Causative links between deglaciation and magmatism have long been hypothesised and, along divergent plate boundaries (i.e., Iceland), quantified to varying degrees. But what happens along convergent margins when large amounts of ice are suddenly removed from atop volcanoes? What is the effect of such unloading on magma chamber evolution? Quite simply, we don't know, yet the question is increasingly important as our planet warms and the glaciers and ice caps mantling active and dormant volcanoes worldwide continue to shrink.
The overarching objective of this new, multi-disciplinary investigation is to help quantify the relationship by reconstructing magmatism during and after past periods of large-scale deglaciation. Focusing on the last ~20,000 years or so, we are applying a combination of geochronology, mineral diffusion profiling, and geomorphology to glaciated volcanic edifices in the Central Volcanic Zone (CVZ), South America, to quantify rates and magnitudes of deglacially induced magma rejuvenation. And while our current project is centred on southern Peru and northern Chile, its scope encompasses all regions that glaciated volcanoes and human populations coincide, such as the Pacific Ring of Fire.