Article Figures & Data
Figures
- Fig. 1.
(a) Location of the Casino porphyry Cu deposit in west-central Yukon, with stream sampling sites, mineralized occurrences, and local bedrock geology; (b) local bedrock geology of the Casino deposit area, location of stream (black circles) and groundwater (black stars) sampling sites. Sample numbers are shown in black beside each sample site. On both maps the geology is from the Yukon Geological Survey.
- Fig. 2.
Piper plot of ground and surface waters from the Casino deposit area. Waters closest to the Casino deposit have proportionally higher SO42− and Ca concentrations and the highest total dissolved solids (TDS).
- Fig. 3.
Histogram of dissolved metal load concentrations for (a) groundwater samples and (b) surface water samples.
- Fig. 4.
Plots of TDS for Casino surface and groundwaters compared to (a) Ca (mg l−1); (b) Na (mg l−1); (c) Mg (mg l−1); (d) Fe (mg l−1); (e) SO42− (mg l−1); (f) HCO3− (mg l−1); (g) Cl (mg l−1); (h) F (mg l−1).
- Fig. 5.
Plots of SO42− concentrations for Casino surface and groundwaters compared to (a) Fe (mg l−1); (b) Mn (µg l–1); (c) Cu (µg l–1); (d) Co (µg l–1); (e) As (µg l–1); (f) Mo (µg l–1).
- Fig. 6.
(a) Cl–chondrite-normalized rare-earth element patterns (McDonough and Sun 1995); (b) Ce anomaly (Ce*) v. Mn concentrations for groundwaters and surface waters from the Casino area. North American Shale Composite normalizing values from (McLennan 1989).
- Fig. 7.
(a) Oxygen and hydrogen isotopic composition of Casino surface and groundwaters compared to the Global Water Meteoric Water Line (GWML; Craig 1961). Also included are monthly weighted averages for precipitation at monitoring stations at Mayo and Whitehorse, Yukon. Data from IAEA/WMO (2019) and Global Network of Isotopes in Precipitation database, accessible at: https://nucleus.iaea.org/wiser; (b) expanded view of Casino waters and the GMWL.
- Fig. 8.
δ34S v. SO42− concentrations for dissolved sulfate in Casino surface and groundwaters.
- Fig. 9.
Strontium isotope ratios in Casino surface and groundwaters compared to (a) 1/Sr; (b) Rb/Sr and Na/Cl; (c) Cu and Mo (µg l–1).
- Fig. 10.
Conceptual model with east–west section with deposit mineralogy, host geology and hydrology. Black stars represent endmember compositions and vertical lines represent drillholes with depths marked.
Tables
- Table 1
Location and physical parameters of stream and groundwaters, including pH, Electronic Conductivity (EC), Eh, dissolved oxygen (DO), dissolved organic carbon (DOC), and total dissolved solids (TDS). Sample types characterized by ‘SW’ for stream water and ‘GW’ for groundwater
Sample Type Location UTM easting UTM northing pH EC (µS cm–1) Eh (mV) DO (mg l–1) DOC (mg l–1) TDS (mg l–1) 115J17-1002 SW Battle Creek 631343 6954446 7.41 119 410 92.3 3.0 120 115J17-1003 SW Selwyn River 639801 6946601 7.41 106 411 92.7 3.1 98 115J17-1004 SW Hayes Creek 640714 6956762 7.82 162 427 88.9 7.8 173 115J17-1005 SW Hayes Creek 640714 6956762 238 7.6 171 115J17-1006 SW Colorado Creek 617063 6937612 7.61 118 417 88.8 3.8 138 115J17-1007 SW Casino Creek 609922 6947632 7.7 194 392 82.2 4.1 227 115J17-1008 SW Casino Creek 611144 6951500 7.86 213 401 84.3 4.2 251 115J17-1009 SW unnamed tributary of Dip Ck 597923 6945670 7.87 199 347 81.7 9.9 252 115J17-1010 SW Casino Creek 612518 6953864 7.81 225 383 6.1 3.2 248 115J17-1012 SW Unnamed tributary of Coffee Creek 600541 6958104 7.38 124 393 81.1 5.2 148 115J17-1013 SW Meloy Creek 