Neotectonics and large-scale geomorphology of Canada

Abstract

Canada includes active convergent and strike-slip plate boundaries, several major mountain systems, two passive continental margins, and a stable craton. Neotectonic activity, as indicated by earthquake occurrence, is highest along the west coast and lowest in the interior of the country. Correlations between tectonics and physiography are strongest in the west. Here, the landscape bears a strong imprint of convergent and strike-slip plate regimes. Late Mesozoic and early Cenozoic tectonic events established the setting in which the present physiography of western Canada developed, but the landscape acquired its present form much more recently, in Pliocene and Quaternary time. In contrast, the neotectonic imprint in eastern and northern Canada is enigmatic, and although major concentrations of earthquakes in many areas are associated with reactivated, early Phanerozoic structures, there has been only limited late Quaternary faulting. The vast Canadian craton, despite its very low seismicity, is deforming isostatically at a moderate rate due to melting of the Laurentide Ice Sheet thousands of years ago.