Landscape of Auvergne
When we think of volcanoes in France, the first image that comes to mind is that of the picturesque landscapes of the Auvergne in the Massif Central.
This region of ancient mountains and dormant volcanoes indeed covers 15% of French territory.
The vast plains of the Limagne and Bourbonnais stretch from Moulins to Montluçon and Vichy in the north.
But as you travel south, the landscape changes. The plains gradually give way to the spectacular gorges of the Allier River, which mark the beginning of the volcanic region near Clermont-Ferrand.
This is where the Land of Volcanoes begins!
Origin of the Volcanoes of Auvergne
Around 60 million years ago, the collision of the African and European tectonic plates sculpted the rugged landscape of the Massif Central. This monumental collision, which also led to the formation of the Alpes, reshaped the landscape as we know it today. When the European plate slid beneath the African plate, the force of this movement weakened the former and caused faults to appear across the region we call the Massif Central.
Twenty-five million years ago, magma began its slow ascent to the surface in the southern part of the Massif Central, marking the beginning of its volcanic activity.
- The volcanoes of the Cantal region appeared between 13 and 3 million years ago.
- The volcanoes of Devès-Velay appeared between 13 and 1 million years ago.
- The volcanoes of Cézallier, between 6 and 3 million years ago.
- Mont-Dore and Puy de Sancy, between 3 million and 200,000 years ago.
- Finally, the volcanoes of the Chaîne des Puys appeared only 150,000 years ago!
The Massif Central remained a centre of intense volcanic activity throughout the Tertiary and Quaternary periods, and is aptly known as the Pays des Volcans – Land of Volcanoes.
Volcanoes of Auvergne
Auvergne boasts 450 volcanoes, scattered across various regions, including the Chaîne des Puys, the Cantal, the Monts Dorés, the Monts d’Artense, the Monts du Cantal, and the Monts du Cézallier (located between the Monts Dorés and the Cantal).
The Chaîne des Puys, also known as the Monts Dôme, is distinguished by its group of 80 volcanoes spread over an area of 45 km by 5 km. These volcanoes, considered the youngest in Auvergne, are between 70,000 and 7,600 years old, and their most intense activity occurred between 45,000 and 30,000 years ago. With their classic conical shape, they have experienced only one relatively brief and recent eruption.
The 1,465m-high Puy-de-Dôme is the highest volcano in the Chaîne des Puys, and the Puy de Sancy (1,886m) is the highest volcano in the Massif Central.
The volcanoes of the Cantal and Monts Doré ranges formed gradually through the accumulation of lava and volcanic material during a series of eruptions that unfolded over a long period. Subsequent glacial erosion sculpted the landscape, creating sharp ridges and cirques, some of which have given rise to lakes.
The flagship volcano of this volcanic chain in the Cantal is the Plomb du Cantal, the highest volcano in Europe, which rises to 1,858m.
As for the volcanoes of the Monts du Cézallier, their average altitude ranges between 1,200m and 1,500m. Their gentle, rounded shapes were formed the fluid lava that spread out instead of accumulating vertically.
These volcanoes are now part of the vast Auvergne Volcanoes Regional Nature Park.
Extinct versus dormant
The question now is whether the volcanoes of the Auvergne region are extinct or dormant?
The debate surrounding their status continues to fascinate volcanologists. While many argue that these volcanoes could potentially awaken, particularly because some were active only 7,000 years ago, a relatively recent period on a geological timescale, others believe the chances are minimal.
One factor contributing to this uncertainty is the thinness of the Mohorovičić discontinuity (Moho), which marks the boundary between the Earth’s crust and the upper mantle. Beneath the Auvergne, this boundary is only 20 km thick, compared to 35 km beneath Paris.
The temperature of the mantle, the layer located between the Earth’s core and crust, is also a cause for concern: it reaches 1,300°C at a depth of 30 km, an abnormally high temperature, while the standard temperature is around 900°C. Interestingly, the hottest zone is located beneath the older volcanoes of the Cantal region, not beneath the relatively young Chaîne des Puys.
However, despite these potential indicators, there is no cause for concern, even though the period of inactivity since the last eruption is much shorter than the previous period. Thus, although the possibility of future volcanic activity remains, such an event won’t occur for millennia.
So, let’s consider these volcanoes dormant for the time being!
Volcano Natural Park and Vulcania
You can discover these volcanoes by hiking through the Parc Naturel Régional des Volcans d’Auvergne – Auvergne Volcanoes Regional Natural Park, which was established on October 25, 1977.
This park covers 389,733 hectares, and stretches 120 km across the Cantal and Puy-de-Dôme departments. It is the largest natural park in mainland France, with altitudes ranging from 400 m to 1,886 m. Vulcania, an educational theme park, located in Saint-Ours-les-Roches, northwest of Clermont-Ferrand, opened in 2002. Most of the park’s attractions are underground, and among the highlights is the immersive 4D film “The Awakening of the Giants of Auvergne,” which offers a fascinating glimpse into the region’s volcanic past. A must-see for families and children!
Photos via Wikimedia Commons: Header and photo1 by Thesupermat CC BY-SA 3.0 – Inside the cone by Aurkawl License – Puy-de-Dôme by Medium69-William Crochot CC BY-SA 4.0 – Puy de Sancy by Torsade de Pointes Public Domain – Puy Mary by Pline CC BY-SA 3.0 – Photo Les Monts Dore by Poustache
