A structural model for the western-central Sudetes: a deformed stack of Variscan thrust sheets

A model based on new structural and geochemical data is presented. It unifi es the structural history of the Izera, Rudawy Janowickie and Kaczawa compl exes with the Fore Sudetic block, despite their current separation by the I ntra-Sudetic and Marginal Sudetic faults. Above the granitoid Izera, Kowary and Wadroze gneisses, at the base of the structural sequence, the ductile Kowary shear zone marks the basal decollem ent of the Swierzawa thrust sheet, comprising often highly strained metased iments associated with enriched tholeiitic and alkaline metabasites. Above it, the ductile Kaczorow shear zone, corresponding to the main mylonitic zo ne within the Leszczyniec shear zone in the Rudawy Janowickie Complex, mark s the base of the Dobromierz thrust sheet, characterized by voluminous MORE -like meta-tholeiites and minor metasediments in the higher parts of the Ru dawy Janowickie and Kaczawa complexes and the Pyszczynska Hill area of the Fore-Sudetic Block. In the east the Sleza ophiolite and the Gory Sowie Bloc k override the entire nappe stack. Kinematic fabrics in the major and related shear zones indicate D-1 compres sional transport towards the northwest, followed by minor D-2 extensional m ovements. The thrust slack was deformed during D-3 by southwest verging fol ds, was subsequently intruded by post-orogenic granites, and later disrupte d by the Intra-Sudetic, Marginal Sudetic and associated faults.