Chemical fingerprinting and tracing of fluids in hydrothermal ore deposit systems

热液矿床系统中流体的化学指纹识别和追踪

• 批准号: RGPIN-2020-05013
• 负责人: Kontak, Daniel
• 金额: $ 2.62万
• 依托单位: Laurentian University of Sudbury
• 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=740347
• 关键词: Chemical; fingerprinting; tracing; fluids; hydrothermal

A wide spectrum of hydrothermal ore-deposit settings (high-T magmatic to low-T diagenetic) are important for a wide variety of metals used to sustain the needs of our modern and continually evolving society. Exploration for resources depend to a large extent on successful mineral exploration, which itself relies on ore-deposit models at different scales; to be effect such models need constant refining. The latter results from the ongoing iteration of many observations which begin in the field and extend to the laboratory where extensive study and analyses occur using the most up-to-date analytical equipment. In addition, as hydrothermal ore deposits represent highly anomalous concentrations of metals, they reflect unusual processes in the Earth's crust. Thus improving our understanding ore-deposit phenomena also contributes to furthering our knowledge of Earth systems on different scales through time in regards to the lithosphere, hydrosphere and atmosphere. My research group uses an integrated field and geochemical approach for a number of ore deposit types (e.g., orogenic and intrusion-related Au,, porphyry (Cu-Au, Sn, rare metals), pegmatites (Li), low T sedimentary-rock hosted (Zn-Pb, Cu)). This approach relies in part on using the chemical signal preserved in both fluid inclusions (<10-50 um size fluid aliquots) hosted in minerals and also mineral phases themselves (e.g., pyrite, scheelite); both can be used as proxies for ore forming processes. The intent of the current proposal is to use the advances made by my research group and modern analytical technology, such as LA ICP-MS, to further explore our understanding of gold deposit settings. The approach used is a fluid-chemical one and relies on the recent advances in several instruments that provide the capability to analyse phases at the micron scale. For example, we can now acquire both the age of formation and geochemical signature for several single mineral phases relevant to ore systems, e.g., scheelite (W), tantalite (Ta, Nb), cassiterite (Sn). Scheeite is of particular importance to this study as it is a common phase in different gold systems which allows them to be contrasted. The project will address the application of the methodology in three graduate student projects specifically addressing issues related to better characterizing the fluids and mineral phases (e.g., scheelite, arsenopyrite) in gold systems in order to better discriminate gold deposit types, in particular the orogenic and intrusion-related clans. Data generated will be used to  further develop robust mineral deposit models for the latter gold deposit settings and better define the overall deposit genesis and thus Earth system processes at different scales. The three projects described below are discrete in their method, but overlap in intent and deposit types. Importantly, the methodology used can be transferred to other ore-deposit settings and thus has widespread application to ore systems in general.

各种热液矿床环境（高温岩浆到低温成岩作用）对于维持现代和不断发展的社会需求的各种金属非常重要。资源勘探在很大程度上取决于。成功的矿产勘探本身依赖于不同规模的矿床模型；为了有效，这些模型需要不断完善，这些模型是从现场开始并延伸到实验室进行广泛研究和不断迭代的结果。此外，由于热液矿床代表了高度异常的金属浓度，因此它们反映了地壳中的异常过程，因此提高我们对矿床现象的理解也有助于加深我们的认识。我的研究小组对多种矿床类型（例如造山矿床和矿床类型）使用了综合场和地球化学方法。与侵入相关的金、斑岩（铜-金、锡、稀有金属）、伟晶岩（锂）、低 T 沉积岩（锌-铅、铜））。该方法部分依赖于使用保存在其中的化学信号。矿物中存在的流体包裹体（<10-50 um 大小的流体等分部分）以及矿物相本身（例如黄铁矿、白钨矿）都可以用作成矿的代表；当前提案的目的是利用我的研究小组和现代分析技术（例如 LA ICP-MS）的进步，进一步探索我们对金矿床环境的理解。所使用的方法是流体化学方法。我们依靠多种仪器的最新进展，这些仪器能够在微米尺度上分析相，例如，我们现在可以获得与矿石系统相关的几种单一矿物相的形成年龄和地球化学特征，例如白钨矿（ W）、钽铁矿（Ta，Nb），锡石（Sn）对于这项研究特别重要，因为它是不同金系统中的共同相，因此该项目将讨论该方法在三个研究生项目中的应用。专门解决与更好地表征金矿系统中的流体和矿物相（例如白钨矿、毒砂）相关的问题，以便更好地区分金矿床类型，特别是造山和侵入相关的矿床类型。用于进一步开发后期金矿床环境的稳健矿床模型，并更好地定义总体矿床成因，从而更好地定义不同尺度的地球系统过程。 下面描述的三个项目在方法上是离散的，但在意图和矿床类型上有重叠。 ，所使用的方法可以转移到其他矿床环境，因此在一般矿石系统中具有广泛的应用。