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

9627324 Deines计划开展的工作的目的之一是，研究是否有可能通过结合氧同位素测量和对金伯利岩锆石的其他同位素和地球化学调查，建立地幔流体的18O年代记录。马萨诸塞州大学的哈格蒂博士从南非的贾格尔斯方丹金伯利岩中收集了一组捕虏体，它们的起源可以假设在过渡带及以下。这些样本提供了一个独特的机会来研究这部分地幔的氧同位素地球化学，这是迄今为止未知的。P.I.s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。私家侦探将执行：1。吉瓦能和奥拉帕金伯利岩中锆石氧和放射性成因同位素记录的研究。伍兹霍尔海洋研究所的N. Shimizu博士，他将对锆石进行年代学研究和微量元素测量。2. 奥拉帕钻石中硅酸盐包裹体氧同位素组成的研究。寄主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。深部地幔捕虏体氧同位素详细研究。这一部分将与马萨诸塞州大学S. E. Haggerty博士的岩石学、矿物学和地球化学研究相协调。所有稳定同位素研究都将在首席研究员的监督下进行。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，并有助于描述金刚石形成过程中存在的流体。

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.