Excursions of the Swiss Tectonic Studies Group
Swiss Tectonic Studies Group Excursion 2024
6-8th of September 2024
The nappe stack in the Cignana valley, Valtournanche (Aosta Valley): from subduction to exhumation
Main topics:
The Valtournenche valley (Aosta valley, Italy) exposes a section across the Penninic nappes from the Zermatt Zone to the dent-Blanche nappe. In the Cignana area, one is able to walk across all tectonic boundaries, and therefore identify the main structural and petrological discontinuities. This provides an exceptional opportunity for discussing the mechanism of exhumation of UHP/HP rocks.
Day 1: Friday 06 September 2024
Meeting point: car park at the entrance of Crépin, Valtournenche (valle d’Aosta) at 14.00h (this should allow most people to join us by car from Switzerland to Aosta across the Grand Saint-Bernard tunnel).
Afternoon: walk from Crépin (1594m) to the Refuge/Rifugio Barmasse (2175m) – c. 575m of elevation gain.
Geological interest: cross-section through the eclogite-facies oceanic units (Zermatt Zone).
Day 2: Saturday 07 September 2024
Full day: walk from the Refuge/Rifugio Barmasse (2175m) to the top of the Pancherot (2616m), i.e. 400m about of elevation gain, using an easy footpath with some exposed (but short) sections. Needs one full day to be completed, taken into account the number of interesting geological topics to be seen and discussed.
Geological interest: Exceptional section trough the nappe stack of the blueschist-facies oceanic and continental (cover) units (Combin Zone). Panoramas up to the Cervino/Matterhorn and Monte Rosa, full view of the nappe stack.
Day 3: Sunday 08 September 2024
Morning: Let’s go to the contact between the Zermatt and Combin Zones.
At about noon, return down to Crépin carpark in the early afternoon.
Additional possibility (displacement by car to Cheneil, with an excellent viewpoint on the right side of the Valtournenche, with a general view on the section we have done Saturday
General discussion on the structure (geometry, and potential kinematic models)
End of the field excursion no later than 16.00.
Excursion leaders: , .
Cost of the excursion: Half-pension in the Refuge Barmasse in Cignana €55 for each night (we stay there two nights, so the total cost will be €110) – to be paid in cash on the spot.
Maximum amount of participants: 20 (the Refuge Barmasse is rather small, and will be almost fully occupied by us). When the maximum number of participants is reached, please note that members of the Swiss Geological Society will be given priority.
To book your participation to the excursion: please send an e-mail to (and eventually a copy to ).
See you in September !
STSG excursion 2023: The easternmost Jura Mountains revisited following Nagra’s regional exploration: Extent, Age and Impact
This years STSG excursion will lead into the easternmost Jura mountains, a region whose tectonics have been intensively investigated by Nagra including field work, seismic surveying and deep exploration drilling. During the first day, some key outcrops around Brugg/Baden will be visited to discuss structure, extent and age of this part of the thrust-belt. On the second day, Nagra will kindly provide access to its corelab where we will be able to study drillcores from the evaporitic section representing the décolllement horizon of the thrust belt and the above-lying units including the Opalinus Clay.
More information on the flyer!
STSG excursion 2022: Relations between the Middle and Upper Penninic nappes (Mont-Fort and Tsaté nappes) between the Val de Bagnes and Mattertal.
Friday 26.08.2022 – Sunday 28.08.2022
- Lead: Adrien Pantet and Jean-Luc Epard
- Meeting point: Friday 26.08.2022, Martigny station, 09h00
- End of Field trip: Sunday 28.08.2022, Sion station, around 18h00
- The meeting point on Saturday 27th and Sunday 28th of August in the morning will be at the train station in Sion.
- It is planned to organize meals in common on Friday and Saturday evening (more information will follow).
- Transportation in the field will be provided by minibuses (UNIL).
- Limited to 24 persons.
Program: In the Western Swiss Alps of Valais, some series close to the boundary between the Middle and Upper Penninics raise problems regarding their tectonic and paleogeographic attribution. These include the series of Mesozoic rocks originally associated to a continental basement that constitute the "Faisceau Vermiculaire" of Argand, the “Cimes-Blanches” nappe or the Frilihorn series. Their relationship with the "Schistes Lustrés" of the Tsaté nappe is also problematic. New data collected between the Val de Bagnes and Zermatt allow to revise some tectonic and paleogeographic attributions and to present a new tectonic model for the area.
Day 1: Val de Bagnes, Mauvoisin. Evolène series (Mont-Fort) and Tsaté nappe
Day 2: Val d’Hérens, Evolène area.
Day 3: Täschtal: Alphubel anticline and its sedimentary cover. Relations between folds associated to nappe emplacement and the early Mischabels backfold.
Lodging: The nights of Friday 26th and Saturday 27th of August are planned in Sion. Each participant is responsible for arranging their own accommodation in Sion. The hotel proposals below are given as an indication.
- Auberge de Jeunesse (Youth Hostel) https://www.youthhostel.ch/fr/auberges/sion/
- Hôtel Elite https://www.hotelelitesion.ch/fr/
- Hôtel du Rhône https://www.durhonesion.ch/
Costs: The participants have to arrange themselves their travel to Martigny and from Sion back home, as well as their accommodation for 2 nights in Sion. The evening meals on Friday and Saturdays nights will be paid directly on site (more info on menu and price will be sent to participants). No other costs will be asked.
Information and registration:
STSG Excursion of 2021 to the Aar Massif
The Swiss Tectonic Studies Group organized an excursion to the Aar Massif in the summer of 2021, from 27-29 August.
The excursion was led by Lukas Nibourel, Marco Herwegh and Alfons Berger. Lukas Nibourel completed his PhD in Geology at the University of Bern in 2019. He studied the structural and thermo-kinematic evolution of the eastern Aar Massif of the Swiss Central Alps, and now works at the Georesources Switzerland Group at the Department of Earth Sciences, ETH Zürich.
Spectacular outcrops were visited, mostly along the basement-cover contact, to discuss the structural and thermo-kinematic evolution of the eastern Aar Massif. The massif's deformation and exhumation history was reconstructed based on field observations and low-T thermochronological data. The influence of inherited normal faults on the distribution and geometry of Alpine compressional fault zones was another imporrtant topic.
The approximate excursion program is visible here: https://s.geo.admin.ch/87028de6e8
The excursion guide is available on request at .
The 2019 Swiss Tectonic Studies Group (STSG) excursion of the SGS visited the Zermatt region from 27-29 September, 2019. The excursion was led by Prof. Lukas Baumgartner of the University of Lausanne.
In summer 2018 the Swiss Tectonic Studies Group visited the Alpine nappe stack at the northeastern border of the Lepontine dome (Swiss Central Alps). The excursion took place from 24th to 26th of August and was led by Michael Wiederkehr (Swiss Geological Survey, Wabern), Federico Galster (University of Texas, Austin) and Jacek Kossak-Glowczewski (University of Bonn).
Below an impression of the La Sarraz Fault Zone at Eclepens visited during a 2017 Swiss Tectonic Studies Group excursion. The excursion was guided by Jon Mosar of the University of Fribourg.
