Reverse slip along the contact Phyllite-Quartzite Unit/Tripolitsa Unit in eastern Crete: implications for the geodynamic evolution of the External Hellenides

The present paper includes new results from mapping, structural investigations and strain analysis carried out southeast of Sitia (Crete, Greece). This part of eastern Crete has been considered as an outcrop region of a major extensional detachment fault, the Cretan Detachment, which separates siliciclastic rocks of the Phyllite-Quartzite Unit (footwall) from carbonates of the Tripolitsa Unit (hanging wall). Based on the new results, this boundary is not related to continental extension but to Neogene thrusting. Upper Violet Slates, which did not undergo Alpine subduction, and Neogene conglomerates are sandwiched between anchimetamorphic rocks of the Phyllite-Quartzite and Tripolitsa Units. The Upper Violet Slates might represent an equivalent to the Ravdoucha and Tyros Beds of western Crete and the Peloponnesus, respectively. On the other hand, extensional structures are documented at deeper structural levels within the Phyllite-Quartzite Unit as is indicated by (1) the lack of metamorphic index minerals in the uppermost Violet Slates, (2) the structural record, microfabrics and related deformation mechanisms of quartz and calcite and (3) the magnitude and geometry of finite strain.