Minerals Report - International Seabed Authority
Minerals Report - International Seabed Authority Minerals Report - International Seabed Authority
on the continental margin. He stated that the present knowledge of these resources is confined to the most accessible, or those that are exposed on or near the sea floor; although there could be deposits deeply buried as well within the sediments of the continental margin. Professor Rona informed the workshop that numerous sites exist on continental shelves around the world where heavy minerals containing metals and non-metals are concentrated, but of these only a small number are or have actually been mined. These materials are eroded from rocks exposed on land and are transported by rivers to the ocean where they are concentrated by waves, tides and currents as placer deposits. With reference to metals, the outstanding resource is tin that is dredged from shallow water (water depth less than 30 metres) at several sites offshore Thailand (Thai Muang; Tongkah Harbour, Takua Pa), Indonesia (Copat Kelabat Bay, Laut Tempilang; Belitung), and Myanmar (Heinze Basin) where tin minerals (cassiterite) were derived by erosion and transportation from continental granites. Goldbearing sands and gravels have been intermittently (depending on the price) dredged from shallow water (water depth less than 15 metres) at several sites offshore Alaska (Nome, Bluff Solomon) and New Zealand (Gillespie’s Beach). Titanium (which is to be found in the minerals limonite and rutile), zirconium (in zircon), Rare Earth Elements (monazite), and the radioactive element thorium (monazite) have been recovered at several shallow water (water depth less than 5 m) sites offshore South Africa, Madagascar, and India. Chromium (to be found in the mineral chromite) is recovered at a site offshore Central Sulawesi island, Indonesia, and barium at a site offshore Alaska. With reference to non-metals, Professor Rona noted that a viable industry has developed exploring for and dredging diamond-bearing gravels offshore Namibia (Chameis Bay) and South Africa (Groen River, Broadacres, Casuarina Prospect) in shallow water (exploration water depth to 400 metres; dredging water depth to 140 metres). The most widely recovered marine mineral he however stated is sand and gravel dredged from beaches and shallow offshore bars at numerous sites worldwide for use in construction materials (concrete) and to replenish beaches. Freshwater is a marine mineral resource critical to life and which may be extracted from seawater by various desalination processes and exists in solid form in the ice sheets of Antarctica and Greenland. Although desalination, which is an energy intensive process, INTERNATIONAL SEABED AUTHORITY 16
is mainly being used in the oil-based economies of Middle Eastern maritime states, desalination plants are spreading to other parts of the world. The element phosphorous is also critical to agriculture and occurs where it has precipitated from deep seawater as the mineral phosphorite at present and past locations of up welling along sections of continental shelves primarily within the trade wind belts (0 to 30 degrees North and South latitude). All phosphorite is presently mined from land deposits precipitated during higher stands of sea level in the geological past, but extensive deposits exist on continental shelves of agriculture-intensive countries like India. He demonstrated that for metals and non-metals, there are fewer than 20 sites that have been or are operational in terms of marine mining. In terms of seafloor mineralisation, he mentioned that the first discovery was in the Red Sea when in the course of a transit during the International Indian Ocean Expedition in the 1960s, echo sounders got reflections from layers within the water column that were totally anomalous. Usually, he remarked, the reflections come back from the seafloor. When sampling, it was found that the reflectors were layers of highly salty metal and rich water at certain places along the axis of the Red Sea. The Red Sea it turns out is a part of a plate boundary where the seafloor is spreading is, i.e., moving Saudi Arabia and Africa further apart. Along its axis, hot rocks are welling up from the earth’s interior in this submerged plate boundary. The mineral deposits that are to be found in certain basins along it, came about as a result of the interaction of the hot metal enriched volcanic rocks up welling at the plate boundary, the restricted circulation of seawater that led to the deposition/precipitation of thick layers of rock salt in the basins, and down welling of cold, heavy seawater through the volcanic rocks and rock salt, forming a metal brine that is both saltier and richer in metals. While there are several deep basins are to be found in the Red Sea, the Atlantis II Deep, just west of Mecca is the largest seafloor hot spring deposit known on earth and is particularly enriched in zinc and is also known to contain silver and gold. Professor Rona noted that this process was extremely efficient for concentrating metals since the metals precipitate as particles that collect at the seafloor, and form the metalliferous sediments of the Red Sea. The latest estimate of the size of this deposit is 94 million tonnes dry weight with about 2 per cent zinc. Since this deposit is to be found within the 200 n-mile zone of Saudi Arabia and Sudan, they undertook a joint survey of this deposit in 1979 INTERNATIONAL SEABED AUTHORITY 17
