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Morphology of calcite crystals in clast coatings from four soils in the Mojave desert regionPedogenic calcite-crystal coatings on clasts were examined in four soils along an altitudinal gradient on Kyle Canyon alluvium in southern Nevada. Clast coatings were studied rather than matrix carbonate to avoid the effects of soil matrix on crystallization. Six crystal sizes and shapes were recognized and distinguished. Equant micrite was the dominant crystal form with similar abundance at all elevations. The distributions of five categories of spar and microspar appear to be influenced by altitudinally induced changes in effective moisture. In the drier, lower elevation soils, crystals were equant or parallel prismatic with irregular, interlocking boundaries while in the more moist, higher elevation soils they were randomly oriented, euhedral, prismatic, and fibrous. There was little support for the supposition that Mg(+2) substitution or increased (Mg + Ca)/HCO3 ratios in the precipitating solution produced crystal elongation.
Document ID
19890064845
Document Type
Reprint (Version printed in journal)
Authors
Chadwick, Oliver A. (California Institute of Technology Jet Propulsion Laboratory, Pasadena, United States)
Sowers, Janet M. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Amundson, Ronald G. (California, University Berkeley, United States)
Date Acquired
August 14, 2013
Publication Date
February 1, 1989
Publication Information
Publication: Soil Science Society of America, Journal
Volume: 53
ISSN: 0038-0776
Subject Category
GEOPHYSICS
Distribution Limits
Public
Copyright
Other