The 198 Ma Lower Jurassic Copper Mountain intrusions outcrop in the Quesnellia Subterrane of Terrane I in the Canadian Cordillera. Thermal demagnetization at 550¿10¿C defines a single stable remanence component of 25.9¿, 41.2¿ (&agr;95=3.6¿) in 11 reliable sites. The resulting pole position of 11.8¿E, 57.3¿N (Δp=2.7¿), (Δm=4.4¿) is discordant for the North American craton and reflects 39¿6¿ of clockwise rotation and 9¿5¿ of northward translation. Combined with previous paleomagnetic and geologic data, a consistent model for the geotectonic evolution of Quesnellia and Terrane I emerges. |