9618101 Kurz The overall goal of this research is to use the noble gas distribution and isotopic compositions in oceanic volcanic rocks to constrain the long-term degassing behavior of the earth's mantle. New measurements will related helium isotropic variations to the heavier noble gases (particularly Ne, ar, and Xe) as well as other geochemical tracers such as Sr, Nd, and Pb isotopes. Of particular interest is a suite of oceanic basalt glasses from the super-fast spreading East Pacific Rise, and the nearby seamounts, which are extremely well documented and are ideal for the noble gas studies. Laser extraction techniques will allow direct examination of the noble gas distribution within individual samples from the mid-ocean ridges and oceanic islands, thus identifying the noble gas residence sites in mantle derived volcanic rocks and constraining the degree of noble gas compatibility within important mantle mineral phases. The data will also help constrain the dynamic of melting beneath the mid ocean ridges and the mechanisms by which seamounts are formed.1
