Proposed Title 1: - Queen's University

3.4J). Py 6 Pyrite and Cpy 5 chalcopyrite are disseminated in the matrix. Ap 1 apatite as
tabular crystals is intergrown with U 5 (Fig. 3.4J).
Athabasca-type U mineralization fills late fractures and consists of U 6 uraninite
associated with Cal 10 calcite, Chl 9 chlorite, Hem 8 hematite, and minor Py 7 pyrite (Fig.
3.4L). These late veins (Fig. 3.4K) crosscut the Murmac Bay Group, the basal
conglomerates of the Martin Lake Group and the mafic dikes and are the youngest
mineralized phase. U 6 uraninite is typically massive and generally rims Cal 10 calcite veins.
Late veins of Cal 11 calcite, Chl 10 chlorite, Qtz 5 quartz and sulfide occur as fracture-filling
minerals cutting primary ore assemblages. The sulfides are Gn 1 galena, Cpy 6 chalcopyrite,
Py 8 pyrite, Sph 1 sphalerite, and copper minerals. Gn 1 galena forms inclusions or fracturefilling
in uraninite and Py 8 pyrite or thin films along Cal 8 calcite cleavage in the breccia
rock. Sph 1
sphalerite occurs as irregular masses or fine blebs in Py 8 pyrite. Copper
mineralization is present as disseminated aggregates of Bn 1 bornite, Dg 1 digenite, and Cv 1
covellite at the Ace-Fay and Gunnar deposits and appears to postdate the main event of U
mineralization.
3.4.2. Crystal Chemistry
3.4.2.1. Mineral chemistry of uraninite and brannerite
Electron microprobe and backscattered images reveal that uraninite from all stages of
mineralization has been variably altered to different forms of uranyl-silicates (Table 3.1,
Fig. 3.5). These uraninites demonstrate evidence of considerable variation in reflectance,
suggesting significant heterogeneity in their chemical composition as a result of variable
alteration by later fluids (Kotzer and Kyser, 1993; Alexandre et al., 2005).
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