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By Tim J. Boyd

Gregg Marine, Inc. (headquartered in Signal Hill, California) has recently introduced an innovative seafloor drill system for offshore geotechnical site investigation and seafloor mineral exploration. The system is capable of working in water depths of up to 3,000 meters and is rated to drill to a depth of approximately 150 meters below mudline. The remote operated system integrates established drilling technology with proven Schilling telemetry and controls. The flexible nature of the patented wireline drilling technology enables the use of standard sampling systems (up to PQ-size core and 3? thin-walled tubes) as well as downhole testing systems (including CPT testing, vane shear testing, downhole sensors and borehole geophysical tools). The modular nature of the seabed drill system and the accompanying launch and recovery system (LARS) enables the use of local vessels of opportunity for projects resulting in reduced project costs and improved mobilization responsiveness times. Keywords: seafloor, seabed, geotechnical, drill, drilling, core, coring, sampling, CPT, cone penetration testing, borehole, logging, survey, exploration, ROV, remote sensing

Jan 1, 2011

By Yannick C. Beaudoin

Southern Explorer Ridge (SER) is an anomalously shallow, intermediate-rate spreading ridge located 200 kilometers off the west coast of Vancouver Island, Canada. It ranges in depth between 2600 m (deepest basins) and 1760 m (bathymetric minimum). At least 60 sulfide deposits are known to be associated with hydrothermal vent fields along the ridge. For the first time geological data, including deposit locations, collected from 15 marine expeditions to SER since 1983 have been assembled in a GIS format. GIS processing techniques were employed to plot the distribution of base metal concentrations for recovered sulfide samples. The highest base metal concentrations are found in the vicinity of the Magic Mountain site (main active vent field), and also proximal to a side scan sonar anomaly referred to as AGOR 171. Individual samples near these locations have yielded values as high as 29.3 wt\% Cu, 34.3 wt\% zinc, 0.97 wt\% Pb, 2.0 ppm gold, and 664 ppm silver. Sample paucity is the key limiting factor that prevents adequate assessment of the areas economic potential.

Jan 1, 2001

By Richard Harrison, Frank Lim

Deepsea Mining will soon become a reality with Nautilus Minerals getting their equipment ready to mine SMS at Solwara 1 off the coast of Papua New Guinea. The vertical transport system (VTS) adopted by Nautilus consists of a riser hanging ‘freely’ from the mining production vessel with a lifting pump unit suspended at its lower end. A compliant jumper connects the pump to the seabed crawler without restraining its movements. In this free-hanging VTS arrangement, the vessel can be re-positioned to follow the crawler should it want to extend the mining area and start stretching the jumper. A recently proposed alternative to this is a free-standing VTS whereby the riser is grounded on the seabed with a base and maintained in an upright position by distributed buoyancy modules or a buoyancy tank at the top. A compliant jumper connects the seabed crawler to the riser base, and another connects the riser top to the vessel. In this free-standing arrangement, the entire VTS can be lifted clear of the seabed for relocation to a new mining area. This paper will describe the important features of the two options and discuss the advantages and disadvantages in respect of riser dynamic behavior, water depth, weather and mining windows, pump maintenance, installation and retrieval, continency measures, etc. The two systems will also be appraised separately for mining SMS and SMnN deposits.

Jan 1, 2018

By M. Geoghegan

Under the provisions of the U.N. Law of the Sea Convention Ireland is likely to have mineral rights to an area of continental shelf some six times its present land area. Apart from the major potential hydrocarbon basins which are currently the focus of active commercial exploration, little is known about the mineral resources of this vast area. In recent years a variety of mineral resources however have been identified from the coastal region. These include Sand and Gravel aggregates, Calcaraeous Algae (Lithothamnion), Heavy Mineral Sands and Coal deposits. The potential also exists in the coastal zone for buried placer deposits and base metal deposits. Several million cubic metres of gravel and hundreds of millions of cubic metres of sand have been identified by the Geological Survey of Irelands (G.S.I) Marine Unit off the east coast. The greater part of these deposits lies within the 10 metre depth contour and are easily recoverable. Irish aggregate needs at present are well supplied by onshore Pleistocene glacial deposits. Commercial interest in offshore deposits is in supplying coastal areas which are locally poor in aggregate and major coastal construction works. The possibility of supplying the large British and Continental European Market nearby also exists.

