A Paleozoic Zircon Age of the Westcoast Crystalline Complex of Vancouver Island, British Columbia

1974 ◽  
Vol 11 (12) ◽  
pp. 1717-1722 ◽  
Author(s):  
J. E. Muller ◽  
R. K. Wanless ◽  
W. D. Loveridge

Zircons from the Westcoast Crystalline Complex near Tofino, Vancouver Island, have yielded the following ages: 206Pb/238U = 265 ± 7 m.y.; 207Pb/235U = 263 ± 7 m.y.; and 206Pb/207Pb = 244 ± 20 m.y. A K–Ar date of an amphibolized dike from the same outcrop yielded 192 ± 9 m.y. This is the first supporting isotopic evidence that the 'basement' complex is derived from late Paleozoic Sicker volcanic rocks and was ultimately migmatized during the major Jurassic plutonic event of Vancouver Island.

2003 ◽  
Vol 40 (7) ◽  
pp. 907-924 ◽  
Author(s):  
Renée-Luce Simard ◽  
Jaroslav Dostal ◽  
Charlie F Roots

The late Paleozoic volcanic rocks of the northern Canadian Cordillera lying between Ancestral North America to the east and the accreted terranes of the Omineca belt to the west record early arc and rift magmatism along the paleo-Pacific margin of the North American craton. The Mississippian to Permian volcano-sedimentary Klinkit Group extends discontinuously over 250 km in northern British Columbia and southern Yukon. The two stratotype areas are as follows: (1) in the Englishman Range, southern Yukon, the English Creek Limestone is conformably overlain by the volcano-sedimentary Mount McCleary Formation (Lower Clastic Member, Alkali-Basalt Member and Volcaniclastic Member), and (2) in the Stikine Ranges, northern British Columbia, the Screw Creek Limestone is conformably overlain by the volcano-sedimentary Butsih Formation (Volcaniclastic Member and Upper Clastic Member). The calc-alkali nature of the basaltic volcaniclastic members of the Klinkit Group indicates a volcanic-arc setting ((La/Yb)N = 2.77–4.73), with little involvement of the crust in their genesis (εNd = +6.7 to +7.4). Alkali basalts in the Mount McCleary Formation ((La/Yb)N = 12.5–17.8) suggest periodic intra-arc rifting events. Broadly coeval and compositionally similar volcano-sedimentary assemblages occur in the basement of the Mesozoic Quesnel arc, north-central British Columbia, and in the pericratonic Yukon–Tanana composite terrane, central Yukon, suggesting that they all represent pieces of a single long-lived, late Paleozoic arc system that was dismembered prior to its accretion onto Ancestral North America. Therefore, Yukon–Tanana terrane is possibly the equivalent to the basement of Quesnel terrane, and the northern Quesnel terrane has a pericratonic affinity.


2018 ◽  
Vol 603 ◽  
pp. 189-200 ◽  
Author(s):  
WD Halliday ◽  
MK Pine ◽  
APH Bose ◽  
S Balshine ◽  
F Juanes

2004 ◽  
Vol 101 (49) ◽  
pp. 17258-17263 ◽  
Author(s):  
S. E. Kidd ◽  
F. Hagen ◽  
R. L. Tscharke ◽  
M. Huynh ◽  
K. H. Bartlett ◽  
...  

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