Mio-Pliocene aridity in the south-central Andes associated with Southern Hemisphere cold periods

Significance This paper identifies two periods of enhanced aridity that are synchronous with faunal turnovers in southern South America. Close temporal coincidence with marine climate proxies suggests a period of latest Miocene aridity was associated with a global glacial period and the expansion of C4 vegetation. We thus argue that continental aridity in the south-central Andes is associated with cold periods at high southern latitudes and propose a model to link global and regional (continental) climate via shifting of the Southern Hemisphere westerlies. This paper also provides an example of how 10 Be paleo-erosion rates can be used as a climate proxy and demonstrates how 10 Be and 36 Cl can be combined to reduce uncertainties associated with this method.