Minerals Report - International Seabed Authority
Minerals Report - International Seabed Authority Minerals Report - International Seabed Authority
equired to make sure that the ship’s position over a drill hole is maintained. He said that at the seafloor, sedimented areas could be directly drilled, but that where there is only a slight sediment cover and hard rock, a so-called reentry core is required. In addition, for hard rock drilling Dr. Herzig said that a so-called hard rock guide base cemented to the seafloor has to be assembled together with the re-entry core. He described this assembly as a routine operation for the ODP. Dr. Herzig informed participants that in 1994, he was part of a team of scientists that conducted a drilling project at the (Trans-Atlantic Geotraverse) TAG active hydrothermal mound. To illustrate the absolute need for drilling in order to know what to expect at mounds, Dr. Herzig volunteered to share the results of this Leg of the ODP with participants. Dr. Herzig showed a slide containing a bathymetric map of the TAG mound. He pointed out the locations of the black and white smoker complexes, and the Kremlin area. He said that 17 holes were drilled in five areas in 2 months. The areas included a high-temperature (363 deg C) black-smoker complex, characterized by chalcopyrite and anhydrite deposits, and a low-temperature (260-300 deg C), sphalerite-dominated white smoker vent field. Dr. Herzig said that total penetration from the 17 drill holes was almost 600 metres, the total core interval 435 m, the total core recovery out of the cored interval 51 m or about 12%, and that the maximum penetration achieved was 125.7 m. He also said that at the beginning of the project a maximum penetration of about 500 metres was expected. He said that the problems encountered were related to the cuttings that were produce while drilling the massive sulphides. He said that cuttings are usually flushed out of the drill holes with seawater but that in this case the cuttings were relatively dense and heavy. As he result, he said that the drill string got caught in the cuttings, necessitating the use of explosives to free the drill string. Dr. Herzig said that through drilling it was discovered that most of the base and precious metals are concentrated in the upper few meters of the mound within massive pyrite, and pyrite breccias underlain by pyrite anhydrite breccias. Based on this discovery, Dr. Herzig said that the new hypothesis is that most of the metals that were precipitated during the growth INTERNATIONAL SEABED AUTHORITY 326
of the mound were later mobilized by hydrothermal fluids, transported to the seafloor and were redeposited in a small horizon on top of the mound. He said that the mound contains only a small amount of metal resources confined to the upper 5 metres. He also said that while this may be not typical for all massive sulphide deposits in hydrothermal systems, the message made it clear that the contrary situation is not universal. Dr. Herzig said that the other information obtained through drilling is the tonnage of the deposit. From drilling, he said that it is estimated that the mound contains about 2.7 million tonnes of sulphides above the seafloor and 1.2 million tonnes of sulphides below the seafloor or a grand total of 3.9 million tonnes of sulphides. Dr. Herzig said that later during the year, the ODP will be drilling the Manus Basin in the area that Nautilus has its exploration licenses. Dr. Herzig pointed out however that the drilling of massive sulphides deposits and hydrothermal vent systems by the Ocean Drilling Programme is the exception rather than the rule. For research and resource assessment, Dr. Herzig said that seafloor drills need to be developed. In this regard, he said that two currently available systems for use on ships of opportunity or ordinary research vessels are the PROD-drill (Portable Remotely Operated Drill) and the Benthic Multicoring System (BMS). Dr. Herzig said that the PROD drill was built in Australia with the help of the US group Williamson and Associates, Inc. It has a depth capability of 2000 metres, core index 100 metres in series and a core diameter of 40 millimetres. Dr. Herzig said that the BMS system (Benthic Multicoring System) was built in 1996 by Williamson and Associates, Inc. for the Metal Mining Agency of Japan (MMAJ). It is installed on the Metal Mining Agency’s research ship Hakurei Maru No 2. The BMS system has a depth rating of 6,000metres, core depth of 20 metres, a core diameter of 44 millimetres, and a cable length of 12,000 metres. INTERNATIONAL SEABED AUTHORITY 327
- Page 284 and 285: Table 1 Potential microbial metabol
- Page 286 and 287: Figure 2 Simplified representation
- Page 288 and 289: Figure 3 Major components of a gene
- Page 290 and 291: the mussel's nutrition. When experi
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- Page 300 and 301: y mining, which is expected to be v
- Page 302 and 303: 2. J. B. Corliss, J. Dymond, L. Gor
- Page 304 and 305: 19. V. Tunnicliffe, A.G. McArthur a
- Page 306 and 307: SUMMARY OF THE PRESENTATION AND DIS
- Page 308 and 309: together with mucus that is secrete
- Page 310 and 311: close to neutral ph conditions, it
- Page 312 and 313: France, Germany, the United Kingdom
- Page 314 and 315: of the sedimentary column, whereas
- Page 316 and 317: Table 2: Research Submersibles and
- Page 318 and 319: 4. Technical Requirements For resea
- Page 320 and 321: 5. Processing Technologies The phys
- Page 322 and 323: grow on substrate rocks because of
- Page 324 and 325: 5. M.D. Hannington, A.G. Galley, P.
