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By V. Soloviev

The world?s data available on near sea-bottom gas-hydrate accumulation and deep-water fluid-discharge areas are presented in this paper. Gas-hydrate accumulation associated with fluid discharge (mud volcanoes, gas seeps, gas-saturated water seeps) is characterized by the following. First, the largest hydrate accumulations in sediments are located at shallow subbottom depths and have well-defined limits, especially in the upper subbottom part. Second, gas-hydrate formation in fluid-discharge areas is a present-day process, with the global occurrence of deep-water fluid-discharge areas numbering up to about ten thousand, and with all the seep areas being favorable for the formation of near-sea-bottom gas-hydrate accumulation. Third and principal, gas resources in the hydrates can be considered as renewable. Estimates of possible gas volume in single accumulations of hydrates and the global budget, as well as possible methods of gas utilization from such gas-hydrate accumulations are discussed in the paper.

Jan 1, 2005

By David A. Clague, James R. Hein, Robert W. Embley, Robert C. Vrijenhoek, Randolph A. Koski

We report preliminary results for a group of unique samples collected with MBARI’s ROV Tiburon on August 12, 2005. The samples were collected from the East Blanco Depression (EBD) diffuse-flow hydrothermal field, which was determined in a previous study to cover an area of at least 100 m by 80 m (Hein et al., 1999). The survey reported on here extends that field to more than 1500 m in an approximately N-S direction. The EBD, a pull-apart basin, occurs near the western end of the Blanco Fracture Zone (BFZ), which connects the Juan de Fuca and Gorda Ridge spreading centers (Fig. 1). The samples were collected from a waterdepth range of 3343-3380 m.

Aug 24, 2006

By Fredrik Søreide

The Norwegian EEZ contains large areas of interest for SMS exploration along the Mid- Atlantic Ridge, from Jan Mayen to Svalbard. At the same time Norwegian companies engaged in oil and gas activities are in the forefront of subsea development. This makes Norway ideally positioned to take a leading role within marine minerals research and commercialization. In the recent minerals strategy from the Norwegian Government marine minerals was pointed out as one of the strategic areas for the future. The Norwegian University of Science and Technology has established a research program in cooperation with Norwegian industry partners to determine the commercial potential of marine minerals in Norwegian EEZ. This presentation will give an overview of the status of marine minerals research and potential in Norway.

Sep 14, 2011

By B. S. Ingole, S. Jai Sankar, A. B. Valsangkar, R. Sharma, B. Nagender Nath, N. H. Khadge, P. A. Loka Bharathi

After the simulated ‘mining’ experiment (INDEX) in the Central Indian Ocean (in 1997); the restoration of benthic environment was monitored for 4 years (2001-2005) at 5 locations in and around the test site and at 3 reference stations (20-80 km) from the test site. A comparison of long-term monitoring data with the pre-mining and post mining observations has shown that: • The concentration of silt fraction which was the highest (50-60%) at most locations during ‘pre-mining’ and ‘post-mining’ phases, had reduced (40-50%) during monitoring phases. • There was a corresponding increase in clay concentration (50-60%) during the monitoring phase, implying change in the size of sediment particles settling on the seabed, a trend that was also observed at the reference locations. • The initial increase in water content and decrease in shear strength after the experiment, which appeared to be returning to normal in monitoring-1 (2001), was reversed during subsequent monitoring phases (2002-2005), indicating changes in benthic environmental conditions. • Sediment organic matter and pore-water chemical data have not only indicated partial restoration of geochemical properties after the experiment, but also cyclic changes during the monitoring period.

Oct 15, 2007

By Paul C. Rusanowski

Mining is a waste intensive industry, oftentimes producing hundreds of kilograms of waste rock and tailings for every gram of metal recovered. Disposal of mine tailings is a major concern in most mining operations. In Southeast Alaska the steep terrain and high seismic hazard province limits cost effective opportunities for land disposal of tailings. The lack of infrastructure and long travel distances generally limits secondary utilization of tailings, as well. Since the mines are located close to tidewater, submarine tailings disposal is an attractive option for tailings management. At the present time the EPA will not issue a permit that authorized marine tailings disposal from any mining process that includes flotation technology. Upland disposal is the "Best available technology" and must be used. Consideration of submarine disposal is generally precluded because the tailings are contaminated with fluids from the flotation process. However, when developing technological solutions to minimize environmental disturbance, destruction, pollution, and risk, submarine tailings disposal deserves another evaluation. In Southeast Alaska it may be the "Best available technology" based on an assessment of all issues and concerns in these mining projects.

