How and when was the Western Cordillera of Peru uplifted?

Liz Cassel samples and ignimbrite in southern Peru

Volcanic glasses are hydrated by ambient water after deposition and are therefore useful for paleoaltimetry through the relationship between hydrogen isotope compositions and elevation. We have sampled ignimbrites and modern soil water across the Andes in southern Peru to examine the modern isoscape and use it to help infer the elevation history of the Western Cordillera where the modern volcanic arc is centered.