PUBLICATIONS Journal of Geophysical Research: Solid Earth RESEARCH ARTICLE Magnetotelluric investigations of the lithosphere 10.1002/2013JB010221 beneath the central Rae craton, mainland Key Points: Nunavut, Canada • Resistivity structure of the litho- sphere beneath the central Rae Jessica E. Spratt1, Thomas Skulski2, James A. Craven2, Alan G. Jones3, David B. Snyder2, craton is modeled 3 • Upper mantle regional resistivity varia- and Duygu Kiyan tions beneath the central Rae craton 1 fi 2 3 are noted Independent Consultant, Wake eld, Quebec, Canada, Geological Survey of Canada, Ottawa, Ontario, Canada, Dublin • Lower crustal conductivity interpreted Institute for Advanced Studies, Dublin, Ireland as Archean metasedimentary rocks Abstract New magnetotelluric soundings at 64 locations throughout the central Rae craton on mainland Nunavut constrain 2-D resistivity models of the crust and lithospheric mantle beneath three regional Correspondence to: J. E. Spratt, transects. Responses determined from colocated broadband and long-period magnetotelluric recording
[email protected] instruments enabled resistivity imaging to depths of > 300 km. Strike analysis and distortion decomposition on all data reveal a regional trend of 45–53°, but locally the geoelectric strike angle varies laterally and with depth. – Citation: The 2-D models reveal a resistive upper crust to depths of 15 35 km that is underlain by a conductive layer Spratt, J. E., T. Skulski, J. A. Craven, A. G. that appears to be discontinuous at or near major mapped geological boundaries. Surface projections of the Jones, D. B. Snyder, and D. Kiyan (2014), conductive layer coincide with areas of high grade, Archean metasedimentary rocks. Tectonic burial of these Magnetotelluric investigations of the lithosphere beneath the central Rae rocks and thickening of the crust occurred during the Paleoproterozoic Arrowsmith (2.3 Ga) and Trans-Hudson craton, mainland Nunavut, Canada, orogenies (1.85 Ga).