Table 5

Estimates of Magmatic Temperature and Oxidation State from Igneous Apatite and Whole-Rock Compositions

Deposit (type)Sample no.Whole- rock SiO2 (wt %)1Whole- rock P2O5 (wt %)1AST2Apatite MnO (wt %) (n)3Estimated log fo24Estimated ΔFMQ5Apatite SO3 (wt %) (n)3 [maximum, minimum]Average magmatic S content (wt %)6Average magmatic S content (wt %)7Maximum magmatic S content (wt %)6Maximum magmatic S content (wt %)7
Carmen de Andacollo (porphyry)CDA-266.740.14905°Cn.a.n.a.n.a.0.23 ± 0.18 (34)
[0.05, 0.81]
0.0160 ± 0.01200.0088 ± 0.02300.05710.1308
CDA-8863.670.21917°C0.12 ± 0.04 (18)−11.8 ± 1.50.4 ± 1.70.27 ± 0.16 (35)
[0.08, 0.61]
0.0230 ± 0.01370.0079 ± 0.01020.05130.0364
Productora (transitional IOCG)PR-564.950.13878°Cn.a.n.a.n.a.0.04 (1)0.00170.00100.00170.0010
PR-857.660.19830°C0.08 ± 0.01 (8)−11.1 ± 0.92.7 ± 1.10.04 ± 0.02 (13)
[0.02, 0.07]
0.0009 ± 0.00030.0010 ± 0.00010.00150.0012
Candelaria (IOCG)CAN-258.450.45951°Cn.a.n.a.n.a.0.04 ± 0.02 (3)
[0.03, 0.06]
0.0051 ± 0.00220.0010 ± 0.00010.00770.0011
CAN-353.360.45880°C0.12 ± 0.06 (6)−11.8 ± 1.91.1 ± 2.10.03 ± 0.02 (29)
[0.02, 0.09]
0.0017 ± 0.00070.0010 ± 0.00010.00430.0013
Casualidad (IOCG)CAS-466.670.13897°Cn.a.n.a.n.a.0.06 ± 0.03(3)
[0.02, 0.08 ]
0.0030 ± 0.00150.0011 ± 0.00020.00500.0013
CAS-1063.650.20911°Cn.a.n.a.n.a.0.04 ± 0.02(4)
[0.02, 0.06]
0.0035 ± 0.00200.0010 ± 0.00010.00460.0011
CAS-1161.560.20886°C0.08 ± 0.03 (10)−11.0 ± 1.21.7 ± 1.40.03 ± 0.01(23)
[0.02, 0.07]
0.0016 ± 0.00060.0009 ± 0.000070.00340.0012
  • n.a. = no data available

  • 1 Normalized to 100 wt % (Supplementary Table S1)

  • 2 Apatite saturation temperature (AST) calculated from whole-rock SiO2 and P2O5 concentrations using the equation of Piccoli and Candela (1994), recast from the data of Harrison and Watson (1984)

  • 3 Average of all igneous apatite analyses (Supplementary Table S4)

  • 4 Average log fo2 calculated from MnO contents of igneous apatite crystals (Supplementary Table S4) using the equation of Miles et al. (2014): log fo2 = −0.0022 (± 0.0003) Mn (ppm) − 9.75 (± 0.46)

  • 5 Average log fo2 value relative to the fayalite-magnetite-quartz (ΔFMQ), where the value of FMQ at different temperatures (provided by the AST estimate) is calculated using the equation of Myers and Eugster (1983): log fo2 = −24,441.9/T (K) + 8.290 (± 0.167); the ΔFMQ error is the sum of the ±0.167 error on FMQ and the uncertainty in the sample log fo2 estimate from the previous column

  • 6 Estimated from apatite SO3 contents (Supplementary Table S4) using the temperature-dependent apatite-melt partition coefficient formula of Peng et al. (1997): lnKD = 21,130/T − 16.2 (where T is in Kelvin)

  • 7 Estimated from apatite SO3 contents (Supplementary Table S4) using the apatite-melt partition coefficient formula of Parat et al. (2011): SO3 apatite (wt %) = 0.157 × ln[SO3] (melt, wt %) + 0.9834 (r2 = 0.62)

  • 8 SiO2 and P2O5 compositions for this sample taken from sample CDA-9 (same lithology as CDA-8 but less altered)