Jan 1, 1991

By John Noakes

Marine scientists at the University of Georgia, have in the past few years, designed, developed and refined two geochemical survelliance systems for the exploration of hard mineral resources on the seafloor. The one first developed is an underwater sled which contains a nuclear radiation detector for measuring naturally occurring gamma radiation that is associated either with marine phosphorites containing uranium and its decay daughters or thorium decay products that are indicative of monzanite. The latter can, in most instances, be used as a pathfinder mineral for placer deposits that may contain other heavy minerals of interest such as rutile, ilmenite, chromite, gold, etc. This sled is operational in continental shelf depths. The second system is capable of more definitive measurements in the form of direct elemental analyses of the silt and clay fractions within the surficial sediments. It consists of a towed sled containing a submersible pump which, upon agitating the sediments, transfers the finer fraction up a hose to a shipboard centrifugal cone then to an automated sample processor. The resultant samples are rendered into sediment wafers, suitable for non-destructive XRF analysis. The system is capable of shipboard analysis for specific elements within minutes after sampling, allowing a cursory look upon which an exploration grid can be formulated while on site. A much wider spectrum of up to 40 elements can be evaluated when the wafers are returned to the land based laboratory.

Jan 1, 2011

By Luana Karvel, Lars Kullerud, Morten Sørensen, Øystein Halvorsen, Øivind Lønne, Elaine Baker, Tina Schoolmeester, Joan Fabres, Yannick Beaudoin

The UNEP Shelf Programme (USP) is the access point for a collaboration of international organizations with expertise in marine geoscience and maritime law. It was established in response to a United Nations resolution, stating that the United Nations Environment Programme (UNEP), working through the Global Resource Information Database (GRID) system, should work in conjunction with Intergovernmental Oceanographic Commission of UNESCO (IOC) and the International Hydrographic Organization, to assist coastal States, and in particular developing States and small island developing States (SIDS) with submissions to establish the outer limits of their continental shelf under Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS).

By Willam R. Normark

During a series of dives with the submersible ALVIN in 1984, samples of massive sulfide were recovered from four vent sites. All sites occur within a linear, steep-walled cleft about 50 m wide and as much as 30 m deep. The cleft bisects the axial valley floor throughout the 15-km-long study area and appears to have been the source for the most recent volcanic eruptions in the valley. Three of the vent sites are defined by a set of discrete hydrothermal discharge zones; as many as eight have been identified over a distance of 500-800 m along the cleft floor. Sulfide deposits occur as individual and coalesced mounds, spires, and chimneys generally less than 3 m in height but a few might be as high as 10 m. The vents are also marked by extensive, yellow-to-amber ferruginous sediment and clots of bacterial matter. Some vents have extensive colonies of tube worms, gastropods, mollusks, and several predator species, such as crabs and squid. The fourth vent site has no visible discharge and consists mainly of "dead" spires and chimneys of massive sulfide. The massive sulfide samples collected with ALVIN are primarily sphalerite with minor marcasite, pyrite, pyrrhotite, isocubanite, chalcopyrite, wurtzite, and anhydrite. Bulk analyses of these chimney and spire samples show Zn contents approaching 60% by weight and significant enrichments in Ag and Cu. Vent fluids have the highest concentrations yet reported for Zn, Fe, and Mn. Thus, the Zn- and Ag-rich nature of massive sulfide from the southern Juan de Fuca Ridge study area

Jan 1, 1985

By D. J. Scarratt

Fisheries make a significant regional contribution to the economy of Canada. In the Atlantic Region, over 70 thousand workers depend on the primary or secondary fishing industry. Fisheries are vulnerable to pre-emption of space by other marine industries and to contamination by chemical discharges. Markets may be affected even by the threat that products may be tainted. Fish may be killed by drags and dredges, and their physiology and behaviour affected by suspended sediments are stirred up by mechanical devices. Virtually no evidence exists of adverse impacts £ran ocean mining on fisheries, but projections from other marine activities such as fishing itself, dredging and other marine discharges give reason for caution. Department of Fisheries and Oceans policy calls for review of ocean mining proposals to ensure adequate protection of fish stocks, fishing activities and fish habitat, and compensation for losses attributable to any industrial project. Adverse impacts can be minimized by careful attention to details of location, technology and timing, and to close co-operation and information exchange between industry and the regulatory agencies.

