Origin and Evolution of Archean Continental Lithosphere: A Pilot Study of the Sao Francisco Craton, Brazil

太古代大陆岩石圈的起源和演化：巴西圣弗朗西斯科克拉通的初步研究

• 批准号: 9218846
• 负责人: Richard Carlson
• 金额: $ 3.1万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9218846&HistoricalAwards=false
• 关键词: Origin; Evolution; Archean; Continental; Lithosphere

The P.I.s propose a multi-national project involving Australian, Brazilian and U.S. geoscientists in a pilot chemical and multi-isotopic study of 3 generations of mantle derived rocks from the Sao Francisco Craton of Brazil. Komatiites may be responsible for the very refractory nature of mantle beneath Archean terrains. Major mafic intrusions often involve the continental lithosphere in their evolution and, hence, give clues as to the composition and history of the lithosphere at the time of igneous intrusion. Lamproites and kimberlites represent small volume melts of incompatible element rich, possibly lithospheric, mantle. The project involves field-work and sample collecting in Brazil. Petrographic and elemental analysis of the samples will be done by Dr. S. Esperanca of Deakin and Monash Universities in Melbourne, Australia. Os and Nd isotopic analysis at DTM by Dr. Esperanca and the P.I. will then be used to constrain the age and chemical history of the melts and their implications for the present composition and formation history of the mantle.

私家侦探们提出了一个跨国项目， 澳大利亚、巴西和美国的地球科学家在一个试点项目中 三代地幔的化学和多同位素研究 源自巴西圣弗朗西斯科火山的岩石。 科马提岩可能是造成 太古宙地体下的地幔。主要镁铁质侵入体 在它们的演化过程中经常涉及大陆岩石圈 因此，它提供了关于 岩浆侵入时的岩石圈 钾镁煌斑岩和金伯利岩代表了 不相容元素丰富，可能是岩石圈地幔。 该项目包括实地考察和样本收集， 巴西 样品的岩相学和元素分析 将由S医生完成。迪肯和莫纳什的埃斯佩兰卡 澳大利亚墨尔本的大学。 Os和Nd同位素 由埃斯佩兰卡博士和P.I.然后将 用来约束熔体的年龄和化学历史 及其对目前组成的影响， 地幔的形成历史。