Collaborative Research: Tracking the Exsolution and Migration of Volatiles in Shallow Magma Reservoirs

点击翻译按钮获取中文摘要

The exsolution and migration of magmatic volatiles have a profound influence over the chemical and physical evolution of magmas. More specifically, the presence of a discrete volatile phase (gas bubbles) affects the transport of a wide variety of metals in and out of magma bodies leading to ore deposit formation and controls the likelihood of an eruption as well as eruption dynamics. Unfortunately, erupted volcanic deposits or exhumed magma bodies have lost most traces of their volatile cargo; so, information about the timing of exsolution and the efficiency of volatile migration in active magma reservoir remain therefore elusive. The proposed study addresses this gap in knowledge with a combination of field work, mechanical models and laboratory experiments focusing on the behavior of volatiles in shallow magma reservoirs. The main challenges that prevent a better understanding of the dynamics of shallow magmatic volatiles in magma reservoirs are (1) the lack of understanding of the dependence of the solubility of complex magmatic fluids (magmatic volatiles) on pressure, temperature and magma composition -thus requiring new experiments- and (2) the lack of understanding of the physics of deforming three-phase magmas (vapors composed of exsolved volatiles, viscous silicate melts and crystals). The work proposed here will not only address the gap in knowledge of magmatic systems described above, it will also push the boundaries of our understanding of the thermodynamics of complex magmatic fluids (with direct application to the chemistry of metallic ore-forming fluids), and multiphase fluid mechanics. This project will generate a massive, systematic volatile solubility data set for 3 melt compositions; these data are required for future expansion of extant thermodynamic models on volatile and fluid behavior in felsic magmas. This project also features a new collaboration which will provide a postdoc and a graduate student with an opportunity to work with and learn from an interdisciplinary research team at different institutions. The PIs have a record of incorporating diverse and under-represented groups within their research and education programs. For example, women and members of other under-represented groups will participate in Earth science teacher-student training events at the AMNH and in an organized field excursion to the Sterling Hill Zinc Mine and Museum, NJ. The PIs from Brown University will participate in the Leadership Alliance SR-EIP summer program, which brings 1st generation and under-represented minorities undergrads to STEM research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.