Andean mountain building since the Late Cretaceous: A paleoelevation reconstruction

Abstract

Mountain building in the Andes, the longest continental mountain range on Earth, started in the Late Cretaceous but was highly diachronous. Reconstructing the timing of surface uplift for each of the different Andean regions is of crucial importance for our understanding of continental-scale moisture transport and atmospheric circulation, the origin and evolution of the Amazon River and Rainforest, and ultimately, the origin and evolution of species on the world most biodiverse continent. Here, I present (1) a compilation of estimates of paleoelevation for 36 geomorphological domains of the Andes from the literature, and (2) a paleoelevation reconstruction of the Andes since 80 Ma. In the northern Andes, uplift started in the Late Cretaceous (~70 Ma) in the Western and Central Cordilleras of Ecuador, while the northwestern corner of the continent was still covered by shallow seas. Mountain building migrated progressively northwards, with the Perija Range and Santander Massif uplifting since the Oligocene and the Eastern Cordillera, Garzon Massif and Mérida Andes since the Miocene. In the central Andes, uplift migrated from west to east, whereby the main phase of uplift in the Western Cordillera took place during the Late Cretaceous-Paleocene, in the western Puna plateau during the Paleocene, in the eastern Puna plateau during the early-mid Miocene, and in the Altiplano and Eastern Cordillera during the mid-late Miocene. In the southern Patagonian Andes, significant elevation was already in place at 80 Ma and in western Patagonia, modern elevations were reached in the early Eocene. A second pulse of uplift and eastward migration of the orogenic front occurred during the early-mid Miocene. The reconstruction developed here is made available as a series of raster files, so that it can be used as input for a variety of studies in the solid Earth, climate, and biological sciences, thereby being a stepping stone on the path towards a better understanding of the coevolution of the solid Earth, landscapes, climate, and life in South America.