Minerals Report - International Seabed Authority

of De Beers and its associated companies is very clear and that is to
recover diamonds. He also said that while his presentation would be
based primarily on the approach of De Beers, it would focus on two
companies; NAMDEB, a joint company between the Government of
Namibia and De Beers, and De Beers Marine.
Dr. Corbett said that diamonds were discovered in Namibia in
1908, in the deflation basin of the Namib Desert by a railway worker who
was living near Luderitz. Dr. Corbett described the location as a very
hostile, an aggressive windswept environment. He said that when the
deposits were discovered, people were able to crawl across the desert floor
and pick up diamonds, and that he had the opportunity to do that in the
early morning sunlight. With the use of slides, Dr. Corbett showed the
area and its proximity to the Orange River, Cape Town and Windhoek
(Figure 1). He said that after the initial discovery, diamonds were then
discovered in Clancy on the Buffels River, then in 1926 in Alexander Bay
by Hans Merensky, and subsequently in 1928 to the north of the Orange
River by Werner Beetz.
Dr Corbett provided participants with information on how the
offshore diamond deposits were formed. He said that kimberlites are
present in the interior of southern Africa, in both South Africa and
Botswana, but that the principle source for many of the diamonds that
were delivered to the west coast are the kimberlites that were intruded
between 120 and 80 million years ago. Following erosion in the interior of
these kimberlite pipes, Dr. Corbett said that the diamonds were
transported westward by the palaeo Orange River. He pointed out that
this very large river system has been in existence for at least 65 to 80
million years. Subsequently, Dr. Corbett said that once the diamonds
were introduced to the continental margin, on one of the highest energy
coastlines in the world, Dr. Corbett said that they were reworked by long
shore processes, predominantly north bound long shore transport and in
the process, the diamonds were deposited in onshore beach complexes
which extend over hundreds of kilometres. Dr. Corbett said that during
regressions, of which there have been many since the Gondwana break-up
and the formation of the Atlantic Ocean, the Orange River had been able
to transport diamonds further west beyond the present day coastline right
down on to the middle continental shelf of Namibia. He also said that in
the process, the Orange River deposited a fan delta or a very large fan
shaped body of extremely coarse clastic material containing diamonds.
Dr. Corbett said that this fan shaped body of material was extensively
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