Book excerpt: The area studied in this paper covers southern Cortes Island, Marina Island, and north-west Hernando Island in the Strait of Georgia, British Columbia. The paper first reviews the geological setting & physiography of the study area, then presents results of mapping Pleistocene (Wisconsinan) strata exposed in the area. The stratigraphic succession, having maximum thickness of 130 metres, is subdivided into six major units, all recording cyclical, climate-controlled, primarily marine deposition. Established names are used for two widespread formations (Cowichan Head and Quadra Sand) and local names are introduced for newly determined formations. Probable sources of the formation sediments are briefly discussed.