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Deformation Related to the Defereggen-Antholz-Vals (DAV) Fault System in the Eastern Alps South of the Tauern Window and West of the Tauferer Valley

Katharina Isabel Doehler
Ludwig-Maximilian University, Faculty of Geosciences, Department of Earth & Environmental Sciences
Munich, Bavaria, Germany
[email protected]

The Defereggen-Antholz-Vals (DAV) fault is a ~E-W trending prominent fault system within the austroalpine basement between the Tauern Window to the north and the Periadriatic line to the south. According to previous studies, across this fault zone a jump in alpine metamorphic grade occurs. North of the DAV, the pre-alpine high grade metamorphic rocks of the austroalpine basement have been overprinted by intense early alpine deformation at metamorphic temperatures in the range of 450±50°C and pressures of about 7.0±1.5 kbar. South of the DAV, the temperatures attained during Alpine history did not exceed 300°C, which largely preserved pre-Alpine structures and mineral assemblages. Displacement along the DAV, an oblique strike slip shear zone active at around 30 Ma, comprises some tens of kilometers of horizontal and a few kilometers of vertical component elevating the northern part of the austroalpine basement relative to the southern part.

The aim of this Master’s thesis is twofold: first, to document the field evidence of the DAV shear zone west of the Tauferer valley and to analyze the meso- and microstructural characteristics of the deformation related to the displacement along the DAV; secondly, to gain information on the deformation conditions with focus on the stress and strain rate history. For this, the thesis focuses on the microstructural inventory across the DAV along an N-S profile. Especially quartz microstructures were analyzed, as they record the deformation conditions within this temperature range best. In addition, other microstructures, such as deformation of feldspar or sheet silicates, were also investigated.

 

AAPG Search and Discovery Article #90157©2012 AAPG Foundation 2012 Grants-in-Aid Projects