| Title | Origin of boron-rich fluids in the formation of unconformity associated deposits of the Sibley Basin |
| Download | Download (whole publication) |
| Author | Kelly, C J; Davis, W J; Potter, E G; Metsaranta, R; Puumala, M |
| Source | Targeted Geoscience Initiative: 2018 report of activities; by Rogers, N (ed.); Geological Survey of Canada, Open File 8549, 2019 p. 353-363, https://doi.org/10.4095/313670 (Open Access) |
| Year | 2019 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is contained in Rogers, N; (2019). Targeted
Geoscience Initiative: 2018 report of activities, Geological Survey of Canada, Open File 8549 |
| File format | pdf |
| Province | Ontario |
| NTS | 42D/02; 42D/03; 42D/04; 42D/05; 42D/06; 42D/07; 42D/10; 42D/11; 42D/12; 42D/13; 42D/14; 42D/15; 42E/02; 42E/03; 42E/04; 42E/05; 42E/06; 42E/07; 42E/10; 42E/11; 42E/12; 42E/13; 42E/14; 42E/15; 42L/02; 42L/03;
42L/04; 42L/05; 42L/06; 42L/07; 52A; 52H; 52I/01; 52I/02; 52I/03; 52I/04; 52I/05; 52I/06; 52I/07; 52I/08 |
| Area | Lake Nipigon; Lake Superior |
| Lat/Long WENS | -89.8333 -86.7500 50.3333 48.1667 |
| Subjects | economic geology; geochemistry; tectonics; mineral deposits; unconformity-type deposit; uranium; mineral exploration; exploration methods; ore mineral genesis; mineralization; fluid dynamics;
tourmaline; veins; isotopic studies; boron geochemistry; major element analyses; spectrometric analyses; petrographic analyses; electron microscope analyses; electron probe analyses; tectonic setting; hydrothermal systems; magmatism; metamorphic
environment; deformation; basins; source rocks; crustal evolution; alteration; diabases; bedrock geology; basement geology; Archean; Sibley Basin; Athabasca Basin; Sibley Group; Quetico Subprovince; Innis Lake Showing; Malborne Lake Showing; ore
systems approach; sensitive high-resolution ion microprobe (SHRIMP) analyses; Precambrian; Proterozoic |
| Illustrations | location maps; geoscientific sketch maps; photographs; photomicrographs; diagrams; tables; bar graphs |
| Program | Knowledge Management Coordination, Targeted Geoscience Initiative (TGI-5) |
| Program | Uranium ore systems - fluid pathways, Targeted Geoscience Initiative (TGI-5) |
| Released | 2019 03 01 |
| Abstract | Hydrothermal magnesio-foitite or dravite (tourmaline) is common within the ore zones of unconformity associated uranium deposits globally. Magnesium-rich tourmaline ranging in composition from dravite
to magnesio-foitite is identified in two uranium showings within the Sibley Basin. Hydrothermal dravite from the Malborne Lake showing (delta-11B = -22.5 permille to -20.2 permille) is significantly isotopically lighter than dravite and
magnesio-foitite analyzed from the Innis Lake showing (delta-11B = 16.5-20.0 permille). The isotopically light delta-11B values of tourmaline from Malborne Lake is consistent with local metamorphic tourmaline, indicating that boron is primarily
basement-derived. This contrasts with the isotopically heavy compositions of hydrothermal tourmaline from the Innis Lake showing that are comparable to values reported from the Athabasca Basin. A positive delta-11B value indicates that boron was
sourced from, or potentially equilibrated with, the overlying marine evaporites, such as the chemical sediments of the Sibley Basin. The delta-11B values of hydrothermal tourmaline from the two occurrences are markedly different and suggest that
vein-hosted mineralization in the basement rocks of the Sibley Basin did not form via a unique mechanism. |
| GEOSCAN ID | 313670 |
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