LATE CENOZOIC TECTONICS OF SLOVENIA: STRUCTURAL STYLES AT THE NORTHEASTERN CORNER OF THE ADRIATIC MICROPLATE

Abstract

We describe the structures and styles of deformation at the northeastern margin of the Adria microplate during Miocene to recent times. Throughout the Miocene, deformation induced by Adria-Europe convergence was partitioned between thrusting in the Dinaric and South-Alpine belts and eastward escape in front of the Adriatic indenter, north of the Periadriatic fault zone. At the Miocene-Pliocene transition, a temporary termination of tectonic escape and the onset of Adria counterclockwise rotation triggered a major change in regional tectonics. At that time, major strike-slip and contractional deformation started between rigid Adria and the Periadriatic fault, accompanied by uplift, folding, strike-slip basin formation, and, perhaps, rigid-block rotation. There is a gradual eastward change in structural style from head-on thrusting in the Italian Alps to oblique and then to predominately strike-slip deformation in the Dinaric and Pannonian regions of Slovenia. Distribution of recent seismicity and first results of GPS measurements suggest that this, or a similar, mode of deformation is still active.