Puys

Puys are a class of volcanic hills or cones found mainly in the Massif Central of France. The term puy comes from the Occitan word for hill or peak and is used in geology to describe isolated volcanic structures formed by eruptions around one or more vents. Puys are typically built by basaltic magma, producing cinder cones, lava domes, and lava flows that accumulate around a vent. The landscape often features grassy summits with craters that may be eroded or partially filled.

The best-known concentration is the Chaîne des Puys, a 40-kilometer-long belt of about 80 lava cones and associated lava flows in the Auvergne region near Clermont-Ferrand. The chain includes notable peaks such as Puy de Dôme, which rises to about 1,465 meters above sea level, and Puy de Côme, among others. The cones vary in size and shape but share a relatively recent geologic age and a predominantly basaltic composition.

Formation and evolution: Puys formed through repeated eruptions that produced tephra (ash and lapilli) and coherent lava flows, building cones around vents. Erosion, drainage, and past glaciation have shaped the current topography, leaving a landscape of rounded hills and lava-field remnants.

Present-day significance: The Chaîne des Puys is a focus of geomorphological and volcanic research and a popular destination for hiking and sightseeing. The area preserves a record of volcanic activity and provides insight into the behavior of basaltic volcanic systems.

Other usage: The term puy is used for similar volcanic hills in the region and appears in many place names, reflecting a long-standing local toponymy for volcanic features.