First paleomagnetic results on tertiary rocks from the Slavonian Mountainsin the Southern Pannonian Basin, Croatia

Five sedimentary localities (Ottnangian through early Pannonian age) and on e igneous site (K/Ar age 17 Ma) were studied paleomagnetically. Apart from one sedimentary locality, all yielded excellent or good paleomagnetic resul ts, with declinations indicating counterclockwise (CCW) rotations. The decl inations are between 300 and 340 degrees and seem to vary in space and not in rime. Since the youngest rock exhibiting CCW rotation is of early Pannon ian age, it is reasonable to connect the rotations to the "intra-Pannonian" or "Rhodanian" tectonic phase, i.e. the most marked and last Tertiary tect onic event manifested in thrusts and strike-slip movements in the south-wes tern part of the Tisza (Tisia) or South Pannonian megatectonic unit. The ne w paleomagnetic results are in harmony with CCW rotations postulated for th e Slavonian Mts. However, the Tertiary paleomagnetic data from the Slavonia n Mts. and the Mecsek Mts. point to extreme mobility within the south-west parr of the Tisza megatectonic unit. This seems to be in conflict with curr ent tectonic models which work with a rigid Tisza megatectonic unit in the Tertiary.