Alison Shaw:

Postdoctoral Researcher

Carnegie Institution

I am a post-doctoral researcher at the Carnegie Institution of Washington, but will soon be heading to Woods Hole as an Assistant Scientist. My research focuses on understanding the role of volatiles in magmatic systems. In particular, I am interested in determining how they are recycled from the Earth's surface back into the mantle, as well as identifying how they can be used as geochemical tracers of various sources (i.e. crust, mantle, sediments, plume) and processes (i.e., degassing, contamination, mixing). I have studied magmatic volatiles from the interior of the Earth in all kind of different types of samples including:

1) hydrothermal vent fluids
2) basaltic glasses
3) fumarole gases
4) thermal springs
5) geothermal well gas
6) melt inclusions in mineral phases.

During my graduate studies at Scripps, I participated in expeditions to several volcanically-active regions of the world such as Iceland, Hawaii, the Gulf of California and Central America. A key aspect of my Central America studies was to look at how CO₂ is recycled through the Central American subduction zone quantitatively assessing how much carbonate from the subducting plate actually makes it out along the volcanic arc.

As a post-doc at the Carnegie Institution, I have been examining the volatile contents and isotope systematics of olivine-hosted melt inclusions from the Izu-Bonin-Mariana subduction zone system. The IBM system is unique in that the subducting oceanic crust is the oldest in the world, resulting in a relatively cold subduction environment which may influence how volatiles are released from the subducting plate. Melt inclusions are thought to represent primitive melts, and thus offer the exciting possibility of characterizing the composition of sub-arc partial melts. Because these tiny inclusions are trapped during crystal growth and assumed to remain isolated after entrapment, they have the potential of revealing valuable clues regarding how melts evolve and to what extent subduction forcing functions (e.g. slab dip angle, sediment thickness, rate of input) control their composition.