| Mineral distribution, alteration and authigenesis was studied in a series of pedons of both Luvisolic and Solonetzic soils developed on texturally different tills in Alberta, Canada. The crystalline clay suite, identified by X-ray diffraction analyses and quantified by analyses for cation exchange, surface area and elemental content, of all parent materials consisted of an admixture of smectites, kaolinite, dioctahedral mica, and chlorite. Beidellite, montmorillonite and nontronite were identified as components of the smectite group. The non-crystalline clay component was determined using selective dissolution treatments.;Examination of Solodized Solonetz pedons showed the presence of both crystalline and non-crystalline authigenic minerals in the Ae horizons and the solodized zones of the columnar Bnt horizons. A zeolite mineral with the characteristics of clinoptilolite was detected in the coarse clay (1.0-2.0 ;Kaolinite was negatively enriched in the Ae horizons in all clay size separates, whereas mica and mectites were enriched in the Bt (Bnt) horizons as a result of lessivage. Although routine chemical and mineralogical characterization suggested apparent neoformation of beidellite in the E horizons of these pedons, the difference in isotopic signature of the detrital crystalline clays from any neoformed clay species disproved the hypothesis. The ;An iron oxyhydroxide enriched band at the organic-mineral interface of a Terric Fibrisol formed on calcareous parent material was essentially pure ferrihydrite, with both microbiological and chemical controls on formation from interstitial waters. |
