Testing new models for sedimentary mineral behaviour

测试沉积矿物行为的新模型

• 批准号: RGPIN-2019-04368
• 负责人: Wilson, Siobhan
• 金额: $ 3.72万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=750915
• 关键词: Testing; new; models; sedimentary; mineral

Minerals are the largest sources and sinks for metals, metalloids and volatile elements on Earth. Sedimentary minerals in particular have played an important role throughout Earth history in regulating element mobility and in preserving a record of biogeochemical change. Sedimentary rocks and metasediments also host important ores of uranium, lead, base metals (including iron, zinc and copper), phosphate, Rare Earth Elements, and precious metals (such as gold and silver). Although the structures, properties and environmental behaviours of sedimentary minerals have been well studied from a classical perspective, recent insights into the behaviour of minerals has thrown into question many of our fundamental assumptions about their stability as stores for contaminants and their role as long-term recorders of environmental change. While new models for sedimentary mineral behaviour continue to see development in the laboratory, their relative importance to geological processes has not been systematically tested in the field. A reassessment of the longevity and behaviour of sedimentary minerals is required in light of new insights that reveal the often transient nature of the isotopic and elemental information that they store. The core objectives of this proposal are to test the impacts of (1) gas-mineral reactions, (2) dynamic dissolution-precipitation (i.e., dynamic equilibrium), and (3) mineral replacement on preservation of the elemental, isotopic and biological information stored in carbonate, sulfate, sulfide, hydrotalcite, halide and hydroxide minerals. Experiments will be done to assess the importance of these behaviours within mineralogically similar lake sediments within the basaltic Cariboo Plateau and the Basque Lakes region in south-central British Columbia, Canada. The novelty of the proposed research lies in taking the study of non-classical mineral behaviour beyond the laboratory to quantify its impacts on real sediments in complex biogeochemical systems. All of the minerals that will be studied are ones that we rely upon for nutrient and contaminant management and that we use to reconstruct life's history on Earth. A greater understanding of how to tune the behaviour of mineral sources and sinks for the elements, and when sedimentary minerals can be relied upon as paleoenvironmental proxies, will result from this work.

矿物是地球上金属、类金属和挥发性元素的最大来源和汇。尤其是沉积矿物，在整个地球历史上，在调节元素活动性和保存生物地球化学变化记录方面发挥了重要作用。沉积岩和变质岩还含有重要的铀、铅、贱金属(包括铁、锌和铜)、磷酸盐、稀土元素和贵金属(如金和银)的矿石。虽然沉积矿物的结构、性质和环境行为已经从经典的角度得到了很好的研究，但最近对矿物行为的洞察使我们关于矿物作为污染物储存库的稳定性以及作为环境变化的长期记录器的作用的许多基本假设受到了质疑。虽然沉积矿物行为的新模型在实验室中继续得到发展，但它们对地质过程的相对重要性尚未在现场得到系统测试。需要根据新的见解重新评估沉积矿物的寿命和行为，因为新的见解揭示了它们储存的同位素和元素信息往往是瞬变的。这一建议的核心目标是测试(1)气体-矿物反应、(2)动态溶解-沉淀(即动态平衡)和(3)矿物置换对保存碳酸盐、硫酸盐、硫化物、水滑石、卤化物和氢氧化物矿物中的元素、同位素和生物信息的影响。将进行实验，以评估这些行为在加拿大不列颠哥伦比亚省中南部玄武岩Cariboo高原和巴斯克湖区内矿物学相似的湖泊沉积物中的重要性。这项拟议研究的新颖性在于将非经典矿物行为的研究带到实验室之外，以量化其对复杂生物地球化学系统中真实沉积物的影响。所有将被研究的矿物都是我们赖以进行营养和污染物管理的矿物，我们用它们来重建地球上的生命历史。这项工作将使人们更好地理解如何调整矿物源和矿汇的元素行为，以及何时可以将沉积矿物作为古环境的替代品。