Ph.D. Research: Exploring the link between magma mixing and super-eruptions

I am interested in magma mixing processes, specifically those associated with the recharge of silicic magmatic systems. My research addresses the settling, buckling and breakup of “depositional” mafic sheets injected at the rheological transition between crystal-rich silicic cumulate mush forming the floor of a magma chamber, and overlying crystal-poor silicic material. It is thought that rejuvenation and filter-pressing of the mush are responsible for the formation of small veins and pipes breaking through the mafic layer. Larger silicic breakouts have also been observed in the field and are plausibly responsible for catastrophic overturn of the system and an associated caldera-forming eruption. My initial goal is to identify the conditions and factors affecting the formation of small versus large silicic breakouts through a mafic layer. The approach I will take will involve the systematic collection of field data (Pleasant Bay Intrusive Complex, Maine) concerning the wavelength of buckling of the mafic layer and the occurrence of silicic breakouts. In addition, a series of analogue laboratory experiments concerning Rayleigh-Taylor instabilities (the buckling of a denser layer of fluid into a less dense layer of fluid) will be performed, in order to build understanding of silicic and basaltic magma interactions and their potential role in generating large volcanic eruptions.