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By Hjalmar Thiel

Issues of deep-seabed mining are discussed since four decades and extensive efforts have been invested in oceanographic studies related to environmentally sound harvesting of polymetallic nodules. Because mining on the deep seafloor seems to range from large-scale, two-dimensional dredging or scooping up of the ore from the uppermost surface sediment layer to more localized drilling or deeper digging into a three-dimensional ore body, it appears to be justified to reconsider some concepts for environmental impact evaluation. Based on the experience gained during preceding years in environmental studies related to polymetallic nodule mining, some interrelated hypotheses and proposals will be presented. It is suggested that these proposals be considered in future plans for environmental impact evaluation and that observations on community re-establishment be conducted before massive sulphide mining or other ore extractions enter the commercial mining phase.

Aug 24, 2006

By Marco Figoni

The increased interest on deep water minerals resources is a challenge for both mining and oil industry. The exploration and production of oceans minerals require a synergy between of different technologies. While mining industry is leading the dredging and processing part of the system, oil industry is contributing through development of ore lifting technology based on existing subsea knowledge. The paper presents an overview, based on published projects around the world, of different approaches to marine mining. Several exploration techniques and offshore production systems were already designed and assessed, all of them with apparently positive results. Exploration phase is well advanced and in continuous expansion allowing the discovery of increasing resources around the world of different nature but production can be considered to be in an early stage. Different from onshore mining, subsea operations require a closer cooperation with international and local authorities to preserve as much as possible the environment. There are still many uncertainties at respect and all the exploration process must be carefully evaluated to allow subsea mining to develop in a sustainable manner. Technically, mining at seabed was already demonstrated and the process is based on three main components, namely seafloor mining tools, riser and lifting system and production vessel support. This layout is based on the concept that ore must be disaggregated at seafloor first, transported to surface in form of slurry that must be dewatered before loading to be transported to processing plants onshore. The challenges are rising because the environment and safety must be taken into consideration as a priority when evaluating the efficiency of the system. The most critical challenges regarding the production operations, especially in deep water are the deep-sea excavation process, the transport of large slurry volumes, the slurry abrasivity, the power supply management and the subsea

Sep 14, 2011

By David Heydon

The big money is backing both manganese nodules and manganese crusts as the most likely deep ocean mining development by 2010, but seafloor massive sulphides of copper/gold/zinc offer an alternative bet for a start-up by 2010. A study of the ?form guide? or comparison of these resources provides direction on which resources are economic candidates for commercial deep ocean mining development by 2010. This paper covers the commercial and technical issues of exploration, resource definition, drilling/sampling, sea bed mining options, mine plans, environmental issues, legal tenure and capital and operating costs (i.e., profitability) of these two mineral types. Nautilus Minerals has just completed a pre-feasibility engineering study of mining sea floor massive copper/gold/zinc sulphides at 2,000 m depth. The Nautilus study reviewed a range of mining and lifting options, settling on tracked continuous drum cutter miners to produce 2 million tons per annum of high grade ore. Capital costs are shown to be at least 30% lower than a land based copper mine of the same production capacity. Likewise 75% of world?s copper would be produced at a higher operating cost that the proposed seafloor mine. This paper then draws on the Nautilus study for comparison with earlier feasibility studies by others on manganese nodule mining to predict the likely directions in deep ocean mining to 2010.

Jan 1, 2004

By Steven D. Scott

Stephen D. Scott Steven Scott is a Professor of Geology, Director of the Marine Geology Research Laboratory and, until May 1997, was Chairman for 9 years of Geological and Mining Engineering, all at the University of Toronto. Steve also holds a cross appointment at the University of Western Brittany's European University Institute of the Sea in Brest, France. He was educated at the University of Western Ontario (B.Sc. and M.Sc.) and at Penn State (Ph.D.). Steve is a geologist/oceanographer specializing in base and precious metal massive sulfide deposits which he and his students have studied on five continents and on the bottom of three oceans. He was the first ore deposits geologist and first Canadian to witness "black smokers" on the ocean floor. Since 1982, he has participated on 21 oceanographic surface and submersible expeditions, many of them as Chief Scientist. His research team is currently carrying out projects in the W and NE Pacific Ocean. Steve has published more than 150 research papers and lectured in more than a dozen counties. Popularized accounts of his work have appeared in various media.. He has been honored by several awards and distinguished lectureships. Steve is President of the Canadian Scientific Submersible Facility, which operates the Canadian ROPOS robotic submersible, and is President of the International Marine Minerals Society.

