Olivo, G.R., Chang, F., and Kyser, T.K., 2006. Formation of the ...

624 OLIVO ET AL.
TABLE 5. TOF-ICPMS Results Showing Composition of Aqueous,
Carbonic, and Aqueous-Carbonic Fluid Inclusion Populations for
North Zone North Dipper, North Dipper, and North Dipper-Related Veins
Aqueous-
Fluids Aqueous Carbonic carbonic
Elements Major
(cps)
Na
Mg
K
Ca
Minor (cps)
Ni
Cu
Zn
Pb
As
Sb
Ag
Bi
Ba
Element/Na
Major
Mg/Na
K/Na
Ca/Na
Minor
Ni/Na
Cu/Na
Zn/Na
Pb/Na
As/Na
Sb/Na
Ag/Na
Bi/Na
Ba/Na
4592.4
322.1
711.5
132.3
476.4
529.7
100.2
275.3
bg
bg
1419.5
bg
308.8
0.070
0.155
0.029
0.104
0.115
0.087
0.060
nc
nc
0.309
nc
0.067
5809.5
543.5
2213.4
62.5
bg
406.4
175.2
500.2
bg
bg
68.3
bg
bg
0.094
0.391
0.011
nc
0.070
0.030
0.086
nc
nc
0.012
nc
nc
16201.8
2389.7
3574.9
693.9
1280.2
4305.0
956.4
980.5
67.8
60.9
62.3
bg
107.0
0.148
0.221
0.043
0.079
0.266
0.059
0.061
0.004
0.004
0.004
nc
0.007
Abbreviations: bg = background values, cps = counts per second, nc = not
calculated because of high background values; see text for explanation
in the auriferous North Dipper and North Dipper-related
veins have higher As/Na ratios than the fluids in the barren
North zone North Dipper vein system.
Stable Isotopes
Sampling and methodology
The δ 18 O values of quartz, tourmaline, calcite, and scheelite
from the auriferous North Dipper and North Dipper-related
veins and the barren North zone North Dipper vein
were determined to further constrain the temperatures during
vein formation and the isotopic compositions of the mineralizing
fluids. The δ 13 C values of carbonates also were measured
to determine the possible sources for CO 2 . The samples
were collected from surface exposures, with the exception of
SDC-OI-1, which is from drill core near the center or footwall
of the North Dipper vein (at 40-m depth). Quartz-tourmaline
pairs that exhibit textural equilibrium were chosen for
the calculation of isotopic equilibration temperatures.
The selected portions of the veins containing the minerals
of interest were crushed and sieved down to