611972 6953572 7.75 162 350 84 2.4 215 115J17-1014 SW Casino Creek 613398 6956248 7.71 208 338 83.6 2.7 221 115J17-1015 SW Excelsior Creek 603857 6968696 7.74 302 412 77.1 8.5 371 115J17-1016 SW Sunshine Creek 626132 6964413 7.86 311 321 81.6 8.4 392 115J17-1017 SW Isaac Creek 626826 6963380 7.62 124 363 80.7 6.0 155 115J17-1018 SW Mascot Creek 630818 6962786 7.79 158 423 79.9 10.3 188 115J17-1019 SW Canadian Creek 610240 6963647 7.13 120 457 80.9 3.4 124 115J17-1020 SW Tributary to Britannia Ck 617609 6965203 8.1 419 444 83.1 6.8 557 115J17-1022 SW Unnamed creek east of Excelsior Ck 605254 6974187 8.32 548 444 83.6 8.5 654 115J17-1023 SW Canadian Creek 617754 6972333 7.63 314 427 81.3 5.9 339 115J17-1024 SW Canadian Creek 617754 6972333 7.63 314 429 81.3 6.1 342 115J17-1025 SW Britannia Creek 616283 6968644 7.74 289 436 81.6 6.3 303 115J17-1026 SW Canadian Creek 615961 6966522 7.65 249 435 79.7 5.1 256 115J17-1027 SW Britannia Creek 616899 6965014 7.75 290 380 78.3 8.0 345 L1992155-1 GW East side of deposit 611593 6958166 6.55 875 210 0.52 1.0 1309 L1992155-3 GW Middle of deposit 611533 6958503 5.41 125 392 0.15 1.1 135 L1992155-4 GW East side of deposit 611504 6958168 6.68 859 203 0.19 1.0 1314 L1992155-5 GW Upper Canadian Creek 609888 6959341 5.58 54 405 0.18 1.0 74 L1992155-6 GW West of adit 610122 6955865 7.6 126 304 6.69 1.1 197 L1992155-7 GW Near mouth of adit 611446 6956176 7.75 187 113 0.15 1.0 295 L1992155-8 GW Near mouth of adit 611433 6956171 8.16 188 159 3.53 1.4 309 L1992155-9 GW East side of deposit 611684 6958225 6.36 514 212 1 1.2 673 L1992155-10 GW East side of deposit 611684 6958225 6.36 514 212 1 1.2 670 - Table 2
Isotopic data and total dissolved solids (TDS) concentrations from stream and groundwater samples. Sample types characterized by ‘SW’ for stream water and ‘GW’ for groundwater
Sample Type δ18O ‰ v. VSMOW δ2H ‰ v. VSMOW δ34S (sulfate) ‰ v. VCDT δ18O (sulfate) ‰ v. VSMOW TDS 87Sr/86Sr 115J171002 SW −22.5 −168 120.06 0.70782 115J171003 SW −22.3 −165 98.1 115J171004 SW −21.9 −165 14.1 173.17 115J171005 SW −21.8 −164 9.8 170.64 115J171006 SW −22.5 −168 138.08 115J171007 SW −22.5 −168 9.2 −16.7 227 0.71167 115J171008 SW −22.6 −164 3.9 −25.4 250.53 115J171009 SW −22.6 −164 251.56 0.70807 115J171010 SW −22.6 −167 5 −24 247.87 115J171012 SW −22.4 −162 9.9 148.06 0.70765 115J171013 SW −22.9 −169 214.7 0.70801 115J171014 SW −22.6 −169 4.6 −25.1 221.26 115J171015 SW −22.5 −167 6.4 −21.2 371.03 0.71331 115J171016 SW −22.6 −172 5.8 392.24 0.71077 115J171017 SW −22.7 −170 154.95 115J171018 SW −22.2 −161 6.6 188.36 0.70775 115J171019 SW −22.4 −166 124.31 115J171020 SW −23 −170 6.7 −29.3 556.69 115J171022 SW −22.9 −165 7.6 653.97 115J171023 SW −22.5 −167 338.68 115J171024 SW −22.6 −168 6.6 −23.4 342.26 0.71224 115J171025 SW −22.4 −169 6.4 −23.6 302.71 0.7075 115J171026 SW −22.3 −167 7.8 −23.2 255.82 0.71151 115J171027 SW −22.6 −160 6 −25.1 344.55 0.71031 L1992155-1 GW −22.8 −171 2.1 −21.8 1,308.70 L1992155-2 FB −20 −150 0.70683 L1992155-3 GW −22.7 −162 −0.3 135.22 0.70792 L1992155-4 GW −22.7 −167 3.1 −35.1 1,314.08 0.70682 L1992155-5 GW −22.5 −165 −0.1 −29.3 74.21 0.70689 L1992155-6 GW −22 −166 197.27 0.7078 L1992155-7 GW −22.9 −170 295.2 0.70735 L1992155-8 GW −23 −171 7.4 308.79 L1992155-9 GW −22.7 −170 0.4 −31.8 672.54 0.70708 L1992155-10 GW −22.8 −170 0.4 −35 669.93
Hydrogeochemistry of porphyry-related solutes in ground and surface waters; an example from the Casino Cu–Au–Mo deposit, Yukon, Canada
