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.