- Page 326 and 327: Dr. Herzig informed participants th
- Page 328 and 329: search for sites of hydrothermal ve
- Page 330 and 331: with such a grab. In addition to th
- Page 332 and 333: Remotely operated vehicles (ROVs) D
- Page 336 and 337: Dr. Herzig summarized the technical
- Page 338 and 339: commercial. Since confidentiality o
- Page 340 and 341: CHAPTER 8 FACTORS IN FINANCING EXPL
- Page 342 and 343: The traditional project stages that
- Page 344 and 345: there is a subset that forms in spe
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- Page 348 and 349: 7. Why SMS Mines will be Lower Cost
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- Page 356 and 357: flow to the metal markets. He also
- Page 358 and 359: shortage in the next couple of year
- Page 360 and 361: starts, the operation could take pl
- Page 362 and 363: Based on this and other considerati
- Page 364 and 365: Mr. Malnic said that the mining ope
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- Page 372 and 373: I think the issue is not as simple
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- Page 378 and 379: 6. Elisabeth Mann Borgese, Ocean Go
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of the mound were later mobilized by hydrothermal fluids, transported to the<br />
seafloor and were redeposited in a small horizon on top of the mound. He<br />
said that the mound contains only a small amount of metal resources confined<br />
to the upper 5 metres. He also said that while this may be not typical for all<br />
massive sulphide deposits in hydrothermal systems, the message made it<br />
clear that the contrary situation is not universal.<br />
Dr. Herzig said that the other information obtained through drilling is<br />
the tonnage of the deposit. From drilling, he said that it is estimated that the<br />
mound contains about 2.7 million tonnes of sulphides above the seafloor and<br />
1.2 million tonnes of sulphides below the seafloor or a grand total of 3.9<br />
million tonnes of sulphides.<br />
Dr. Herzig said that later during the year, the ODP will be drilling the<br />
Manus Basin in the area that Nautilus has its exploration licenses.<br />
Dr. Herzig pointed out however that the drilling of massive sulphides<br />
deposits and hydrothermal vent systems by the Ocean Drilling Programme is<br />
the exception rather than the rule. For research and resource assessment, Dr.<br />
Herzig said that seafloor drills need to be developed. In this regard, he said<br />
that two currently available systems for use on ships of opportunity or<br />
ordinary research vessels are the PROD-drill (Portable Remotely Operated<br />
Drill) and the Benthic Multicoring System (BMS).<br />
Dr. Herzig said that the PROD drill was built in Australia with the<br />
help of the US group Williamson and Associates, Inc. It has a depth capability<br />
of 2000 metres, core index 100 metres in series and a core diameter of 40<br />
millimetres.<br />
Dr. Herzig said that the BMS system (Benthic Multicoring System) was<br />
built in 1996 by Williamson and Associates, Inc. for the Metal Mining Agency<br />
of Japan (MMAJ). It is installed on the Metal Mining Agency’s research ship<br />
Hakurei Maru No 2. The BMS system has a depth rating of 6,000metres, core<br />
depth of 20 metres, a core diameter of 44 millimetres, and a cable length of<br />
12,000 metres.<br />
INTERNATIONAL SEABED AUTHORITY 327
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