权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Isotopic and chronological studies of primitive Achondrites

原始无球粒陨石的同位素和年代学研究

基本信息

批准号：
09440192
负责人：
NAKAMURA Noboru
金额：
$ 4.22万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440192/
关键词：
primitive achondrites Sm-Nd isotopes time-scale early solar system meteorite parent bodies chondrites trace elements mass spectometer 始原的エコンドライト火成岩質異質岩片アイソクロン Sm-Nd 年代 Rb-Sr 年代始原的隕石 Sm-Nd年代 Rb-Sr年代

项目摘要

In order to investigate fine time-scales and detailed chemical fractionations during igneous processes in the early solar system, I.e. differtiation from chondrites to achondrites, we aimed in this work to establish analytical methods for precise isotopic analyses and then to carry out analyses of trace amounts of isotopes and accurate age determination for the primitive achondrites, as well as analyses of other related meteoritic materials. Due to heavy delay of modification works for the mass spectometer MS9 at a company, the isotopic analysis using the machine were carried out in the second year of the project for at first standard samples and later primitive achondrites successfully, which is in turn promising future low-blank level, precise isotopic works for meteorites, typically for precise age determination of primitive achondrites in the near future. Results obtained in this project are as follows ;1. Adjustment of detectors (cup widths) of the mass spectormeter (MS9) were performed, which enable us now to analyze precisely trace amounts (up to a few nanogram of Nd) of Nd and Cr isotopes and then led us to recognition of new problems arise in isotopic measurements.2. A new computer system for the fast data processes has been established3. Additional trace element analyses were carried out for a few primitive achodrites, and then a manuscript of primitive chondrites including new results has been prepared for journal submission.4. Precise Sm-Nd isotopic analyses were carried out for bulk samples of a few primitive achondrites.5. The precise age determination of a martian meteorite was carried out successfully.

为了研究早期太阳系火成岩过程中精细的时间尺度和详细的化学分异，即球粒陨石与无球粒陨石的分化，本研究旨在建立精确的同位素分析方法，并在此基础上对原始无球粒陨石进行微量同位素分析和精确年龄测定，以及对其他相关陨石物质进行分析。由于某公司MS9质谱仪的改装工作严重延误，在项目的第二年，使用该机器对第一个标准样品和后来的原始无球粒陨石进行了同位素分析，这又为未来的低空白水平，精确的陨石同位素工作提供了希望，特别是在不久的将来对原始无球粒陨石进行精确的年龄测定。本项目取得的成果如下：1。对质谱仪（MS9）的检测器（杯宽）进行了调整，使我们现在能够精确地分析微量的Nd和Cr同位素（高达几纳克的Nd），然后使我们认识到同位素测量中出现的新问题。一种用于快速数据处理的新型计算机系统已经建立起来。对一些原始球粒陨石进行了额外的微量元素分析，然后准备了一份包含新结果的原始球粒陨石手稿，准备提交期刊。对一些原始无球粒陨石的大量样品进行了精确的钐钕同位素分析。成功地测定了火星陨石的精确年龄。