caliche

• Nom désignant une croûte dure ou un horizon cimenté dans le sol, formé par l'accumulation de carbonates de calcium dans les régions arides, ou une roche ou un gravier contenant des nitrates, extrait des gisements de nitrate de sodium au Chili et au Pérou.

A noun referring to a hardened layer of subsoil encrusted with calcium carbonate, found in arid regions, or a nitrate-bearing rock or gravel from sodium nitrate deposits in Chile and Peru.

1. Hard subsoil crustC1formal

   A hardened layer of soil found in dry regions, often containing calcium carbonate.

   Croûte calcaire du sol

   • Farmers in the desert struggled to break through the caliche layer.
   • The caliche made it difficult for plant roots to penetrate the ground.
   • Construction crews had to use special equipment to dig through the caliche.

   Synonymeshardpan

2. Nitrate-bearing depositC2formal

   A mineral deposit containing sodium nitrate, found in the deserts of Chile and Peru.

   Caliche (gisement de nitrates)

   • The caliche deposits in the Atacama Desert were a major source of nitrates.
   • Miners extracted caliche for use in fertilizers and explosives.
   • The region's economy once relied heavily on caliche mining.