Pierre-sur-Haute (; ) is the highest point of the

Forez mountains The Forez mountains (, ) are a mountain range in the Massif Central separating the Dore (river), Dore valley from the Forez plain. They reach their highest point at Pierre-sur-Haute, with an altitude of 1,631 meters. Geography Location The Fo ...

(1,631 m) in the Massif Central, at the boundary of the

Loire The Loire ( , , ; ; ; ; ) is the longest river in France and the 171st longest in the world. With a length of , it drains , more than a fifth of France's land, while its average discharge is only half that of the Rhône. It rises in the so ...

( Sauvain) and

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.Job Work, labor (labour in Commonwealth English), occupation or job is the intentional activity people perform to support the needs and desires of themselves, other people, or organizations. In the context of economics, work can be seen as the huma ...

)

departments Department may refer to: * Departmentalization, division of a larger organization into parts with specific responsibility Government and military * Department (administrative division), a geographical and administrative division within a country, ...

. It is also the highest point in the Loire department.

Geology

Pierre-sur-Haute is a mountain composed of

gneiss Gneiss (pronounced ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. This rock is formed under p ...

and

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

, rocks that are remnants of an ancient mountain range that appeared in the

Paleozoic The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma a ...

era, 300 million years ago. This ancient Hercynian relief was subsequently leveled during the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

era due to

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

, resulting in a tabular relief. Following the Alpine orogeny, the Forez mountains were rejuvenated, faults appeared, and this granite block was uplifted ( horst). Pierre-sur-Haute is the highest point of this uplifted block.

Geology

References

See also