The Origin of Caliche on the Northeastern Llano Estacado, Texas
1956; University of Chicago Press; Volume: 64; Issue: 1 Linguagem: Inglês
10.1086/626313
ISSN1537-5269
Autores Tópico(s)Soil Geostatistics and Mapping
ResumoCaliche underlies the soils of the northeastern Llano Estacado as single, double, or, in a few places, multiple layers, each consisting of relatively unindurated caliche grading upward into the indurated cap-rock. Laboratory studies show that the caliche is composed of varying but roughly equal parts of calcite and/or, rarely, silica gel, silt-size quartz particles, and small water-filled vacuities, all arranged isotropically in space with the elastics being largely non-adjoining. Physiographic and theoretical considerations indicate that the caliche is a product of long continued deposition and results from subsurface evaporation of soil moisture in an eolian aggrading soil profile. The ultimate source of the $$CaCO_{3}$$ appears to have been fine eolian elastics. The caliche, with interruptions, apparently has been forming continuously since its inception in the Pliocene, and its multiple occurrence is a reflection of climatic variations in the Pliocene and Pleistocene.
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