Multiple Approaches to Study of the Hafnium Isotope Evolution of the Crust and Mantle: 4.3 b.y. ago to Present

本文的工作主要包括三个方面， 从4.3Ga至今的壳幔演化， 使用哈夫里什同位素变化作为共同主题。 的 我们选择的项目反映了 确定关键地点和样本组及区域 PI和Co-PI有广泛的研究， 体验. 我们对次大陆的调查 地幔集中在代表主要、迅速- 在地幔中产生了热异常， 来自地幔柱、亏损地幔和 岩石圈地幔 致力于最早的分化 富集在Nd、Hf和U/Pb比值上 最古老的地球物质的同位素工作：4.3至 4.0西澳大利亚Ga锆石和4.0Ga超铀云母 加拿大西北部片麻岩。 壳幔研究 在威斯康星州的Penokean造山带的回收重点，通过 全岩/矿物Nd和Pb以及组合Nd、Hf和U/Pb 继承、元古宙和太古代同位素分析 锆石 这项工作是一项合作努力， 7个研究机构的11名研究人员。

The proposed work involves three parts aimed at the study of crust-mantle evolution from 4.3 Ga to present, all of which use Hafnium isotope variations as the common theme. The projects we have chosen reflect a balance between identification of key localities and sample suites and areas of research in which the PI and Co-PI have extensive experience. Our investigations of the sub-continental mantle focus on sites which represent major, rapidly- developed thermal anomalies in the mantle that involved various contributions from plume, depleted mantle, and lithospheric mantle. Work on the earliest differentiation of the Earth concentrates on integrated Nd, Hf, and U/Pb isotope work on the oldest terrestrial materials: 4.3 to 4.0 Ga zircons from western Australia and the 4.0 Ga Acasta Gneiss, NWT Canada. Investigations of crust-mantle recycling focus on the Penokean Orogen in Wisconsin through whole-rock/mineral Nd and Pb and combined Nd, Hf, and U/Pb isotope analysis of inherited, Proterozoic, and Archean zircons. This work represents a collaborative effort with 11 other researchers at seven institutions.