EOR: Reactive Melt Migration in the Lower Oceanic Crust in IODP Hole U1309D at the Atlantis Core Complex, 30°N, Mid-Atlantic Ridge

University Of Hawaii, Honolulu

Investigators

Abstract

This investigators of this project, supported by the Ocean Drilling Program, plan to investigate the extent by which reactive flow caused by magma infiltration and melt migration alters the geochemical and petrologic characteristics of the lower crust underneath the Mid Atlantic Ridge. This geochemical study will focus on samples from the Atlantis Oceanic Core Complex on the Mid-Atlantic Ridge that were recovered in IODP expeditions 304 and 305, and where seismic refraction data indicate mantle velocities of 8 km/s at shallow depth. This project is an international collaboration involving researchers from Germany and France. The intellectual merit of the project proposed is to better constrain an important crust formation process by obtaining precise major, trace element and isotopic analyses of very fresh samples of this oceanic crust. The research plan include an integrated geochemical approach that will deliver detailed characterization of minerals recovered from core sections that are dominated by noritic gabbros at shallower levels, olivine-gabbros at mid levels and olivine-rich troctolites at deeper levels of the crust. The results will shed light into the geochemical and petrologic modifications that occur in the oceanic crust during magma infiltration and melt migration. The various collaborators will work at integrating their results to better understand lower crustal melt emplacement, infiltration, and interaction in this 200+ meter intrusive interval. In terms of broader impacts, the project will contribute to enhancing infrastructure for research and education at the University of Hawaii and the United States by introducing a state-of-the-art ICP-MS analytical technique developed at Max Planck Institute in Germany by the post-doctoral trainee on this proposal, Dr. Matthias Willbold. This study will also promote an international partnership between the University of Hawaii and international laboratories. Results will be disseminated in the scientific literature and will also be accessible through the IODP system of outreach programs and general education websites. Finally, the project will support the early-career development of two new NSF-supported investigators.