A STUDY OF THE MINERALOGICAL COMPOSITION OF SAND IN SOUTHERN ONTARIO

Abstract

A mineralogical study of the fine sand fraction of unweathered tills and stratified sands chosen to represent the deposits of the major ice lobes of southern Ontario was carried out. In addition, a few analyses were made of the coarse silt and coarser sands.In general there was the same variety of minerals in all samples and they varied only in their proportions. Tills overlying Palaeozoic bedrock contained abundant carbonates and shale fragments constituting up to 70 per cent of some fine sands. In the coarse sands, carbonates and shale increased sharply. In the coarse silt and fine sand, feldspars were more abundant than quartz whereas in the medium and coarse sand the reverse was true. Quartz increased in quantity with increasing grain size and reached a maximum in the medium sand. Heavy minerals usually constituted less than 15 per cent of the fine sand. Some of the minerals present in the coarse silt and fine sand were not found in the coarser sands. Usually the order of abundance of the heavy minerals was: hornblende, garnet, micas, magnetite, pyroxenes and sphene. Epidote, rutile, apatite, tourmaline, staurolite, kyanite and others were also noted. A chart listing the plant nutrient elements found in these minerals was prepared.