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: 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=751198
• 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.

广泛的热液矿床环境（高温岩浆到低温成岩）对于用于维持我们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，而矿产勘探本身又依赖于不同尺度的矿床模型;要使这些模型产生效果，就需要不断完善。后者是由许多观察的不断重复产生的，这些观察开始在实地，并延伸到实验室，在实验室中使用最新的分析设备进行广泛的研究和分析。此外，由于热液矿床的金属含量异常高，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认识也有助于我们进一步了解岩石圈、水圈和大气层等不同时间尺度的地球系统。 我的研究小组对许多存款类型（例如，与造山和侵入有关的Au、斑岩（Cu-Au、Sn、稀有金属）、伟晶岩（Li）、低T沉积岩（Zn-Pb、Cu）。这种方法部分地依赖于使用保存在矿物中的流体包裹体（<10-50 μ m大小的流体等分试样）以及矿物相本身（例如，黄铁矿、白钨矿）;两者均可用作成矿过程的代用指标。本提案的目的是利用我的研究小组取得的进展和现代分析技术，如LA ICP-MS，进一步探索我们对金存款设置的理解。所使用的方法是流体化学方法，并依赖于几种仪器的最新进展，这些仪器提供了在微米尺度上分析相的能力。例如，我们现在可以获得与矿石系统相关的几个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）、钽铁矿（Sn）。白钨矿对这项研究特别重要，因为它是不同金体系中的常见相，可以将它们进行对比。 该项目将解决该方法在三个研究生项目中的应用，具体解决与更好地表征流体和矿物相有关的问题（例如，白钨矿、毒砂），以便更好地区分金存款类型，特别是造山型和侵入型金矿床。所产生的数据将用于进一步为后一种金存款环境开发可靠的矿物存款模型，并更好地确定整个存款成因，从而确定不同尺度的地球系统过程。下文所述的三个项目在方法上互不相关，但在意图和存款类型上有重叠。重要的是，所使用的方法可以转移到其他矿床环境，从而广泛应用于一般的矿石系统。