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.
Source Coney, P. J., Jones, D. L., & Monger, J. W. H. (1980). “Cordilleran Suspect Terranes.” Nature, 288(5789), 329-333.