Seafloor Hydrothermal Systems: Recent Advances in Mineralogy, Geochemistry and Microbiology

Dear Colleagues,

Global warming and sustainable technological development are in governments’ agendas as challenges for the coming years in terms of climate resilience and energy transition. Seabed minerals, under the jurisdiction of coastal states and in international waters, may provide an alternative sustainable resource to land-based mineral deposits supporting climate actions and growth strategies. In recent years, the research and exploration of marine minerals have increased exponentially due to the mounting demand for strategic and critical metals in the so-called high-tech and new green economy, including batteries, electric automobiles, mobiles, laptops or renewable energy. These current and expected future demands present a pressing challenge in international research, technological innovation, environmental management and protection, marine spatial planning and social license. Currently, little is still known about our oceans, which cover more than 70% of the planet’s surface. Yet, only a small part of this knowledge refers to seabed hydrothermal systems, discovered in the 1970s. Hydrothermal systems are mostly located along mid-ocean ridges, but also in arc and back-arc areas and are associated with hotspot volcanoes. They encompass a wide diversity of environments (shallow and deep seated, high and low temperature, ultramafic to felsic or sediment hosted) and resource styles (SMS, SEDEX). Seafloor hydrothermal systems are potentially promising new frontiers for the research and exploration of minerals, typically exhibiting a polymetallic mineralization that includes strategic and critical metals such as copper, zinc, indium, bismuth, tellurium, gallium and germanium. They are also a hotspot for unique biological activity and microbial organisms (free living and in symbiosis with larger fauna) that occupy an important position in the biomineralization and bioaccumulation of these minerals. Those microbe–rock interactions as well as the overall microbial landscape impact on specific element budgets (e.g., sulfur, iron, carbon) and the extent of mineral weathering. Furthermore, hydrothermal systems are of great interest due to their resemblance to early life conditions. This topic has a multidisciplinary approach and invites contributions that deal with research on submarine hydrothermal systems, including geological and biological studies in distinct tectonic settings with hydrothermal activity, from shallow waters to the deep sea. We welcome contributions describing seafloor and subseafloor exploration techniques and cutting-edge technologies for the characterization and mapping of mineral hydrothermal deposits around the world, including contributions to exploration and protection issues within hydrothermal systems in national or international programs and organizations, such as the International Seabed Authority (ISA) or InterRidge. We are inviting contributions on high-resolution imaging and new techniques to explore and characterize the mineralogy and geochemistry of strategic and critical metals, like energy-critical elements concentrated in marine hydrothermal deposits. Contributions on genetic/evolutionary models of mineral deposits, their forming fluids and associated extremophile ecosystems are also welcome. In the same way, we invite contributions on the role of microorganisms in shaping these ecosystems, including the precipitation, biomineralization, bioaccumulation and formation of (new) submarine minerals. We look forward to hearing from you.

Dr. Francisco J. González
Dr. A. Filipa A. Marques
Dr. Blanca Rincón-Tomás
Topic Editors