Polyphase deformation of the Tatric Unit in the southwest part of the Malé Karpaty Mts. (Slovakia)

The study area is located in the Devnske Karpaty Mts., which represents the southwestern part of the Mal Karpaty Mts. It is formed by the Tatric crystalline basement and its Permian-to-Cretaceous sedimentary cover, which is thrust over the Jurassic sediments of the Borinka Unit. The basement consists of Lower Paleozoic metamorphosed rocks of the Pezinok and Pernek groups with granite intrusions of the Lower Carboniferous. The analysis of deformation structures allowed us to identify Variscan and Alpine deformations within the Tatric Unit. The Variscan deformation ( ) is accompanied by middle-grade metamorphism and is characterised by penetrative metamorphic foliations ( ), which are intensely folded. The deformation is pre-Carboniferous because it does not affect granite intrusions. The Alpine deformations ( ) are marked by structural evolution under low-grade metamorphism with the evolution of phyllitic, crenulation, and mylonitic foliations ( and ). The Eo-Alpine (Cretaceous) shortening is evidenced by asymmetric folds with an ENE-WSW orientation of fold axes ( ) and line intersections ( ) with pronounced top-to-NW tectonic transport over the Borinka Unit.