Mountains, Rejuvenated

or activated platforms, mountain structures that have arisen on the sites of ancient peneplained (leveled and lowered) mountain areas as a result of very recent movements of the earth’s crust. The rejuvenated mountains have preserved highly uplifted sections of the peneplains (leveled-off surfaces) from the epoch that pre-ceded the most recent mountain formation. Some examples of rejuvenated mountains in the USSR are Tien-Shan and the Altai Mountains, in North America the Rocky Mountains, and in Africa the East African plateau.