Stress-induced late-stage subsidence anomalies in the Pannonian basin

Abstract

Subsidence, sedimentation and tectonic quiescence of the Pannonian basin was interrupted a few million years ago by tectonic reactivation. This recent activity has manifested itself in uplift of the western and eastern flanks, and continuing subsidence of the central part of the Pannonian basin. Low- to medium-magnitude earthquakes of the Carpathian-Pannonian region are generated mostly in the upper crust by reverse and wrench fault mechanisms. There is no evidence for earthquakes of extensional origin. 2-D model calculation of the subsidence history shows that a recent increase in magnitude of horizontal compressional intraplate stress can explain fairly well the observed Quaternary uplift and subsidence pattern. We propose that this stress increase is caused by the overall Europe/Africa convergence. In Late Pliocene, consumption of subductible lithosphere at the eastern margin of the Pannonian basin was completed, and the lithosphere underlying the Pannonian basin became locked in a stable continental frame. Consequently extensional basin formation has come to an end, and compressional inversion of the Pannonian basin is in progress.