Puy de Chalard, Extinct volcano in Manzat, Puy-de-Dôme, France

Puy de Chalard is an extinct composite volcano on the territory of Manzat, in the Combrailles, about 40 km northwest of Clermont-Ferrand. It consists of a phreatomagmatic maar, now largely buried, topped by a strombolian scoria cone of potassium-rich trachybasalt. An explosion later blew out part of its northwest flank and sent a lava flow in that direction. The wooded hill rises above pasture.

The Puy de Chalard began as a phreatomagmatic maar, a crater formed by explosive steam-driven eruptions. A strombolian scoria cone of potassium-rich trachybasalt later built up inside it, almost completely burying the maar. A subsequent explosion blew out part of the northwest flank and sent a lava flow in that direction. Thermoluminescence dating of a sample from this flank by Guérin in 1983 gave an age of 51,050 ± 7,900 years BP.

The name derives from Occitan: "puei" (puy, a volcanic hill) and "chaslar", which in the northern Occitan area designates a medieval castle. The peak stands on the land of Manzat, in the Combrailles, and its name thus records a castle that the toponym still evokes.

The volcano lies in the commune of Manzat, about 40 km northwest of Clermont-Ferrand and some 7 km west of the Limagne graben's boundary fault. The Gour de Tazenat maar is 2.5 km to the north-northeast and the Beaunit maar 7 km south. Breccias of the buried maar, 6 to 7 m thick, are visible east of the hamlet of Touzet, south of the hill.

The volcano sits on a hidden maar, an older explosion crater almost entirely buried by the later slag cone; its near-circular depression can still be traced in the land, with bedrock outcrops marking the rim. East of the hamlet of Touzet, ejecta breccias 6 to 7 metres thick hold angular granite, microgranite and Viséan rhyolite tuff fragments, plus lapilli and basalt blocks, some with bread-crust surfaces.