THE CHEMICAL AND MINERALOGICAL COMPOSITION OF SOIL PARENT MATERIALS IN NORTHEAST ALBERTA

Abstract

Seven major parent materials from the Athabasca oil sands area were investigated for detailed mineralogy and chemistry. The clay mineral species identified and quantified were mica, smectite, kaolinite, chlorite and vermiculite. The fine (50–250 μm) sand mineralogical suite was dominated by quartz, with lesser amounts of Na-, K-, and Ca-feldspars, and minor amounts of individual heavy mineral species. Electronoptical examination indicated that the feldspar grains in the parent materials have undergone extensive preglacial weathering. Regional mean levels of all analyzed elements (Al, Ca, Fe, K, Mg, Na, Mn, P, Cr, Co, Cu, Ni, Pb, Sr, V, and Zn), with the exception of Ca, are related to textural variability. The variability of Ca levels within the study area is related to the occurrence of calcareous parent materials. The highest levels of all major, minor, and trace elements were associated with either the Legend unit derived largely from Cretaceous bedrock or with the modern sediments of the Athabasca delta. Key words: Soil parent materials, clay mineralogy, trace element levels, sand mineralogy, feldspar morphology