SUPPLEMENT DR1: SAMPLE DESCRIPTION

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Egbert Knight
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1 GSA DATA REPOSITORY Yunxing Xue et al. SUPPLEMENT DR1: SAMPLE DESCRIPTION Three gold deposits from the EGST and one from Abitibi belt have been selected for this study. Bellerophon, Wallaby, and Beattie are all spatially related to alkaline felsic intrusions. Detailed geochronology and radiogenic isotopic studies suggest that the Wallaby gold deposit is genetically related to a spatially associated syenite-carbonatite intrusion complex (Mueller et al., 2008; Stoltze, 2006). The Victory gold deposit has been selected for two reasons: first, it is a typical Archaean orogenic gold deposit, and second it is spatially related to porphyry intrusions. Sulfides in black shales from the St Ives gold camp and Golden Mile deposit at Kalgoorlie were also sampled for comparison. Bellerophon gold deposit: The Bellerophon deposit is a newly discovered prospect in St Ives camp about 60 km southeast of Kalgoorlie. Gold is mostly found in mineralized veins and ductile shear zones. The altered wall rocks are also mineralized, but account for a small proportion of the gold resource. The mineralized wall rocks include greenschist metamorphosed volcanic sedimentary rocks and felsic intrusions. There are two types of mineralized veins: quartz-albite-carbonate-pyrite veins and quartz-pyrite veins. Sulfide minerals and alteration are closely associated with the gold mineralization. Three occurrences of native gold grains have been observed in both types of the veins, which are in intergrown with pyrite, in fractures in pyrite, and enclosed by pyrite with round boundaries (Fig. 1a). All these textures indicate that pyrite was synchronous with native gold crystallization. Pyrites from both vein types were analyzed for sulfur isotopes. Victory gold deposit: The Victory deposit in the St Ives gold camp is about 30 km southeast of Kambalda. Clark et al. (1986) described the geological characteristics of the deposit in detail. Mineralization occurs in all wall rocks (e.g. Kapai Slate, dolerite, Paringa basalt, and komatiites), with the highest gold grades found in albite-dolomite alteration zones. Native gold was found in both quartz veins and altered wall rocks. Pyrites from the quartz-pyrite veins and albite-dolomite-biotite-pyrite alteration zones were collected for multi-sulfur isotope measurements. The genetic relationship between pyrite and gold mineralization is indicated by gold inclusions in pyrite from the veins (Fig. 1b) and by the abundance of pyrite being the best indicator of high gold grade (Clark et al., 1986). Wallaby gold deposit: The Wallaby deposit in north EGST is about 25 km southwestern of Laverton. It has been described in detail in Salier (2003). A mafic conglomerate hosts the majority of mineralization. Dykes of a fractionated suite of monzonite-syenite-carbonatite intrusions host low-grade ore. The dolomite-albite-quartz-pyrite-sericite alteration assemblage hosts higher-grade gold. In all ore zones, the gold grade is proportional to pyrite abundance (Salier, 2003). Gold forms as irregularly shaped grains of native gold along margins of pyrite, as filled in fractures in pyrite, and as inclusions within pyrite. Samples selected for multi-sulfur isotope analyses include mineralized quartz-pyrite veins and pyrite-dolomite-albite±sericite altered conglomerate wall rocks.

2 Sedimentary rocks: Carbonaceous shales were collected from St Ives camp and the Golden Mile deposit at Kalgoorlie. At St Ives, the shale rocks contain abundant pyrite, with lesser pyrrhotite, and rare chalcopyrite in layers parallel to the bedding. The Golden Mile pyrites were collected from shales and consist of two types: pyrite parallel to the sedimentary bedding, and rounded pyrite nodules enclosed by carbonaceous shale (Fig. 1c). Beattie gold deposit: The Beattie gold deposit, located in the Duparquet district Abitibi greenstone belt, Canada, is genetically related to proximal syenite intrusions (Robert, 2001), and has been fully described in Davidson and Banfield (1944) and Bigot (2012). Besides syenite porphyries, the host rocks include tuff, basalt, and meta-sedimentary rocks. More than half of the production in Beattie is from brecciated wall rocks, which consist of angular wall rock fragments cemented by quartz-carbonate stringers. Two distinct mineralization styles are present: mineralized iron-carbonate syenite, in which pyrite encloses invisible gold in its core; mineralized silicified breccias with cherty veins and silica veins. In the second style, gold is visible as electrum either filling microfractures of brecciated pyrite or enclosed by pyrite grains (Fig. 1d). Pyrite grains in the quartz-carbonate veins, which cement the mineralized brecciated ore rocks, were analyzed for multiple sulfur isotopes. Figure DR1. a) the association between native gold and pyrite in the quartz-albite-carboante-pyrite vein in Bellerophon deposit, gold can be intergrown with or enclosed by pyrite; b) native gold grains enclosed by pyrite in a quartz-pyrite vein from Victory deposit; c) the pyrite nodule in a black shale from Golden Mile gold deposit; d) electrum grains that fill pyrite factures and are enclosed by pyrite show the genetic relations between gold and pyrite in Beattie gold deposit.

