COMPARISON OF CHEMICAL COMPOSITION OF SOILS AND BEDROCK OF MONT ST. HILAIRE, QUEBEC

Abstract

Soil samples from Mont St. Hilaire, one of the Monteregian Hills of Quebec, were analyzed by X-ray fluorescence for the elements Fe, Ca, K, Ti, Mn, Sr, Zr, Nb, Zn, and Rb. The samples were taken below the surface organic-rich horizon.The composition of the parent material was calculated by comparing the soils with local rocks having similar Ti/Zr ratios, assuming that the Ti/Zr ratio has not changed appreciably during the soil-forming process. This comparison indicates that there has been little change in the concentration of most of the elements during weathering. Average ratios of concentration in soils to concentration in calculated parent material for the elements were Fe 1.25, Nb 1.11, Ca 1.08, Rb 1.07, Zn 1.02, Zr 0.96, Ti 0.94, Mn 0.82, Sr 0.69, K 0.54; that is, Fe showed a tendency to accumulate, and K, Sr, and possibly Mn showed a tendency to be depleted in the soils.The areal distribution of elements in the soils is in general agreement with what is known of the distribution of syenitic and essexitic intrusive rocks which make up most of the mountain.