H. Maroukian

The Spatial Distribution of Middle and Late Pleistocene Cirques in Greece

Abstract In reece, iddle to ate leistocene mountain glaciations appear to have been quite extensive, along the mountain range of indus, on t lympus and in the highlands of eloponnesus and rete. This study focuses on the extent of the iddle to ate leistocene glaciations in reece based on the examination of cirque formations. An initial spatial database of these glacial forms was created for the first time in Greece, including cirque location and morphometric properties. In total, 265 cirques were recorded covering a total area of 94.9 km2 with limestone as the dominant underlying lithology. The number of cirques has decreased in southern reece. Cirques occur at altitudes ranging from 2770 to 1600 m a.s.l. The largest cirque areas are observed in northern reece. Since several highlands of reece have uplifted, the mean elevations of these cirques have increased in time. In northern reece the cirques are wider, longer and deeper. The vast majority of cirques are facing towards the northeastern hemisphere due to more severe climatic conditions originating from the northeast during glacial periods.

The significance of tectonism in the glaciations of Greece

Abstract Glaciers were common features in the highlands of Greece during the Middle to Late Pleistocene glacial periods and cirques are characteristic landforms of mountain glaciation. This study examined the cirques of Greece and the role of tectonic uplift in determining their altitude across the country, from Mount Olympus to the Peloponnesus and Crete. An inventory of 227 Middle to Late Pleistocene age limestone cirques was compiled. The number and total area of the cirques decreased from northern mainland Greece (Macedonia, Epirus) to the south (the Peloponnesus, Crete) and on moving to higher elevations. Continued tectonic uplift of the Olympus massif, the Peloponnesus and Crete has led to altitudinal changes in cirques in every subsequent ice age. The formation of cirques at lower elevations during Marine Isotope Stage 12 suggests extreme climatic conditions. On Mount Olympus, the mean elevation of cirques was estimated to have increased by c. 450 m since Marine Isotope Stage 12; in the northern and southern Peloponnesus the elevation increased by c. 500 m and 190 m, respectively, and in Crete by c. 400 m. The cirques have uplifted at approximately the same rate in northern Greece, but at different rates in southern Greece during this period.

Geomorphological study of Cephalonia Island, Ionian Sea, Western Greece

In this paper a geomorphological map, at a scale of 1:50,000, of the Cephalonia Island located in the Ionian Sea (western Greece) is presented and discussed. The geology of the island is represented in an individual smaller inset map. The map was produced from field surveys based upon 1:50,000 scale topographic maps and 1:5000 topographic diagrams, differential global positioning system surveys, aerial photos and visual inspection and interpretation of Google Earth images, and analysis of a digital elevation model of the island derived from 1:50,000 scale topographic maps. Landforms were grouped on the basis of the main morphogenetic processes and include fluvial landforms, erosional landforms, gravitational landforms, karst landforms, and coastal features. The objective of this map is to provide information about the landscape evolution of the island during the Quaternary. The study of the landforms depicted on the geomorphological map showed that the recent evolution of the landscape is dependent mostly on neotectonic processes and eustatism.

Palaeogeographic Evolution of the Cyclades Islands (Greece) During the Holocene

The Cycladic islands are located in the central Aegean Sea (Greece) forming a partly submerged plateau separated into two parts: the eastern shallower one (Andros, Tinos, Mykonos, Naxos, Paros, Syros, Ios, Sikinos, Folegandros) which formed one big island (6.978 km2) at the end of the last glacial period; the western islands (Kea, Kythnos, Serifos, Sifnos, Milos) which remained separated during the same period. The eastern islands constitute an erosional plateau which is the end product of a Neogene palaeosurface that was partially submerged due to thinning of the crust during the Quaternary. The presence of numerous Neolithic sites both on land and submerged indicates the existence of an advanced civilization in the area for thousands of years. The location of the lost Atlantis could be found in this area probably between Naxos, Paros and Antiparos.

Effects of Lithology, Mineralogy, and Weathering on Particle Size Variability of Sediments in the Coastal Environment of Livada Bay in SE Tinos Island, Greece

Abstract The Livada torrent in Tinos Island (Cyclades, Aegean Sea), a fourth-order dendritic-type stream, has developed almost alongside the lithologic contact of granites (42% of drainage basin area) and schists (58%). The drainage network has not developed equally because of the differential permeability capacity and erosive susceptibility of the two rock types, the eastern part (schists) being more developed than the western (granitic) one. Within the study area, detailed coastal geomorphologic mapping, lithologic determination of fluvial and coastal pebbles and cobbles, and grain size distribution combined with mineralogical analysis of the sand fraction were performed. Chemical spheroidal weathering takes place through the joints of granite, forming tors and core stones. Tafoni are usually found closer to the coastline because of saltwater action. Near the shore, the coarse material (pebbles, cobbles) is almost exclusively composed of schists (90%) and only 10% of granite, as schists are highly and deeply fractured. The finer sandy material is composed mainly of quartz. Garnet, feldspar, magnetite, amphibole, biotite, and minerals of ophiolitic origin are minor constituents. Particle size analysis of fluvial and coastal sands between the 200–315-μm and 800–1000-μm grain size range showed a difference in percentage of quartz participation originating both from granite and schist. The predominance of grains of sand size rather than of boulders and cobbles of granitoid rocks in the stream sediments indicates that granitoid rocks disintegrate relatively faster than schists.

The Uplifted Terraces of the Arkitsa Region, NW Evoikos Gulf, Greece: A Result of Combined Tectonic and Volcanic Processes?

The Arkitsa-Kamena Vourla area of central Greece occupies a zone of accommodation between the two tectonic provinces of the North Aegean Trough (the extension of the North Anatolian fault system) and the Gulf of Corinth and is characterized by a series of very prominent tectonic landforms, notably the large (ca. 1000 m elevation) footwall ridge of the Arkitsa-Kamena Vourla fault system. Despite the highly prominent nature of this footwall ridge and the presence of very fresh tectonic landforms, this fault system is not known to have hosted any major historical earthquakes, and the tectonic and geomorphic evolution of the Arkitsa-Kamena Vourla area remains poorly constrained. This article utilizes a combined geomorphological, sedimentological, and macro-/microfossil approach to evaluate the Late Quaternary evolution of the Arkitsa area, in the eastern part of the fault system, focusing on prominent uplifted terraces present in the hanging wall of the Arkitsa fault. Three distinct raised glaciolacustrine terraces and previously reported uplifted marginal marine deposits suggest sustained uplift of the coastline at a rate of 1–1.5 mm/yr over the past at least 40,000 yr, possibly dating to 75,000 BP. While movement on an offshore normal fault strand may explain more recent coastal uplift, purely fault-driven, longer-term uplift at this rate requires anomalously high fault-slip and extension rates. Consequently, the development of the terraces and other geomorphic indicators of uplift may be at least partly due to nonfaulting processes, such as Quaternary (intrusive and/or extrusive) volcanic activity associated with evolution of the nearby Lichades volcanic center.