Isotope and Geochemical Studies on Mantle Zircons, Diamonds, and Deep Mantle Xenoliths

9627324 Deines计划工作的目的之一是研究是否有可能通过氧同位素测量与金伯利石锆石的其他同位素和地球化学调查相结合，建立地幔流体的18O年代学记录。马萨诸塞大学的哈格蒂博士从南非Jagersfontein金伯利岩中收集到一套捕虏体，可以推测其起源于过渡带及以下。这些样品为研究地幔这一部分的氧同位素地球化学提供了一个独特的机会。P.I.计划对这些非常深的地幔样本进行系统的氧同位素研究。研究计划在三个不同但相关的环境中进行。P.I.将进行以下工作：1.对吉瓦能和奥拉帕金伯利岩中的锆石的氧和放射性同位素记录进行检查。清水博士，伍兹霍尔海洋研究所，他将进行锆石的地质年代学工作和微量元素测量。2.俄拉帕钻石中硅酸盐包裹体的氧同位素组成研究宿主的氮含量和聚集状态的测量将与格拉斯哥大学的J.W.Harris博士协调进行。3.深部地幔包体的氧同位素研究。这一部分将与马萨诸塞大学S.E.Haggerty博士的岩石学、矿物学和地球化学学研究相协调。所有稳定同位素研究都将在首席调查员的监督下进行。这项工作将表明是否有可能开发一种工具来研究地幔流体的年代学，并有助于描述钻石形成过程中存在的流体的特征。

9627324 Deines It is one of the aims of the planned work to examine whether it is possible to establish a chronological 18O record of mantle fluids through a combination of oxygen isotope measurements with other isotopic and geochemical investigations of kimberlitic zircons. From the Jagersfontein kimberlite, South Africa, a suite of xenoliths for which an origin in the transition zone and below can be postulated, has been collected by Dr. Haggerty, University of Massachusetts. These samples provide a unique opportunity to examine the, as yet unknown, oxygen isotope geochemistry of this part of the mantle. The P.I.s plan to carry out a systematic oxygen isotope study on these very deep mantle samples. Studies are planned in three different, but related, settings. The P.I.s will carry out: 1. An examination of the oxygen and radiogenic isotope record of zircons from the Jwaneng and Orapa kimberlites. Dr. N. Shimizu, Woods Hole Institute of Oceanography, who will carry out the geochronological work and trace element measurements on zircons. 2. An investigation of the oxygen isotopic composition of silicate inclusions in diamonds from Orapa. The measurements of the nitrogen content and aggregation state of the host will be coordinated with Dr. J. W. Harris, University of Glasgow. 3. A detailed oxygen isotope study on deep mantle xenoliths. This part will be coordinated with petrographic, mineralogical and geochemical studies by Dr. S. E. Haggerty, University of Massachusetts. All stable isotope studies will be carried out under the supervision of the principal investigator. The work will show whether it is possible to develop a tool for the study of the chronology of mantle fluids, and aid in the characterization of fluids present during diamond formation.