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了解海底块状硫化物（SMS）矿床的资源潜力，开发这些矿床的定年方法，并开发定位和描绘这些矿床的勘探技术。为了充分了解海底发生的过程，如沉积速率，迁移的栖息地，火山作用和矿床的形成，有必要确定这些过程发生的时间和速率。 使用铀系放射性同位素进行同位素测年是测定海洋环境中年轻（小于50万年）地质和生物样品年龄的有效工具。 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状硫化物矿床的形成和演变。这项研究很重要，因为这些矿床保存了随时间推移的热液喷发的空间、时间和地球化学记录，并且由于高浓度的有价值的贱金属和贵金属，越来越多地被视为潜在的采矿目标。有待开发的测年技术同样可应用于沉积岩芯、玄武岩和深海动物（例如，申请者实验室目前有能力利用伽马光谱测定技术测定相对年轻的富含重晶石的热液样品的年代，这些样品的年代在约500年至16 000年之间，重点是古老、不活跃的海底块状硫化物矿床的组成、保存和勘探。然而，随着我们发现古老的离轴矿床的能力的增加，对更古老的矿床进行测年的需求也在增加。同样，随着气候变暖引起的环境迅速变化，也需要开发测定样品年龄小于500年的技术。 拟议的方案将建立在使用质谱法和伽马光谱法相结合来测定样品日期的能力之上。这一能力的提高将建立一个主要的U系列地质年代学中心，并有能力对热液矿床的地质和生物样本进行长达50万年的整个年龄范围的测年。 这项研究的成果将有助于更好地了解海底发生的自然过程。 这对新兴深海采矿业的利益攸关方，包括商业公司、政府监管机构和非政府组织尤其重要。 这项研究还将有助于我们了解气候变化和人类活动的影响（例如，渔业、近海石油生产）对海洋环境的影响。