Collaborative Research: Testing Models that Describe the Origin of Compositional Diversity of Subduction Zone Magmatism, Aeolian Islands

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

Volcanic rocks provide an integrated, multi-scale record of the processes that govern how magmas form. Using both theoretical and analytical tools, this work will document the critical processes that led to the formation of magmas in the Aeolian Islands, Italy. The volcanoes of the Aeolians were chosen as the study sites because they are compositionally diverse and geologically young; they thus represent prime places to study to how and why young volcanoes erupt. In addition to augmenting our understanding of how these magmas form and evolve, this work will also help characterize features of this young magmatic system such as the depth at which the magma bodies reside under the surface of Earth and the volatile content of the magmas prior to eruption. Such data can provide information to volcanologists who explore when and how volcanic eruptions initiate, thereby potentially enhancing volcanic hazard assessment and mitigation. This work utilizes two approaches. One is application of a phase equilibria model, the development of which was funded by the National Science Foundation, to document the thermodynamics of processes that led to formation of magmas in the Aeolian Islands. Results of computer modeling allow predictions to be made about particular characteristics of the volcanic rocks. Using state-of-the-art analytical tools, these predictions will be tested by collecting geochemical, textural and field data on a selected suite of rocks. Comparison of theoretical expectations and these new data will allow the strengths and weaknesses of the phase equilibria model to be assessed and will also lead to well documented hypotheses about how the Aeolian volcanoes formed. If this marriage of state-of-the-art theoretical and analytical tools is successful, it will impact how scientists approach studying complex magmatic systems by providing a methodology by which source to surface compositional diversity can be understood. Because improvements to the phase equilibria model are an on-going goal, this work will also provide input that will inform model improvements.