9633353 Alt Circulation of sea water through the ocean crust has a major effect on the chemistry of the oceans. This is fairly well understood at mid-ocean ridges because the composition of the exiting fluids is known. However, off-axis venting has a larger effect on ocean chemistry but the venting is widespread and has not yet been sampled. Our only knowledge of the effect of off-axis circulation on seawater is from rocks that have been recovered by drilling. The PIs will measure the composition of minerals from drill hole and determine their abundance to estimate how much water has circulated through the crust and how it changed the crust.
