Geochemistry and Petrology of Archaean Supracrustal Rocks from West Greenland

西格陵兰太古宙表壳岩石的地球化学和岩石学

• 批准号: 8619457
• 负责人: Robert Dymek
• 金额: $ 22.7万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-06-15 至 1990-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8619457&HistoricalAwards=false
• 关键词: Geochemistry; Petrology; Archaean; Supracrustal; Rocks

The evolution of the Earth's early crust will be investigated through studies on the Isua and Malene supracrustal rocks from West Greenland. X-ray fluorescence and instrumental neutron activation analyses for major and trace elements will be integrated with results from isotopic studies in order to: (a) characterize the diversity of crustal components in clastic metasedimentary rocks; (b) identify the nature of ancient crustal components of the Isua rocks by carrying out multivariate mixing calculations on metasediment chemical compositions; (c) evaluate the origin of Malene gneisses as possible products of hydrothermal alteration of ancient oceanic rust by heated sea-water; and (d) determine whether metasedimentary granulite show element depletions, as found in many granitic gneisses metamorphosed to the granulite facies. Mineral compositions will be determined by electron microprobe analysis and relevant geothermometers and geobarometers will be used to refine the metamorphic history of this region. Field work will be carried out in order to evaluate the relationship of Malene Supracrustal rocks to granitic gneisses and characterize their stratigraphic and lithologic variations. The Principal Investigator is a leading authority on early Earth geochemistry and petrology, and has a great deal of field experience in Greenland. The facilities required for this investigation are adequate at Washington University.

地球早期地壳的演化将通过以下方式进行研究 西格陵兰Isua和Malene表壳岩的研究。 X射线荧光和仪器中子活化分析 主要和微量元素将与同位素结果相结合， 研究，以便：（a）确定地壳多样性的特征 （B）鉴别碎屑变质沉积岩的性质 伊苏阿岩石的古地壳成分， 变质沉积物化学的多元混合计算 （c）尽可能评价Malene片麻岩的成因 热液蚀变产物的古大洋锈 海水;及（d）确定变沉积麻粒岩是否显示 在许多变质的花岗质片麻岩中发现的元素亏损 麻粒岩相 矿物成分将由 电子探针分析和相关的地质温度计， 地质压力计将被用来完善这一变质历史， 地区 将开展实地工作，以评估 Malene表壳岩与花岗质片麻岩的关系， 描述它们的地层和岩性变化。 首席研究员是早期地球的主要权威 地球化学和岩石学，并有大量的实地经验， 在格陵兰岛。 本次调查所需的设施是 在华盛顿大学学习。