Together but separate: decoupled Variscan (late Carboniferous) and Alpine (Late Cretaceous–Paleogene) inversion tectonics in NW Poland

Abstract. In Europe, formation of the Palaeozoic Variscan orogenic belt, and Mesozoic–Cenozoic Alpine–Carpathian belt led to a widespread inversion events within forelands both domains. We used legacy 2-D seismic data together with newly acquired 3-D that, for first time, precisely imaged sub-Zechstein (i.e. sub-evaporitic) upper successions in NW Poland order develop quantitative, balanced model late Palaeozoic–recent evolution this area, characterised by complex pattern repeated extension inversion. Four main tectonic phases have been determined: (1) Late Devonian–early Carboniferous subsidence possibly related extensional reactivation Caledonian thrusts, (2) caused orogeny, (3) Permo-Mesozoic development Polish Basin (4) its Cretaceous–Paleogene Alpine structures form superimposed multilayer system, mechanically decoupled Zechstein evaporites.