1. A hard, crusty layer of calcium carbonate and other minerals that forms in soil, especially in arid and semi-arid regions.
Usage: geology; soil science
2. Gravel or sediment cemented together by calcium carbonate, used as a building material or road base.
Usage: construction; regional (southwestern U.S.)

Examples

• The caliche layer beneath the desert soil prevented water from draining deeper into the ground.
• Farmers in the Southwest often have to break through caliche to dig wells.
• The road was constructed using crushed caliche as a base layer.
• Caliche deposits are common in arid climates where evaporation concentrates minerals.
• The archaeologist found pottery shards embedded in the caliche layer.
• Mining operations sometimes extract caliche for use in cement production.