Proposed Title 1: - Queen's University

Gunnar formed from reducing hydrothermal brines that exsolved from magmatic fluid at
315 o C. However, uranium associated with this metasomatic style of mineralization is
overprinted by the more significant breccia-vein and later, minor volcanic-type
mineralizations. The Gunnar deposit contains all three styles of mineralization.
During the Paleoproterozoic, reactivation of major fault zones is related to the
dominant breccia-type mineralizing event. Syn-ore chlorite crystal chemistry and stable
isotope geochemistry of H, C, and O of syn-ore minerals indicate that the main U-
mineralizing event at 1.85 Ga in all deposits in the Beaverlodge area, formed from Ca-Na-
F-rich fluids at 330 o C associated with regional metamorphism coincident with the postpeak
Thelon-Taltson Orogen or, more likely, early stages of the Trans-Hudson Orogen.
During the late Paleoproterozoic, formation of the Martin Lake Basin and associated
volcanic rocks is related to the volcanic-type mineralization at 1.82 Ga. Syn-ore chlorite
crystal chemistry and stable isotope geochemistry of H, C, and O of syn-ore minerals
indicate that this mineralization formed at 320 o C from magmatic fluids originating from
the alkaline mafic dikes. The last stage of mineralization formed at ca. 1.62 Ga from
oxidizing basinal brines at 235 o C originating from the Athabasca Basin. Subsequent
erosion of the Athabasca and Martin Lake Basin rocks and weathering of the deposit
resulted in the formation of secondary uranium minerals and late veins.
These results improve the current genetic model for uranium mineralization in the
Beaverlodge area to a level that takes into account the multiple stages of deformation and
fluid overprinting that occurred over a period of at least 2.3 Gyrs. Although the
Beaverlodge area represents several distinct mineralizing events, the major event is the
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