Geology and Mineral Occurrences of the Nehalliston Plateau , South - Central British Columbia ( 92 P / 7 , 8 , 9 , 10 )

The Bonaparte project is a new multi-year bedrock mapping program of the British Columbia Geological Survey (BCGS) concentrating on Mesozoic arc volcanic and plutonic rocks of the Quesnel Terrane in the northeastern part of the Bonaparte Lake (92P) map sheet (Figure 1). The area encompasses a northwest-trending belt of high mineral potential that includes a number of interesting mineral occurrences, as well as numerous regional geochemical survey and till geochemical anomalies. The project will improve the quality and detail of bedrock maps for the area, which are based primarily on 1:250 000-scale mapping carried out by the Geological Survey of Canada in the 1960s. The mapping will be facilitated by much-improved road access, and will benefit from a more thorough understanding of regional geology and mineral occurrences provided by earlier BCGS projects on the same belt of rocks to the north (Nelson and Bellefontaine, 1996; Panteleyev et al., 1996). The new mapping will help attract mineral exploration to the region by providing an improved geologic framework for interpreting the mineral occurrences and geochemical anomalies, and for predicting favourable settings for future discoveries. Here, we present preliminary results of the first year of mapping for the Bonaparte project. The fieldwork was carried out by the authors in July and August, 2000. The area mapped covers about 700 square kilometres within and adjacent to the informally-named Nehalliston Plateau, which comprises the northeastern tip of the Thompson Plateau of the south-central interior of British Columbia (Holland, 1976). The area is bounded on the east by the North Thompson River, which is followed by Highway 5 and the main line of the Canadian National Railway. It is bisected by Highway 24, which branches westward from Highway 5 at the town of Little Fort, eventually to connect with Highway 97 south of 100 Mile House. Access to most parts of the area is easily attained by an extensive network of logging and Forest Service roads that branch from highways 5 and 24.