Teleseismic studies of the Canadian landmass: Lithoprobe and its legacyThis article is one of a series of papers published in this Special Issue on the themeLithoprobe — parameters, processes, and the evolution of a continent.ESS Contribution 20090305.

Abstract

Although teleseismic research was only modestly represented within the Lithoprobe program, the analysis of deeper lithospheric structure beneath Canada using teleseismic methods has intensified in the past decade. This development is due in large part to a legacy of improved understanding of shallower lithospheric structures afforded by Lithoprobe. Most recent teleseismic experiments have been conducted in regions lying within Lithoprobe transects and coverage is particularly good in the Slave Province, southern and eastern Ontario, and southwestern British Columbia. A number of key results have arisen out of this collective body of work. Studies on the Slave Province and environs have placed strong constraints on the origin of the high-velocity continental root that underlies most of the Canadian Shield. Fine-scale, anisotropic stratigraphy in this region has been definitively tied to underplated lithosphere, indicating that shallow subduction has played a fundamental role in craton stabilization. Modification of continental lithosphere by the underlying convecting mantle has been extensively documented in the southeastern Canadian Shield and Slave Province, yielding insights into the forces driving plate motion and those that induce intraplate volcanism. Teleseismic investigations in British Columbia point to the importance of water in controlling the structure and dynamics of subduction zones, but have rekindled controversy concerning the location and characterization of the downgoing oceanic plate.