Geochronology of Seafloor Hydrothermal Systems

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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.