Marine Mineral Resources and Metals in the Oceans

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Metal mining is one of the largest sectors of the global economy, and increasing demand for land-based resources is now encouraging exploration in the oceans. A number of countries (China, Japan, Korea, Russia, France and Germany) are actively exploring for mineral deposits at seafloor hydrothermal vents, with the aim of establishing seabed mining operations in the next decade. Other countries have leased portions of their EEZs for offshore mineral exploration. Recent articles in Nature and Science have raised concerns about the pace of this development in the absence of a coordinated scientific effort to understand the origin and distribution of the resources and the likely impacts of mining. Important questions remain about the diversity of seafloor hydrothermal systems, the loading of metals to the oceans from different volcanic and hydrothermal sources, and the geological processes that contribute most to their metal endowment. These aspects are poorly known, even at a qualitative level, but are fundamental to assessing the viability of a future marine minerals industry. To address these questions, we are participating in an international effort to explore and document the mineral deposits in different volcanic and tectonic settings of oceans. PhD students are gathering data on scientific cruises to the Mid-Atlantic Ridge, Iceland, the Mariana arc, the Melanesian Archipelago (PNG, Solomons, Vanuatu), the Tonga-Kermadec arc, and in the Tyrrhenian Sea. They employ marine geology, geophysics, and geochemistry to identify the controls on the distribution of mineral resources, the large-scale magmatic and tectonic processes that influence metal budgets, and the behaviour of metals in the marine environment. This ambitious program is made possible by established partnerships with German, U.S., N.Z. and other institutions who are providing shiptime and other sea-going assets. At the same time, knowledge from the modern seafloor is greatly enhancing models of mineral endowment in ancient volcanic belts, with direct practical application to mineral exploration on land. Our group is one of the only scientific teams worldwide to bridge this knowledge of modern marine minerals to the understanding of ancient ore deposits.