Minerals Report - International Seabed Authority

eroded during regression and transgression. Dr. Corbett informed
participants that as a result of erosion, this high-energy shore face has
moved in a northerly direction on the continental shelf reworking and
retransporting the diamonds. He said that in many cases, during the
regressions and transgressions, arid-zone processes have operated because
the coastline is an extremely high-energy wind environment that supports
the Namib Desert. According to Dr. Corbett, diamonds were transported
by these winds back up the palaeo slope, across the continental shelf, and
on shore into the deflation basin of the Namib Desert. Dr. Corbett said
that some of the deposits to be found here are actively being mined at
Elizabeth Bay by NAMDEB.
With slides, Dr. Corbett showed participants the deposit at
Elizabeth Bay. He described the environment as exceptional, from both a
scientific and a diamond quality point of view. He said that the deposit is
to be found under 126 metres of seawater in a high energy environment
has essentially destroyed any diamonds that were flawed in any way. He
described the quality of the Namibian diamonds as absolutely
extraordinary, higher than 95 percent of high quality gems. He said that
from this deposit, the science behind how placers are formed not only in
fluvial environments but also in aeolian and marine environments could
be determined. He said that through the work of De Beers Marine (DBM)
and NAMDEB in shallow waters, the science behind these offshore
deposits have been studied in some detail.
In this regard, Dr. Corbett identified some of the many
opportunities for scientific interaction between industry and academia.
He said that these included work on the paleontological side. As an
example, Dr. Corbett revealed that the Orange River is the southern-most
example of Miocene bearing, vertebrate faunas in southern Africa
containing fantastic deposits for research on vertebrate palaeontology. He
informed participants that a French team from the Musee de Paris is
currently undertaking vertebrate paleontological work. Dr. Corbett said
that De Beers and NAMDEB have built up an extremely detailed
knowledge of diamond introduction, transport and concentration in a
wide variety of different placer environments that have operated over 50
million years on this remarkable stretch of coastline. On the onshore side,
Dr. Corbett pointed out that the deposits have now been mined for almost
a century because there has been continuous innovation and improvement
of diamond extraction technology, with new types of systems being
introduced periodically. Through slides, Dr. Corbett showed examples of
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