The PIs will conduct multidisciplinary borehole experiments in oceanic crust, to assess hydrogeologic, solute and colloid transport, and microbiological processes and properties at multiple spatial and temporal scales (meters to kilometers, seconds to years). Results of these experiments will comprise a major advance in our understanding of fluid processes within oceanic crust, and will develop new tools and methods that can be applied in many settings.
Possible geochemical highlights from this project include an assessment of fluid circulation within and through the boreholes and the extent of mixing of deep formation fluids with shallow formation fluids (based on the concentration and distribution of tracers that have been deployed in these holes), differences in the composition between deep and shallow 2 basement reservoirs, and mapping the geochemical rebound, which will be slower than the thermal and pressure rebound, for the future assessment of microbiological and geochemical experiments.
Funding from this award will support construction of scientific instrumentation; emplacement, recovery and replacement of long-term instruments by remotely operated vehicle; collection of seafloor and subseafloor data and samples from observatory systems; analysis of data and samples; numerical modeling of coupled fluid-heat-solute transport using conditional simulation; training of students; and presentation and publication of results.
