mediterranean lagoons.

Last glacial geomorphologic records in Mt Chelmos, North Peloponnesus, Greece

This study deals with the analysis of the glacial processes that have affected the relief of Mt Chelmos in northern Peloponnesus, Greece during middle and Late Pleistocene. The goal was to compile a combined geomorphological-geological map of the study area which would enable the chronological stratification of the glacial landforms cropping up on Mt. Chelmos. Chronological stratification was further aided by optically stimulated luminescence (OSL) dating. The map served as the basis upon which the reconstruction and discussion on the phases of the Middle-Late Quaternary paleoclimatic history of Mt. Chelmos have been made. A sophisticated semiautomated method was first used to analyze the Digital Elevation Model (DEM), combined with Aster, Quickbird and ALOS imagery in order to identify glacial and periglacial, as well as karstic features. Then, these features along with other nonrecognizable features from the remote-sensing images were documented in the field. In this way, several glacial landforms were identified, such as moraines and cirques, indicating extended glaciation phases during the middle and Late Pleistocene. Additionally, a ground moraine located at an altitude of 1900-2050 m, within the Spanolakos glacial valley, was dated using the OSL-dating method. The resulting ages indicate a phase of glacier advance/stabilization during MIS-5b (89-86 ka), which is in consistence with pollenrecord evidence from Greece and the Mediterranean.