Proposed Title 1: - Queen's University

University, Canada. Monomineralic fractions, typically >95% pure, were used for stable
isotope analyses at the Queen’s Facility for Isotope Research. Oxygen isotopic
compositions of muscovite and kaolinite were measured using the BrF 5 method of Clayton
and Mayeda (1963) and a dual inlet Finnigan MAT252 isotope ratio mass spectrometer.
Hydrogen isotope compositions were determined using a Thermo Finnigan TC/EA in-line
with a DeltaPlus XP Finnigan Mat mass spectrometer. Isotopic compositions are reported
in the δ notation in units of permil (‰) relative to V-SMOW. Analyses of δ 18 O were
reproducible to ±0.2‰, and δ 2 H values were reproducible to ±3‰. The isotopic
composition of fluid was calculated using the oxygen isotope fractionation factors proposed
by O’Neil and Taylor (1969) for water-muscovite and Sheppard and Gilg (1996) for
kaolinite-water. The hydrogen isotope fractionation factors of Sheppard and Gilg (1996)
were used for water-muscovite and of Capuano (1992) for kaolinite-water.
U-Pb isotope ratios were determined by laser ablation-high resolution inductivelycoupled
plasma mass spectrometry (LA-HR-ICP-MS; Chipley et al., 2007) using a
Finnigan MAT Element 1 HR-ICP-MS and a Neptune HR-MC-ICP-MS, both equipped
with a high-performance Nd.YAG New Wave UP-213 laser ablation system at Queen's
Facility for Isotope Research. Ablation of uraninite was achieved on polished thin sections
using a 30 to 40μm spot size with 35% to 40% laser power at a frequency of 2Hz. The
argon gas flows were as follows; cooling gas, 1.5l/min; auxiliary gas, 1.0l/min; and sample
carrier gas, 1.0 l/min. A low resolution of 350 defined as the ratio of mass over peak width
mass at 5% of the signal height was used. For each sample, 204 Pb, 206 Pb, 207 Pb, 235 U, and
238 U were measured and corrections for common Pb were made scan-by-scan to each spot.
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