Geophysics and Geodynamic Implications for the Evolution of the Hellenides

Abstract

A synthesis of geophysical data from the Aegean Sea reveals high heat flow and strong vertical uplift related to a general expansion of this area. It appears that the continental crust has been stretched considerably and thinned to about half its original thickness. The direction of expansion is north-south and northwest-southeast. In contrast to the Aegean Sea where tensional tectonics prevail, the outer Hellenic zones are structurally in a phase of compression. Extensional deformation is recorded by normal faults and a flexure, and also by important listric faults. The nature of seafloor spreading which may have induced some deformation of the Hellenides is questioned: the amount of lateral movement in the Red Sea has not been large enough to trigger the type of motion suggested by some workers. It is envisioned that the present-day deformation of the Aegean is a response to vertical movement of lithothermal masses rather than to horizontal deformation and subduction.