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

地幔锆石、钻石和深部地幔包体的同位素和地球化学研究

• 批准号: 9627324
• 负责人: Peter Deines
• 金额: $ 11.02万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 1999-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9627324&HistoricalAwards=false
• 关键词: Isotope; Geochemical; Studies; Mantle; Zircons

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.

9627324 Deines计划工作的目的之一是检查是否有可能建立一个按时间顺序排列的 通过金伯利岩锆石氧同位素测量与其他同位素和地球化学研究相结合的地幔流体18O记录。 马萨诸塞州大学的Haggerty博士在南非的Jagersfontein金伯利岩中收集到一套捕虏体，可以推测它们的起源于过渡带及其以下。 这些样品提供了一个独特的机会，以检查，迄今未知的，氧同位素地球化学的这一部分地幔。 研究人员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. s将执行：1。Jwaneng和Orapa金伯利岩中锆石氧和放射性同位素记录的研究。 N医生他将对锆石进行年代学研究和微量元素测量。 2.奥拉帕金刚石中硅酸盐包裹体的氧同位素组成研究。 氮含量和宿主聚集状态的测量将与J.W.哈里斯，格拉斯哥大学。 3.深地幔捕虏体的氧同位素研究。 这一部分将与S. e.哈格蒂，马萨诸塞州大学。 所有稳定同位素研究将在主要研究者的监督下进行。 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。