Canadian deposits of uranium and thorium

From a relatively small beginning, stemming from a radium mine operated before World War II, uranium deposits were quickly found in several parts of Canada and production has grown so that uranium became the leading metal produced in Canada in 1958. The value of Canadian uranium production in that year was more than $274,000,000. This report is a summary of information on the geology of more than 1,000 mining properties containing uranium. Thorium is discussed also, because it is related to uranium and occurs with it in several deposits; a few deposits contain only thorium, or thorium with only traces of uranium. The descriptions of areas and deposits are as of December 31, 1957; generalizations include information gained in 1958 and early 1959. Seventy uranium or thorium minerals and varieties have been found in Canada, but of these the only important ore minerals are brannerite, uraninite (and its variety pitchblende), uranothorite, and uranophane. Uranium occurs in small amounts in a wide variety of deposits, but the ores are of three main types: 1) conglomerate; 2) pitchblende veins and disseminations; and 3) pegmatitic granite and syenite. Occurrences are widespread, but most are in the Canadian Shield, particularly in its margins. Most Canadian production of uranium now comes from conglomerate ore in Blind River area, Ontario, where ore reserves in 1958 were sufficient for about 20 years at current rates of production. Additional ore is partly blocked out; when still more is required the better prospects now known in various districts can be tested further, and additional prospecting can be done in areas suggested, using techniques explained.