Glacial transport and secondary hydromorphic metal mobilization: examples from the southern interior of British

Abstract: Glacial transport of trace elements was studied at seven mineral occurrences in the southern interior of British Columbia; a region where mineral exploration is hampered by the scarcity of bedrock outcrop and by a variable sediment thickness a ociated with the Cordilleran Ice Sheet. The till deposited in the region was, for the most part, a product of the last glacial period. A review of previous geochemical studies conducted by the mineral exploration industry provides an indication to the variable configuration of the local dispersal patterns in the area. Dispersal trains in till are short, generally < 1-2 km, rarely exceeding 10 km in length and are usually proximal to bedrock source. They are commonly ribbon-shaped and rarely exceed 1 km in width. Observed dispersal p tterns uggest that drastic hanges in topography might have affected basal ice velocity which increased the distance of glacial transport. In addition, the distance that separates bedrock mineralization from its urficial geochemical expression in till varies with drift thickness and topography. Several glacial dispersal tr ins have been modified in shape by secondary hydromorphic dispersion. Mineral exploration in the southern interior of British Columbia is hampered by a scarcity of bedrock outcrop and by a variable sediment thickness associated with the glaciation of the Canadian Cordillera. Studies of the physical and compositional characteristics of glacial sedi-ments in the Cordillera have for some years, provided basic models for the application of drift prospecting methodologies in this topogra-phically rugged and geologically complex terrai