OCE 98-11453 Lesher The recommended project involves funds for two researchers from the University of California, Davis to take part in the Danish Lithosphere Centre (DLC) drilling cruise to the Southeast Greenland volcanic rifted margin, scheduled for August 20, 1998, and for three years of follow-up petrologic studies on the volcanic rocks cored. The primary drilling objectives of the cruise are the recovery of basement lithologies (Tertiary lavas, sediments, and continental basement) along the feather-edge of the seaward-dipping reflector sequences (SDRS) between latitudes 63 degrees north and 66 degrees north, and on the Greenland-Iceland Rise at latitude 68 degrees north. Drill core from these sites will be used to achieve three primary research goals: 1) to more fully characterize the earliest magmatic products and the tectonic evolution associated with continental breakup; 2) to close critical gaps in our understanding of mantle sources along the southeast Greenland margin away from the axis of the ancestral Iceland mantle plume (expanding on a primary theme of ODP Legs 152 and 163); and 3) to unite the volcanic records for the East Greenland flood basalt succession, the offshore SDRS comprising the East Greenland-Iceland Rise, and the volcanic succession of western Iceland. Salary support is being recommended for the UC Davis participants during the 40 day cruise and for 3 years of post-cruise science. A post-cruise report for general distribution will be produced, containing a complete core description, site reports, and preliminary results (modeled after the ODP Initial Reports). Follow-up analytical work and the synthesis will be a collaborative effort between the PI's group at UC Davis, the DLC (funding the drill ship charter) and R. Duncan's group at Oregon State University (40Ar/39Ar age determinations), building on cooperative science programs related to ODP Legs 152 and 163 and onshore work in the East Greenland flood basalt province. The UC Davis group will conduct petrog raphic and electron microprobe studies of the core material, and will perform whole rock trace element analyses by inductively-coupled plasma mass spectrometry. Major element analyses (by XRF) and radiogenic isotope studies (Sr-Nd-Pb-Os) will be undertaken at the Copenhagen Geoscience Center. This upcoming drilling program will be a direct extension of drilling investigations by ODP Legs 152 and 163, and is expected to contribute fundamentally to the understanding of rifted margin evolution, plume-lithosphere interactions, and the nature of continent-ocean transition. The core recovered and associated scientific discoveries also will be highly germane and crucial to the preparation of future proposals for deep water drilling in the North Atlantic Ocean for consideration by ODP-IODP. ***