Jan 1, 1988

By Georgy Cherkashov, Livia Ermakova

Active development of the exploration and further exploitation of deep-sea minerals requires special emphasis on the protection of the marine environment. The complexity of this subject lies in the fact that potential impact and effects of future mining activity are not completely known. One of the main sources of potential impact near the seafloor, as it expected, would be a generation of sediment plumes, their dispersion and redeposition of sediment. Meanwhile, their dimensions, rates of dispersion and redeposition are a big issue. Other plumes are expected in the surface layer as a result of discharges of processing waters and particles after sorting on board of mining vessel, and their features are also not clear. At the same time, understanding of these aspects would be crucial for definition of environment impact area, delineation and designation of different types of protected areas (Areas of Particular Environmental Interest, Impact and Preservation Reference Zones) and future assessment of environmental impacts. Attempts to address these issues demonstrated wide variations between the data of field experiments on the one hand and the results of analytical and numerical models on the other. According to in situ measurements, plumes were detected at a distance vary from one to less than 20 km [e.g., Burns et al., 1980; Sharma et al., 2001; Nautilus Minerals, 2008 etc.], whilst some models show results up to 100 km [Rolinski S. et al., 2001] and more. It seemed that results of in-situ experiments are preferable, but they were not many indeed. However, these data were used in different investigations rather widely, but their focus, as far as we know, was not on the matters related directly with plumes.

Jan 1, 2018

By Kurt Aasly, Przemyslaw B. Kowalczuk, Rolf Arne Kleiv

Seafloor massive sulphides (SMS) can serve as a potential resource of metals such as Cu, Zn, Au and Ag. SMS rock samples from the Loki’s Castle area at the Arctic Mid-Ocean Ridge are comprised of sulphide bearing minerals such as pyrite, chalcopyrite, isocubanite, galena, sphalerite, whereas the gangue consists mainly of barite and silica. Sphalerite, chalcopyrite and isocubanite show complex intergrowth textures on the nano- to microscale. Various mineral processing tests were conducted in order to recover copper, zinc and silver. It was shown that sensor-based sorting can be efficiently used for preconcentration of SMS rock samples. A significant amount of waste (i.e. barite and silica) was removed in the preconcentration stage with very low losses of copper and zinc to the waste fraction. The upgraded samples were sent to the next processing stages. The results showed that the complex mineralogy of the SMS material provided challenges to conventional mineral processing methods. Hydrometallurgical processing was applied as an alternative method for extraction of metals from SMS. Leaching experiments were conducted using solutions of different lixiviants, and it was shown that leaching of SMS together with manganese nodules would facilitate efficient recovery of metals from these resources.

Jan 1, 2018

By Sabrina Warwas, Thomas Kuhn

"Due to rising prices and increasing demand of raw materials over the last years, marine mineral resources including manganese nodules have become a focus of study for industry and science. Marine ferromanganese nodules consist of micro-layers of different chemical and mineralogical composition which incorporate metals of high economic interest (Ni, Cu, Co, Zn, Mo, Li, rare earth elements; Hein & Koschinsky, 2015).The varying composition of the layers depends on different growth processes, such as hydrogenetic (metal precipitation from the water column under oxic conditions; Mn/Fe = 3), diagenetic (metal precipitation from the sediment pore water) under oxic (Mn/Fe 3-10) or suboxic (Mn/Fe = 10) conditions; (Wegorzewski & Kuhn, 2014) or hydrothermal (metal precipitation from low-temperature hydrothermal fluids; Kuhn et al., 2003).METHODSIn this study, manganese nodules from three different locations of the Atlantic Ocean (Galicia Bank; Vema-Fracture-Zone and Brazilian Basin) were analyzed for their geochemical and mineralogical composition. Detailed information about the samples are given in table 1. The geochemical and mineralogical composition of bulk nodules were determined by XRF, ICP-MS/OES as well as XRD and the single micro-layers by high resolution analyses with electron microprobe and LA-ICP-MS."