Jan 1, 1998

By R. W. Nesbitt

The TAG and Broken Spur hydrothermal mounds are located on the Mid Atlantic Ridge (MAR) at 260N and 290N (respectively). Both were initially discovered by exploratory work from surface vessels and both have since been investigated by submersibles. The discovery of TAG resulted from a NOAA Trans-Atlantic Geotraverse (Rona et al. 1975) which fortuitously sampled low temperature materials on the east wall of the MAR rift valley and follow up operations (Rona et al. 1986) located the high temperature (365°C) mound some 5km to the west. In 1994, ODP deep sea drilling (Leg 158) at over 3,500 metres of water recovered core to a depth of 150 m below surface (Herzig et al. 1998) and for the first time allowed a geological interpretation of an active mound. The Broken Spur mound was accidentally discovered in 1993 when sulphide fragments were observed on a deep-sea towed camera system (Murton 1993). Later that year, exploratory submersible dives by Alvin located the hydrothermal field and the area was again explored by submersible in 1994 and 1997. Despite the amount of work carried out, our geological understanding of the MAR mounds is limited. Much effort has gone into measuring fluid chemistry whilst practical difficulties have inhibited good geological mapping of the sulphide areas. It is clear from both TAG and Broken Spur that the mounds are not necessarily located in the areas of highest heat potential. Indeed, TAG is some 2 km from the rift valley axis and has been operational for several tens of thousands of years. Hence, heat availability is not a major consideration and the most obvious control is a structural one. Mapping on Broken Spur indicates a series of isolated vent-sulphide areas, concentrated around a minor graben. Their distribution, size and nature all indicate that they are residual parts of a much larger sulphide body which was at least the size of the present TAG field. The evidence is for a cyclical pattern of mound growth -mass wasting? rejuvenation and the Broken Spur mound appears to be in the rejuvenation stage of the cycle. Mound cyclicity must be related to the supply of hot water which itself is a function of the connectivity of fracture systems. Hence, we return to the theme that the major controls in mound development are structural ones.

Jan 1, 1998

By Ian Selby

Resource management is a key factor in the operation of a successful marine aggregates business; it is integral to the development of sustainability, satisfying increasing commercial, quality, and environmental performance standards. Resource management is based on the combination of; (i) a thorough evaluation and understanding of the resources on the sea bed and (ii) a dredging plan targeted to permit the effective and efficient extraction of the resources whilst mitigating impacts and leaving the sea bed ready for recolonisation.

Jan 1, 2004

By Teruyoshi Narita

In Japan, the Ministry of Economy, Trade and Industry (METI) commenced a research and development (R&D) project on seafloor massive sulphides (SMS) in Japan?s exclusive economic zone (EEZ) in the 2008 fiscal year. In this plan, the road map of Resource evaluation, environmental impact study, mining system technology and processing technology fields consisting of the first and second stage has been shown for the commercialization of SMS. Based on this road map, Japan Oil, Gas and Metals

