Seminar: More than just sulfides...Assessing the global diversity of seafloor hydrothermal systems

Abstract: Since the discovery of black smoker-style hydrothermal venting at EPR 21°N in 1979, over 400 sites of high-temperature venting have been discovered on the seafloor. Vent fields are typically characterized by the formation of metal-rich chimneys and mounds dominated by sulfide and sulfate minerals, and host unique ecosystems composed largely of vent obligate species. Mineralogical, geochemical, and isotopic characterization of the deposits show variability that reflects regional tectonic and local geological controls on hydrothermal deposit compositions. Despite these advances, recent discoveries continue to exceed the known limits of compositional variability. These new discoveries range from sulfur-poor, talc-rich deposits (e.g., Von Damm Vent Field on the Mid-Cayman Spreading Centre or Loki’s Castle on the Mohns Ridge) to deposits dominated by primary oxidized mineral assemblages (e.g., the Suye field on the Southwest Indian Ridge). In this presentation, I will discuss this increasing variety of hydrothermal depositional styles and compositions, with a focus on the implications of this variety on our understanding of global submarine hydrothermal chemical budgets, and the mineral resource potential of hydrothermal deposits on the seafloor.