Geology of Ammouliani Island (Northern Greece) – implications for the tectono-magmatic evolution of the Serbo-Macedonian Massif

Abstract

Ammouliani Island is located in Northern Greece with its exposed rocks belonging to the Serbo-Macedonian Massif of the Hellenic hinterland. Its geology is of great importance because it lies in an area where a striking change in trend of the orogenic fabric from NW-SE to ENE-WSW occurs. For this purpose, a geological map at a scale of 1:10,000 is presented based upon detailed fieldwork and the interpretation of satellite imagery. In addition, special interest has been paid to the tectonic elements of the map units. This detailed mapping results in the definition of a new unit, the Ammouliani Unit, which is placed between the underlying Kerdilion and the overlying Vertiskos Unit of the Serbo-Macedonian Massif. The main features of the Ammouliani Unit are the predominance of leucosomes and the intense migmatization and strong shearing. Three main folding events (F1, F2 and F3) have been defined in the exposed rocks of the island with the first related to intense migmatization and shearing, whereas the last two are progressive to each other and are related to Mesozoic orogenic processes. In addition, NE-ENE striking shear zones were observed with the Ammouliani granite placed parallel to these. The bending of the orogenic fabric from NW-SE to ENE-WSW is younger than the F2 and F3 folding events and is related to Tertiary orogenic (tectono-magmatic) processes due to the convergence between Apulia and Eurasia and the ongoing retreat of the Hellenic subduction zone.