Jan 1, 2017

By Robert M. Owen

The reconstruction of ocean history has been a major focus of marine research over the past decade. A significant outcome of these investigations is the recognition that certain types of marine mineral deposits are linked to regional to global scale changes in ocean composition and climate conditions. Manganese-bearing deposits are of particular interest in this regard because changes in their occurrence, distribution and/or composition are responsive to both biochemical and geological factors. Analyses of such deposits whose formation spans critical age/epoch boundaries thus provide clues concerning the interplay of different process during anomalous periods in Earth history. Recent studies demonstrating this deposit - event - process relationship include: (1) Changes in the bulk chemical composition of ferromanganese crusts during the Late Miocene-Early-Pliocene (-7-3 Ma) that coincide with a period of enhanced biological productivity in the eastern equatorial Pacific upwelling zone; (2) The formation of large statiform manganese deposits at the Cenornanian- Turonian Boundary (-92 Ma) in association with widespread oceanic anoxia; and (3) Increased deposition of hydrothermal precipitates caused by tectonic reorganizations at the Paleocene - Eocene boundary (-55 Ma) that resulted in global-scale changes in atmospheric and oceanic circulation and climate.

Jan 1, 1995

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 Georgy Cherkashov, Vladislav Kuznetsov

The presentation describes new data concerning the age of the Mid-Atlantic Ridge (MAR) hydrothermal fields. The collection of massive sulfides recovered from six hydrothermal fields has been dated using the 230Th/U method. The range of the data obtained is rather wide: from 2.2 up to 65.1 thousand years BP. Three stages of hydrothermal activity were detected for this 65 Kyr period of geological evolution: modern (0 -5), 20-25 and 58–65 thousand BP (Figure 1). This conclusion was confirmed by dating the associated metalliferous sediment layers which also indicate the hydrothermal events led to the formation of sulfide mineralization. There is a correlation between the age and size of massive sulfide deposits: older deposits are larger (Table 1). This and other applications of obtained data will be discussed in presentation.

Aug 24, 2006

By Yves Fouquet

Recent exploration demonstrates that hydrothermal systems related to upper mantle ultramafic outcrops are common in the modern ocean. Most sites are located on slow spreading ridges with a low magmatic budget. Volcanogenic Massive Sulfide (VMS) deposits, associated with basalt, along the Mid Atlantic Ridge (MAR) are volcanically controlled near the topographic highs at the center of the segments. Three preferential settings are identified for ultramafic sulfide mineralization: 1) Off axis, on rift valley walls, near the amagmatic ends of the segments; 2) Non-transform offsets and 3) Ultramafic dome structures at the ridge transform fault intersection. The upper surface of these domes is often interpreted as a detachment fault. Three processes are considered for driving hydrothermal cells in ultramafic rocks: 1) regional heat flow at the ridge axis 2) Cooling of a deep gabbroic intrusion and 3) exothermic heat produced during serpentinisation. Along the Mid Atlantic Ridge, four types of ultramafic hydrothermal mineralization are observed: 1) High temperature (>350°C) sulfide mineralization related to low pH fluids, (ex. The Logachev field at 14°45? N and the Rainbow field at 36°14 N); 2) Medium temperature carbonate chimneys (<100°C) related to high pH fluids (ex. The Lost City site at 30°N); 3) Low temperature diffuse venting associated with extremely high methane discharge and pervasive alteration and silicification of both volcanic and ultramafic rocks (ex : The Saldanha field at 36°34 N); 4) Stockwork mineralization and quartz veins with sulfides related to gabbroic intrusions within ultramafic rocks (15°N). When compared to mineralization in a basaltic environment, sulfide deposits are enriched in copper, zinc and specific elements related to an ultramafic rock source such as Ni and Co. They are also significantly enriched in gold which, unlike in basaltic environments, has a bimodal occurrence both in low temperature Zn-rich assemblages and in high temperature Cu-rich mineral assemblages. The Cu-Zn-Co-Au deposits along the Mid Atlantic Ridge seem to be more common than on land where few similar VMS deposits are known. We consider that ultramafic VMS deposits on slow spreading ridges constitute a specific marine type of mineralization that is less easily than back arc deposits, incorporated into the continent during obduction processes.

Jan 1, 2004

By J. R. Woolsey

The cost of an offshore exploration project is mainly dependent on the size of the vessel engaged for the work and increases dramatically with increasing size. Of the various factors influencing vessel size, the type and size of the sampling equipment is typically the principal consideration. This scenario is particularly true of shallow sampling programs employing a vibracore system. The problem develops when certain bottom materials such as densely packed fine sand require sampling. This type of material being one of the most difficult for the standard vibracore systems, with integral core liner, to penetrate to a reasonable depth of some five to seven meters. The problem is mainly related to the excessive cross sectional area of the cutting bit required to accommodate the core liner. The typical solution has been to apply more power to the vibracore drive head which results in a considerable scale-up for the entire system with attendant increase in vessel size. In order to reduce operating cost, M.M.R.I. has developed several systems for deployment from vessels in the 20 meter range. Two systems are modifications to the basic vibracore and a third is a vibralift system. Basically, one of the vibracore units is employed where core liners are required, utilizing a special jet bit designed to reduce the cutting pressure on the bit while not affecting the integrity of the core. The other designed for core extrusion on

