The Ucayali Peneplain is a large near-flat erosion surface, a peneplain, located in the Amazon basin. The Ucayali Peneplain is largely buried by sediments forming an unconformity. Its origin has been dated to the Miocene epoch. The Peneplain was first described in 1948 in the Contamana region of Peru.

Where does peneplain occur?

Pediplains are usually formed in arid or semi-arid climates and may have a thin veneer of sediments. It is postulated that the pediplain may be the last stage of landform evolution, the final result of the processes of erosion.

How was peneplain formed?

A peneplain is considered to have formed by the lowering of an entire region containing more than one watershed to a common base level. Later uplift may lead to a rejuvenation of erosional processes so that the area is cut by new valleys and interfluves to produce a dissected peneplain.