Fold/cleavage relationships as indicator for late Variscan sinistral transpression at the Rheno-Hercynian–Saxo-Thuringian boundary zone, Central European Variscides

• Late Variscan sinistral transpression during NNW–SSE shortening
• Different fold–cleavage types result from strain partitioning
• Reactivation of inherited mechanical anisotropies is the cause for transpression
• New model for this part of Rheic suture is proposed

The boundary between the Rheno-Hercynian and the Saxo-Thuringian zones of the European Variscides is characterized by a NE–SW striking late orogenic fold-and-thrust belt affecting the intervening Rheic suture. Classical models used the first-order strike of this zone as an indicator for perpendicular plate convergence, i.e. NW–SE. We present structural data from both sides of the suture, focusing on fold–cleavage relationships. The statistical analysis reveals an orientation maximum of the youngest cleavage that deviates from the strike of the fold-and-thrust belt by c. 22°. The presence of clockwise transection of the folds by the cleavage (up to − 16°) indicates pervasive sinistral transpression. Three types of fold–cleavage relationships are observed: NE trending folds (I) with or (II) without a transecting cleavage, and (III) non-transected ENE trending folds. We explain the occurrence of different fold–cleavage types by strain partitioning due to NNW convergence obliquely to pre-existent NE trending mechanical anisotropies. In terms of plate tectonics we propose that the classical boundary of the Rheno-Hercynian and the Saxo-Thuringian Zone represents an initial transform plate boundary that was finally affected by sinistral transpression.