NEW PALEOMAGNETIC RESULTS FROM THE AEGEAN EXTENSIONAL PROVINCE

Various Oligocene formations from NE Greece (ignimbrites from the Medo usa area, rhyolites from Zagradenia, granodiorites from Elatia) show d iscordant paleomagnetic signatures, in each case indicating small cw ( clockwise) rotation and also inclination flattening. Marls from Pithio n were partly remagnetized in a present-day field. Samples that contai n ancient magnetization components also indicate small cw rotation and inclination flattening. However, the magnetization of andesites from Peplos reflects a considerably larger rotation, likely owing to local tectonics. In the context of previous work in the area, these results are used to propose a subdivision of NE Greece into four structural zo nes of distinctive rotational behaviour (from east to west): sites in zone 1, east of the Kavala-Xanthi-Komotini fault (KXK), show various c w and ccw (counterclockwise) rotation angles owing to complex kinemati cs resulting from the interaction of the KXK and the north-Anatolian f ault zone. However, zone 2, between the KXK and the Strymon valley, is structurally homogeneous (similar to 10 degrees cw rotation). The pal eomagnetic signature of the Vertiskos massif (zone 3) implies a larger (> 30 degrees) cw rotation, whereas sites in the Vardar basin (zone 4 ) contain a paleomagnetic signature similar to that of zone 2. This su ggests a motion of the Vertiscos massif, a meta-ophiolitic nappe, rela tive to underlying strata. Indeed, zones 2 and 4 may be parts of the s ame structural unit which underlies this nappe.