A review of the history of the nomenclature of the Medina Formation and of the previous studies of its members, particularly those studies dealing with the source of the Whirlpool sandstone. This is an attempt to show the direction of origin of the detrital materials of the Whirlpool sandstone by a study of the lateral variation of its grain size along the Niagara Escarpment. It is illustrated with maps and with photographs taken by the writer. / Thesis / Master of Science (MSc)

A field and textural investigation of the Medina Formation has been made. The thesis includes a brief analysis of the microscopic sedimentological properties of the sandy facies, a detailed study of the paleocurrent indicators, and a study of the distribution of the more typical sedimentary structures. Analytical laboratory data, primary sedimentary structures, and outcrop data have been used to reconstruct the paleoenvironmental setting of the Lower Silurian rocks exposed along the Niagara Escarpment from Hamilton (Ontario) to Fulton (New York). They indicate a complex of sub-environments within the broad model of a delta, with the direction of current movement being from the South-East in the eastern part of the area under study and from South-West and North-East in the western part. The determination of these two paleocurrent systems forms a major contribution of this work. / Thesis / Doctor of Philosophy (PhD)