Abstract In Europe, North Africa and Asia Minor, the remains of Pennsylvanian sedimentary basins bearing continental deposits either intimately mixed with shallow-marine strata or deposited in exclusively continental settings are preserved. Long-lasting research on these basins allowed the definition of regional stages and substages based on marine fauna and terrestrial flora, later extended by terrestrial and freshwater faunal biostratigraphies. Glacioeustatically driven marine bands provide laterally widespread correlation markers; however, where such bands are missing only biostratigraphic control exists. Resolution of biostratigraphic zonations combined with gaps in sedimentary successions and variable quality of the fossil record throughout the basin fills do not allow in all cases a precise correlation between the Pennsylvanian basins in Europe and, in turn, the timing of tectonic, climatic and biotic events, and thus an absolute complete understanding of the response of terrestrial and freshwater biota to climate changes across eastern tropical Pangaea. A helpful tool is new radioisotopic ages of intercalated volcaniclastics that reveal the partial diachroneity of some widely used biostratigraphies. We attempt to present the current state of the art to stimulate further research to mitigate gaps in our knowledge.

ABSTRACT For the first time, modern seismic reflection data along with gravity and magnetic data were used to image the structure of a fold-and-thrust belt overlying the SW margin of the East European craton in SE Poland. These data demonstrate that the Variscan orogen extends eastward much farther than previously believed and terminates against the East European craton basement slope. The structural setting of this newly documented eastern extension of the Variscan fold-and-thrust belt in SE Poland is comparable to that of the Alleghanian orogen emplaced on the margin of the North American craton. Variscan deformation documented in SE Poland is more intense than anywhere else beneath the Permian–Mesozoic German-Polish Basin east of the Harz Mountains, probably because of buttressing by the relatively shallow basement of the East European craton. Our study focused on two regional tectonic units: (1) the Radom-Kraśnik block, a NW-SE–elongated structural high where early Paleozoic to Devonian strata subcrop beneath the Permian–Mesozoic cover, and (2) the Lublin Basin, a major Paleozoic sedimentary basin developed above the SW slope of the East European craton. The seismic data image the Radom-Kraśnik block as a thin-skinned fold-and-thrust belt with a 10–12-km-thick pile of Ediacaran (?) to Devonian sediments tectonically emplaced on the margin of the East European craton. These sediments are involved in a NNE-vergent stack of thrust units striking oblique to the East European craton margin slope. Individual thrusts branch off from a basal detachment that is located in the basal part of Ediacaran sediments unconformably overlying the East European craton crystalline basement. The frontal part of the Radom-Kraśnik fold-and-thrust belt is a triangle zone related to the jump of the basal detachment from the intra-Ediacaran position to the base of the Silurian shales. The base-Silurian detachment continues under the gently folded Lublin Basin and emerges along the Kock fault zone, which is a thin-skinned ramp placed over a basement step at depth. The Kock fault zone could be considered an analogue to the so-called mushwad structures described within the frontal part of the Appalachians.