Proposed Title 1: - Queen's University

decompression and hydration reactions was the mechanism of veins formation. U was
transported as uranyl-carbonate-fluoride complexes. C: At Gunnar, U 3 was derived from
magmatic fluids from the Gunnar granite. PO -3 4 and F - were important ore transporting
complexes. D: Reactivation of fault zones during early regional metamorphism of the Trans-
Hudson or post-peak Thelon-Taltson Orogen resulted in massive brecciation at shallow
structural levels. Metamorphic-hydrothermal U-mineralizing fluids derived from dehydration
of hydrous minerals during metamorphism ascended upward along deep fractures and
decompression caused decrease in the solubility of the carbonate complexes promoting U
deposition. E: During the Paleoproterozoic, the Martin Lake Basin and associated alkaline
mafic dikes formed and hydrothermal U 5 -mineralizing solutions resulted in magmatichydrothermal
degassing along pre-existing fractures. F: Ore-forming brines from the
Athabasca Basin descended along fractures in the basement rocks and U 6 deposition was via
reduction through interaction between oxidizing basinal brines and reduced metamorphic
basement lithologies. G: Post-ore incursion and circulation of meteoric water through
structurally reactivated fault zones that remain a zone of preferential fluid circulation. H:
Erosion of the Athabasca and part of Martin Lake basin rocks and weathering of the deposit
resulted in the recent formation of secondary uranium minerals and late alteration veins.
Deposition of the 2.33 Ga Murmac Bay Group sediments (Hartlaub and Ashton,
1998) was followed by intrusion of the ca. 2321±3 Ma Gunnar granite (Evoy, 1969;
Hartlaub et al., 2004a), which hosts the granite-related metasomatic-type U 3 uranium
mineralization (Fig. 3.11C). The timing of this mineralization is constrained between the
age of the granite (ca. 2321±3 Ma) and the brecciation event (1850 Ma; Dieng et al., 2011)
that overprinted the granite-related U-mineralization at Gunnar. δ 18 O, δ 13 C and δ 2 H
isotopic compositions of syn-ore Cal 5 calcite and Chl 5 chlorite (Figs. 3.7 and 3.8) indicate
that U 3 mineralization has ore-forming components consistent with derivation from
magmatic fluids (Fig. 3.11C). The strong negative Eu anomaly in U 3 uraninite indicates
retention of plagioclase during albitization of the granite. Collectively, these results
demonstrate that fluids involved in the metasomatic alteration of the Gunnar granite could
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