Tertiary tectonic evolution of the external South Carpathians and the adjacent Moesian platform (Romania)

Abstract

Depth‐interpreted seismic sections of the Getic Depression foredeep, paleostress indicator data and analysis of outcrop‐ to regional‐scale structures are integrated to derive the tectonic evolution of the South Carpathians ‐ Moesian platform area. Following Late Cretaceous and older orogenic phases, the South Carpathians ‐ Moesian platform area underwent strike‐slip deformation with NE‐SW oriented compression and NW‐SE tension. In Paleogene to Early Burdigalian times, tensional deformation is recorded which led to the opening of WSW‐ENE to E‐W trending extensional basins. In the Late Burdigalian, NE‐SW oriented contraction took over causing the oblique inversion of preexisting extensional structures. During Sarmatian times, NW‐SE and slightly younger N‐S trending compression caused the activation of mainly NW‐SE dextral strike‐slip faults and, in the frontal areas, south directed thrusting. The NW‐SE direction of extension determined for Paleogene to Early Burdigalian times is hardly compatible with presently accepted models of substantially continuous dextral wrenching between the Intra‐Carpathians units to the north of the South Carpathians and the Moesian platform to the south. In contrast, we have demonstrated dextral transpressive to transtensional movements within an E‐W trending corridor from the Late Burdigalian to Late Sarmatian which are compatible with available models.