Jan 1, 1986

By Tina Schneider

Scientists show that polymetallic nodules and massive sulfides from deep sea mining contain valuable metals. These metals have the potential to overcome future shortages of supply. Hence, companies, government agencies and industrial associations increasingly evaluate deep sea mining as a promising supplement of land mining. Technologies to extract, exploit, transport and smelt polymetallic nodules and massive sulfides industrially are still in conceptual stage and not sufficiently advanced for operation. According to the International Seabed Authority, large scale exploitation would require a successful pilot mining test in order to demonstrate e.g. the technological feasibility but also the conservation of environmental systems services. At the same time, NGO´s and a some scientists point out that large scale extraction of polymetallic nodules and massive sulfides could disturb the habitat of benthic organisms, with unknown long-term effects. Aside from the direct impacts of mining, indirect consequences about leakage are likely. In the oral presentation I will show how companies, government agencies, scientists and association/interest groups perceive and assess economical/technological, social and environmental risks and opportunities of deep sea mining. In order to analyze the perspectives of each stakeholder group on deep sea mining, we conducted 15 interviews with four stakeholder groups and a large scale survey (n = 500, return rate = 13 %) in Germany. We used the concept of sustainability with its economical/technological, ecological and social dimensions for the interpretation of the results. The empirical research shows the following core results:

Jan 1, 2018

By Hans Smit

Start here.

Jan 1, 2018

By Sander van Leeuwen

Outline: · De Regt Marine Cables. · The link between system requirements and umbilical requirements (which system requirements have the largest impact on the umbilical design). · Design options for deep sea mining umbilicals (showing the various options for strength member constructions, power conductors and data-transmission). · Technical challenges and risks (outline on the most important technical challenges and risks involved in the construction, production and usage of deep sea umbilicals). · Umbilicals for the SWORD and Blue Nodules project.

Jan 1, 2018

By Odyssey Marine Exploration

Odyssey is a world leader in marine exploration and has undertaken expeditions in varying environments throughout the world addressing many commercial and regulatory demands. Odyssey works in a variety of settings such as shallow coastal territorial waters, abyssal plains in exclusive economic zones, and high seas in international waters on projects involving mineral exploration, environmental analysis, oceanographic survey, and recovery operations. Odyssey Marine Exploration (Odyssey) excels in adaptively managing programs from initial concept through realization of commercial goals while successfully satisfying the regulatory and engineering demands of deep sea projects. This poster presentation reveals best practices throughout a project life cycle and presents case studies in areas including but not limited to: • Research practices to identify and define valuable subsea resources • Project planning and licensing to achieve project goals and meet regulatory requirements • Optimizing offshore operations to achieve desired results • Designing projects to support processing and commercial programs

Jan 1, 2018

By M. E. Williamson

From December 2004 through March of 2005 an extensive geophysical program was conducted to delineate polymetallic sulfide deposits in the Bismark Sea for a major mining concern. Deeply towed sidescan sonar, interferometric swath bathymetry, subbottom profiling, magnetic gradiometry, electrical resistivity, induced polarization. self-potential, gravimetry, water temperature/conductivity and towed video were among the methodologies tested against known occurrences of polymetallic sulfides in 1500 m -- 2200 m water depths. Known active and currently inactive sulfide areas were characterized using the various remote sensing techniques followed by survey with these same tools in other areas where they successfully discovered new prospects. Dredge sampling was used to ground truth both previously known sulfide areas and newly found deposits.

Jan 1, 2005

By M. E. Williamson

In September 2005 Williamson & Associates, Inc. delivered the BMS2 remotely operated seafloor coring system to the Japan Oil, Gas & Minerals National Corporation (JOGMEC). During acceptance trials aboard the JOGMEC research vessel R/V Hakurei Maru No. 2 the BMS2 successfully recovered 7.44 m of rock core in 3377 m water at a site near the crest of a seamount about 500 nm SE of Japan. Hydrogenous ferromanganese oxide crust, basaltic lava, sandstone and volcanic sediments were sampled with near 100% core recovery. The BMS uses rotary rod coring tools to collect samples to a maximum depth of 30 m in water depths up to 6000 m. Depending on bottom type to be sampled, the BMS tool magazine can be loaded with various drilling tools including core barrels with different bit types, drill rod and bore hole casing. The drill has 9 video cameras, a suite of sensors and 60 hydraulic functions powering thrusters, telescoping legs, seawater pumps and all of the standard drilling controls. The BMS provides deep water investigations with the functionality of conventional diamond bit rod drilling currently the mainstay of exploration programs in land mining.

