Research project: Ridge flank hydrothermal circulation: Juan de Fuca Ridge Flank
Currently Active:
Yes
The circulation of seawater through Mid Ocean Ridge Flanks accounts for more than two thirds of the global hydrothermal heat flux and is driven by the cooling of the oceanic lithosphere (e.g. Stein & Stein 1994, Elderfield & Schultz 1996) (Figure 1). This fluid flux is of a similar magnitude to the global riverine flux into the ocean, and modifies the composition of ocean crust and the oceans.
Project Overview
Case Study: Juan de Fuca Ridge Flank
A natural observatory into fluid-rock interactions within the oceanic crust.
Covered by anomalously thick sequences of Pleistocene sediments, resulting in a young hydrologically and thermally 'sealed' oceanic crust.
Three stage ocean drilling campaign: ODP Leg 168 and IODP Expeditions 301 and 327, recovering 0.7 to 3.6 Ma hydrothermally altered basaltic crust (Figure 2).
Methods and Techniques
We characterize the petrology of hydrothermal alteration to determine the relative timings of alteration events (Figure 3). The geochemistry and iron oxidation state of basalt samples is measured to quantify the total hydrothermal alteration of the oceanic crust.