Jan 1, 1985

By V. Zaykov

The Urals massive sulfide deposits are concentrated in Silurian -Devonian fold belt extending for 1500 km with length from 50 to 150 km. By paleodynamic reconstmction it is established that they were formed in submarine parts of island arcs, in inter arc and back arc basins, marginal seas. When "black smokers" were found in rift zones of present oceans, problem searching their analogues in the Urals Paleozoic complexes was arisen. For solving this problem and demonstration of seafloor origin of massive sulfide many quarries and drill cores were carefully sketched and studied. Particular attention was given to correlation between ores and synchronous sedimentary rocks and fossils. Various laboratory methods were used for comparing sulfides from ore hills with ore-clastic sulfides.

Jan 1, 1993

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 Hyun Sub Kim

Subsea mineral deposit exploration aboard the R/V Onnuri was performed along the northern Central Indian Ridge (CIR) between 8°S and 17°S in December 2009 ~ January 2010 (09IR Leg01 and 09IR Leg02) and December 2010~ January 2011 (10IR Leg01, 10IR Leg02, and 10IR Leg03). Final goal of the expedition for the first Korean research cruise on mid ocean ridge system is to define seafloor massive sulfide ore bodies through searching the active hydrothermal vents nearby spreading centers as well as to elucidate the nature of spreading segments of the northern CIR area where no systematic survey have been operated before by mapping and sampling of volcanic rocks. The preliminary result of topographical interpretations of bathymetry clearly display ocean core complex between 10°S and 11°S. The ocean core complex is featured by topographic-high area with corrugated surface. Lineaments of corrugations of the ocean core complex are clearly perpendicular to abyssal hill direction which is triggered by symmetric-normal faults. Ocean core complex are favor for hydrothermal fluid path because of the long-lived faults. In further exploration, more detailed examination, including systematic CTD casting and tows, need to narrow down actual venting site around ocean core complex. Magnetic field survey is able to estimate the location of hydrothermal vents with the properties that high temperature of hydrothermal fluids over Curie-point can cause thermal demagnetization. In magnetization intensity map, most of low magnetization zones are located at the nodal point over the ridge axis and the ocean core complex.

Jan 1, 2011

By Richard T. Haworfh

The United Nations Convention on the Law of the Sea (UNCLOS) entered into force, for those nations who had ratified it, on November 16, 1994. The Convention deals with nearly every aspect of ocean affairs, including marine scientific research, fishing zones, freedom of the high seas, protection of the marine environment and deep seabed mining. Article 76 of the Convention defines edge of the continental shelf in a way that many earth scientists find bizarre. Out to this limit, a coastal state has sovereignty over the seabed and sub-seafloor resources. Beyond that limit, the key principle of UNCLOS, that "the resources of the deep seabed represent the common heritage of mankind and should be developed to benefit all nations" is invoked. Establishing that limit and managing development in the different areas of jurisdiction is no small task. Canada's continental shelf as defined by UNCLOS covers an area approximately equal to half the area of the Canadian land mass. Interpretation and application of the convention is therefore highly significant for Canada. For example, the sedimentary basin in which the offshore Hibernia oil field is found, extends beyond the 200 mile limit but lies predominantly within the limits of the (UNCLOS) continental shelf. Responsibility for development of inshore placer deposits rests firmly with the coastal state. However, development of deep sea mining, in which the international community plays a management role under UNCLOS, has raised many concerns. Of particular interest to Canada will be the application of the provisions of the convention to interest in the polymetallic sulfides sampled on the mid-ocean ridges such as the Juan da Fuca Ridge. A further complicating factor for Canada is management of fishing stocks. Canada has sought to resolve this "problem" through multilateral negotiations under the UN. Under its "Oceans Act," currently being debated by Parliament, Canada intends to become a world leader in oceans and marine resource management. Similar activity in most maritime nations is setting the stage for a revolution in the way in which use of the world's oceans is managed. Much of this revolution will be guided by UNCLOS. Coastal states that have ratified the convention have ten years in which to define the limits of their continental shelves the clock is already ticking for them! We have yet to see how their actions will guide, or be guided by, those who have not yet ratified. We also have yet to see how national legislation and aspirations will mesh with international conventions that were drawn up in a previous era of environmental standards. This is a time in which many questions have been raised and few firm answers received. However, we must ensure that everyone is aware of what is happening, with what potential consequences, in order that rational decisions can be made. Canada has taken a few small steps that it is happy to share with the world community.

