Geodynamics of the South Balkan and Northern Aegean Regions Driven by the Westward Escape of Anatolia

The Plio-Quaternary deformation pattern of the northern Aegean and south Balkan regions is interpreted as an effect of the interaction between the Anatolian-Aegean-Pelagonian system (Tethyan belt), undergoing westward extrusion and strong deformation, and the surrounding plates (Nubia, Europe and Adriatic). Since the middle-late Miocene, the collision of the Tethyan belt with the continental Adriatic domain has caused strong E-W shortening in the outer Hellenides and Albanides, also involving the southward extrusion of the Peloponnesus wedge, at the expense of the Ionian oceanic domain. The roughly E-W extension recognized in the western South Balkan zones (Macedonia and eastern Albania) is related to the divergence between the Pelagonian belt (Albanides and Hellenides) and the Rhodope-Moesia domain. Stressed by the westward displacement of the central Anatolian plateau and by the southward bowing of the Cycladic Arc, the northern Aegean zone has contemporaneously undergone E-W compression and N-S extension, which has generated a series of dextral shear faults, delimiting a number of slats. The westward displacement and deformation of such slats can explain the morphological features of the northern Aegean zone. During this phase, the push of the central Anatolian plateau also caused the separation of the Rhodope massif from the Moesian European domain, with the consequent formation of the upper Thrace basin. This hypothesis can explain the Plio-Quaternary compressional deformations recognized in a sector of the North Anatolian fault system, the Ganos-Gelibolu zone. The proposed geodynamic/tectonic interpretation may help to explain some features of the time-space distribution of major earthquakes in the study area.

Spatiotemporal variation of shallow water fish assemblages along the coastline of Çanakkale,Turkey

Objective:To determine the shallow water fish species richness ofÇanakkale and to analyse the spatiotemporal variations of these fish assemblages.Methods:Samplings were carried out monthly with a beach seine between January and December 2007.Samples were collected from 6 stations(No.1,2,3,4,5,6).Stations 1 and 4 located in theÇanakkale Strait,2 and 5 in North Aegean Sea,3 and 6 in Sea of Marmara.Results:A total of 112 fish species were sampled and the two most common species were Atherina boyeri and Pomatoschistus marmoratus.A total of 93 species were sampled in theÇanakkale Strait,85 in the Aegean Sea,and 77 in the Sea of Marmara.Shannon diversity index was the highest in the Aegean Sea.Dominant species were caused significant differences of both regional and seasonal fish assemblage fluctuations.Species richness and abundances decreased significantly in winter.Although more species were caught at night and a greater abundance of fishes was obtained during the day,no significant differences were found between day and night in terms of species richness and abundance.Conclusions:The results supported the biogeographical differences between the Aegean Sea,theÇanakkale Strait and the Sea of Marmara in terms of the shallow water fish community.The inventory in the current study can serve as baseline data prior to management strategies to ensure sustainable conservation of the area.