Palaeomagnetic and rock magnetic study of Devonian olistoliths set in early Carboniferous flysch, West Sudetes, Poland

The Upper Devonian greywacke. mudstone and limestone olistoliths from the Z danow-Bardo-Mlynow (ZBM) allochthonous complex of the Gory Bardzkie (GB), W est Sudetes, have been sampled for palaeomagnetic investigations (46 hand s amples and 30 drill cores from seven sites). The random distribution of the olistolithic blocks within early Carboniferous flysch provides an opportun ity for the megaconglomerate test. Microscopic and rock magnetic studies sh owed that pyrrhotite and magnetite are the carriers of magnetic remanence. Thermal and AF demagnetization revealed four components of characteristic r emanence. The C-component, found in one site only, yields an in situ pole p osition of 19 degreesS, 340 degreesE, close to early Carboniferous data for Baltica. The P-component, also found in one site, yields an in situ pole p osition of 42 degreesS, 339 degreesE, which coincides with late Permian pol es for Baltica. The R-component of moderate inclinations and northwesterly and northeasterly declinations, found in all but one site, is probably part ial remagnetization of a Devonian component during Carboniferous and Permia n times. The D-component found in all sites shows significant dispersion of declination of site-mean directions in geographical and stratigraphic coor dinates, but inclinations after tilt correction are consistent with inclina tions expected for the Middle-Late Devonian calculated for the Sudetes from the palaeopoles for Baltica. Significant dispersion of declination is expe cted for primary magnetization of olistoliths distributed at random within flysch. The fold test for inclination only, applied to the site-mean direct ions of the D-component for the ZBM complex, is positive. The D-component i s therefore interpreted as representative of the Middle-Late Devonian local field inclination. The calculated palaeolatitudes. 15 degreesS-7 degreesS, indicate that the West Sudetes were positioned in that time at the same la titude as the southwestern margin of Baltica.