Late Cretaceous–early Palaeogene inversion-related tectonic structures at the northeastern margin of the Bohemian Massif (southwestern Poland and northern Czechia)

Abstract. A brief, regional-scale review of the Late Cretaceous–early Palaeogene inversion-related tectonic structures affecting Sudety Mountains and their foreland at NE margin Bohemian Massif is presented complemented with results new seismic studies. The Sudetes expose Variscan-deformed basement, partly overlain by post-orogenic Permo-Mesozoic cover, containing a wide spectrum structures, both brittle ductile, in past this area referred to as young Saxonian or Laramide. We have used newly reprocessed legacy seismics study these two main post-Variscan structural units area: North Sudetic Intra-Sudetic synclinoria. were discussed together regionally distributed examples from quarries underground mines well those known literature. consecutively reviewed units, north south, typically include gentle moderately tight buckle folds, locally detachment type fault-related high-angle reverse normal faults, low-angle thrusts – often rooted crystalline basement. termed grabens local literature are same time frequently interpreted bounded faults (hence we use here term “reverse grabens”) reveal strongly synclinal pattern sedimentary fill. top imaged data Synclinorium below faulted folded synformally down-warped wavelength up 30 km, whereas on elevated areas, where basement exposed surface, it tectonically up-warped (i.e. antiformally buckled). compressional show an orientation that fits shortening direction NE–SW NNE–SSW. applies regional jointing pattern, comprising orthogonal system steep joints ca. NW–SE strikes. All regarded being due episode, although some strike-slip component motion may been modified, even produced, late Cenozoic tectonism.