Miocene orographic uplift forces rapid hydrological change in the southern central Andes

• DOI: 10.1038/srep35678
• Publication Date: 2016-10-21T10:03:24Z
• Authors: Alexander Rohrmann; Dirk Sachse; Andreas Mulch; Heiko Pingel; Stefanie Tofelde; Ricardo N. Alonso; Manfred R. Strecker
• Keywords: Orographic lift; Atmospheric Circulation; Paleoclimatology; Global cooling; East Asian Monsoon

Rainfall in the central Andes associated with South American Monsoon and Low-Level Jet results from orographic effects on atmospheric circulation exerted by Andean Plateau Eastern Cordillera. However, despite its importance for climate, no reliable records exist that allow decoding evolution of thresholds interactions between topography circulation, especially regarding onset humid conditions inherently dry southern Andes. Here, we employ multi-proxy isotope data lipid biomarkers, pedogenic carbonates volcanic glass Cordillera NW Argentina present first long-term evapotranspiration record. We find regional eco-hydrology vegetation changes are initiation moisture transport via at 7.6 Ma, subsequent lateral growth orogen 6.5 Ma. Our highlight topographically induced patterns, not global climate change, were responsible late Miocene environmental change this part hemisphere. This suggests mountain building over time fundamentally controlled habitat along