Asst. Prof. Dr. Roy Price 

A growing body of evidence supports the existence of hydrogen-based microbial communities using H2 generated from water-rock reactions in the subsurface. However, little is known about how H2 is generated from water-rock reactions in basalts with groundwater aquifers. With this HWK fellowship, I am attempting to dramatically improve our understanding of the mineralogical changes during water-rock reactions in the low-temperature settings of northwestern Iceland. My approach will be to use fresh tholeiite basalts from the now erupting Fagradalsfjall volcano, providing an accurate picture of the evolution of rocks and fluids over time. Perhaps the most significant contribution will come from using the unique hydrothermal flow-through apparatus coupled to µ-CT imaging. For the first time, this approach will allow us to evaluate, in real-time, mineral evolution/dissolution of basaltic rocks, as well as porosity and permeability changes over time. My ongoing work on these systems includes artificial saponite chimney growth, which to date is a unique approach. These artificial chimneys will be evaluated in detail to determine their usefulness as astrobiology analogs. Finally, data from these experiments will be used in thermodynamic models designed to predict the liberation of H2 from basalts and the precipitation of saponite upon mixing of vent fluids with seawater. Broadly, this work will significantly improve our understanding of the fluid-mineral-microbe interface