- Page 2 and 3: Workshop on Minerals Other than Pol
- Page 4 and 5: Published in Jamaica 2004 by the In
- Page 6 and 7: Chapter 6* Impact of the Developmen
- Page 8 and 9: PART 4 REGULATORY AND PROMOTIONAL F
- Page 10 and 11: The Authority designates one of two
- Page 12 and 13: deposits and gas hydrates of the co
- Page 14 and 15: Prof. Chris German, Challenger Divi
- Page 16 and 17: Mr. Sven Petersen, Research Associa
- Page 18 and 19: SECRETARIAT Ambassador Satya N. Nan
- Page 20 and 21: is to submit “an application that
- Page 22 and 23: that was established to help protec
- Page 26 and 27: with the German firm Preussag. As p
- Page 28 and 29: metre or metres of these black smok
- Page 30 and 31: nodules in terms of these metals -
- Page 32 and 33: Professor Herzig stressed however t
- Page 34 and 35: While noting that the continuity of
- Page 36 and 37: asal diameter at 1,600 m water dept
- Page 38 and 39: discovery of the new hydrothermal s
- Page 40 and 41: esearch cruises dedicated to ferrom
- Page 42 and 43: global mid-ocean ridge system. He p
- Page 44 and 45: athymetric map of the seafloor. A s
- Page 46 and 47: were encouraging. In the course of
- Page 48 and 49: that this matter was sensitive, he
- Page 50 and 51: complete a preliminary evaluation o
- Page 52 and 53: metals - nickel, cobalt, manganese,
- Page 54 and 55: 12. Issues to be taken into account
- Page 56 and 57: entities. Many of them included min
- Page 58 and 59: In this regard, the Secretary-Gener
- Page 60 and 61: According to Dr. Vysotsky, as estim
- Page 62 and 63: With regard to current knowledge ab
- Page 64 and 65: Dr. Corbett gave a brief account of
- Page 66 and 67: River resulting in the introduction
- Page 68 and 69: Ms. Zaamwani pointed out that as th
- Page 70 and 71: geochemical and geotechnical survey
- Page 72 and 73: of its continental shelf through bi
on the continental margin. He stated that the present knowledge of these<br />
resources is confined to the most accessible, or those that are exposed on or<br />
near the sea floor; although there could be deposits deeply buried as well<br />
within the sediments of the continental margin.<br />
Professor Rona informed the workshop that numerous sites exist on<br />
continental shelves around the world where heavy minerals containing metals<br />
and non-metals are concentrated, but of these only a small number are or have<br />
actually been mined. These materials are eroded from rocks exposed on land<br />
and are transported by rivers to the ocean where they are concentrated by<br />
waves, tides and currents as placer deposits. With reference to metals, the<br />
outstanding resource is tin that is dredged from shallow water (water depth<br />
less than 30 metres) at several sites offshore Thailand (Thai Muang; Tongkah<br />
Harbour, Takua Pa), Indonesia (Copat Kelabat Bay, Laut Tempilang;<br />
Belitung), and Myanmar (Heinze Basin) where tin minerals (cassiterite) were<br />
derived by erosion and transportation from continental granites. Goldbearing<br />
sands and gravels have been intermittently (depending on the price)<br />
dredged from shallow water (water depth less than 15 metres) at several sites<br />
offshore Alaska (Nome, Bluff Solomon) and New Zealand (Gillespie’s Beach).<br />
Titanium (which is to be found in the minerals limonite and rutile), zirconium<br />
(in zircon), Rare Earth Elements (monazite), and the radioactive element<br />
thorium (monazite) have been recovered at several shallow water (water<br />
depth less than 5 m) sites offshore South Africa, Madagascar, and India.<br />
Chromium (to be found in the mineral chromite) is recovered at a site offshore<br />
Central Sulawesi island, Indonesia, and barium at a site offshore Alaska.<br />
With reference to non-metals, Professor Rona noted that a viable<br />
industry has developed exploring for and dredging diamond-bearing gravels<br />
offshore Namibia (Chameis Bay) and South Africa (Groen River, Broadacres,<br />
Casuarina Prospect) in shallow water (exploration water depth to 400 metres;<br />
dredging water depth to 140 metres). The most widely recovered marine<br />
mineral he however stated is sand and gravel dredged from beaches and<br />
shallow offshore bars at numerous sites worldwide for use in construction<br />
materials (concrete) and to replenish beaches. Freshwater is a marine mineral<br />
resource critical to life and which may be extracted from seawater by various<br />
desalination processes and exists in solid form in the ice sheets of Antarctica<br />
and Greenland. Although desalination, which is an energy intensive process,<br />
INTERNATIONAL SEABED AUTHORITY 16
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