Jan 1, 2005

By Ulrich Von Stackelber

Deep sea mining of manganese nodules actually will have an environmental impact to the seafloor and to the water column. However, we are far from being able to predict the possible consequences. Therefore, in 1992 environmental studies were conducted with the R/V Sonne in a manganese nodule field of the Peru Basin. The bathymetry of the seafloor was mapped using the hydrosweep system and the distribution and type of sediments were investigated by the parasound system and by collecting surface samples and sediment cores. Deep towing of a side-scan sonar system revealed a Mn encrustation of sediments and a nodule coverage of variable density. Along the tracks of a photo sledge a great variability of bottom fauna and of bioturbation was observed. Bottom-mechanical investigations of surface-near sediments were completed on board. Additionally water samples were collected near the sea floor to determine character and amount of dissolved and suspended particles. Manganese nodules and crusts were collected at 80 locations. In many aspects the nodules differ from those of the Clarion-Clipperton Zone: Big cauliflower-shaped nodules with growth rates up to 160 mm/ Ma may reach a maximum size of 24 cm in diameter, maximum abundance may be 44 kg/m2, the mean size of buried nodules is greater than that of surface nodules. The reason for that difference is due to the relatively high bioproductivity in surface waters and to a Mn redox boundary in the sediment column 10 cm below the seafloor. Histograms of nodules showing the distribution of size and growth type clearly indicate that the growth history is different for basins, slopes and tops of seamounts and ridges. Nodules with diameters >7 cm show mainly diagenetic and to a minor degree hydrogenetic growth. Smaller nodules of the same assemblage are composed mainly of hydrogenetically grown Mn oxide. The optimum diagenetic growth occurs within the sediment immediately above the Mn redox boundary, a level which is not reached by the small nodules.

Jan 1, 1994

By R. C. Newell

The primary objective of this study was to establish the fate and distribution of material rejected during marine aggregate dredging, and the extent to which this is associated with spatial changes in biological community composition. Two actively dredged sites in the southern North Sea (Licence Areas 430 and 106) were selected in order to provide a comparison of impacts between sites subjected to different levels of dredging intensity and of contrasting environmental conditions. Dispersal of material rejected during the dredging process was monitored by means of acoustic doppler current profiling techniques (ADCP). Composition of the substratum and benthic invertebrate assemblages were investigated by the analysis of seabed grab samples. It was found that dredging in both areas had an impact on seabed bathymetry in the form of dredge furrows and also led to a reduction of the coarse gravel-sized components of the worked area. Sand sized particles were shown to increase in the surface deposits of both dredged areas. This is likely to reflect both the removal of coarse particles as cargo and the settlement of finer particles rejected during overboard screening. Dispersion and settlement profiles of material rejected by dredging vessels suggested that the majority of the suspended sediment load resulting from overboard screening settles to the seabed within 500 m. Some evidence of suspended sediment loads above background levels were noted at distances of up to 2 km from the working vessel. Analysis of the particle size composition of the deposits, along the axis of transport of material from the dredged sites, suggested that the impact on the sediment composition outside the boundaries of the dredged sites is dependent on the strength and direction of net sediment flux at the seabed. Benthic invertebrate communities within the dredged zones of both areas were found to differ significantly from communities in nearby undredged deposits. A major suppression of species richness and abundance was noted in the dredged sectors of both sites when compared to control locations. A ?footprint? of potential impact on the benthic fauna was noted in samples taken along the axis of sediment transport at distances of up to 1750m outside the boundaries of Area 430. In contrast, impacts on benthic community structure at Area 106 appeared to be confined to the immediate vicinity of the dredged zone itself. This apparent difference in impacts, beyond the boundaries of the dredged sectors between the two study sites, was thought to be a reflection of the smaller quantities of material rejected at Area 106 and the weak seabed sediment flux which is characteristic of this area. These findings, along with those of numerous dredging impacts studies, were then used to make generalised predictions of macrobenthic community recovery following marine aggregate extraction in a variety of seabed habitats.

Jan 1, 2004