• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>South African Journal of Geology: Being the Transaction of the Geological Society of South African: Syndie die Verhandelinge van die Geologiese Vereniging van Suid-Afrika >Tracking sources of selected diamonds from Southern Africa based on carbon isotopic and chemical impurities
【24h】

Tracking sources of selected diamonds from Southern Africa based on carbon isotopic and chemical impurities

机译：基于碳同位素和化学杂质跟踪来自南部非洲的所选钻石来源

获取原文
获取原文并翻译 | 示例
       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The morphological, chemical impurities and carbon isotope properties of diamonds may reveal subtle details of their mantle source and growth characteristics, supporting efforts towards identifying their original place of harvesting. Here we investigate the mantle carbon and nitrogen sources and growth patterns from selected diamonds mined from four kimberlites: macro-sized diamonds from River Ranch kimberlite in Zimbabwe and the Swartruggens and Klipspringer kimberlitic deposits from South Africa, and micro-sized diamonds from the Klipspringer and Premier kimberlite intrusions in South Africa. Type IaAB diamonds are found in all the samples; Type IaB diamonds only occur in samples from the Swartruggens, River Ranch and Premier kimberlites. A single Type II diamond (nitrogen below the detection limit) was also observed in the River Ranch and Premier kimberlites. Both the micro- and macro-sized diamonds from Klipspringer have similar nitrogen contents. Based on the % B-defect, the diamonds from Klipspringer are grouped into low- and high-nitrogen aggregates (i.e. % of B-defect <40% and >56%, respectively) that likely represent two different diamond forming episodes. Time averaged mantle storage temperatures for Type IaAB diamonds are calculated to have been: 1060°C for Swartruggens; 1190°C for River Ranch; 1100°C (low aggregated); and 1170°C (highly aggregated) for Klipspringer, and 1210°C for Premier diamonds. The CL-images of the River Ranch, Klipspringer and Premier diamonds reveal multi-oscillatory growth zones. The carbon isotopic analyses on the diamonds reveal an average δ~(13)C_(VPDB) value of: -4.5‰for Swartruggens;- 4.7‰ for River Ranch; -4.5‰ for Klipspringer; and -3‰ for Premier. With the exception of the diamond from Premier, the average δ~(13)C value of the diamonds are similar to the average δ~(13)C value of the mantle (-5‰), which is similar to the occurrence of diamonds in the other kimberlites. The internal carbon isotopic variation of i
机译：钻石的形态学，化学杂质和碳同位素特性可能揭示其披风源和生长特性的微妙细节，支持识别其原始收获地点的努力。在这里，我们研究了由四个金伯利特的所选钻石的地幔碳和氮源和生长模式：Zimbabwe河牧场金伯利特的宏观大小的钻石，以及来自南非的滚动和klipspringer金伯利塞矿床，以及来自klipspringer的微型钻石和微型钻石在南非的首映金伯利特入侵。在所有样品中发现IAAB型钻石; IAB钻石类型仅发生在滚动者，河牧场和先生金伯利特的样本中。在河牧场和首屈一指的金伯利特也观察到单一的II型金刚石（低于检测极限的氮气）。来自Klipspringer的微型和宏观大小的钻石都具有相似的氮含量。基于％B缺陷的百分比，来自Klipspringer的金刚石分组成低氮和高氮聚集体（即B缺陷的百分比<40％和> 56％），其可能代表两个不同的金刚石形成发作。计算IAAB型钻石的时间平均型号储存温度已计算出：1060°C用于滚动;河牧场1190°C; 1100°C（低聚集）; 1170°C（高度汇集）用于Klipspringer，为首选钻石1210°C。河牧场，克利普斯普林格和总理钻石的CL-icillics揭示了多振荡的生长区。钻石上的碳同位素分析显示滚动的平均δ〜（13）C_（VPDB）值：-4.5‰。 - 河牧场的4.7‰; Klipspringer的-4.5‰;和总理-3‰。除了总理的钻石外，钻石的平均δ〜（13）C值类似于地幔（-5°）的平均δ〜（13）C值，这与钻石的发生类似在另一个金伯利特。 I的内部碳同位素变异

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号