Source to deposit tracing of metals in the lithosphere

造山带金矿床形成于各种历史复杂的寄主岩中，具有形成大面积金矿的潜力，这些大面积金矿的金源和形成强地壳剖面禀赋的条件尚未确定。研究项目旨在从金属遗产和地质演化的角度，识别形成世界级金矿区的地壳尺度金富集过程。作为该项目的一部分，选取了太古宙阿比提比绿岩带和两个显生宙造山带，即北美科迪勒拉和北阿巴拉契亚，三个不同年龄和不同金赋存的地壳剖面进行了详细的构造和同位素研究。短期目标是：1)开展必要的野外工作和构造填图，以解释流体生成到矿床形成地区地壳的地质演化；2)确定矿石矿物和地壳寄主岩的放射性成因同位素（Pb-Pb和Re-Os）系统，从而确定特定矿床和流体路径的同位素金属特征；利用激光烧蚀ICP-MS对源岩矿石进行S和Pb-Pb同位素分析，深入研究金的富集过程。将对选定的地壳剖面采用类似的科学方法，并根据现有的地质数据和暴露的矿化进行调整。专题实地工作将与岩石地球化学和同位素地球化学选定剖面的详细取样相结合。该研究项目将影响我们对太古宙—中生代含金系统、前寒武纪—显生宙地壳结构在构造演化和金赋存方面的认识。在我正在进行的研究中，结合最先进的同位素示踪（Re-Os、原位Pb和S同位素）、定量微量元素矿物填图（激光烧蚀ICP-MS）和造山过程研究，将提出地壳中金浓度的新模型，以及它们对形成世界级和贫富集金带的影响。在地质知识有限的地区（如加拿大北部）进行勘探时，详细了解导致世界级金矿区形成的关键组成部分是至关重要的，特别是对于高度寻找的低品位散装吨矿床，这些矿床通常具有离散的地质足迹。识别金属的独特同位素特征（例如，区域性），结合有利的构造演化和流体生成和循环时间的记录，将有助于确定该行业的黄金肥力评估和勘探标准。

Orogenic gold deposits form in a variety of host rocks with a complex history, and have the potential of forming large districts in which gold source and conditions leading to strong endowment of crustal sections are unresolved. The research program aims at the identification of crustal-scale gold concentration processes that lead to formation of world-class gold mining districts in terms of metallic heritage and geologic evolution. As part of this program, three crustal sections of different age and variable gold endowment are selected for a detailed tectonic and isotopic studies: the Archean Abitibi greenstone belt, and two Phanerozoic orogenic belts, i.e. the North American Cordillera and the Northern Appalachians. Short term objectives are 1) to initiate fieldwork and structural mapping necessary to interpret the geological evolution of the crust in areas of fluid generation to deposit formation, 2) define the radiogenic isotope (Pb-Pb and Re-Os) systematics of ore minerals and crustal host rocks, thus defining the isotopic metal signature of specific deposits and fluid pathways, and 3) use in-situ trace element, and S and Pb-Pb isotopic analyses (Laser ablation ICP-MS) of ore minerals in source rocks for a thorough investigation of gold preconcentration process. A similar scientific approach will be used for selected crustal sections and adjusted according to existing geological data and exposed mineralization. Thematic field work will be combined with detailed sampling of chosen sections for lithogeochemistry and isotope geochemistry. The research program will impact our understanding of crustal scale Archean to Mesozoic auriferous systems, and Precambrian vs Phanerozoic crustal architecture in terms of tectonic evolution and gold endowment. The integration of state-of-the art isotopic tracing (Re-Os; in-situ Pb and S isotopes), quantitative trace element mineral mapping (Laser ablation ICP-MS), and study of orogenic processes as conducted in my ongoing research, will allow to propose new models of gold concentration in the crust, and their influence on forming world-class vs poorly endowed gold belts. A detailed understanding of key components leading to formation of world-class gold districts is paramount when exploring in areas of limited geological knowledge (e.g. northern Canada), especially for highly sought low-grade bulk-tonnage deposits that generally have a discrete geological footprint. Identification of distinct isotopic signature of metals (e.g. provinciality) combined with documentation of favourable structural evolution and timing of fluid generation and circulation, will contribute to the definition of gold fertility assessment and exploration criteria for the industry.