The relationship between soil properties and micromorphological features was studied in six Alfisol and six Spodosol profiles from Southern Ontario. The total porosity of the soil material was largely related to the size, shape and conformation of the soil voids in thin sections, while the differential development of plasma fabric could be used to discern a sequence of degrees of weathering which was also expressed by various mineralogical and physico-chemical indices. The relative proportions of soil constituents in thin sections was successfully used to indicate the existing textural discontinuities in five of the profiles studied. The elementary structure of soil thin sections is considered the most important micromorphological feature in the investigation of the degree of B horizon development in both Alfisol and Spodosol profiles. / Thesis / Doctor of Philosophy (PhD)