Das Relief der Andenwestflanke bei Antofagasta (Nordchile) unter dem Einfluß langfristiger und extremer Trockenheit

Abstract

In the course of the uplift of the Central Andes the very dry climate on their western slope became even drier. Extreme and long-term aridity led to very low erosion rates. The widespread layer of highly soluble nitrates (saltpeter) covering the landforms of the extreme desert in the Central Depression, and the thin but vast sheets of ignimbrites overlying the western slope of the high cordillera have therefore been preserved from the Miocene and Pliocene until today. The insignificant erosion on the western slope of the Andes is related to the lack of accumulation in the Atacama trench immediately west of the North Chilean coast. Therefore near Antofagasta the driest desert and the highest slope on earth (nearly 15 000 m) coincide. There is even an interdependence of both extremes: the higher the cordillera was lifted up, the drier became the climate of its western slope, and the increasing aridity in turn led to a slower erosion and thus to an even higher cordillera.