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In the western Woodlark Basin, propagation of seafloor spreading is occurring directly into the continental crust of Papua new Guinea. The spreading is not strictly in a back-arc tectonic setting, rather it appears associated with microplate rotations related to the complex convergence of the Indo-Australian and Pacific plates in the southeastern Pacific region. Volcanic rocks along the western Woodlark spreading axis range from normal mid- ocean ridge basalts to basaltic andesites with back-arc geochemical affinities. Rare peralkaline rhyolites also occur. Hydrothermal deposits occur at a basaltic andesite volcano located on the neovolcanic zone near its westernmost propagating tip. Franklin Seamount is a 250m-high cone constructed largely of pillow lavas and talus which sits astride a 450m-high ridge of similar lavas oriented subnormal to the spreading direction. At its crest, 2150m below sea level, there is a 100m-deep caldera.

Jan 1, 1993

By Chul H. Jo

The functions of miner mainly include the pick-up manganese nodules laying on the surface of the seafloor, the separation them from sediments, the crushing the nodules and the covey to the inlet of the flexible hose. The miner is connected with umbilical cable that can supply power, instrument signal, communication data, etc. The major concerns of the system is to monitor and control the launching and retrieval operation, the landing, maneuvering and track keeping, to monitor the pick-up operation and to monitor the hydraulic system. Also as per the seafloor profile the track and pick-up processes need to be controlled. The recent research and development of deep sea miner is mainly focused on the efficient performance and workability in deep water. To communicate and control the miner, navigation and positioning system have been applied. As the miner is being deployed or retrieved, it is very critical to avoid any damage to the device that would be caused by the dynamic behavior of surface vessel or the minor itself with wave and current motion. The fast deployment and retrieve should be considered very important to minimize the possible damage. The paper introduces the various type of deployment devices and recommend the possible system to the miner developed by KRISO.

Jan 1, 2003

By Fredrik Søreide

Several potential marine mineral deposits of various types have been identified within the Norwegian EEZ. The Norwegian University of Science and Technology has recently designed and built a new remotely operated vehicle (ROV) system for scientific investigations of the deep-ocean and seafloor. A program to locate and investigate the most interesting of the identified marine mineral deposits using the new ROV system is underway. The ROV has been designed for detailed survey and sampling tasks. Although initially built for a major marine archaeology project, the design is equally suited to locate and investigate marine mineral deposits. The ROV is equipped with a high precision multi-sensory package that consists of various high quality cameras and lighting systems (together with state-of-the-art video and photo mosaic systems), several sonar systems, magnetometer and various other sensors. The ROV is also equipped with a 7-function manipulator arm and an excavation system. Internal collection baskets are used to store material for retrieval to the surface. A closed-loop control dynamic positioning system is used for detailed positioning of the ROV. Position data and other information are stored in a digital data management system. The ROV will also be used together with a specially developed remotely operated tool (ROT). The size and shape of this benthic lander can be adjusted before it is carefully lowered to the seafloor. The ROV can be docked on a moving platform on the ROT, to do detailed scientific investigations. The ROT can also be equipped with a separate sensor and system package, including drilling, excavation and coring units. This paper will present the new remotely operated system and the planned projects in Norway.

Jan 1, 2004

By Terence Day

The traditional approach to mineral resource development is to identify the resource and then to undertake an environmental impact assessment of the effects of developing the resource. However, the traditional approach tends to ignore or underestimate cumulative, indirect and synergistic effects (Therivel et al., 1992). Moreover, traditional environmental impact assessment puts the project proponent in a position where the environmental impact assessment is used to defend on environmental grounds, a decision which has already been taken on technical and economic grounds. An alternative approach is to undertake an area-wide or strategic environmental assessment, (United States Department of Housing and Urban Development, 1981; Kelly et al., 1987). Strategic environmental assessment consists of the compilation and analysis of environmental data and information on an area. The data and information includes physical and chemical oceanographic data, biological surveys, social and economic parameters such as recreation and resource use, and ecosystem stressors such as dumping areas and sewage outfalls. Strategic environmental assessment is being increasingly used in the U.S. to provide scientific information to evaluate national or regional objectives for development and conservation of coastal and oceanic resources (National Oceanic and Atmospheric Administration, 1991). The strategic environmental assessment process lends itself very well to an evaluation of offshore sand and gravel re- sources in Atlantic Canada, because although the potential resource is widespread, the environmental constraints on development are potentially serious, but highly variable. The approach has the merits of identifying areas which are least susceptible to environmental damage, and of concentrating the exploration efforts on that part of the resource which is most viable from the perspective of integrated resource management and marine conservation.

