Tertiary extension development and extension/compression interplay in the West Carpathian mountain belt

Abstract

This paper describes palaeostresses calculated from fault-striae data, the inferred palaeostrain patterns and determines the inter-relation of the compression and extension during the Tertiary development of the West Carpathians. The calculated stress and inferred strain patterns for the Palaeogene–Burdigalian indicate that the ancestral West Carpathians formed a more-or-less straight orogenic belt. This belt underwent contraction and uplift in its narrow frontal zone, stretching along its strike during the Paleocene–Chattian, and regional contraction and uplift during the Chattian–Burdigalian. The strain/stress pattern is similar to the collision-related pattern known from the Eastern Alps for the Paleocene–Burdigalian. During the Burdigalian–Tortonian, the calculated and inferred West Carpathian stress and strain patterns indicate narrow frontal contractional and lateral sinistral transpressional zones in the orogenic front and broad extensional and dextral transtensional zones in the orogenic interior. The stress/strain pattern is similar to the subduction-related pattern known from areas such as the Hellenic or Sunda/Banda Arcs.