MINERALOGICAL PROPERTIES OF TEN REDDISH BROWN SOILS FROM THE ATLANTIC PROVINCES IN RELATION TO PARENT MATERIALS AND PEDOGENESIS

The clay mineralogy data were consistent with previous findings in showing marked weathering in the Ae horizons of Podzols (Spodosols), an intermediate degree of weathering in Degraded Dystric Brunisols (Cryochrepts), and weak weathering in the Ae horizons of Luvisols (Alfisols). Mica was apparently partly altered to montmorillonite and chlorite was weathered out of the clay of Podzol Ae horizons, but chlorite remained and only slight alteration of mica to vermiculite had occurred in Luvisol Ae horizons. The apparent weathering of clays in the Gleysolic (Aqualf and Aquept) Ae horizons varied. In one, the clay mineralogy was like that of a Podzol Ae, but in another little weathering was evident. Thus, in general, but not in all instances, clay mineralogy was related to the classification of the soils based on morphological, physical, and chemical data.Both the sand and the clay mineralogy indicated some differences in parent materials, and some relationships of the soil materials with the underlying bedrock.