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TitleYukon-Tanana terrane in the Scotia-Quaal belt, Coast Plutonic Complex, central-western British Columbia
 
AuthorGareau, S A; Woodsworth, G J
SourceTectonics of the Coast Mountains, southeastern Alaska and British Columbia; by Stowell, H H (ed.); McClelland, W C (ed.); Geological Society of America, Special Paper 343, 2000 p. 23-43, https://doi.org/10.1130/0-8137-2343-4.23
Image
Year2000
Alt SeriesGeological Survey of Canada, Contribution Series 25193
PublisherGeological Society of America
Documentserial
Lang.English
Mediapaper; on-line; digital
File formatpdf
ProvinceBritish Columbia
NTS103I
AreaSkeena River; Eestall River
Lat/Long WENS-130.5000 -129.0000 54.2500 53.5000
Subjectsstructural geology; general geology; amphibolites; amphibolite facies; terranes; orthogneisses; continental margins; crustal studies; mineral assemblages; Coast Plutonic Complex; Alexander Terrane; Stikine Terrane; Devonian
Illustrationsgeological sketch maps; tables; graphs; photographs
AbstractThe Scotia-Quaal belt of amphibolite facies metamorphic rocks is in the core of the Coast Plutonic Complex southeast of Prince Rupert, inboard of the Alexander terrane and outboard of the westernmost documented extension of the Stikine terrane. Correlation of the Scotia-Quaal assemblage with continental margin strata of the Yukon-Tanana terrane is based primarily on lithologic grounds, including the presence of abundant quartz-rich sedimentary rocks and Middle Devonian orthogneiss associated with metavolcanic rocks hosting massive sulfide deposits. Evolved Nd and Sr isotopic signatures in the Scotia-Quaal belt also support the correlation. Dissimilarities in age, lithology, and isotopic signatures differentiate the Scotia-Quaal units from those of the Wrangellia, Alexander, and Taku terranes. The Scotia-Quaal belt shows some similarities with the Stikine terrane, mainly the presence of Devonian igneous rocks, suggesting that part of the Scotia-Quaal belt is correlative with the Stikine terrane. However, the isotopic and lithological differences make it unlikely that all of the Scotia-Quaal rocks should be included in the Stikine terrane. The Scotia-Quaal belt is part of a discontinuous belt of Proterozoic to lower Paleozoic continental margin strata overlain and intruded by middle to upper Paleozoic arc-type rocks; the belt extends longitudinally through the Coast Plutonic Complex from the Yukon Territory to at least as far south as lat 52°N. If the Scotia-Quaal belt contains some Stikine terrane rocks, then accretion of continental margin rocks to Stikine terrane occurred prior to Early Jurassic time. The possible presence of Stikine strata in the Scotia-Quaal belt or of continental-margin assemblages in the Central Gneiss Complex also suggests that the Work Channel structural zone may not mark the boundary between the Insular superterrane and the Stikine terrane. Even if the Stikine terrane strata are absent from the Scotia-Quaal area, the presence of Early Jurassic plutons hints at an Early Jurassic or older link between the Scotia- Quaal and the Yukon-Tanana assemblage and the Stikine terrane.
GEOSCAN ID204233

 
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