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

P.I.s提出了一项涉及澳大利亚、巴西和美国地球科学家的多国项目，对巴西圣弗朗西斯科克拉通3代地幔衍生岩石进行化学和多同位素试验研究。科马提岩可能是造成太古宙地下地幔非常难成岩性质的原因。主要的基性侵入通常涉及大陆岩石圈的演化，因此，为火成岩侵入时岩石圈的组成和历史提供线索。煌斑岩和金伯利岩是不相容元素丰富的小体积熔体，可能是岩石圈、地幔。该项目包括在巴西进行实地考察和取样。样品的岩石学和元素分析将由澳大利亚墨尔本迪肯大学和莫纳什大学的S. Esperanca博士完成。Esperanca博士和P.I.在DTM进行的o和Nd同位素分析将用于确定熔体的年龄和化学历史，以及它们对地幔当前组成和形成历史的影响。

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.