Mass Spectrometric Studies of U-Th Series Isotopes in MORBs and Young Seamount Basalts

传统上，年轻的大洋中脊岩石的U-Th-Ra同位素测量是用阿尔法光谱进行的。因此，观测火山系统和地幔的能力受到计数技术的精确度和大样本要求的限制。最近购买了一台IsoLab 54质谱仪，这将使首席研究员能够进行更精确的测量。因此，该项目的首要目标是：继续开发必要的分析技术；更多地了解U、Th和Ra在岩浆系统中的行为；并试图了解熔融前和熔融期间以及随后的大洋中脊管道系统中熔体输送和分馏过程中地幔中U/Th分馏的性质和原因。

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.