2024 AFEQ FIELD TRIP
The Quaternary of the Pays de Savoie: A Story of Glaciers and Humans
Report by Igor Girault (postdoctoral researcher, UMR 7194 HNHP, University of Perpignan; igor.girault@univ-perp.fr) & Clément Recq (geomorphologist, INRAP, Dijon; clement.recq@inrap.fr). The report is published in issue no. 2 of the October 2024 edition of the AFEQ Gazette.
The excursion departing from Chambéry, organized by Christian Crouzet with the collaboration of Jean-François Buoncristiani, Stéphane Grange, Christophe Griggo, Fabien Houbléa, Julien Jacquet, Erwan Messager, Gérard Nicoud, Pierre-Jérôme Rey, and Ricardo Vassallo, brought together about thirty participants representative of the diversity of the French Quaternary science community, from May 27 to 29, 2024, including the authors of these lines. C. Crouzet and his collaborators invited us to travel by bus following the course of the former Lyon ice lobe and one of its main tributaries, the Arc glacier, from the Savoyan foreland to Haute Maurienne via the Isère valley. Despite capricious weather, the itinerary booklet, which emphasized glacial geomorphology, prehistoric human settlement of the valleys, and gravitational hazards, largely fulfilled its promises. Following the chronology of deglaciation like an Ariadne’s thread, we progressed in time as we ascended towards the heart of the former Alpine ice sheet.
The first morning of the excursion led us to the shores of Lakes Aiguebelette and Cerin, located upstream of the Würmian terminal moraine complex of the Lyon lobe, where E. Messager presented results from studies on Late Glacial and Holocene lacustrine sediment cores. We had lunch at Innimond, at the southern edge of the Jura massif, before being caught by a downpour. We then took the forest path leading to Mont Pela. Along the way, R. Vassallo drew the participants’ attention to the presence of crystalline pebbles evidencing the glacier’s passage over the limestone slope, before presenting recent mapping and cosmogenic nuclide dating efforts of the Würmian frontal moraines of the Lyon ice lobe. As the trail emerged from the forest, we enjoyed a lull in the weather to stop and observe to the west the Würmian moraine complex occupying the Innimond plateau. Bad weather forced us to cancel two initially planned stops at Culoz and Yenne. Thus, the first day ended on the bus, sheltered from heavy rain, with a presentation by S. Grange on the glaciolacustrine sediment fill and aquifers of the Chautagne plain. We spent the evening in Yenne at Clos des Capucins.
The next morning, under brilliant sunshine, we crossed the drumlin field of Saint-Paul-sur-Yenne by bus. The delightful sight of this “herd” of green, humped “monsters,” frozen in their movement by the melting of the Lyon lobe, filled participants with joy. We headed to the Couz valley to discover Paleolithic industry sites indicating human occupation of ice-free valleys. We first stopped at Saint-Christophe-la-Grotte, where C. Griggo presented excavation results from the Magdalenian-to-Azilian site of La Fru and the Azilian site of Gerbaix, then at Saint-Thibaud-de-Couz, near a talus of scree at the top of which open the Jean-Pierre I and II caves with Magdalenian to Mesolithic industries. C. Crouzet then presented studies of reconnaissance drillings from the Lyon-Turin high-speed rail line documenting the lacustrine fill of the Couz valley.
We had lunch on the shores of Lake Saint-André facing the eastern slope of Mont Granier. F. Houbléa and G. Nicoud presented a synthesis of work related to the 1248 landslide, including controversies about the triggering factor, deposit extent, and human toll of the disaster. In the afternoon, Thomas Cobessi, geological engineer, opened the doors of the Vicat aggregate quarry of La Gache in the Isère valley. A stepped outcrop nearly one hundred meters high exposed pre-Würmian glaciolacustrine sediment fill with delta foresets and dropstones, then fluvial deposits. A colony of European bee-eaters nesting in sandy escarpments added colorful charm to our visit. We then left the Alpine trough to ascend the Maurienne valley to the Fleurs et Neige lodge in Aussois, where a tasty tartiflette awaited us.
Our Maurienne exploration continued the next morning. The bus first took us to Sollières, where we examined an outcrop of fluvial deposits overlain by till indicating a glacial advance attributed to the Early Dryas based on exposure ages of several erratic boulders. We then stopped in front of the Lanslebourg-Mont-Cenis landfill site. J.-F. Buoncristiani presented recent work on an astonishing 45-meter-high outcrop exposing a proglacial subaqueous cone deposited during the last glacial termination in the former lake fed by the Arc glacier and dammed downstream by the Doron glacier. With its opposing dips, backsets, dropstones, imbricated pebbles, normal faults, and climbing ripples resembling Baroque moldings, this outcrop, worthy of appearing in glacial geology textbooks alongside North America’s finest sites, left a strong impression on the sedimentologists of the excursion.
After passing the Collet de la Madeleine, formed by the collapse of the northern slope of the Mont Cenis massif, we had lunch at Villarons upstream from two frontal moraines whose erratic boulders yielded exposure ages coinciding with the Late Dryas. We then walked along the right bank of the Arc to the Rocher du Château, a monumental serpentine boulder from the collapse of the southern slope of the Vanoise massif, its walls covered with glacial striations and adorned with Neolithic rock paintings. After an archaeological context presentation by P.-J. Rey and an overview of ongoing geomorphological evolution studies by J. Jacquet, the excursion ended with the dreamy contemplation of the mysterious red deer painted by our predecessors. What meaning did they give to this artwork? Could they have imagined it would miraculously survive through the centuries? Nothing better captures the participants’ emotion than borrowing from Joseph Conrad’s prose: “We could not understand because we were too far away and no longer remembered, because we were traveling in the night of the earliest ages, of those ages vanished without leaving hardly a sign or a memory.”
The authors wish to thank, on behalf of all participants, the conductor of the excursion, C. Crouzet, and his collaborators for introducing us to the geomorphological and sedimentological riches of the Quaternary in Savoie. We will not soon forget G. Nicoud’s erudition, R. Vassallo’s drawing talents, J.-F. Buoncristiani’s facies analyses, nor the cheerful spirit that animated this excursion.
OpenEdition suggests that you cite this post as follows:
Amélie Duquesne (October 26, 2024). 2024 AFEQ FIELD TRIP. AFEQ CNF-INQUA. Retrieved June 9, 2026 from https://doi.org/10.58079/14b3n


