Lithospheric sulfur cycling during Archean orogenesis

太古代造山作用期间岩石圈硫循环

• 批准号: RGPIN-2019-05035
• 负责人: LaFlamme, Crystal
• 金额: $ 2.55万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738022
• 关键词: Lithospheric; sulfur; cycling; during; Archean

My research program focuses on our understanding of sulfur cycling through the lithosphere. Sulfur can act as a volatile component of many geological reservoirs on Earth. Consequently, the complex sulfur cycle plays a critical role in a variety of fundamental Earth processes such as regulating the global climate, the living cell, and ore deposit formation. Sulfur is a critical ligand that complexes, transports and concentrates gold in hydrothermal fluids. Similarly, base metals such as nickel, cobalt, copper and zinc, due to their chalcophile nature in sulfur-bearing magmatic and hydrothermal systems, are concentrated in sulfides. Metals are a cornerstone of the Canadian economy and are increasingly important in the development of renewable energies. The global move toward sustainable energies in a low-carbon society has increased the demand for metals (such as nickel and cobalt) to manufacture long lasting batteries. Further, copper remains an important metal in building construction and electronics. While mining is one of Canada's most important sectors and gold being Canada's third most profitable (13 billion$) export, increasingly rare surficial deposits are pushing exploration under cover and to more remote locations. Canada's remote north holds a wealth of these precious and base metals; however, the exploration and mining industries increasingly rely on technologies to predict where metals are localised. My research program focuses on the evolution of tectonic mechanisms that play a role in focusing metals and sulfur in order to better understand how and where metals precipitate and where and on what time-scale sulfur is stored in the Earth's deep lithosphere before being returned to the surface. This knowledge gap is addressed by examining the nature of the mass-independent fractionation of sulfur (MIF-S), which was imparted to sulfur-bearing reservoirs prior to 2.4 billion years ago. This fractionation process led to the unique preservation of this anomalous isotope signature in the Archean sedimentary rock record and has enabled the understanding of the chemical evolution of the atmosphere and hydrosphere. Thanks to recent analytical developments we are now in the privileged position to use MIF-S as an indelible tracer of various lithospheric-scale processes. The research will employ state-of-the-art analytical tools to characterise the temporal evolution of the multiple sulfur isotope composition of metalliferous hydrothermal fluids in the Slave and Superior cratons and magmas in the Ungava Orogen. The outcomes will: 1) enhance the application of MIF-S as a powerful and indelible tracer to understand the source and emplacement pathways of metal-bearing fluids and magmas through the lithosphere, and 2) improve our understanding of the lithospheric-scale transport mechanism of sulfur among different reservoirs, and 3) better align ore deposit research to the targeting critical metals for the global move to renewable energies.

我的研究项目重点是我们对岩石圈硫循环的理解。硫可以作为地球上许多地质水库的挥发性成分。因此，复杂的硫循环在各种基本地球过程中起着关键作用，如调节全球气候，活细胞和矿石存款形成。硫是热液中金络合、迁移和富集的重要配体。同样，镍、钴、铜和锌等贱金属由于其在含硫岩浆和热液系统中的亲铜性，集中在硫化物中。金属是加拿大经济的基石，在可再生能源的发展中越来越重要。在低碳社会中，全球向可持续能源的发展增加了对金属（如镍和钴）的需求，以制造持久的电池。此外，铜仍然是建筑结构和电子产品中的重要金属。虽然采矿业是加拿大最重要的行业之一，黄金是加拿大第三大利润最高的出口（130亿美元），但越来越稀有的硫化物矿床正在推动勘探隐蔽和更偏远的地区。 加拿大偏远的北部拥有丰富的贵金属和贱金属;然而，勘探和采矿业越来越依赖技术来预测金属的位置。我的研究项目侧重于构造机制的演变，这些机制在聚焦金属和硫方面发挥作用，以便更好地了解金属沉淀的方式和位置，以及硫在返回地表之前在地球深部岩石圈中储存的时间尺度。 这一知识缺口是通过研究硫的质量无关分馏（MIF-S）的性质来解决的，该分馏在24亿年前就被赋予了含硫储层。这种分馏过程导致了这种异常同位素特征在太古代沉积岩记录中的独特保存，并使人们能够了解大气圈和水圈的化学演化。由于最近的分析发展，我们现在处于特权地位，使用MIF-S作为各种岩石圈尺度过程的不可磨灭的示踪剂。 这项研究将采用最先进的分析工具，以确定昂加瓦造山带的奴隶和上级岩浆和岩浆中含金属热液流体的多种硫同位素组成的时间演变。这些成果将：1）加强MIF-S作为一种强大且不可磨灭的示踪剂的应用，以了解含金属流体和岩浆通过岩石圈的来源和定位途径，2）提高我们对不同储层之间硫的岩石圈尺度迁移机制的理解，3）更好地将矿石存款研究与全球转向可再生能源的目标关键金属相结合。