Layer Charge Characteristics of Smectites in Salt-Affected Soils in Alberta, Canada

Connie K. Kohut and M. J. Dudas
Department of Soil Science, University of Alberta Edmonton Alberta, T6G 2E3

Abstract: The layer charge characteristics of expanding phyllosilicates in four salt-affected soils in Alberta, Canada were investigated using X-ray diffraction analysis of alkylammonium saturated samples. The layer charge was found to be lower and more heterogeneous than previously reported for non-saline Alberta soils, with the mean layer charge ranging between 0.261 to 0.339 tool (—)/O10(OH)2. Layer charge characteristics varied inconsistently with location, depth and particle size, likely the result of both different origins and weathering processes. Different degrees of K depletion from the micaceous component after equilibration with alkylammonium compounds may also account for some variability between samples. Extreme broadening and essential disappearance of smectite diffraction maxima was noted for some samples after intercalation with alkylammonium cations of all carbon chain lengths, indicating unusual alteration of the layer charge characteristics in some salt-affected soils.

Key Words: Layer charge • Salinity • Smectite

Clays and Clay Minerals; February 1995 v. 43; no. 1; p. 78-84; DOI: 10.1346/CCMN.1995.0430109
© 1995, The Clay Minerals Society
Clay Minerals Society (www.clays.org)