Mineralogical, petrochemical and petrographic-textural studies of ore grade and lower grade radioactive rocks from the Bancroft area, Ontario

Results of rapid chemical, spectrographic, scanning electron microscope and neutron activation analyses for U are discussed in relation to metamorphism, recrystallization, replacement textures and mineralization of hybrid rocks collected at mine sites in the Bancroft area. The samples represent the following: 1. gneisses, migmatites and granitoid rocks in and adjacent to the Faraday granite; 2. Cheddar granite, mylonite and surrounding gneisses with sedimentary textures; 3. pegmatite and adjacent high grade metamorphic rocks surrounding Halo mine; 4. selected ore specimens from the Madawaska, Greyhawk, Bicroft and Halo mines, and their relation to petrographic-textural characteristics and ore and accessory mineral associations. Relicts of diverse metasedimentary rocks, prophyroblastic and anatectic textures, impregnations, mylonitiation and alteration account for the mineralogical and petrochemical diversity of the hybrid rocks. With a few exceptions which contain radioactive accessory minerals, most of the metasediments contains less than 4 ppm U and are unlikely sources for the uranium mineralization