The Chaîne des Puys () is a north-south oriented chain of

cinder cone A cinder cone (or scoria cone) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around a volcanic vent. The pyroclastic fragments are formed by explosive eruptions or ...

s, lava domes, and maars in the

Massif Central The (; oc, Massís Central, ; literally ''"Central Massif"'') is a highland region in south-central France, consisting of mountains and plateaus. It covers about 15% of mainland France. Subject to volcanism that has subsided in the last 10,00 ...

of France. The chain is about 40 km (25 mi) long, and the identified volcanic features, which constitute a

volcanic field A volcanic field is an area of Earth's crust that is prone to localized volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. Volcanic fields usually consist of clusters of up to 100 volcanoes ...

, include 48 cinder cones, eight lava domes, and 15 maars and explosion craters. Its highest point is the lava dome of

Puy de Dôme Puy de Dôme (, ; oc, label=Auvergnat, Puèi Domat or ) is a lava dome and one of the youngest volcanoes in the region of Massif Central in central France. This chain of volcanoes including numerous cinder cones, lava domes and maars is ...

, located near the middle of the chain, which is high. The name of the range comes from a French term, ''

puy Puy () is a geological term used locally in the Auvergne, France for a volcanic hill. The word derives from the Provençal ''puech'', meaning an isolated hill, coming from Latin ''podium'', which has given also ''puig'' in Catalan, ''poggio'' ...

'', which refers to a volcanic mountain with a rounded profile. A date of 4040 BCE is usually given for the last eruption of a Chaîne des Puys volcano. An outstanding example of plate tectonics in action and continental

rifting In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben w ...

, the Chaîne des Puys region became a UNESCO World Heritage Site in 2018.

Formation

The Chaîne des Puys is located on the Limagne fault, a major part of the

European Cenozoic Rift System The European Cenozoic Rift System (ECRIS) is a long system of rifts formed in the foreland of the Alps as the lithosphere responded to the effects of the Alpine and Pyrenean orogenies. The system began to form during the Late Eocene and parts ...

which formed during the creation of the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...

roughly 35 million years ago. The region has a wide variety of geologic features formed by the rifting. The mountain chain itself began to form approximately 95,000 years ago, and the volcanic activity that formed the range stopped about 10,000 years ago. The majority of the cones were formed by Strombolian eruptions, and these cones usually have well-defined summit craters. Some have nested craters, and others show broken rims where lava poured through. In contrast, Puy de Dôme was created by a

Peléan eruption Peléan eruptions are a type of volcanic eruption. They can occur when viscous magma, typically of rhyolitic or andesitic type, is involved, and share some similarities with Vulcanian eruptions. The most important characteristic of a Peléan eru ...

; this type of eruption is characterized by long dormant periods periodically interrupted by sudden, extremely violent eruptions. Future eruptions at the Chaîne des Puys are possible and would result in the formation of new mountains.

Research

Before 1750 and the chain's identification as volcanic, the Puys were rumored to be man-made mounds of mining waste or Roman forge furnaces. The chain was the subject of the pioneering research of English geologist

George Julius Poulett Scrope George Julius Poulett Scrope FRS (10 March 1797 – 19 January 1876) was an English geologist and political economist as well as a Member of Parliament and magistrate for Stroud in Gloucestershire. While an undergraduate at Cambridge, thr ...

, starting in the 1820s. In 1827 he published his ''Memoir on the Geology of Central France, including the Volcanic formations of Auvergne, the Velay and the Vivarais'', which was later re-published in a revised and somewhat more popular form in ''The Geology and extinct Volcanos of Central France'' in 1858. These books were the first widely published descriptions of the Chaîne des Puys, and the analysis therein laid the foundation for many of the basic principles of volcanology.

References

Bibliography

* (reprinted in 1978 by Arno Press) * * * * {{DEFAULTSORT:Chaine des Puys Volcanoes of Metropolitan France Landforms of Auvergne-Rhône-Alpes Maars of France Pleistocene Europe Pleistocene volcanism Cenozoic France Potentially active volcanoes World Heritage Sites in France VEI-4 volcanoes