TECTONIC CONNECTION OF THE HELLENIC AND CYPRUS ARCS AND RELATED GEOTECTONIC ELEMENTS

The Cyprus Arc System forms part of a well-defined, presently active, plate boundary and is a critical area for understanding the evolution of the Eastern Mediterranean Sea. The available seismic reflection profiles are utilised in order to establish the nature and origin of the main tectonic features of the arc, which include: (a) The Cyprus Trench, displaying evidence of underthrusting and morphostructural features typical of subduction zones. (b) The Pytheus Trench, associated with right-lateral strike-slip movement and connecting the western end of the Cyprus Trench to the Strabo Trench sector of the Hellenic Trench System. (c) A predominantly transtensional fault zone connecting the easternmost part of the Cyprus Trench via the Baer Bassit overthrust zone in Syria to the Dead Sea Tranform Fault System. (d) A zone of complex deformation, involving thrust and transform elements, running from the Misis Mountains of southeast Turkey through the Kyrenia Range in Cyprus to the Gulf of Antalya and transected by roughly N-S major shears (notably the Cape Gelidonya-Anaximander Mountains strike-slip zone), which appears to form the western boundary of the present active system of the Cyprus Arc. The nature of the shallow structures associated with the Cyprus Arc is consistent with a geotectonic model involving some post-Miocene rotation of the South Anatolian-Cyprus Block, probably induced by "escape dynamics" resulting from continent-continent collision in eastern Turkey and the development of the Maras triple junction in southeastern Turkey. The alternation of plate boundary sectors respectively characterised by thrusting and strike-slip displacement suggests that the shallow crust in this part of the eastern Mediterranean is in a compartmented and relatively brittle state, allowing accumulated boundary stresses to be accommodated largely by displacements and deformation along secondary features.