Traditionally, measurements of U-th-Ra isotopics in young mid-ocean ridge rock have been made by alpha sepctroscopy. Thus the ability to see into the volcanic system, and into the mantle, has been limited by the precision and large sample requirements of the counting techniques. Recent acquisition of a Isolab 54 mass spectrometer will enable the principal investigator to make more precise measurements. Thus the first-order goals of this project are to: continue development of necessary analytical techniques; learn more about the behavior of U, Th,and Ra in magma systems; and try to understand the nature and causes of U/Th fractionations that occur in the mantle prior to and during melting, and during subsequent melt transport and fractionation in the mid-ocean ridge plumbing system.
