| Title | Superimposed auriferous structural events along the Llewellyn-Tally Ho deformation corridor in southern Yukon and northwest British Columbia |
| Download | Download (whole publication) |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Ootes, L; Castonguay, S ; Friedman, R; Devine, F |
| Source | Targeted Geoscience Initiative: 2018 report of activities; by Rogers, N (ed.); Geological Survey of Canada, Open File 8549, 2019 p. 49-58, https://doi.org/10.4095/313636  Open Access |
| Year | 2019 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is contained in Targeted Geoscience
Initiative: 2018 report of activities |
| File format | pdf |
| Province | Yukon; British Columbia |
| NTS | 104M/07; 104M/08; 104M/09; 104M/10; 104M/11; 104M/12; 104M/13; 104M/14; 104M/15; 104M/16; 105D/01; 105D/02; 105D/03; 105D/04; 105D/05; 105D/06; 105D/07; 105D/08 |
| Area | Mount Hodnett; Tally Ho Mountain; Annie Lake; Wheaton River; Engineer; Montana Mountain; Mount Skukum; Tutshi Lake; Moon Lake; Racine Lake; Taglish lake; Bennett Lake; Middle Ridge |
| Lat/Long WENS | -135.5833 -134.0000 60.3667 59.2500 |
| Subjects | economic geology; structural geology; tectonics; geochronology; mineral deposits; gold; mineral exploration; epithermal deposits; mesothermal deposits; ore mineral genesis; mineralization; ore controls;
structural controls; tectonic history; deformation; foliation; mylonites; lineations; intrusions; plutons; dykes; bedrock geology; structural features; faults; shear zones; lithology; igneous rocks; intrusive rocks; granodiorites; volcanic rocks;
sedimentary rocks; metamorphic rocks; radiometric dating; uranium lead dating; zircon dates; mineral occurrences; Llewellyn Fault; Tally-Ho Shear Zone; Nisling Terrane; Stikinia Terrane; Tintina Gold Belt; Juneau Gold Camp; Sloko Group; Windy Table
Coplex; Carmacks Group; Stuhini Group; Laberge Group; Boundary Ranges Metamorphic Suite; Whitehorse Plutonic Suite; Bennett Granite; Lewes River Group; Povoas Formation; Phanerozoic; Cenozoic; Tertiary; Mesozoic; Cretaceous |
| Illustrations | location maps; geoscientific sketch maps; tables; photographs; cross-sections; geological time charts |
| Program | Targeted Geoscience Initiative (TGI-5) Knowledge Management Coordination |
| Program | Targeted Geoscience Initiative (TGI-5) Gold ore systems - tectonic drivers and conduits |
| Released | 2019 03 01 |
| Abstract | The Llewellyn-Tally Ho deformation zone in northwest British Columbia and southern Yukon demarcates the eastern limit of the Nisling terrane and the western limit of the Stikine terrane and has
spatially related epithermal, mesothermal, and intrusion-related gold deposits and occurrences. The Llewellyn fault is a southeast-striking, steeply dipping brittle dextral strike-slip structure that overprints 'early' penetrative fabrics and ductile
deformation. The Tally Ho shear zone, in the Yukon, represents an early ductile deformation zone, comprising one penetrative foliation (Smain) and mylonite zones that are overprinted by late brittle faulting, analogous to the Llewellyn fault.
Previous work and this study demonstrate that brittle strike-slip deformation along the Llewellyn fault occurred between ca. 56 and 50 Ma. Two granodiorite intrusions (ca. 75 Ma) crosscut the early ductile deformation fabrics. In the Tally Ho shear
zone, Smain crosscuts a granodiorite pluton and porphyry dyke, which have yielded preliminary U-Pb zircon dates of ca. 98 and 95 Ma, respectively. As such, we infer that the early ductile fabrics formed before ca. 75 Ma and after ca. 95 Ma. This
study further demonstrates that the early ductile and late brittle deformation are separated by at least ca. 20 Ma, indicating the various styles of gold mineralization developed during temporally distinct tectonic events: an 'early' late Cretaceous
ductile event typical of the Tintina gold belt; and a 'later' Eocene brittle event matching the timing and structural framework of the Juneau gold camp. |
| Summary | (Plain Language Summary, not published)
The Targeted Geoscience Initiative (TGI) is directed towards providing next generation knowledge and methods to facilitate more effective targeting of
buried mineral deposits. The program aims to enhance the effectiveness of exploration for Canada's major mineral systems by resolving foundational geoscience problems that constrain the geological processes responsible for the liberation metals from
their source region, transportation of these ore metals and control their eventual deposition. TGI supports projects on gold, Ni-Cr-PGE, porphyry-style mineralization, uranium and volcanic- and sedimentary-hosted base metal mineralization ore
systems, with each project divided into subprojects focused on resolving specific knowledge gaps by integrating data and studies from multiple sites across Canada. Herein, we present interim results and interpretations from a selection of the
research activities currently being conducted under the auspices of TGI. |
| GEOSCAN ID | 313636 |
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