Minerals Report - International Seabed Authority

sampling sites based on acquired information. Afterwards, Dr. Hein said that
video and still camera surveys are undertaken, and water column work
conducted during which oxygen profiles are acquired to find the oxygen
minimum zone. Dr. Hein said that once a prospective area is found, new
techniques that have not yet been used yet for studying crusts would be
required. He pointed to the need for using deep towed side scan sonar and
swath bathymetry to map small-scale topography. He also pointed out that
during advanced stages of exploration, manned submersibles or remotely
operated vehicles may be used for observations and sampling. Finally he said
that there is no sampling device that has been invented that is appropriate for
the detailed sampling required to evaluate a crusts deposit.
With regard to the chemistry of crusts, in particular metal enrichments
in them, Dr. Hein said that an approach is to determine their enrichments
relative to the earth’s crust, the lithosphere. Using Table 1 of his report, he
illustrated enrichments for manganese, iron cobalt, nickel, platinum, cerium,
copper and tellurium in seawater, the lithosphere and in crusts. Based on this
table, Dr. Hein pointed out that cobalt is enriched relative to the earth’s crust
about 280 times. He described the enrichment of tellurium in crusts as
phenomenal and said that that it is enriched orders of magnitude over any
other metal in crusts. He noted that if the tellurium content of the earth’s
crust is as indicated tellurium is enriched in crusts 50,000 times the content of
the lithosphere.
Dr. Hein said that for enrichments between 100 and 1000 times the
lithosphere, there is a large group of metals in crusts that may have economic
potential besides cobalt, such as nickel and platinum. He also said that while
gold and palladium are not enriched in crusts, everything else in the periodic
table practically is. He showed maximum values that have been recorded
from crusts samples for metals like zirconium, thallium, tungsten, bismuth
and platinum.
Dr. Hein reported that after about 6 years of looking at crusts, along
with two other scientists, he had developed criteria for exploring for and
mining cobalt-rich crusts. He said that these consisted of 6 regional and 6 sitespecific
criteria. With regard to regional criteria, Dr. Hein said that an
explorer should look for: large volcanic edifices (seamounts) that are
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