title: States of paleostress north and south of the Periadriatic fault: Comparison of the Drau Range and the Friuli Southalpine wedge.
abstract: This study focuses on the analysis of structures and kinematics of a N-S profile along the axis of maximum shortening of the European Eastern Alps. The area includes the southern Austroalpine unit in the north and the Southalpine unit, which is a part of the Adriatic indenter. The stratigraphically different units are separated by the Periadriatic fault, the major strike-slip fault within the Alps. In order to assess the kinematics of these units, mainly fault-slip data from north and south of the Periadriatic fault were analyzed. We distinguish a succession of five main kinematic groups in both units: (1) N-S compression; (2) NW-SE compression; (3) NE-SW compression, σ3changes gradually from subvertical to subhorizontal; (4) N-S compression; and (5) NW-SE compression. Our study reveals that the deformation sequence on either sides of the PAF is similar. The mean orientations of the principal stress axes, however, show small, but consistent differences: The subhorizontal axes north of the Periadriatic fault plunge northward, in the south southward. A counterclockwise (CCW) rotation of the southern part in respect to the north is evident and in line with the well-known counterclockwise rotation of the Adriatic indenter as well as dextral displacement of the N-fanning stress-field along the Periadriatic fault. Opposing plunge directions are interpreted as a primary feature of the internal stress-field within an orogenic wedge further increased during ongoing compression.
authors.affiliation: Dept. Geography and Geology, University of Salzburg, Hellbrunnerstr. 34, A-5020 Salzburg, Austria.
authors.forename: Esther Maria
authors.initials: EM
authors.lastname: Bartel
authors.affiliation: Dept. Geography and Geology, University of Salzburg, Hellbrunnerstr. 34, A-5020 Salzburg, Austria.
authors.forename: Franz
authors.initials: F
authors.lastname: Neubauer
authors.affiliation: Dept. Geography and Geology, University of Salzburg, Hellbrunnerstr. 34, A-5020 Salzburg, Austria.
authors.forename: Johann
authors.initials: J
authors.lastname: Genser
authors.affiliation: Dept. Geography and Geology, University of Salzburg, Hellbrunnerstr. 34, A-5020 Salzburg, Austria.
authors.forename: Bianca
authors.initials: B
authors.lastname: Heberer
keywords: Adriatic indenter; Drau Range; Orogenic wedge; Paleostress analysis; Periadriatic fault; Southern Alps