Sep 14, 2011

By Alexander Malahoff

Accumulation of cobalt -rich ferromanganese crusts on Pacific seamounts located off-ridge in the Hawaiian EEZ, represents a complex process that involves geologic aging of the seamounts, geographic transportation- of the seamounts on the Pacific plate during the past 80 million years, and geochemical history of the oceans for that period. A comparative study of the building and erosion processes of the young Loihi Submarine Volcano, located south of the Island of Hawaii , and the 80 million year old Cross Seamount, located west of Hawaii , shows that both edifices show wide armchair-shaped talus chutes and intervening ridges of exposed dikes. The similarity between the observed mass wasting process on Loihi and Cross suggests that the slopes of submarine volcanoes are geologically unstable from the time of their origin on the seafloor through their entire geological history. The slopes of Cross are covered by coalesced ferromanganese crust covered talus, steep exposed dike faces, and crust covered dike ridges. A study of the stratigraphy of the crusts shows a range of thicknesses and number of unconformities present. The thickest crusts, up to 8 centimeters, are found preserved within the larger coalesced slabs along the shallower slopes of the talus chutes and along the crests of the ridges between water depths of 400 and 1800 meters. The platinum content was used in stratigraphic correlation between the crusts in the coalesced slabs and those collected from ridges with the PISCES V submersible. In the samples studied, the highest platinum content of 0.7 ppm

Jan 1, 1991

By Tetsuo Yamazaki

Natural methane hydrate has been scientifically studied as a global carbon reservoir. However, in Japan, it?s potential as an energy resource has been industrially highlighted, because there are few domestic oil and natural gas resources in Japan, but many potential deposition areas for methane hydrate in the sea around Japan. Less CO2 discharge from methane compared with coal, oil and conventional natural gas for the same calorie value is considered an advantage for its use as an energy resource. Because methane hydrate is distributed at shallow depth in sediments on the ocean floor, accidental leakage of methane may occur while we utilize methane hydrate. Methane itself has a considerable impact on the greenhouse effect, if it reaches the atmosphere. Therefore, it is necessary to estimate its behavior in the environment after leakage if we want to use methane hydrate as energy resource. The mass balance after leakage of methane on the seafloor and in the water column can be studied through the analyses of natural cold seepages and hydrothermal activity.

Jan 1, 2004

By S. Rajendran

Much advance has been made in offshore hydrocarbon exploration and exploitation in India. But the same amount of success could not be achieved in the case of other offshore minerals which are amenable for mining. However, employing present technology, there should not be any difficulty in successful exploitation with minimum environmental hazards. A demonstration is provided by considering the conditions prevailing in the Kerala offshore (southwest coast of India) scenario of monazite, ilmenite, phosphatic mud and calcareous deposits. Mud banks are unique phenomenon of the Kerala coast during monsoon season. Acting as barriers to waves, mud banks protect portions of the beaches from being eroded and trap sediments from either side facilitating growth of adjacent beach. The easy minable possibilities of the phosphatic mud during non-monsoon season with less pollution hazards and dumping back the waste material after processing for phosphate at the breaker zones to reduce the erosional effects on the coast make the exploitation economic and ecofriendly unlike the benefication of the lowgrade phosphate ores on land on a comparatively larger area and subsequent crushing, transport and resulting pollution.

Jan 1, 1993

By Stewart B. Nelson

With the pending U.S. ratification of the United Nations Convention on the Law of the Sea (UNCLOS), the subject was raised as to the Convention's potential impact on U.S. ocean science. The Ocean Studies Board (National Academy of Sciences) elected to convene a two-day workshop in October 1995 to consider the potential impacts and to determine whether or not they warranted a more formal and intensive study. A review of the workshop discussions and deliberations concerning the matter of UNCLOS and U.S. ocean science will be presented.

Jan 1, 1996

By Brenda J. Burd

A very extensive spatial and temporal database on benthic infauna and associated sediment metals has been collected for Island Copper Mine on Vancouver Island, B.C. Canada from 1969 (pre-discharge) to 1998 (3 years post-discharge). The tailings deposited as organically impoverished, copper-rich, clays, silts and sands distributed according to particle size, bottom turbidity currents and strong, vertically mixed tidal currents. In addition, a large deposition of coarser waste rock along the north shore of Rupert Inlet contributed substantial material in the shallower, near-field area.

