Abstracts with Programs - Geological Society of America

Itinerary
Sunday, August 28: Munich – Hohenpeißenberg – Altenau (100 km) – Weilheim Naturfreundehaus 35 km
(accommodation).
Program: Molasse Zone. Pähl gorge (glacial sediments and Upper freshwater Molasse in fine grained facies), Hohenpeißenberg
(overview over the Alpine front, folded Molasse, Upper Freshwater Molasse in coarse grained fan facies), overturned Upper
marine Molasse; delta sediments at the Schnals caves, transition from the Lower marine Molasse to Lower Freshwater Molasse
at Scheibum, Marine Molasse and Flyschmolasse with turbidites near Altenau at Meyersäge)
Monday, August 29: Weilheim – Benediktbeuern – Grafenaschau ‐ Weilheim (70 km, accommodation)
Program: Rhenodanubian Flysch Zone of the Lainbachtal and Lahnegraben: sedimentology, tectonics and geodynamic
evolution
Tuesday, August 30: Weilheim – Rohrdorf (116 km) – Kufstein – Kaiserhaus (80 km, accommodation)
Program: Helvetic Zone, Kögl of Murnau; Cement factory of Rohrdorf, historic millstone quarry of Hinterhör
Wednesday, August 31: Kaiserhaus – Erzherzog-Johann-Klause (accommodation) (walk ca. 15 km)
Program: Kaiser gorge in the north limb of the Guffert anticline; Gosau unconformity, Tectonics and stratigraphy of the
Northern Calcareous Alps (NCA), Achental thrust.
Thursday, September 1: Erzherzog-Johann-Klause ‐ Pinegg - Kaiserhaus (accommodation) (walk back to Kaiserhaus,
by car to Pinegg 3 km)
Program: Late Triassic onset of extensional tectonics, Triassic Coral reefs wit Early Jurassic extensional fissures, slumping und
rapid deepening of the basin; marine Gosau transgression surface with rudists at Pinegg
Friday, September 2: Kaiserhaus – Imst (120 km) – by cable lift and 1 h walk to Muttekopf Hütte (1934 m, accommodation)
Program: Inneralpine Molasse near Kramsach, Inn valley fault, glacial history of the Inn valley, Tschirgant landslide, section
through basal, continental to shallow marine part of Gosau sediments.
Saturday, September 3: Muttekopf area, all day walk in mountainous area, in part without trail; ~800 m up and down)
Muttekopf Hütte (accommodation)
Program: Deep marine upper part of Gosau sediments: Sedimentology of a extremely coarse‐grained sediment gravity flow
deposit. Erosional unconformities und angular unconformities due to structural growth; Soft‐sediment deformation in slumps
und folds due to syn‐depositional shortening. Spectacular, partly mountain‐size outcrops!
Sunday, September 4: By cable lift down to Imst, by car back to Munich 150 km
Theme: cross section through the Northern Calcareous Alps, Fernpass landslide. Arrival at Munich in the afternoon.
Field Trip E3
Two Orogens and their Subduction Records in the Eastern Alps
Departure: Thursday, September 1, 8:00, main entrance of LMU Geology, Luisenstr. 37, Munich
Return: Sunday 4 September, ~18:00, main entrance of LMU Geology, Luisenstr. 37, Munich
Cost: € 440; maximum: 24 participants
Included: lodging, breakfast
Not included: lunch, dinner, drinks
Difficulty: DAV: Bergwanderung mittelschwer / Moderate mountain hike
USA Class 2. USA National Parks Rating: Moderate.
Leaders: Bernhard Fügenschuh, University of Innsbruck
Mark Handy, Freie Universität Berlin
Description
The Alps comprise two orogens that are exposed in piggy-back fashion in the Eastern Alps. These orogens preserve different
relics of subduction: (1) In the overlying Austroalpine nappes Cretaceous eclogites record E- to SE-directed, intracrustal
subduction within the Adriatic/Apulian microplate that preceded Alpine orogenesis. This early subduction was probably related
to (possibly triggered by?) Jurassic subduction and obduction of the northern branch of the Neotethys Ocean; (2) In underlying
units of the Tauern Window, Early Cenozoic eclogite and blueschist document later S- to SSE-directed subduction of the Alpine
Tethys Ocean and distal parts of the European continental margin. This later subduction was continuous with Europe-Adria
collision and Alpine orogenesis in Oligo-Miocene time.
The first part of this field trip will be devoted to the tectonometamorphic evolution of the Ötztal continental basement and its
neighboring Austroalpine units. HP metamorphism was followed by Late Cretaceous nappe stacking, exhumation and amphibolite-facies
regional metamorphism. In the second part of the field trip we will visit the Cenozoic HP rocks of the Tauern
Window that derive from Alpine Tethys (Glockner Nappe) and from distal European continental crust (Eclogite Zone, Rote
Wand unit). In addition, we will show how collisional structures modified the entire nappe edifice in the eastern part of the
Tauern Window. We will visit spectacular km-scale folds and shear zone systems that accommodated N-S shortening and eastdirected
lateral escape. This late orogenic deformation in the Eastern Alps manifests the response of the crust to a combination
of Adriatic indentation and Miocene roll-back subduction in the Carpathians.
28 Fragile earth: geological Processes from global to local Scales