Controls on fluid flow and metal deposition in sediment-hosted hydrothermal ore deposits

沉积物热液矿床中流体流动和金属沉积的控制

• 批准号: RGPIN-2022-04416
• 负责人: Barker, Shaun
• 金额: $ 2.62万
• 依托单位: University of British Columbia
• 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=751289
• 关键词: Controls; fluid; flow; metal; deposition

Sediment-hosted hydrothermal ore deposits represent globally significant sources for many metals including copper, cobalt, lead, zinc, uranium, arsenic and germanium. Sediment-hosted deposits are difficult to discover because they have "cryptic" mineral alteration (i.e. alteration invisible to the eye). In addition, processes responsible for forming high-grade ore deposits are uncertain. This means that new geochemical tools are required that will enable recognition and mapping of the key processes and alteration footprints for these deposits. During the flow of hydrothermal fluid through rock, a series of reaction fronts will be established. These reaction fronts will manifest as changes in ore metal abundances, mineralogical alteration, stable isotope ratios and temperature. Accurate mapping of temperature variations is difficult, with index alteration minerals (e.g. illite, biotite) providing insufficient temperature precision, and fluid inclusions often not well preserved in sediment-hosted hydrothermal deposits. This research program will develop new methods for providing precise temperature measurements from carbonate minerals formed at up to 350 oC  utilizing clumped carbon and oxygen isotopes. The program will develop new methods and datasets for quantifying alteration mineralogy and variations in primary and secondary textures across scales (from the thin section to deposit scale) within sediment-hosted ore deposits in order to create new ore deposit models. Finally, we will seek to test and develop new exploration tools for sediment-hosted copper deposits focussing on recognizing unique textures and chemistry of resistate indicator minerals such as apatite, rutile and monazite. Collectively, this research program will both develop fundamental new knowledge on the genesis and alteration of sediment-hosted ore deposits, develop new exploration tools and methods suitable for discovering new deposits, and train the highly qualified personnel who will be needed to deliver the mineral resources required for the low-carbon energy transition.

沉积物中的热液矿床是许多金属的全球重要来源，包括铜、钴、铅、锌、铀、砷和锗。沉积物矿床很难被发现，因为它们有“隐蔽的”矿物蚀变(即肉眼看不见的蚀变)。此外，形成高品位矿藏的过程也不确定。这意味着需要新的地球化学工具，以便能够识别和绘制这些矿床的关键过程和蚀变足迹。在热液流体在岩石中流动的过程中，会形成一系列的反应前沿。这些反应前沿将表现为矿石金属丰度、矿物蚀变、稳定的同位素比和温度的变化。由于折射率蚀变矿物(如伊利石、黑云母)提供的温度精度不够高，而且沉积热液矿床中的流体包裹体往往不能很好地保存，准确绘制温度变化图是困难的。这项研究计划将开发新的方法，利用块状碳和氧同位素，从高达350摄氏度形成的碳酸盐矿物中提供精确的温度测量。该计划将开发新的方法和数据集，用于量化沉积物赋存矿床内蚀变矿物学和原生和次生结构在不同尺度(从薄片到矿床尺度)的变化，以创建新的矿床模型。最后，我们将致力于测试和开发沉积物铜矿床的新勘探工具，重点是识别磷灰石、金红石和独居石等抗蚀指示矿物的独特结构和化学成分。总体而言，这一研究计划将发展有关沉积物矿床成因和蚀变的基本新知识，开发适用于发现新矿床的新勘探工具和方法，并培训提供低碳能源转型所需矿产资源所需的高素质人员。