Jan 1, 1995

By Chan Min Yoo, Jung-Keuk Kang, Wonnyon Kim

Recently high-resolution paleomagnetic age determination of ferromanganese crust in less than millimeter scale has been successfully carried out using a superconducting quantum interference device microscopy magnetometer (SMM). However, it has not been clearly identified how the crust is keeping ancient geomagnetic field records. Here we try to identify magnetic mineralogy of the crust obtained in the Magellan Seamounts, the West Pacific (~20 °N). As a record, age of the crust used in this study is extended to ~10 Ma at ~40 mm depth and ~28 Ma at ~100 mm depth, respectively, based on the combination approach of SMM measurements, Be-isotope and Co-chronology. Thermal demagnetization revealed a Curie temperature of ~560oC, corresponding to (titano)magnetite. Component analysis of isothermal remanent magnetization identified a presence of two types of magnetite. Measurements of first order reverse curve showed a dominance of non-interacting single-domain magnetite, which is one of the intrinsic feature of biogenic magnetite. Although most of the magnetic particles on transmitted electron microscopy are covered by amorphous Fe-Mn minerals, some are observed as a prototype of biogenic magnetite showing a chain of ~10 nm sized magnetite cubes. However, a magnetite signal (i.e., Verway transition at ~ –120 oC) was not detected in low-temperature treatment probably due to surface oxidation of magnetite. Contribution of interacting magnetite of detrital origin is <30% throughout a crust. Interestingly, contribution of detrital magnetite is almost three times higher since ~10 Ma. At this boundary, a growth rate of the crust is double up and flux of other detrital signals, including Al, Mg, Ti and Zr, are also increased.

Jan 1, 2017

By Tetsuo Yamazaki

The importance of cobalt-rich manganese crusts on the Pacific seamounts for possible future rare metal sources has currently been recognized. The thin layer-type deposit characteristics affect not only the excavation efficiency but also the economy of mining venture. Considering the thin layer-type distribution and the utilization of some rare metals in cobalt-rich manganese crusts, a preliminary economic feasibility of the mining venture is evaluated. Under some preliminary technical assumptions, the possibility of cobalt-rich manganese crusts for future rare metal sources for Japan is examined. The important role of utilization of rare metals in the crusts is highlighted.

Jan 1, 2010

By Chris Castle

The Chatham Rise is a submarine topographic feature lying off the east coast of New Zealand between the South Island and the Chatham Islands and within New Zealand?s jurisdiction. The Chatham Rise hosts economically significant deposits of rock phosphate and other potentially valuable minerals. The deposits comprise nodules lying on, or just below the surface of the seabed in shallow waters. Rock phosphate is an essential ingredient of fertilizer and can be applied directly to pasture. There is a realistic opportunity the phosphate deposits could supply New Zealand?s agricultural requirements for an estimated 30-year period at current rates of consumption.

Jan 1, 2011

By Tobias Hens, Andrew Frierdich, Joël Brugger

The rapid advancement of green technologies in recent years is closely tied to an ever- increasing demand for raw materials. Innovative forms of zero-emission transportation and sustainable power generation will require a variety of traditional metals such as Ni and Co, but also many non-traditional metals (e.g., REY). Many of these elements are known to be highly enriched in deep-sea ferromanganese (Fe-Mn) nodules and crusts. However, unlocking these metals from their deposits through metal processing is – aside from deposit exploration and production – expected to be a critical component that will affect the overall economics of the marine mining value chain. Hence, research and development of tailored metal processing solutions which can target specific metals of interest in Fe-Mn nodules and crusts, is required. Dynamic mineral recrystallization (DMR) of Fe-Mn oxide phases is a geochemical process that may have notable potential for hydrometallurgical applications. We have recently demonstrated that Ni can effectively be cycled between deep-sea Fe-Mn nodules and crusts and solutions through dynamic mineral recrystallization. DMR occurs in nature as abiotic background process during biogeochemical Mn cycling when dissolved Mn(II) is in direct contact with Mn oxides. Trace metals which are incorporated in the Mn host phases, are cycled between solid phase and solution via coupled dissolution (trace metal release) – reprecipitation (trace metal incorporation) mechanisms.

