| Magnetotelluric (MT) soundings were made at 54 sites in the northern British Columbia and Yukon, Canada, along the SNORCLE Transect Corridor 2, in the summer and fall of 1999. The sites are located in the Northern Cordillera between latitude 56°–61°N and 128°–134°W, and cross over the Stikine, Cache Creek, Quesnellia, Dorsey, Kootenay, Slide Mountain and Cassiar terranes.; Analysis of MT data indicates that the region has approximately two dimensional (2D) structure with a geoelectric strike azimuth of −45°. The methods used in the strike analysis included Groom Bailey tensor decompositions, multi-site multi-frequency tensor decompositions, induction vector examinations, and skew determinations.; Two-dimensional MT model images show narrow (<20 km) conductive zones (<2 ohm.m) beneath the Cache Creek Terrane (<5 km depth), Slide Mountain Terrane (Sylvester Allochthon)(<3 km depth), and Dorsey Terrane (<2 km depth) in the shallow upper crust.; The MT models reveal enhanced conductivity (<1 ohm.m) centered at 10 km depth on two separate profiles along Corridor 2 and enhanced conductivity (<1 ohm.m) centered at 15 km depth along Corridor 3. (Abstract shortened by UMI.)... |
