Puy () is a

geological Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth s ...

term used locally in the

Auvergne Auvergne (; ; or ) is a cultural region in central France. As of 2016 Auvergne is no longer an administrative division of France. It is generally regarded as conterminous with the land area of the historical Province of Auvergne, which was dis ...

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 ...

for a

volcanic A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often fo ...

hill A hill is a landform that extends above the surrounding terrain. It often has a distinct summit, and is usually applied to peaks which are above elevation compared to the relative landmass, though not as prominent as Mountain, mountains. Hills ...

. The word derives from the Provençal ''puech'', meaning an isolated hill, coming from Latin ''podium'', which has given also ''puig'' in Catalan, ''poggio'' in Italian, ''poio'' in Galician and Portuguese. Most of the puys of central France are small

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 ...

s, with or without associated

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

, whilst others are domes of trachytic rock, like the of the

Puy-de-Dôme Puy-de-Dôme (; or ''lo Puèi Domat'') is a department in the Auvergne-Rhône-Alpes region in the centre of France. In 2021, it had a population of 662,285.Eifel The Eifel (; , ) is a low mountain range in western Germany, eastern Belgium and northern Luxembourg. It occupies parts of southwestern North Rhine-Westphalia, northwestern Rhineland-Palatinate and the southern area of the German-speaking Com ...

and in the small cones on the

Bay of Naples A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, a lake, or another bay. A large bay is usually called a ''gulf'', ''sea'', ''sound'', or ''bight''. A ''cove'' is a small, ci ...

, whilst the relics of puys denuded by erosion are numerous in the

Swabian Alps The Swabian Jura ( , more rarely ), sometimes also named Swabian Alps in English, is a mountain range in Baden-Württemberg, Germany, extending from southwest to northeast and in width. It is named after the region of Swabia. It is part of th ...

Württemberg Württemberg ( ; ) is a historical German territory roughly corresponding to the cultural and linguistic region of Swabia. The main town of the region is Stuttgart. Together with Baden and Province of Hohenzollern, Hohenzollern, two other histo ...

, as pointed out by W. Branco. Sir A. Geikie has shown that the puy type of eruption was common in the British area in

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

and

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

times, as abundantly attested in central

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

by remains of the old volcanoes, now generally reduced by

denudation Denudation is the geological process in which moving water, ice, wind, and waves erode the Earth's surface, leading to a reduction in elevation and in relief of landforms and landscapes. Although the terms erosion and denudation are used interchang ...

to the mere neck, or volcanic vent, filled with

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock co ...

and

agglomerate Agglomerate (from the Latin ''agglomerare'' meaning "to form into a ball") is a coarse accumulation of large blocks of volcanic material that contains at least 75% bombs. Volcanic bombs differ from volcanic blocks in that their shape records flui ...

, or plugged with lava.

References

* *Sir A. Geikie
''Ancient Volcanoes of Great Britain''
(1897). {{Authority control Volcanic landforms Geology of France

See also

References