1. A sample of pitchblende from LaBine Point, Echo Bay, Great Bear Lake, N. W. T., Canada, yields a "corrected" lead-ratio of 0.193, corresponding to an age of 1323 million years. 2. As the atomic weight and isotopic composition of the lead, and the Pa/UI ratio of this same sample have been determined, ages, etc., calculated by different methods should agree. This agreement has not been obtained in all instances, and possible reasons have been outlined. 3. The age found indicates that a possible Keewatin granite may be the source of the pitch-blende.
Additional publication details
Lead-uranium ratio of siliceous pitchblende from Great Bear Lake, N. W. T., Canada, and its possible age