Nature of sensitive clays from Québec

Abstract

Quantitative mineralogical analyses of sediment samples from 18 sites in Québec indicate that plagioclase is the most abundant mineral in all soils and that chlorite is generally the dominant clay mineral followed by illite and expandable clays consisting of mixed-layer clays minerals involving vermiculite. The study also illustrates how specific surface area and constitutive water content can be used to evaluate departures from average in the mineralogical composition of sensitive clays. The relationship between activity and specific surface area of sensitive clays shows that when compared to soils from different sedimentary basins that have different mineralogy, they are characterized by a much lower activity and specific surface area.