Significance of Alteration Assemblages for the Origin and Evolution of the Proterozoic Nabarlek Unconformity-Related Uranium Deposit, Northern Territory, Australia

Geochronology of Hydrothermal Processes Leading to the Formation of the Au–U Mineralization at the Rompas Prospect, Peräpohja Belt, Northern Finland: Application of Paired U–Pb Dating of Uraninite and Re–Os Dating of Molybdenite to the Identification of Multiple Hydrothermal Events in a Metamorphic Terrane

“…Isa basins in Australia [3,[47][48][49]. Results of these studies also demonstrated that age populations obtained by dating of uraninite usually match well with the timing of overprinting tectonic and magmatic processes.…”

“…Considering the model for the tectonic evolution of the Peräpohja belt proposed by [12,13], the uranium mineralization event at around 1.95 Ga took place during the Paleoproterozoic basin stage because this age is older than the maximum 1.91 Ga age of the Martimo suite sedimentary rocks (Figures 2 and 9). During the extensional stages of basin evolution, re-activation of fracture systems with multiple flux of basin fluids is a rather common feature: this is exemplified by the hydrothermal uranium deposits in the McArthur River Basin in Australia [3] or in the Athabasca basin in Canada [1]. The 1.91-1.89 Ga time period corresponds to the first series of deformations (D1-D3) during the onset of the Svecofennian orogeny in the Peräpohja belt, followed by establishment of peak metamorphic conditions at around 1.85 Ga.…”

“…This peculiarity of uraninite complicates or may even exclude direct determination of the crystallization age, but, on the other hand, also opens the opportunity to evaluate the timing of processes leading to modification of the primary mineralization. This latter is especially interesting in Precambrian terranes where uraninite-bearing ores frequently show mineralogical-textural evidences for overprinting by metamorphism, deformation and/or fluid exchange [3][4][5].…”

An evaporated seawater origin for the ore-forming brines in unconformity-related uranium deposits (Athabasca Basin, Canada): Cl/Br and δ37Cl analysis of fluid inclusions

“…The Kombolgie sub-Basin (McArthur Basin), Northern Territory, Australia, hosts very similar unconformity-related uranium deposits that were formed from comparable NaCl-rich and CaCl 2 -rich brines (Ypma and Fuzikawa, 1980;Wilde et al, 1989;Derome et al, 2003Derome et al, , 2007Polito et al, 2004Polito et al, , 2005. Continuing their use of crush-leach techniques, Derome et al (2007) found molar Cl/Br ratios between 151 and 220 in fluid inclusion leachates from quartz veins.…”

Oxygenation of the Earth's atmosphere–ocean system: A review of physical and chemical sedimentologic responses

“…The paragenesis of diagenetic and metamorphic mineral assemblages in Proterozoic sedimentary basin-hosted uranium and PbeZn deposits demonstrate that periods of elevated fluid flow and concomitant alteration are driven by tectonic events that changed basin hydrology (Kotzer et al, 1992;Polito et al, 2004Polito et al, , 2011Alexandre and Kyser, 2005;Alexandre et al, 2009;Hiatt et al, 2010;Polito et al, 2011). In these systems the punctuated recrystallization of iron oxides (Kotzer et al, 1992) and uraninite (Polito et al, 2004(Polito et al, , 2011Alexandre and Kyser, 2005;Polito et al, 2011) as well as the precipitation of diagenetic illite (Polito et al, 2004;Alexandre et al, 2009;Hiatt et al, 2010;and Polito et al, 2011) indicate fluid/rock ratios increased during regionalscale tectonic events, which created the hydraulic gradients necessary for fluid flow. All successions used to interpret the nature of the GOE have been subjected to these conditions.…”