Reports research conducted in the Vernon area of southern interior British Columbia to search out and map marker units in high-grade Neoproterozoic and Palaeozoic metamorphic rocks, and to map the east-west extent of overlying Triassic Slocan Group strata. Stratigraphic relations in the area are summarized and detailed stratigraphy of a calcareous quartzite marker unit is described. Regional correlations of this marker unit with map units farther east & north and elsewhere in the Vernon map area are then discussed. The paper examines the hypothesis that the marker unit is the same succession that hosts the Kingfisher and Big Ledge lead-zinc occurrences, with implications for the exploration potential for base metals in the study area.