Jan 1, 2018

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&apos;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 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 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

By Wenbin Ma, Cees van Rhee, Dingena Schott

Since the concept of deep sea mining (DSM) was proposed by J. L. Mero with his book, The Mineral Resources of the Sea, in the 1960s, many research and significant developments have been implemented. However, its commercial mining process still has not yet commenced. One of the most important issues is that a sustainable DSM transport plan is difficult to determine, taking into consideration the DSM technological, economic, and environmental aspects simultaneously. The objective of this paper is to propose a method to determine the sustainable DSM transport plan utilizing a fuzzy analytic network process method, which is a typical multi-criteria decision making method (MCDM). The DSM transport plans evaluating major criteria consist of technological, economic, environmental, and social aspects with both qualitative and quantitative attributes. Different major criteria include several sub-criteria, respectively:  Technological aspect: energy consumption, proven technology, technology reliability, production rate, technology availability;  Economic aspect: gross income, capital cost, operation and maintenance cost, investment recovery period;  Environmental aspect: species disturbance variance, severity of ill effect, turbidity of ocean water, total organic carbon content, sedimentation thickness;  Social aspect: social acceptability, policy support; The weights for all evaluating criteria and sub-criteria are determined through a questionnaire survey interviewing experts at different research fields. All the transport plan candidates are ranked based on a comprehensive index. The conducted research in this paper is meaningful to promote the DSM commercialization process.

Jan 1, 2018

By B. Prause

Ferromanganese crust samples collected from Central Pacific sea-mount areas became of special interest after surprisingly high nobel metal contents have been analyzed. Hydrogenetic crust growth is controlled by the conditions of the oceanic water column. Thicker encrustations show two crust generations of different age ranges. The mean values of the chemical composition state that the older generation is richer in P, Ca, Ni, Cu, Zn, and Pt and depleted in Fe, Ti, Co, Al, and Si. The differences apparently indicate a distinct change of the geochemical environment. The Pt concentrations vary up to 1800 ppb and do not clearly correlate to one of the other metals. This might indicate a bond of multiple nature. Several mechanisms have been proposed to explain the Pt concentrations in ferromanganese samples. Our models consider seawater and cosmic spherules as responsible Pt sources. In seawater the main species of dissolved Pt probably exist as the doubly negatively charged tetrachloro-complex. A precipitation of Pt in seawater may take place if the chloro-complex is decomposed by reduction of pt2+ to pt0. On the other hand, the Mn02 precipitation is caused by an oxidation of Mn2+ which is supplied from the oxygen-minimum zone. The large activation energy needed for the oxidation of divalent ~n" in solution has been recognised, and the resulting slowness in the formation of Mn(V1)-oxihydrate sug

Jan 1, 1989

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 David Gwyther

There is increasing recognition that in order for a development project to proceed successfully, it must first obtain a ?social licence to operate? from concerned stakeholders. Obtaining this ?licence? is in many ways a separate process to the legal one which involves, among other things, submitting an environmental and social impact assessment (ESIA) to the appropriate regulatory authority for review. Essentially, the function of an ESIA is to present a project?s technical, financial and social benefits, together with its environmental and social impacts in a transparent way to enable regulators to make an informed decision about whether the benefits outweigh the impacts, and thus whether or not the proposed project should proceed. The focus in the early days of ESIAs was primarily technical and was aimed to answer two fundamental questions: ?Can the project be built?? and ?Can we minimise impacts to a level that is acceptable to the community?? Basically, the ESIA process was a technical test of competence, but more recently, ESIAs have become much more than this. The main ESIA risk is now more akin to a test of a project?s legitimacy ? i.e., with more weight placed on the social licence, or the political test of moral authority ? with the process involving stakeholders from multiple backgrounds and disciplines, including some anti-development NGOs/civil society groups with their views on mining, (particularly in developing nations), often already pre-determined. Within the backdrop of this potential maelstrom, now enter a proposal for a new industry (such as deep sea mineral extraction).

