From: Chris Yeats, SciDevNet, More from this Affiliate
Published November 7, 2012 09:38 AM

Exploring the Ocean for Minerals

Global demand for metals continues to grow, fuelled largely by increasing populations and the industrialization and urbanization of China and India. To meet this demand, the international minerals industry has had to search new areas of the globe for additional resources.

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As Africa — the last underexplored continent — becomes more developed, it is inevitable that the oceans, which cover three-quarters of our planet, will be explored and exploited for their mineral wealth. It is a question of when and how, not if.

The emergent and submerged volcanic island arcs of the Western Pacific region potentially contain rich deposits of copper, zinc, gold and silver mineralization. Under the sea, these metals are associated with so-called black smokers — volcanic hot springs on the sea floor that belch hot, acidic, metal- and sulphur-rich fluids into the ocean.

These fluids cool rapidly on contact with cold seawater and deposit metal-rich sulphides at, or just beneath, the seabed. The metal content or 'grade' in the resulting seafloor massive sulphide (SMS) deposits is often at least ten times higher than that of similar deposits on land, particularly for copper and gold.

The economic viability of deep marine mining hinges on the high value of the SMS ores, even though current technological limitations mean that mining can occur only at or just below the seabed (on land, mining can occur up to a kilometer or more below the surface). Every ton of ore mined will produce significantly more metal than a terrestrial deposit and very little, or no, waste material.

Additionally, in contrast to the land, there is no need to build infrastructure such as roads, rail and port facilities. SMS mining operations will therefore be 'low footprint' in terms of overall environmental impact, compared with land operations.
This makes SMS ores highly valuable and economically attractive to mineral explorers willing to take the plunge.

Many island nations of the Western Pacific have limited land areas with scarce mineral resources, but they do have enormous maritime territories with largely unexplored mineral potential. And so the economic attraction of the nascent deep sea mining industry to these countries is obvious.

West Pacific governments, such as that of Papua New Guinea (PNG), are keen to encourage potential seafloor miners to explore their waters, with the hope that success will bring wealth (through stockpiling ore for export and royalty payments, for example) and employment opportunities for their people — although these are likely to be minimal.

Continue reading at Science and Development Network.

Sea exploration image via Shutterstock. 

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