An exotic terrane is a fragment of crustal material that has been transported and accreted onto a continent, typically as a result of plate tectonic processes. These terranes often have a different geological history and composition compared to the surrounding crust, providing valuable insights into the processes of continental growth and the tectonic evolution of regions.
Reference: Coney, P. J., Jones, D. L., & Monger, J. W. H. (1980). “Cordilleran Suspect Terranes.” Nature, 288(5789), 329-333.