A STUDY OF CLAY MINERALS IN PODZOL SOILS IN NEW BRUNSWICK, EASTERN CANADA

ABSTRACT: Clays from the Ae and C horizons of five Podzol soil series in New Brunswick were examined by X-ray, chemical and infrared absorption methods. ALl the experimental evidence indicated that the Ae horizons contained predominantly a dioctahedral randomly interstrafified mica-vermiculite--smectlte clay, whereas the C horizons contained abundant dioctahedral mica (illite) and trioctahedral chlorite. Since no trace of chlorite as a separate phase or as one component of the interstratified structure was found in the Ae horizons, it was concluded that, while the inherited chlorite was decomposed in all of the Ae horizons, mica was differentially hydrated giving an interstratified structure. Fourier transforms of the three-component i erstratified clay revealed ifferent ratios of hydrated layers (vermiculite and smectite) to non-hydrated layers and different stacking sequences. The proportion of hydrated layers and randomness of stacking was related to the degree of weathering as measured by the accumula-tion of TiO 2 in the Ae horizon and it was suggested that they may be related to the degree of podzolization