Geochronology of Seafloor Hydrothermal Systems

海底热液系统地质年代学

• 批准号: RGPIN-2017-05548
• 负责人: Jamieson, John
• 金额: $ 2.33万
• 依托单位: Memorial University of Newfoundland
• 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=751146
• 关键词: Geochronology; Seafloor; Hydrothermal; Systems

The overarching goal of my research program is to develop an understanding of the resource potential of seafloor massive sulfide (SMS) deposits, develop methods for dating these deposits, and develop exploration techniques for locating and delineating these deposits.In order to fully understand processes that occur on the seafloor, such as sedimentation rates, shifting habitats, volcanism and formation of ore deposits, it is necessary to determine the timing and rates at which these processes occur. Isotope dating using U-series radioisotopes is an effective tool for dating young (<0.5 million years) geological and biological samples in the marine environment. The primary focus of the proposed research program is to develop dating techniques and train HQP in the application of these techniques to better understand geological and biological processes on the seafloor, especially, but not limited to, hydrothermal systems and the formation and evolution of seafloor massive sulfide deposits. This research is important because these deposits preserve a spatial, temporal and geochemical record of hydrothermal venting over time and are increasingly seen as potential mining targets, due to the high concentrations of valuable base and precious metals. The dating techniques to be developed can equally be applied to sediment cores, basaltic rocks and deep-sea fauna (e.g., corals), either in relation to hydrothermal systems or related to other marine processes.Capacity in the applicant's lab currently exists to date relatively young barite-rich hydrothermal samples between ~500 and 16,000 years using gamma spectrometry techniques and is focused on the composition, preservation and exploration of old, inactive seafloor massive sulfide deposits. However, as our ability to find old, off-axis deposits increases, so to does the need to date older deposits. Likewise, with rapid environmental change associated with climatic warming, developing techniques for dating samples younger than 500 years is also required. The proposed program will build on the capacity to date samples using a combination of mass spectrometry and gamma spectrometry. This increased capacity will create a major centre for U-series geochronology, and the capability to date both geological and biological samples from hydrothermal deposits over a full age spectrum up to 500,000 years. The outcomes of this research will lead to a better understanding of the natural processes that occur on the seafloor. This will be particularly relevant for stakeholders in the emerging deep-sea mining industry, including commercial companies, government regulators and NGOs. This research will also help our understanding of the effects of climate change and human activities (e.g., fisheries, offshore petroleum production) on the marine environment.

我的研究计划的总体目标是加深对海底块状硫化物 (SMS) 矿床资源潜力的了解，开发这些矿床的年代测定方法，并开发定位和描绘这些矿床的勘探技术。海底发生的各种过程，例如沉积速率、栖息地变化、火山活动和矿床的形成，有必要确定这些过程发生的时间和速率。 使用 U 系列放射性同位素进行同位素测年是对海洋环境中年轻（<50 万年）地质和生物样本进行测年的有效工具。 拟议研究计划的主要重点是开发测年技术并培训 HQP 应用这些技术，以更好地了解海底的地质和生物过程，特别是但不限于热液系统以及海底块体的形成和演化硫化物矿床。这项研究很重要，因为这些矿床保存了随着时间的推移热液喷发的空间、时间和地球化学记录，并且由于有价值的贱金属和贵金属的高浓度而越来越多地被视为潜在的采矿目标。待开发的测年技术同样可以应用于沉积物岩心、玄武岩和深海动物群（例如珊瑚），无论是与热液系统有关还是与其他海洋过程有关。申请人实验室目前的能力相对较强使用伽马能谱技术研究约 500 至 16,000 年的年轻富含重晶石的热液样本，重点关注古老、不活跃的海底块状硫化物的成分、保存和勘探存款。然而，随着我们发现旧的、离轴矿床的能力不断增强，对旧矿床进行年代测定的需求也随之增强。同样，随着气候变暖导致的环境快速变化，还需要开发对 500 年以下样本进行年代测定的技术。 拟议的计划将建立在结合使用质谱法和伽马能谱法测定样本年代的能力的基础上。容量的增加将创建一个主要的 U 系列地质年代学中心，并能够对来自热液沉积物的地质和生物样本进行年代测定，范围长达 50 万年。 这项研究的结果将有助于更好地了解海底发生的自然过程。 这对于新兴深海采矿业的利益相关者尤其重要，包括商业公司、政府监管机构和非政府组织。 这项研究还将有助于我们了解气候变化和人类活动（例如渔业、近海石油生产）对海洋环境的影响。