Jan 1, 2001

By Alan Foley

The Portable Remote Operated Drill was developed in Sydney, Australia in the 1990’s. The device is a platform for many in-situ seabed sampling and coring tasks. The range of tools developed for use in PROD’s magazine now includes gas detectors, vane testers, penetrometers and corers. This paper presents aspects of the soils testing undertaken in deepwater since 2005, focusing on testing of methane hydrates and reefal accumulations. The varied selection of tools carried in PROD’s magazines allow the unit to perform several functions from the seafloor in one deployment.

Sep 24, 2006

By D. Cronan

Both the S.W. Pacific and Caribbean island arcs are host to submarine hydrothermal mineral deposits, the former more so than the latter. In the S.W. Pacific, the whole gamut of such deposits occurs on the sea floor, sulphides, silicates, Fe and Mn oxides, whereas during the limited studies to date in the Caribbean only hydrothermal Mn oxides have been found to occur on the sea floor there in any abundance. Comparisons between the respective Mn oxides are thus the most fruitful at the present limited stage of our knowledge of Caribbean submarine hydrothermalism. Southwest Pacific hydrothermal ferromanganese oxides and their possible relationships to underlying sulphide mineralisation or bedrock anomalies (the geochemical window concept) has been a fruitful field of research in recent years. Certain element enrichments in crusts may be indicative of underlying mineralisation (Rogers et al. 2001). However, more recent studies on buried hydrothermal crusts in the S.W. Pacific (Cronan et al. 2002) have shown there to have been postdepositional diagenetic uptake of elements in them, and thus these elements cannot be used with any confidence in geochemical exploration for buried sulphide deposits unless sediment involvement can be eliminated.

Jan 1, 2002

By Campbell McKenzie

Substantial consideration has been given to the implications that the morphology of the Chatham Rise deposit will have on mining operations. The glacio-tectonic processes involved in the distribution of nodules on the rise has in several areas been quite significant. The recent cruises by Chatham Rock Phosphate Limited (CRPL) have collected data which has affirmed the assumptions previously made and catered for in historic resource estimations. The deformation and displacement of the phosphorite during glacial periods and the redistribution of the mobile sand during interglacial periods is interpreted to have produced a highly variable pattern of phosphorite concentration (kg phosphorite/m2) and coverage (% phosphorite/sample weight). The phosphorite resource probably has a significant spatial variability at a scale of tens of metres. Results of recent surveys show phosphorite-rich patches alternating with phosphorite-poor areas at distances of less than 20 m. The high spatial variability of the deposit has had a bearing on how historical information for the project has been regarded and integrated with the recent exploration approach and data collection process. This coupled with the proposed extraction tool has influenced the size, nature, extent and siting of the proposed mining blocks

Sep 14, 2011

By J. M. (Mac) Beggs

With New Zealand?s ratification of the United Nations Convention on the Law of the Sea in 1996, the government of the day increased work on developing an oceans strategy to help create a governance framework for the country?s extensive existing and potential maritime territories. This project took a new direction in 2001 with the establishment of an ad hoc committee of 6 Ministers, and their appointment of a Ministerial Advisory Committee (on which the senior author served) to consult with the public, identify widely held values and inform the development of a Vision for subsequent policy development. The current second stage of the policy development process involves a working group of officials from the relevant agencies completing a stock-take of existing laws and regulations to identify overlaps and gaps that should be addressed in the third and final stage. The public consultation process revealed, as might be expected, a wide range of perspectives but a solid consensus in favour of a coherent, and balanced, framework to enable the realization of economic benefits of ocean development so long as appropriate environmental standards (broadly expressed in terms of sustainability) are not compromised.

