Caliche generally forms when minerals are leached from the upper layer of the soil (the A horizon) and accumulate in the next layer (the B horizon), at depths of approximately three to 10 feet under the surface
sedimentary rock, a hardened deposit of calcium carbonate. This calcium carbonate cements together other materials, including gravel, sand, clay, and silt. It is found in aridisol and mollisol soil orders. Caliche occurs worldwide, generally in arid or semiarid regions, including in central and western Australia, in the Kalahari Desert, in the High Plains of the western USA, and in the Sonoran Desert. Caliche is also known as hardpan, calcrete, kankar (in India), or duricrust. The term caliche is Spanish and is originally from the Latin calx, meaning lime.
vary from a few inches to feet thick, and multiple layers can exist in a single location.
can form when water rises through capillary action. In an arid region, rainwater will sink into the ground very quickly. Later, as the surface dries out, the water below the surface will rise, carrying dissolved minerals from lower layers upward with it
plant roots take up water through transpiration, leaving behind the dissolved calcium carbonate, which precipitates to form caliche
an impermeable caliche layer prevents water from draining properly - Salts can also build up in the soil due to the lack of drainage - cause the surrounding soil to be basic