The Gypsum Quarry

The Gypsum Quarry

Formed about 220 million years ago in a salty lagoon, gypsum is a soft rock composed of calcium-sulphate. When heated in a furnace, it loses its water through evaporation and is transformed into plaster. Then, after being ground in the open air or in a mill, it can be rehydrated and used in construction. In the 19th century, many small extraction sites existed in Haute-Provence.

Traditional architecture has many uses for plaster: from the very coarse plaster used as mortar for building walls to the finest used for making gypsum.

In Thoard, gypsum-quarries have been recorded since 1840, but extraction probably began much earlier. The best known is the Siron quarry, documented from 1890, which was in operation until 1940. The stone was extracted in the open air with picks and pickaxes and then loaded onto sledge-like carts commonly used in the valley for agricultural work in areas with steep slopes. It was then transported to the village to the plaster factory. There, a water-powered mill, created by a waterfall on the Riou mountain-river, operated a heavy vertical millstone.

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Adresse

UNESCO Géoparc de Haute-Provence
Musée Promenade
Parc Saint-Benoît BP 30 156
04990 DIGNE-LES-BAINS
France

Téléphone

+33(0)4 92 36 70 70

ACTUALITÉ / PLAN DU SITE

L’UNESCO Géoparc de Haute-Provence est un service de Provence Alpes Agglomération,
administré au travers d’une Entente Intercommunale avec la Communauté de Communes du Sisteronais-Buëch
et financé par la région Provence Alpes Côte d’Azur et le Conseil Départemental de Haute-Provence.

Provence Alpes AgglomérationCommunauté de communes du sisteronnais buëch
Région Sud Provence Alpes Côte d'AzurConseil départemental Alpes de Haute-Provence

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