Mapping the Archean mantle through the geochemistry of TTG and lamprophyres

本研究将在苏必里尔省几个克拉通根厚度和上地壳发育历史不同的地区，研究2.7 Ga的闪长岩-闪红石-花岗闪长岩（TTG）套及其主要和副矿物相的场域、地球化学和同位素特征。通过对空间关联的晚太古宙煌斑岩壳幔捕虏体的研究，将主要研究中上部地壳过程与下地壳和地幔同时期事件联系起来。这将使我们能够澄清世界上最大克拉通的形成和稳定，并为正在进行的花岗岩岩浆成因和侵位过程的争议提供重要的见解。此外，结合TTG和煌斑岩包体的地球化学和同位素研究，将使我们能够评估太古宙构造过程的性质，并将其与显生宙的构造过程进行比较。通过阐明太古宙俯冲过程的性质和次大陆岩石圈地幔性质的变化，以及捕虏体套印流体与含金溶液之间的相关性，本研究将对造山带金系统的规模和结构争论作出重要贡献。

This study will investigate the field, geochemical and isotopic characteristics of 2.7 Ga tonalite-trondjhemite-granodiorite (TTG) suites and their major and accessory mineral phases, in several areas of the Superior Province that differ in terms of the thickness of their cratonic roots and histories of upper crustal development. This study of mainly mid- and upper-crustal processes will be linked to contemporaneous events in the lower crust and mantle via a study of crustal and mantle xenoliths in spatially associated late Archean lamprophyres. This will allow us to clarify the formation and stabilization of the world's largest craton, and also provide important insights into the ongoing controversy of granite magma genesis and emplacement processes. In addition combining geochemical and isotopic studies of TTG and lamprophyre hosted xenoliths in well-mapped and geochronologically well-constrained greenstone belts, will allow us to evaluate the nature of Archean tectonic processes and compare them with those of the Phanerozoic. By illustrating the nature of Archean subduction processes and variations in the nature of subcontinental lithospheric mantle, as well as demonstrating correlations between xenolith-overprinting fluids and gold-bearing solutions, this study will make a significant contribution to the debate about the scale and architecture of orogenic gold systems.