Proposed Title 1: - Queen's University
Proposed Title 1: - Queen's University 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. 145
No corrections were made to the 238 U/ 235 U ratios as they were near the 137.8 natural ratios. Instrument checks were done using an in-house uraninite standard. Mineral name abbreviations used in this chapter are those from Kretz (1983). The superscript numerical value on the mineral name abbreviations reflects the mineral growth stages. 4.5. Results 4.5.1. Mineral Paragenesis 4.5.1.1. Coronation Hill uranium deposit Mineral paragenesis for the Coronation Hill deposit is based on textural relationships shown in Figures 4.4, 4.5, 4.6 and 4.7. Quartz-feldspar porphyry and granophyre rocks host the U mineralization and three main stages of alteration: pre-ore, syn-ore, and post-ore alteration. The quartz-feldspar porphyry is composed of Qtz 0 quartz and Kfs 0 feldspar xenoliths of variable size embedded in a fine-grained matrix composed of Qtz 0 quartz, Kfs 0 feldspar, and Ms 0 muscovite (Fig. 4.5A). The granophyre rock consists of Qtz 0 quartz and Kfs 0 alkali feldspar in characteristic angular intergrowths, embedded in a groundmass consisting of fine-grained Qtz 0 quartz and Kfs 0 feldspars, Ms 0 muscovite and Bt 0 biotite (Fig. 4.4). 4.5.1.1.1. Pre-ore alteration Pre-ore alteration of the quartz-feldspar porphyry is characterized by fine-grained Qtz 1 quartz grains as overgrowths on Qtz 0 quartz xenoliths (Fig. 4.5A). Src 1 sericite is the most extensive alteration and occurs as fine-grained replacement of Qtz 0 quartz and Kfs 0 146
- Page 113 and 114: Figure 3.4. Photomicrographs of typ
- Page 115 and 116: 3.4J). Py 6 Pyrite and Cpy 5 chalco
- Page 117 and 118: mineralization varies from 25.70 to
- Page 119 and 120: 6137APt71 60.67 13.73 4.59 6.48 0.0
- Page 121 and 122: Fig. 3.6A). The Ca may result from
- Page 123 and 124: Sample ID 1 ± 2 ± 3.a ± 4 ± 5.a
- Page 125 and 126: Stable isotopic O and C composition
- Page 127 and 128: Sample ID Deposit Mineral Mineral v
- Page 129 and 130: equilibrium with a fluid having δ
- Page 131 and 132: Syn-ore Chl 8 chlorite sampled from
- Page 133 and 134: Figure 3.9. Binary diagrams showing
- Page 135 and 136: Figure 3.10. Chondrite-normalized R
- Page 137 and 138: Retrograde metamorphism Early vein
- Page 139 and 140: contents in syn-ore Chl 4 chlorite
- Page 141 and 142: decompression and hydration reactio
- Page 143 and 144: mineralizations, which upgraded the
- Page 145 and 146: metamorphic origin of the main U 4
- Page 147 and 148: y the abundance of Ap 1 apatite and
- Page 149 and 150: of late fluid events that have affe
- Page 151 and 152: CHAPTER 4 FLUID EVOLUTION AND GENES
- Page 153 and 154: 1990, 1991; Wyborn et al., 1990). H
- Page 155 and 156: stable isotope geochemistry, U-Pb g
- Page 157 and 158: coincident with the initiation of s
- Page 159 and 160: plasma mass spectrometry (LA-HR-ICP
- Page 161 and 162: The Coronation Hill deposit occupie
- Page 163: arsenides, nickel selenide and copp
- Page 167 and 168: which was interpreted as being asso
- Page 169 and 170: porphyry and coated by Chl 1 formin
- Page 171 and 172: Mineralized breccias showing quartz
- Page 173 and 174: SOUTH ALLIGATOR RIVER GROUP EL SHER
- Page 175 and 176: A Carbonaceous Shale B Src 1 Qtz 1
- Page 177 and 178: A Granite Qtz 0 fragments Qtz 0 B M
- Page 179 and 180: chemical composition as a result of
- Page 181 and 182: Sample I.D SiO 2 CaO FeO ThO 2 MnO
- Page 183 and 184: site occupancy (Cathelineau, 1988).
- Page 185 and 186: Mineral values Temperature Fluid va
- Page 187 and 188: Corrected ratios Apparent ages ( ±
- Page 189 and 190: G H Figure 4.12. U-Pb concordia dia
- Page 191 and 192: Figure 4.13. Pb-Pb isochron diagram
- Page 193 and 194: and 4.12B), and to 207 Pb/ 206 Pb a
- Page 195 and 196: 160 o C at Coronation Hill. The tem
- Page 197 and 198: Figure 4.15. Conceptual genetic mod
- Page 199 and 200: of the Koolpin Formation, while dep
- Page 201 and 202: at ca. 1820 Ma, approximately 40 My
- Page 203 and 204: culminating with the formation of R
- Page 205 and 206: deposits is related to fluids deriv
- Page 207 and 208: CHAPTER 5 GENERAL DISCUSSION 5.1. I
- Page 209 and 210: ed-bed strata and associated volcan
- Page 211 and 212: character of the fluid that formed
- Page 213 and 214: 5.2.1.2. Metamorphic-related uraniu
No corrections were made to the 238 U/ 235 U ratios as they were near the 137.8 natural ratios.<br />
Instrument checks were done using an in-house uraninite standard.<br />
Mineral name abbreviations used in this chapter are those from Kretz (1983). The<br />
superscript numerical value on the mineral name abbreviations reflects the mineral growth<br />
stages.<br />
4.5. Results<br />
4.5.1. Mineral Paragenesis<br />
4.5.1.1. Coronation Hill uranium deposit<br />
Mineral paragenesis for the Coronation Hill deposit is based on textural relationships<br />
shown in Figures 4.4, 4.5, 4.6 and 4.7. Quartz-feldspar porphyry and granophyre rocks host<br />
the U mineralization and three main stages of alteration: pre-ore, syn-ore, and post-ore<br />
alteration. The quartz-feldspar porphyry is composed of Qtz 0 quartz and Kfs 0 feldspar<br />
xenoliths of variable size embedded in a fine-grained matrix composed of Qtz 0 quartz, Kfs 0<br />
feldspar, and Ms 0 muscovite (Fig. 4.5A). The granophyre rock consists of Qtz 0 quartz and<br />
Kfs 0<br />
alkali feldspar in characteristic angular intergrowths, embedded in a groundmass<br />
consisting of fine-grained Qtz 0 quartz and Kfs 0 feldspars, Ms 0 muscovite and Bt 0 biotite<br />
(Fig. 4.4).<br />
4.5.1.1.1. Pre-ore alteration<br />
Pre-ore alteration of the quartz-feldspar porphyry is characterized by fine-grained<br />
Qtz 1 quartz grains as overgrowths on Qtz 0 quartz xenoliths (Fig. 4.5A). Src 1 sericite is the<br />
most extensive alteration and occurs as fine-grained replacement of Qtz 0 quartz and Kfs 0<br />
146
Change language