| Title | Recognizing porphyry copper potential from till zircon composition: a case study from the Highland Valley porphyry district, south-central British Columbia |
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| Author | Lee, R G; Plouffe, A ; Ferbey, T; Hart, C J R; Hollings, P; Gleeson, S A |
| Source | Geology 2021 p. 1-11, https://doi.org/10.5382/econgeo.4808  Open Access |
| Image |  |
| Year | 2021 |
| Alt Series | Natural Resources Canada, Contribution Series 20180190 |
| Publisher | Geological Society of the America |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | British Columbia |
| NTS | 92I/06; 92I/07; 92I/10; 92I/11 |
| Lat/Long WENS | -121.2667 -120.7667 50.6875 50.2625 |
| Subjects | economic geology; surficial geology/geomorphology; geochemistry; geochronology; Science and Technology; Nature and Environment; mineral deposits; mineral potential; porphyry deposits; porphyry copper;
glacial deposits; tills; detrital minerals; zircon; provenance; geochemical analyses; trace element analyses; europium; radiometric dating; uranium lead dating; zircon dates; mass spectrometer analysis; bedrock geology; lithology; igneous rocks;
intrusive rocks; tectonic setting; magmatism; intrusions; batholiths; dykes; glacial history; ice flow; sediment dispersal; dispersal patterns; Upper Triassic; Highland Valley Porphyry District; Highland Valley Copper Deposit; Guichon Creek
Batholith; Gump Lake Stock; Highmont Deposit; Lornex Deposit; Valley Deposit; ice-flow directions; Phanerozoic; Cenozoic; Quaternary; Mesozoic; Triassic |
| Illustrations | location maps; photographs; photomicrographs; tables; histograms; plots |
| Program | Targeted Geoscience Initiative (TGI-5) Porphyry systems |
| Released | 2021 01 23 |
| Abstract | The detrital zircons in tills overlying the Guichon Creek batholith, British Columbia, Canada, have trace element concentrations and ages similar to those of zircons from the bedrock samples from which
they are interpreted to have been sourced. Rocks from the core of the batholith that host porphyry copper mineralization have distinct zircon compositions relative to the distal, barren margin. We analyzed 296 zircons separated from 12 subglacial
till samples to obtain U-Pb ages and trace element compositions. Laser ablation U-Pb ages of the detrital zircons overlap within error with chemical abrasion-thermal ionization mass spectrometry U-Pb ages of the Late Triassic Guichon Creek batholith
and confirm that the detrital zircons are likely derived from the batholith. The youngest intrusions of the batholith produced the Highland Valley Copper porphyry deposits and contain distinctive zircons with elevated Eu/EuN* >0.4 attributed to high
magmatic water contents and oxidation states, indicating higher porphyry copper potential. Zircon from till samples adjacent to and 9 km down-ice from the mineralized centers have mean Eu/EuN* >0.4, which are indicative of potential porphyry copper
mineralization. Detrital zircon grains from more distal up- and down-ice locations (10-15 km) have zircon Eu/EuN* mean values of 0.26 to 0.37, reflecting background values. We conclude that detrital zircon compositions in glacial sediments
transported several kilometers can be used to establish the regional potential for porphyry copper mineralization. |
| Summary | (Plain Language Summary, not published)
We need to improve mineral exploration methods to discover the next generation of mineral deposits for the future. With this objective in mind, we have
tested the composition of a mineral called zircon which occurs in intrusive rocks like granite. Certain intrusive rocks can contain copper. We demonstrate that zircon has a specific composition if the intrusion contains copper. Furthermore, we
identify the presence of zircon with a positive mineralization signal in glacial sediment. Tracing the source of zircon grains with a positive mineralisation signal allows the detection of buried copper deposits. |
| GEOSCAN ID | 311197 |
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