PALEOMAGNETIC EVIDENCE FOR CENOZOIC CLOCKWISE ROTATION OF THE EXTERNAL ALBANIDES

A paleomagnetic study of 750 samples obtained from 55 late Eocene to middle Pliocene sedimentary sites demonstrates a clockwise rotation of about 45 degrees of the external zones of Albania. This rotation occurred either in two phases of roughly equal amplitude during the early-middle Miocene and Plio-Pleistocene or in a single phase with a clear acceleration of the movement during the Plio-Pleistocene. The good agreement of these results with those from southern Albania and northwestern Greece indicates that a large geographical area is involved in the rotation. The active 'Aegean' compressive front thus extends much farther north than hitherto believed and the rotational pattern is not significantly distorted by the tectonic discontinuities recorded by geological studies. The external zones of the Albano-Hellenic Belt appear to have rotated virtually as a single entity from the Peloponnesos to northern Albania over a deep decollement level probably involving the basement itself.