Minerals Report - International Seabed Authority

that there are a variety of placer deposits, that range from heavy
minerals/metals (cassiterite, platinum and gold), to light heavy minerals
(monazite, zircon, ilmenite, rutile, magnetite, diamond). He said that some of
these are actively being mined in coastal areas. He also said that during the
workshop, participants had heard of diamonds being mined in water depths
of 150 metres or more, with licenses being granted or offered for deeper water
situations. He pointed out that in order for any of these deposits to occur
beyond 200 nautical miles, significant reworking and redistribution of these
deposit have to take place. Even then, he said that if any of these deposits
were found beyond 200 nautical miles, they would have to be considered as
very marginal or sub-marginal resources. With a slide, Dr. Parson showed
participants a map of the world that indicated known locations of marine
placers as well as locations of marine placer mines. He informed participants
that all of the deposits and mines are well within 200 nautical miles of coastal
baselines.
Turning his attention to chemogenous deposits, namely submarine
deposits of phosphorite, Dr. Parson said that they deposits created when
phosphate forms compounds either as sedimentary cement or in nodular
horizons. He said that the criteria for their formation include, areas of upwelling,
medium water depths, and in tropical or subtropical environments.
He also said that there are huge reserves of phosphorite, with estimates of
hundreds of billions of tonnes of phosphorite in coastal areas and distant
areas from the coasts. He said that the downside of this picture that
phosphorite is a low value commodity. He said that there are plenty of
phosphatic ores that can be used for, inter alia, the fertilizer industry, the
chemicals industry, and in pharmaceuticals. He pointed out that there are
significant phosphorite deposits on land that are accessible and rich, making it
difficult to imagine its exploitation on the extended continental shelves. With
the use of a slide containing a map showing the distribution of marine
phosphorites, he did, however, point out that some of these deposits are very
close to the extended continental shelves. He gave the extended continental
shelf of Argentina as an example of an area where phosphorites are known to
occur.
With regard to evaporates, saline minerals formed from the
evaporation of seawater, Dr. Parson said that they widespread in the
INTERNATIONAL SEABED AUTHORITY 755