The evolution of North America in terms of plate tectonic processes presently operating on the "passive" Atlantic seaboard and the tectonically active Pacific coast.
(plate tectonic processes; operating; L:on the "passive" Atlantic seaboard and the tectonically active Pacific coast; T:presently)
plate tectonic processes
operating
L:on the "passive" Atlantic seaboard and the tectonically active Pacific coast T:presently