Proposed Title 1: - Queen's University

etween ca. 2.3 Ga and 1.9 Ga. Later stages are related to minor U veins at ca. 1.82 Ga
linked to Martin Lake mafic dikes and to minor late veins at ca. 1.62 Ga corresponding
to the timing of unconformity-type U mineralization in the Athabasca Basin.
d) The main event of U mineralization in the South Alligator River area formed at ca.
1820 Ma, subsequent to deposition of the El Sherana Group at 1840-1830 Ma. The
formation of these deposits is related to fluids derived from diagenetic processes in
sandstone of the El Sherana Group. The source of the ore was likely U-bearing
minerals in the sandstone and volcanic rocks of the El Sherana Group and the source of
metals such as Au and PGE are from basement rocks, similar to some of the multielement
deposits (i.e. Nicholson) in the Beaverlodge area of Canada. These deposits
can be classified as a variation on unconformity-related U mineralization similar to
those in the overlying Kombolgie Basin. Tectonic reactivation of the El Sherana-
Palette fault during the Nimbuwah event would have provided structural conduits for
hydrothermal basinal brines that descended downward into the metamorphic basement
rocks. Interaction between the oxidizing U-bearing basinal brines and the reducing
carbonaceous shale of the Koolpin Formation would have led to U precipitation.
Uranium deposits in the Beaverlodge and South Alligator River areas record late
alteration fluid events related to both near and far-field tectonic events. These late
events represent circulation of meteoric water through fault zones.
e) Uraninite in major structures is greatly sensitive to fluid events stimulated by both
near- and far-field tectonic events. It can serve as vehicle to understand the complex
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