Erosion surfaces and ignimbrite eruption, measures of Andean uplift in northern Peru

Publisher Website
Google Scholar
Abstract
Remnants of five mature erosion surfaces occur on the rugged western flank of the Andes, and each is deeply incised. They indicate alternation of arid with more humid conditions, and that the western Andes were raised in five major pulses from a subdued early Tertiary landscape of volcanic flows. Each pulse of uplift was accompanied by south‐westward tilting of the older erosion surfaces. The surfaces developed before an ignimbrite was erupted down the ancestoral Rio Fortaleza valley 6 m.y. ago. Since then, renewed uplift has led to further incision of the main valleys and the formation of canyons.