| Title | Geologic and geochronologic update of the Turtle Lake area, NTS 104M/16, northwest British Columbia |
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| Author | Mihalynuk, M G; Zagorevski, A ; Milidragovic, D; Tsekhmistrenko, M;
Friedman, R M; Joyce, N; Camacho, A; Golding, M |
| Source | Geological fieldwork 2017: a summary of field activities and current research; British Columbia Geological Survey Geological Fieldwork Paper 2018-1, 2018 p. 83-128  Open Access |
| Links | Online - En ligne (pdf)
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| Image |  |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20180243 |
| Publisher | British Columbia Ministry of Energy, Mines and Petroleum Resources (Victoria, BC, Canada) |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | British Columbia |
| NTS | 104K/14; 104M/16 |
| Area | Turtle Lake; Sinwa Creek; Tagish Lake; Atlin |
| Lat/Long WENS | -133.5000 -133.0000 59.0000 58.7500 |
| Lat/Long WENS | -134.5000 -134.0000 60.0000 59.7500 |
| Subjects | regional geology; stratigraphy; structural geology; geochronology; paleontology; geochemistry; bedrock geology; lithology; igneous rocks; volcanic rocks; lava flows; breccias; basalts; tuffs; volcanic
conglomerates; rhyolites; andesites; intrusive rocks; harzburgites; granodiorites; diorites; gabbros; quartz feldspar porphyries; granitic rocks; lamprophyres; sedimentary rocks; cherts; argillites; limestones; sandstones; mudstones; greywackes;
siltstones; metamorphic rocks; tectonites; ophiolites; structural features; faults; folds; unconformities; mineral occurrences; talc; mineral deposits; mineral potential; epithermal deposits; gold; silver; radiometric dating; uranium lead dating;
zircon dates; argon argon dating; micropaleontology; microfossils; conodonts; tectonic history; crustal studies; oceanic crust; mantle; intrusions; sills; dykes; emplacement; thermal history; magmatism; crystallization; volcanism; crustal uplift;
deformation; faults, extension; stocks; sedimentary structures; isotopic studies; mass spectrometer analysis; major element analyses; trace element analyses; stratigraphic correlations; kinematic analysis; Eocene; Stikine Terrane; Cache Creek
Terrane; Windy Table Suite; Laberge Group; Horsefeed Formation; Nakina Formation; Fourth Of July Batholith; Silver Salmon Fault; Nahlin Fault; Llewellyn Fault; King Salmon Fault; Whitehorse Trough; Coast Belt; Coast Belt Arc; Engineer Mine; Kedahda
Formation; Richthofen Formation; Sunday Peak Stock; Lost Sheep Peak Intrusion; Three Sisters Plutonic Suite; geological contacts; Phanerozoic; Cenozoic; Tertiary; Mesozoic; Cretaceous; Jurassic; Triassic; Paleozoic; Permian; Carboniferous |
| Illustrations | location maps; geoscientific sketch maps; photographs; tables; Concordia diagrams; photomicrographs; spectra; bar graphs; geochemical plots; schematic cross-sections |
| Program | GEM2: Geo-mapping for Energy and Minerals Western Cordillera, Stikine Terrane |
| Released | 2018 01 01 |
| Abstract | The Turtle Lake map area straddles the boundary between exotic, oceanic crustal and mantle rocks of the Cache Creek terrane, and Laberge Group (Early Jurassic) Whitehorse trough forearc strata atop the
Stikine terrane. Exposed in the Turtle Lake area are extensive platformal carbonate rocks of the Horsefeed Formation, a regional hallmark of the Cache Creek terrane, that were deposited over at least 25 m.y. Juxtaposition of Stikine and Cache Creek
terranes was accommodated by collapse of the Whitehorse trough in mid-Middle Jurassic (starting ~174 Ma) and creation of a fold and thrust fault belt. This belt was cut by the Fourth of July batholith (~172 Ma) and lamprophyre dikes, emplaced and
cooled by ~162 Ma, and followed by a magmatic lull between ~165-130 Ma. In the Turtle Lake area, we fi nd a single granitic dike that crystallized in this time interval, at ~145 Ma. By 125 Ma, the Coast Belt arc had ignited, as recorded by voluminous
volcanic and intrusive rocks in the west, and persisted until ~50 Ma. In the Turtle Lake area, volcanism accompanied uplift by ~110 Ma, as indicated by a unimodal detrital zircon population in karst deposits. The youngest known representative
intrusions are ~56 Ma quartz diorite stocks. One of these stocks cuts the faulted contact between Whitehorse trough strata and harzburgite mantle tectonite. An analogous geological setting hosts epithermal gold-silver vein mineralization at the
Engineer Mine, ~30 km to the south-southwest. The youngest rocks affected by crustal scale faulting and linked, mainly south-side-down, extensional faults are the ~80 Ma Windy-Table suite volcanic strata. We have yet to properly document the
extensional faulting episode, but future work aimed at doing so will have important implications for regional tectonic reconstruction, and evaluation of mineral potential. |
| Summary | (Plain Language Summary, not published)
The Geomapping for Energy and Minerals Program is a collaborative federal geoscience program that provides industry and stakeholders with the next
generation of geoscience knowledge. Tectonic models provide regional geoscience knowledge frameworks for understanding distribution of rock units, associated mineral deposits and duration of mineral-prospective systems. This research builds on
mapping activities in British Columbia and provides a modern tectonic and stratigraphic framework of the area. We identified that volcanism and sedimentation occurred in the area over 200 million years. these rocks comprise distinct terranes and
overlap assemblages that have their own unique mineral potential. Identification of these assemblages will aid mineral exploration in the area. |
| GEOSCAN ID | 311339 |
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