Late Paleozoic geodynamics of the Małopolska Massif in the light of new paleomagnetic data for the southern Holy Cross Mountains

Abstract

Paleomagnetic studies of Devonian carbonate rocks in the southern Holy Cross Mountains have been conducted, the general aim being to verify the occurrence of hypothetical pre-Variscan rotations of the Małopolska Massif as well as to examine time-relationships between remagnetizations and successive stages in tectonic deformations. The paleomagnetic analysis confirms the presence of the three components of characteristic remnant magnetization. Two magnetite-bearing components display reversed (component A) and normal (component B) polarity. The third component (C) is recorded on hematite and shows reversed polarity. Component B is of synfolding origin and has been recorded during the Visean, whereas components Aand C are of postfolding origin and represent Early Permian and Permo-Triassic overprints. These results confirmthe stable position of the Małopolska Massif with respect to the East European craton, at least since the Visean. Results of fold tests imply that the earliest phases of Variscan deformation can be datedmost probably as Visean, while formation of the main Variscan fold structures was completed during the Early Permian. It is also documented that representative Variscan folds did not significantly change their geometry during Maastrichtian-Paleocene reactivation.