Excursions
Various excursions are organized by different sections of the SGS. These trips are generally restricted to members of the SGS. If you would like to participate in any of the excursions, kindly register to the SGS.
Swiss Tectonic Studies Group Excursion 2025
12-14th of September
Multistage exhumation of subducted continental lithosphere - The Sesia Zone, Lower Val d’Aosta and Val Chiusella
Preliminary program subject to change
The detailed program is available on this PDF.
Theme:
The lower Aosta and Chiusella Valleys (Italy) expose a tract of the Sesia Zone containing the oldest subducted and exhumed remains of the distal margin of the Adriatic Plate. The fabrics and mineral assemblages preserve a record of subduction (D1, D2) following by multistage exhumation involving three further phases of deformation: Oblique extensional exhumation under retrograde blueschist-to-greenschist facies conditions (D3, Chiusella Shear Zone), top-SE normal shearing and folding under greenschist-facies conditions (D4, Ometta Shear Zone) followed by top-SE backfolding (D5, Vanzone). We will visit outcrops where the latter three phases overprint the classical lithological units of the Sesia Zone (Eclogitic Micaschists, EMS; Gneiss Minuti, GM; Secunda Zona Dioritico-Kinzigitica, IIZDK). This trip is an opportunity to continue last year’s discussion on how UHP/HP rocks are exhumed.
Day 1: Friday 12 September, lower Val d'Aosta
Meeting point at 14.00h: car park at Quincinetto. People coming by car from Switzerland will reach this stop most easily through the Grand Saint-Bernard Tunnel and Aosta.
Overnight in Albergo Ristorante Miniere - Traversella (TO)
Day 2 : Saturday 13 September, Val Traversella
Overnight in Albergo Ristorante Miniere - Traversella (TO)
Day 3: Sunday, 14. September, Val d'Aosta
The field trip will end no later than 16.00.
Field trip leader: Mark Handy (Freie Universität Berlin, Germany)
Cost:
Hotel half-pension, costs per room type:
- Single room (incl breakfast) = 60 euro
- Double room (incl breakfast) = 110 euro
- Triple room (incl breakfast) = 135 euro
Dinners will cost per person per night 35 euro.
Accommodation and dinner can be paid in cash on the spot. Please, bring your own lunches for all days.
Maximum number of participants: 25 people. 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 on the excursion: please send an e-mail to the 1st of June 2025. Please note that registration is binding. In case you have a preference for a room type and/or any dietary wishes please indicate.
See you on September 12, 2025!
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: Michel Ballèvre (michel.ballevre@univ-rennes.fr), Paola Manzotti (paola.manzotti@geo.su.se)
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 Vénice Akker vakker@erdw.ethz.ch (and eventually a copy to Michel Ballèvre michel.ballevre@univ-rennes.fr)
See you in September !
Swiss Tectonic Studies Group 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!
Swiss Tectonics Studies Group, Field 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
Limited to 24 persons. Transportation in the field will be provided by minibuses (UNIL).
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.
Follow the link below for more information.
STSG Excursion 2021 to the Aar Massif
The Swiss Tectonic Studies Group excursion visited the Aar Massif from 27-29 August, 2021.
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 in the Swiss Central Alps, and now works at the Georesources Switzerland Group at the Department of Earth Sciences, ETH Zürich.
The participants visited spectacular outcrops, 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 important topic.
The excursion guide is available on request at .
