caliche

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caliche(calcrete) A carbonate horizon (the K horizon) formed in a soil in a semi-arid region, under conditions of sparse rainfall (20–60 mm/yr) and a mean annual temperature of about 18°C, normally by the precipitation of calcium carbonate carried in solution. The soil profile develops over several thousand years, initially in the form of nodules (glaebules), more mature caliches taking a massive, laminar form. It may become cemented and indurated on exposure, when it gives rise to a tabular landscape. See also calcic horizon; duripan; and petrocalcic horizon.

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