Project One
The first project for my Ph.D. was a detailed geochemical study of the FAMOUS segment, Mid-Atlantic Ridge. Because the FAMOUS area was the first site of focused ridge research back in the early 1970's, it is one of the best-sampled ridge segments in the world. This extensive sampling enables us to ask detailed segmentation questions, including:

  • Are there differences in extent of melting along a segment?
  • Is melt being focused from the edges of the segment toward the segment center?
  • Can variations in mantle source composition be observed in samples at the segment scale?
  • Is segmentation controlled by mantle composition?
  • Are melts delivered centrally or to multiple points along a given segment?

    Although many insightful studies on the FAMOUS area have been published previously, nearly all came before the advent of the ICP-MS technique for collecting trace element data. Our project is also one of the first to include samples from both the French and American collections, thereby increasing our spatial coverage. This project culminated in an EPSL paper (see "publications").
  • Project Two
    The second project for my Ph.D. was a more global MORB project in collaboration with Colleen Dalton at Brown University. We set out to test the fundamental question of whether or not mantle temperature estimates from petrology and geochemistry agree or disagree with seismological mantle temperature estimates. [Results of the comparison between seismological and petrological data were published in Science in April, 2014. ]

    This involved the extensive tasks of carefully selecting global MORB geochemical data, locating global ridge segment positions while assigning each MORB sample to a ridge segment, and then correcting for crystal fractionation processes. We now have a high-quality MORB dataset with which to compare seismological data, available as supplemental data in Gale et al., 2013. Moreover, our dataset can be used to answer other first-order issues regarding the mid-ocean ridges, including compositional changes associated with spreading rate or ocean basin and the architecture of ridge segments as it varies with spreading rate or location.