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The inversion of a sedimentary basin could be associated with compressional reactivation of basin-forming normal faults, upwards movement of the basement blocks and partial or complete erosion of its sedimentary infill. Basin inversion might be also related to whole-basin uplift that is not linked to the reactivation of basement faults, and results in the development of regional stratigraphic gaps and unconformities. Both types of basin inversion have been documented in SE Poland using seismic data. Regional NW–SE seismic profiles illustrate earliest Late Jurassic (earliest Oxfordian) and earliest Late Cretaceous (Cenomanian) regional unconformities related to regional basin-scale uplifts in the SE segment of the Polish Basin. Late Cretaceous (Turonian?–Maastrichtian) progressive uplift of the Mid-Polish Swell has been documented along the NE border zone of this regional anticlinal structure. The Upper Cretaceous inversion-related sedimentary succession is characterized by an overall progradational character directed from the SW towards the NE. Buried contourite drifts that were detected within the Upper Cretaceous succession using seismic data indicate the existence of contour currents encircling inversion-related intrabasinal morphological barriers. A new tectonic scenario of the Mesozoic evolution of SE Poland would have a significant impact on the modelling of tectonic subsidence and the history of petroleum systems.

Palaeomagnetic results are presented for 205 samples of cores from the Ksi¹¿ Wielkopolski IG-2, WoŸniki K1 and Patoka 1 wells, drilled in the Polish part of Germanic Basin. The magnetic polarity stratigraphy is based on the inclination of the characteristic remanent magnetization, isolated in 60% of the total samples and found to be in general agreement with the expected Late Triassic inclination at the sampling sites. A total of 22 magnetozones from the integration of the three records correspond to about 25% of the published polarity zones for the Upper Triassic sediments that were combined in the worldwide composite polarity-time scale. The magnetic polarity pattern, defined for the Schilfsanstein, fits very well with the one defined in the Tethys area for the upper part of the Julian sub-stage. According to the magnetostratigraphic data, the uppermost part of the Upper Gypsum Beds (equivalent to the Ozimek Member of the redefined Grabowa Formation) and the lowermost part of the Patoka Member, containing the Krasiejów bone-breccia horizon, can be correlated with the latest Tuvalian (~228.5 Ma) or with the middle part of Lacian (~225 Ma). However, if the "Long-Tuvalian" option for the Late Triassic Time Scale is taken into consideration, the parts of these substages mentioned above should be correlated with ~221.5 Ma and ~218.5 Ma, respectively.

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