Proposed Title 1: - Queen's University

Ukraine (Cuney and Kyser, 2008) wherein both U and Ti are mobilized in F-rich and CO 2 -
rich fluids (Hynes, 1980; Gieré, 1990). U 4 uranium precipitation in the breccia system is
likely caused by a decrease in the solubility of the carbonate complexes resulting from a
loss of CO 2 and a decrease in temperature caused by fluid decompression during
brecciation so that pressure and temperature conditions may have been the most dominant
factors controlling U 4 uranium mineralization. However, U transported by F-rich oxidized
fluids in metamorphic-related U-systems may be deposited via reduction reactions
(Skirrow et al., 2009) as the U 4 -mineralizing fluid reacted with reducing Ca-Fe-rich
metamorphic host rocks, resulting in the following reaction (Langmuir, 1978):
2Ca 2+ + UO 2 (CO 3 ) 3
4-
+ 2Fe 2+ +4HCO 3
-
= UO 2+ ↓ + Fe 2 O 3 ↓ + 2CaCO 3 ↓ + 2H 2 O + 5CO 2 ↑.
This process may explain the abundance of Hem 6 hematite associated with U 4 uraninite,
the Cal 8 calcite alteration in the breccia matrix, and the Fe-rich Chl 7 chlorite. In hightemperature,
reduced F-rich metamorphic-related U-systems, the activity of calcium and
pH may be more important than redox in controlling U deposition due to the low
solubility of fluorite (Skirrow et al., 2009).
These results corroborate the findings of Hoeve (1982) who proposed that the
Beaverlodge U deposits may represent a Na-Ti-U style mineralization related to Nametasomatism
during regional metamorphism by the Trans-Hudson Orogen. He suggested
that the resulting Na-alteration involving addition of Na and Ca and loss of K, Mg, Fe, Ti,
and U from the rocks are related to interaction between metamorphic-related hydrothermal
fluids and country rocks. The mineralizing brine deposited the U mineralization in fracture
and breccia systems at structurally shallow levels. Others have also proposed a
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