Magmatic and tectonic evolution of the Intermontane Superterrane and Coast Plutonic Complex in southern Yukon Territory ...

• Main Author: Hart, Craig Joseph Ronald
• Format: Text
• Language: English
• Published: University of British Columbia 2009
• Subjects: Carmacks; Whitehorse; Yukon
• Online Access: https://dx.doi.org/10.14288/1.0052733; https://doi.library.ubc.ca/10.14288/1.0052733

The Intermontane Superterrane and Coast Plutonic Complex in southern Yukon Territory are characterized by four episodes of Mesozoic and Cenozoic magmatism which are defined by geological mapping, geochronometry, and whole rock and Sr isotopic geochemistry. Late Triassic to Early Jurassic Klotassin Episode (220-175 Ma), mid-Cretaceous Whitehorse Episode (115-106 Ma), Late Cretaceous Carmacks Episode (85-68 Ma) and Early Tertiary Skukum Episode (61-54 Ma). There was a pronounced magmatic lull between 172-120 Ma. Twenty-two U-Pb, 25 K-Ar dates and greater than 60 strontium isotopic analyses from plutonic and volcanic rocks across the study area are presented to define the timing and nature of magmatic and tectonic events. U-Pb dates are mostly concordant to mildly discordant with minor amounts of Pb-loss-older inherited components are rare. Each magmatic episode is represented by two or more plutonic suites. The Klotassin Episode comprises the pre-accretionary Stikine and Red Ridge suites, the syn-accretionary ...