3 SUPPLEMENT DR2: METHODOLOGY After detailed observation under an optical microscope, appropriate samples were selected, and cast in 25mm epoxy mounts together with Ruttan pyrite and Anderson pyrrhotite as standards. 1μm diamond paste was used for final polishing of the mounts, which were coated with about 100Ǻ of gold to ensure conductivity. The SHRIMP SI (Sensitive High Mass Resolution Ion Microprobe, Stable Isotopes) was used to simultaneously analyze the sulfides for 32 S- 33 S- 34 S isotopes using Faraday cups (Ireland et al., 2008). A primary beam of 3 na, 10 kev Cs + was focused to a 25 um spot on the target minerals. The mass resolution was set at 5000 (10% valley definition), which is sufficient to completely resolve the H 32 S from 33 S. Count rates on 32 S - 33 S - and 34 S - were about 630 MHz, 5 MHz, and 28 MHz, respectively. Prior to analysis, the primary beam was rastered across the area to be analyzed for 200s. The spot was then sputtered for an additional 2 min, followed by data acquisition with 10 cycles of 10 seconds integrations. The total time per analysis was about 12min, which included moving time between spots. Analyses on standards were performed after every five unknowns to correct for instrumental mass-dependent fractionation. TABLE DR1. MULTI-SULFUR ISOTOPE COMPOSITION OF RUTTAN PYRITE AND ANDERSON PYRRHOTITE Sample number 34 Error Error * 33 Ruttan Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py

4 Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Py Anderson Po po po po Note: * the formula for error calculation: 2 (external error 2 + internal error 2 ) 0.5. The external error is the reproducibility of the standard samples, and the internal error is the uncertainty on any single individual analysis. Py = pyrite Po = pyrrhotite

5 TABLE DR2. MULTI-SULFUR ISOTOPE COMPOSITION OF PYRITES FROM THE BELLEROPHON GOLD DEPOSIT Sample δ 34 Error 33 Error Py* in QACP vein QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py QACP vein Py Py in QP vein QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py QP vein Py Note: * Py = pyrite QACP vein = quartz-albite-carbonate-pyrite vein QP vein = quartz-pyrite vein

6 TABLE DR3. MULTI-SULFUR ISOTOPE COMPOSITION OF PYRITES FROM THE VICTORY GOLD DEPOSIT Sample number δ 34 Error 33 Error Pyrite in quartz-pyrite veins Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Pyrite in wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock

7 TABLE DR4. MULTI-SULFUR ISOTOPE COMPOSITION OF PYRITES FROM THE WALLABY GOLD DEPOSIT Sample number δ 34 Error 33 Error Pyrite in quartz-pyrite vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Vein Pyrite in wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock

8 Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock Wall rock

9 TABLE DR5. MULTI-SULFUR ISOTOPE COMPOSITION OF SULFIDES FROM SEDIMENTARY ROCKS FROM ST IVES GOLD CAMP AND GOLDEN MILE GOLD DEPOSIT Sample number δ 34 Py * from St Ives Error 33 St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py St Py Po ** from St Ives St Po St Po St Po St Po St Po St Po Py layers from Golden Mile GM Py GM Py GM Py GM Py GM Py GM Py Py nodules from Golden Mile GM Py GM Py GM Py GM Py GM Py GM Py Note: *Py = pyrite ** Po = pyrrhotite St = St Ives gold camp GM = Golden Mile gold deposit Error

10 TABLE DR6. MULTI-SULFUR ISOTOPE COMPOSITION OF PYRITES FROM THE BEATTIE GOLD DEPOSIT Sample number δ 34 Error 33 Error Pyrite in quartz -carbonate stringers Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer Stringer

11 REFERENCES Bigot, L., 2012, Gold mineralization at the Syenite hosted Beattie gold deposit at Duparquet, Neoarchean Abitibi belt, Quebec, Canada [Master Student thesis]: Université du Québec à Montréal, p Clark, M.E., Archibald, N.J., and Hodgson, C.J., 1986, The structural and metamorphic setting of the Victory gold mine, Kambalda, Western Australia: in Macdonald, A.J., ed., Gold 86: Willowdale, Ontario, Konsult International Inc., p Davidson, S., and Banfield, A.F., 1944, Geology of the Beattie gold mine, Duparquet, Quebec: Economic Geology, v. 39, p Ireland, T.R., Clement, S., Compston, W., Foster, J.J. et al., 2008, Development of SHRIMP: Australian Journal of Earth Sciences, v. 55, p Mueller, A.G., Hall, G.C., Nemchin, A.A., Stein, H.J., Creaser, R.A., and Mason, D.R., 2008, Archaean high Mg monzodiorite syenite epidote skarn, and biotite sericite gold lodes in the Granny Smith-Wallaby district, Australia: U-Pb and Re-Os chronometry of two intrusion related hydrothermal systems: Mineralium Deposita, v. 43, p Robert, F., 2001, Syenite-associated disseminated gold deposits in the Abitibi greenstone belt, Canada: Mineralium Deposita, v. 36, p Salier, B.P., 2003, The timing and source of gold bearing fluids in the Laverton greenstone belt, Yilgarn craton, with emphasis on the Wallaby gold deposit [Ph. D. thesis]: the University of Western Australia, 308 p. Stoltze, A.M., 2006, Is proximal carbonatite magmatism the source of gold at the Wallaby deposit, Western Australia? [Ph.D. thesis]: the Australian National University, 338 p.

Evaluating the Intrusion-Related Model for the Archean Low-Grade, High- Tonnage Côté Gold Au(-Cu) Deposit

Evaluating the Intrusion-Related Model for the Archean Low-Grade, High- Tonnage Côté Gold Au(-Cu) Deposit L.R. Katz, D.J. Kontak, Laurentian University, B. Dubé, V. McNicoll, Geological Survey of Canada