Jan 1, 2011

By N. J. Poll

The Zacarias gold-silver-barite deposit appears to be a Precambrian analogue of present-day exhalative deposits on the sea floor. Geochemical, stratigraphic and structural studies of the latter can be useful in elucidating the ore environment at Zacarias, thereby assisting exploration. The Zacarias mine is about 300 km north of Brasilia, within the Goiás Massif, Brazil. It is the southernmost of three auriferous quartzite occurrences along 1 km of a northeasterly striking amphibolite. Zacarias and its neighboring smaller deposit to the north, the Central Pit, contained a premining ore reserve of 650,000 tons at 4.4 g/t gold, 48 g/t silver, and about 20% barite. Gold mineralization is hosted by concordant quartzite strata also containing layered barite, pyrite, barium-mica, sphalerite, galena, chalcopyrite, magnetite, sulfosalts, free gold, and electrum. The host amphibolite is intercalated with barren mica-quartz-chlorite-pyrite schists that are more voluminous in the footwall and are associated with the ore horizons. Above the amphibolite in the hangingwall lies a thin graphitic shale, then a feldspathic arenite. The strata and regional foliation strike northeast and dip 42° northwest. Crenulation and small-scale folds plunge 30 to 40° to the west.

Jan 1, 1993

By John W. Padan

The 1982 United Nations Convention on the Law of the Sea contains major provisions that U.S. negotiators have sought for over two decades. The internationally recognized right to the mineral resources of a broad continental margin is of potentially enormous future importance to the United States. Although water depths reach 10,000 feet in some of the deeper areas of the margin, technology is rapidly making those depths economically accessible. In 1997, production in the Gulf of Mexico will reach a world record water depth of 5400 feet. Of perhaps even greater importance to the oil and gas industry is the broadly acknowledged right for tanker transport of oil to take place throughout all parts of the world&apos;s oceans.

Jan 1, 1996

By Jan Stenlokk

The Norwegian Petroleum Directorate, which is the Government agency for the management of offshore geo-resources including seabed minerals, is about to finish this year’s marine data acquisition cruise in the Norwegian Sea. We would very much like to present the preliminary results of that cruise, including the discovery of a new black smoker and surrounding sulphide deposits.

Jan 1, 2018

By Du Gon Lee

This study presents a model to predict fate of resuspended sediment in the development of deep-sea mineral resources including manganese nodules under Clarion-Clipperton area of the Pacific Ocean. The manganese nodules are expected to be developed near future and major research is undergoing in Korea recently concerning many aspects of the mineral resources development. One aspect is about environmental concern related to the deep-sea development, and a major environmental problem is the resuspended deep-sea sediment. In order to quantitatively analyze the resuspended sediment in the water column during the deep-sea development, particle size distribution (PSD) was considered an important factor in this research. The model developed here includes PSD and coagulation process, as well as sedimentation process. The model is one dimensional in the vertical profile, and was designed to describe the change of particle size distribution in the water column in the given vertical point. Based on the mathematical modeling, a numerical model was developed. Using the model, basic simulation was performed under representative environmental setting of the deep-sea environment. The simulation showed the dynamics of change of particle size distribution for 50 m depth of water column from the deep-sea bed, up to 10 days of simulation time. The simulation results indicate that coagulation seemed an important factor in the fate of resuspended deep-sea sediment. As a result, this research shows that the particle size distribution approach, as well as considering the coagulation process, is needed and may be effectively applied to environmental impact analysis of deep-sea resuspended sediment. Key Word: Deep-sea Mineral Resources, Resuspended Sediment, Environmental Impact, Particle Size Distribution, Coagulation, Modeling and Simulation

Jan 1, 2003

By Carl H. Hobbs

The marine mineral resources of the U.S. middle and south Atlantic shelf are little utilized. The largest resource, sand and gravel, is used for beach nourishment and protection and, to a much lesser degree, as construction aggregate. The potential for increased utilization is great. Submarine deposits of shell have been mined for lime and for use in the oyster industry. Although significant quantities of manganese nodules and crusts are present on the Blake Plateau, exploitation in the foreseeable future is unlikely. Similarly, major phosphorite deposits in North Carolina&apos;s inner shelf probably will remain unexploited as long as onshore deposits remain available. Placer deposits of heavy-mineral sands, especially the titanium minerals, offer the possibility of exploitation. This possibility might be enhanced by consideration of joint development of sand or aggregate with heavy minerals.

Jan 1, 1992