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

cinder cone A cinder cone or scoria cone is a steep, volcanic cone, conical landform of loose pyroclastic rock, pyroclastic fragments, such as volcanic ash, clinkers, or scoria that has been built around a volcanic vent. The pyroclastic fragments are forme ...

lava dome In volcanology, a lava dome is a circular, mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions ...

s, and maars in the Massif Central of

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

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

, include 48 cinder cones, eight lava domes, and 15 maars and explosion craters. Its highest point is the lava dome of Puy de Dôme, located near the middle of the chain, which is high. The name of the range comes from a French term, '' puy'', which refers to a volcanic mountain with a rounded profile. A date of 4040 BC 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 Fault (geology), downfaulted depression, called a graben, or more commonly ...

, the Chaîne des Puys region became a

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World Heritage Site World Heritage Sites are landmarks and areas with legal protection under an treaty, international treaty administered by UNESCO for having cultural, historical, or scientific significance. The sites are judged to contain "cultural and natural ...

in 2018.

Formation

The Chaîne des Puys is located on the Limagne fault, a major part of the European Cenozoic Rift System which formed during the creation of the

Alps The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

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 eruption In volcanology, a Strombolian eruption is a type of volcanic eruption with relatively mild blasts, typically having a Volcanic Explosivity Index of 1 or 2. Strombolian eruptions consist of ejection of incandescent Scoria, cinders, lapilli, and vo ...

s, 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; 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 Fellow of the Royal Society, 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 und ...

, 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