Jan 1, 2002

By Nobuyuki Okamoto

Ferromanganese crusts on the seamounts in the Pacific Ocean are potential resources of cobalt, nickel, platinum and REEs. Particularly, those of the Republic of Marshall Islands and the Federated States of Micronesia (FSM) waters are believed to be of the highest resources potential area in the Pacific Ocean. The total six cruises using the Japanese Research Vessel Hakurei Maru No. 2 were carried out in the seamounts of the Marshall Islands in 1996, 1998 and 2002, and of the FSM in the 1997, 1998 and 2005 for evaluation of economic potential for cobalt-rich ferromanganese crusts as part of the Japan-SOPAC joint project. During these cruises numerous data such as bathymetric, geological, geophysical and environmental data were obtained. Geophysical exploration with backscatter mapping and side scan sonar, visual imaging using towed TV camera and geological sampling using dredge bucket and/or benthic multi-coring system (BMS) were conducted on these seamounts. In this presentation, we will report the mode of distribution of the crusts and calculated resource estimation based on the results of these geological and geophysical shipboard survey and land-based analyses. Keywords: ferromanganese crusts, Marshall Islands, Micronesia, resource potential

Jan 1, 2011

By Ian B. Corbett

De Beers Marine Pty Ltd. (South Africa) (DEBMARINE), a wholly owned subsidiary of De Beers Consolidated Mines Ltd. specializes in the provision of contracting and consulting services for offshore diamond exploration, Mineral Resource Management and mining. Established in 1983, the company is strongly focused on driving and sustaining growth of the offshore diamond mining industry into the 21st century. DEBMARINE provides full Mineral Resource Management and produce almost half a million carats annually for the Namibian Diamond Corporation (Pty) Ltd. from their offshore mining licence. The company is also extensively involved in feasibility studies to establish new mining ventures and in the exploration of several offshore Prospecting Licence Areas for other clients. As a pioneer in this field, DEBMARINE remains highly focused on technological development. A specialized section, the Technical Development Business Unit, has been established. Through relationships with various technology leaders, this unit develops new sub-sea mining technology and delivers productivity innovations aimed at realizing maximized carat extraction. This talk provides a broad perspective on the development of the Namibian offshore deposits and examines the critical role played by high-resolution orebody characterization and high-confidence Mineral Resource development at De Beers Marine.

Jan 1, 1998

By Felix Lehnen, Peter Kukla, Mirjam Rahn

"Significant uncertainty is associated with predicting future trends in deep-sea mining projects, especially when attempting to assess markets for associated products such as ships and collectors. In order to help European Original Equipment Manufacturers (OEMs) to appraise the future market share of deep-sea mining equipment, a methodology was developed that allows to assess and predict equipment turnover. This study presents a market analysis, which evaluates the scale of the potential market for deep-sea mining equipment for seafloor manganese nodules (SMnN) and seafloor massive sulfides (SMS) based on six key drivers: (i) the worldwide deposit potential of SMnN and SMS deposits, (ii) the profitability of deep-sea mining projects, (iii) the metal market of seven associated metals (Cu, Zn, Au, Ag, Co, Ni, Mn), (iv) the current legal and environmental situation in the Area, (v) investment and maintenance costs, and (vi) a competitor analysis.Figures for the different key drivers are based on public reports and expert interviews. Large uncertainties as well as contrasting views and expectations resulted in different options (scenarios) for the future development of the deep-sea mining market. Several scenarios were developed and based on the future number of “mining projects” in the short-term (2022-2041) and the long-term (2042-2061). The number of such mining projects has been calculated based on the combined analysis of the different key drivers.In the scope of this study, the definition of a “mining project” is a deep-sea mining operation for SMnN or SMS lasting for 20 years. This operation includes the purchase of a set of deep-sea mining equipment consisting of a mining support vessel, a vertical transport system and the seafloor mining equipment, in line with other work within the EU FP7 project “Blue Mining” (GA No. 604500)."

Jan 1, 2017

By W. D. Siapno

Marine mineral resources have been reviewed in great detail on numerous occasions over the past few years. A summary of these efforts would indicate there is little new on the horizon as far as economic programs are concerned. Deep ocean minerals, though not forgotten, hold little promise for development in the immediate future, i. e., manganese nodules, cobalt crusts, polymetallic sulfides, etc. Nearer to shore, within the EEZ, and particularly within waters under state control greater industrial interest is expressed. Interest in sand and gravel not only persists but is growing, dependent largely upon the construction industry. Precious metals demonstrate the greatest growth potential.

Jan 1, 1988