Title | Development of a laser ablation ICP-MS method for the analysis of fluid inclusions associated with volcanogenic massive sulfide deposits |
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Author | Schmidt, M A; Leybourne, M I; Peter, J M ; Petts, D C; Jackson, S E; Layton-Matthews, D |
Source | Geochemistry: Exploration, Environment, Analysis vol. 21, issue 3, geochem2020-043, 2021 p. 1-32, https://doi.org/10.1144/geochem2020-043 |
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Year | 2021 |
Alt Series | Natural Resources Canada, Contribution Series 20200750 |
Publisher | Geological Society of London |
Document | serial |
Lang. | English |
Media | paper; on-line; digital |
File format | pdf; html |
Subjects | Science and Technology; geochemistry |
Illustrations | graphs; charts; cross-plots |
Program | Targeted Geoscience Initiative (TGI-5) Volcanic and sedimentary systems - volcanogenic massive sulphide ore systems |
Released | 2021 06 11 |
Abstract | There is increasing acceptance of the existence of variable magmatic contributions to the mineralizing fluids in the formation of volcanogenic massive sulfide (VMS) deposits. The world-class Windy
Craggy Cu-Co-Au deposit (>300 MT @ 2.12 wt.% Cu) in northwestern British Columbia is of particular interest for this investigation because, like most VMS deposits, fluid inclusions from within the deposit range from relatively low to intermediate
salinity (most 6-16 wt.% equivalent). In this study we used an excimer (193 nm) laser ablation system interfaced to a quadrupole inductively coupled plasma mass spectrometer to quantify key metals and metalloids that are considered by many to be
indicative of magmatic contributions to hydrothermal ore deposits. Although LA-ICP-MS signals from these low-salinity inclusions are highly transient, we were able to quantify Na, Mg, K, Ca, Mn, Fe, Co, Cu, Zn, Sr, Sn, Ba, Ce, Pb and Bi consistently
- of the total 34 elements that were monitored. Furthermore, Cl, Sb, Cd, Mo, Rb, Br, and As were also detected in a significant number of inclusions. Comparison of the fluid inclusion chemistry with unaltered and altered mafic volcanic and
sedimentary rocks and ore samples from the deposit indicate that enrichment in the main ore metals (Cu, Zn, Fe, Pb) in the inclusions reflects that of the altered rocks and ores. Metals and metalloids that may support a magmatic contribution
typically show enrichments in the fluid inclusions much greater than in the host rocks at the same Cu concentration; in particular Bi, Sn and Sb are significantly elevated. These data are consistent with the ore-forming fluids at Windy Craggy having
a strong magmatic contribution. |
Summary | (Plain Language Summary, not published) This paper details the methodology developed to analyze single fluid inclusions associated with mineralized samples from the Windy Craggy volcanogenic
massive sulfide deposit, northwestern British Columbia. Concentrations of thirty four elements are determined essentially simultaneously. The focus is mostly on methodology, but some conclusions and inferences are drawn for the Windy Craggy deposit,
suggesting that there was a magmatic input for some elements. |
GEOSCAN ID | 328120 |
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