| Title | Hydrogeochemistry of porphyry related solutes in ground and surface waters; an example from the Casino Cu-Au-Mo deposit, Yukon, Canada |
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| Author | Kidder, J A ;
McClenaghan, M B; Leybourne, M I; McCurdy, M W; Pelchat, P; Layton-Matthews, D; Voinot, A |
| Source | Geochemistry: Exploration, Environment, Analysis vol. 22, 2022 p. 1-16, https://doi.org/10.1144/geochem2021-058  Open Access |
| Image |  |
| Year | 2022 |
| Alt Series | Natural Resources Canada, Contribution Series 20210245 |
| Publisher | Geological Society of London |
| Document | serial |
| Lang. | English |
| Media | paper; digital; on-line |
| File format | pdf |
| Province | Yukon |
| NTS | 115J/09; 115J/10; 115J/11; 115J/14; 115J/15; 115J/16 |
| Lat/Long WENS | -139.5000 -138.0000 63.0000 62.5000 |
| Subjects | environmental geology; geochemistry; hydrogeochemistry; isotopes; stable isotope studies; groundwater; stream water geochemistry; minerals; mineral exploration; porphyries; porphyry deposits |
| Illustrations | location maps; tables; plots; histograms; schematic models |
| Program | Targeted Geoscience Initiative (TGI-6) Ore systems |
| Released | 2022 02 21 |
| Abstract | The Casino Cu-Au-Mo deposit is one of the largest and highest-grade porphyries of its kind in Canada, residing in an unglaciated region of west-central Yukon. A batch of 22 stream water samples and
eight groundwater samples were collected proximal to the deposit for the purpose of identifying the most diagnostic trace element and isotopic pathfinders associated with the hydrothermal mineralization, as well as establishing natural
hydrogeochemical baselines for the area. Water chemistry around this deposit was investigated because: (i) the deposit has not yet been disturbed by mining; (ii) the deposit was known to have metal-rich waters in local streams; and (iii) the deposit
has atypically preserved ore zones. Surface and ground waters around the Casino deposit are anomalous with respect to Cd (up to 5.4 ug l-1), Co (up to 64 ug l-1), Cu (up to 1657 ug l-1), Mo (up to 25 ug l-1), As (up to 17 ug l-1), Re (up to 0.7 ug
l-1) and Zn (up to 354 ug l-1) concentrations. Sulfur and Sr isotopes are consistent with proximal waters interacting with the Casino rocks and mineralization; a sulfide-rich bedrock sample from the deposit has d34S = -1.2 per mil and proximal
groundwaters are only slightly heavier (-0.3 to 3.1 per mil). These geochemical and isotopic results indicate interaction and dispersion of porphyry-related solutes in ground and surface waters and point to the suitability of hydrogeochemistry as a
medium for mineral exploration for porphyry-style mineralization in the Yukon, and elsewhere in Canada. |
| Summary | (Plain Language Summary, not published)
Increasing the domestic supply of critical metals in Canada will require increased mineral exploration. However, discovery is notoriously difficult when
the potential metal deposits are located deep in the bedrock or buried beneath surficial geological deposits, such as glacial sediments. Yet, in such scenarios, chemical interaction between waters and mineral deposits can result in the dispersion of
dissolved metals, which can be an effective tool for mineral exploration. To demonstrate this, water samples in this study were collected from around the Casino Porphyry (Yukon) and underwent geochemical and isotopic analysis, with the results then
interpreted to identify the extent of element dispersion in waters. The research results demonstrated that ground and surface water geochemistry is a suitable medium for mineral exploration for porphyry-style mineralization in the Yukon, and
elsewhere in Canada. |
| GEOSCAN ID | 328865 |
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