Field Trip 10

Subduction, Collision and Indentation in the Tauern Window

Mark R. Handy, Phillip Groß, Ralf Schuster

 10_Tauern

The field trip is devoted to the structure and evolution of the eastern Tauern Window. The first day deals with the record of Cenozoic subduction of the Alpine Tethyan ocean (Glockner Nappe) and distal European continental margin (Modereck unit). Structures visited include the limb of a spectacular crustal-scale sheath fold formed during rapid exhumation from HP conditions. The second day is devoted to structures associated with indentation of the Alpine orogenic crust, including km-scale upright folds, mylonitic shear zones and brittle faults that accommodated coeval shortening and lateral orogenic escape. On the final day, we visit basement nappes forming a duplex in the structurally deepest level of accreted European crust. The field trip ends with a hike to the eastern margin of the Tauern Window where a low-angle normal fault (Katschberg Normal Fault) exhumed the hot Penninic units in its footwall. This late orogenic structure manifests the response of orogenic crust to a combination of Adriatic indentation of the Eastern Alps and Miocene roll-back subduction in the Carpathians.

Day 1: Innsbruck-Grossglocknerpass: View of Eastern Tauern Dome with its nappes and folds as seen looking east (Törlkopf, Grossglockner Passstrasse); Complete section of Modereck Nappe (hike from Hochtor). Overnight: Das Glocknerhaus.

Day 2:Grossglocknerpass-Gmünd: eclogite and blueschist-facies assemblages of the Glockner Nappe (behind hotel or drive to outcrops in Pasterzetal, near Franz-Josefshöhe), Pasterze Glacier (Franz-Josefshöhe), Sonnblick Lamellae and southern branch of Katchberg Shear System (Obervellach), cataclasites of Mölltal Fault (Metnitz, Möll Valley). Overnight: Gmünd

Day 3, Gmünd-Innsbruck: Core units of the Hochalm Dome, prasinite of Glockner Nappe, gneiss of Modereck and Storz Nappes (Malta Valley, Ballonwald); Katchberg mylonite affecting gneiss of Storz Nappe, beautiful view of Eastern Tauern Dome as seen looking west (hike in Malta Valley, Faschauer Törl), drive back to Innsbruck.

Physical requirements:
Accessible for everybody, moderate hikes of ca. 3-4 hrs on the first and third days

Equipment:
Complete hiking gear required, warm and waterproof clothing. Please bring packed lunch for the first day

Transportation:
Minibusses from and to Innsbruck

Accommodation:
First night in Glocknerhaus, second night in Gmünd

Number of participants:
Minimum 10, maximum 20

Departure:
29.09.2016  8:30 . Innsbruck, Bus parking area behind SOWI building

Return:
01.10.2016 evening.  Innsbruck, Bus parking area behind SOWI building

Fees:
250 € (including bus transfer from/to Innsbruck, accomodation, breakfast, packed lunch for day 2 and 3)