Title | Reconnaissance investigation of magnetite trace-element compositions from the New Afton Cu-Au deposit, British Columbia |
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Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
Author | Percival, J A; Schetselaar, E ; Petts, D C ; Jackson, S E ; Wade, D |
Source | Targeted Geoscience Initiative 5: contributions to the understanding and exploration of porphyry deposits; by Plouffe, A (ed.); Schetselaar, E (ed.); Geological Survey of Canada, Bulletin 616, 2021 p. 91-108, https://doi.org/10.4095/327990 Open Access |
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Year | 2021 |
Publisher | Natural Resources Canada |
Document | serial |
Lang. | English |
Media | on-line; digital |
Related | This publication is contained in Targeted Geoscience
Initiative 5: contributions to the understanding and exploration of porphyry deposits |
File format | pdf; xlsx (Microsoft® Excel®) |
Province | British Columbia |
NTS | 92I/09; 92I/10 |
Area | Kamloops |
Lat/Long WENS | -120.5500 -120.4833 50.7000 50.6167 |
Subjects | economic geology; geophysics; geochemistry; Science and Technology; Nature and Environment; mineral deposits; porphyry deposits; copper; gold; skarn deposits; vein deposits; polymetallic ores; mineral
exploration; exploration methods; mineralization; magnetite; trace element geochemistry; iron geochemistry; magnetic interpretations; magnetic anomalies; core samples; tectonic setting; hydrothermal systems; fracturing; thermal regimes; magmatism;
alteration; bedrock geology; lithology; igneous rocks; intrusive rocks; monzonites; diorites; volcanic rocks; New Afton Deposit; Pothook Deposit; Nicola Group; Kamloops Group; Phanerozoic; Mesozoic; Triassic |
Illustrations | location maps; geoscientific sketch maps; 3-D images; tables; photomicrographs; plots |
Program | Targeted Geoscience Initiative (TGI-5) Intrusion/Porphyry ore systems - porphyry processes - mineral markers |
Released | 2021 09 01; 2022 11 17 |
Abstract | Abundant magnetite occurs sporadically in variable textural settings within the New Afton Cu-Au porphyry deposit. A study to test the utility of magnetic anomalies as an exploration vector was conducted
by analyzing magnetite in drill core samples from a variety of rock types and alteration facies. Magnetite samples from various settings (i.e. disseminated, isolated, vein, breccia grains) were analyzed by a laser-ablation inductively coupled
plasma-mass spectrometer for iron and trace elements. New Afton magnetite compositions were compared to previously defined compositional fingerprints of porphyry, iron oxide copper gold, skarn, polymetallic vein, and layered intrusion deposit types.
On multi-element plots using bulk continental crust as the normalizing factor, most New Afton magnetite analyses plot within the high-temperature hydrothermal magnetite field, although most samples have elevated V and 6 of 19 samples have notably
higher W than other deposit types. A hydrothermal origin is supported by a Ti versus Ni-Cr plot, which discriminates hydrothermal from magmatic magnetite; however, a Ti versus V plot suggests mainly magmatic compositions. Copper is generally depleted
relative to bulk crust; gold and platinum values are near their detection limits. Veins, one of the main magnetite habits, define brittle fracture patterns, and trace-element characteristics support formation by pulses of oxidized, high-temperature
hydrothermal fluid. The texture and composition of the samples suggest that magnetite crystallized from late magmatic fluids that drove porphyry mineralization. |
Summary | (Plain Language Summary, not published) This Bulletin published by the Geological Survey of Canada contains ten articles summarizing the results of five-year research projects conducted on
porphyry deposits in Canada as part of the Targeted Geoscience Initiative (TGI). Porphyry deposits are ore bodies, including past-producing and active mines, associated with intrusive rocks such as granite. They are significant producers of a variety
of metals, including copper, molybdenum, tin and tungsten. Nine out of ten papers describe projects conducted in the Canadian Cordillera where most Canadian porphyry deposits occur and a paper on similar, but older deposits in the Appalachians of
Atlantic Canada. The main objective of these TGI research projects was to better define the geological conditions where porphyry deposits form and test techniques to detect buried porphyry deposits in support of mineral exploration. |
GEOSCAN ID | 327990 |
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