Volcano-tectonics under intra-arc transpression

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Most magmatic arcs form at plate margins that are characterized by oblique plate convergence. An understanding of the genetic link between volcanism and crustal deformation is paramount for risk assessments in populated areas of such magmatic arcs. In this regard, the prime objective of our study is to better understand, on multiple scales, the effects of intra-arc transpression, including the influence of inherited crustal discontinuities, on the formation of calderas and stratovolcanoes. We will focus our assessment on the volcano-tectonic relationship at the transition between the two upper-plate crustal segments of the Southern Volcanic Zone in the Andes between 37°S and 40°S. Specifically, we will explore to what extent deformation at the tip of a large intra-arc transpression zone, the Liquine-Ofqui Fault Zone (LOFZ), influences the formation of the Agrio Caldera and the active Copahue volcano, which are frequented by thousands of visitors in winter time. The volcano-tectonic characteristics of this area will be compared to those at a segment of the LOFZ near Lanin volcano, characterized by strike-slip deformation. The methods conducted in this project include remote sensing, scaled analogue experiments, morphotectonic analysis, structural field work and geochemical analyses and will be conducted in collaboration with CICTERRA in Cordoba, Argentina.