Jan 1, 1996

By Walter L. O?Niell

The Continental Shelf Division of the Marine Minerals Technology Center has recently completed field tests of the percussion- waterlift drill and the vibracore/vibralift convertible drill. The two systems have been modified from existing drills to increase their effectiveness and flexibility for nearshore minerals exploration. Originally the percussion-waterlift drill was designed for iand based operations, but it has been modified for use in protected shallow water areas. This drill is easily maintained, inexpensive to construct and operate, and is able to accurately recover representative samples from a variety of sedimentary deposits. Sampling is accomplished using either a reverse circulation method for the recovery of a slurry of sediment cuttings and water or employing a thin walled "Shelby tube" to core zones of interest. The vibracore/vibralift convertible drill is a modification of the remote placer drill (RPD). By combining these drills into one convertible system, it is possible to recover continuous cores of unconsolidated fine-grained sediments (vibracore), a slurry of clay to gravel size sediments over 1.0 meter intervals (vibralift), and to sample sedimentary material in environments where indurated

Jan 1, 1991

By Carl H. Hobbs

The needs of the on-going basic maintenance operations and proposed enhancement and hurricane protection projects in the City of Virginia Beach exceed the capability land-slide sources of sand. Through the past several years our studies have concentrated on locating and defining suitable quantities of sand appropriate for use on the area's beaches and assessing some of the consequences of dredging in shallow offshore areas. By providing information concerning the geological setting of sand resources, the local wave climate, and benthic infauna, the overall research project has strengthened the knowledge and understanding of several facets of Virginia's inner continental shelf. We have identified three distinct settings for deposits of beach-quality sand, two of which (filled channels and surficial shoals) are distinguishable in relatively unprocessed sub-bottom profiles and cores. The third, a sand facies within a larger stratum, is discernable only with a suite of cores. Sandbridge Shoal, about 5 km offshore of the resort and residential community of Sandbridge appears to contain a substantial quantity of sand that could be exploited with comparatively few problems. It already is designated as the source of material for use in a shoreline protection protect for a federal facility. Fluvial(?) fill of a late Pleistocene channel lust offshore of the main, commercial, resort area may offer a proximal alternative to existing and proposed resources. Ongoing work to describe the local wave climate and the possible impacts of anthropogenic alterations of the bottom topography on wave transformation and studies of the biological community as it might be affected by dredging will help fill-out our series of studies. Prior to utilization of the resource additional work is needed to provide better definition of the limits and magnitude of the sand bodies. Finally decisions concerning the use of specific resources will have to include physical, biological, economic, technical, and social considerations.

Jan 1, 1996

By Benjamin W. Haynes

The Federal government has a lengthy history in supporting and conducting research in the ocean mining and minerals field. The Federal effort has been and is currently focused primarily in four agencies: the National Oceanic and Atmospheric Administration (NOAA) within the Department of Commerce, and the Geological Survey (USGS), the Bureau of Mines (BuMines), and more recently the Minerals Management Service (MMS) within the Department of the Interior. While NOAA and the USGS have played dominant roles in mapping and geologic studies, and the MMS has recently provided funding for several task force studies within the Exclusive Economic Zone (EEZ) , the Bureau of Mines has conducted research in mining technology, minerals processing, resource definition, and economic evaluation of minerals from the seabed for over 20 years. These studies have yielded considerable minerals information regarding manganese nodules and crusts, placers, mineral sands, phosphorites, and sulfides. This paper reviews the past achievements in ocean mining and minerals programs starting in the late 1960's, describes current research and information efforts, and presents an outlook for Bureau of Mines research and information gathering efforts. Specific topics

Jan 1, 1989

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 Gerald R. Dickens

Massive sulfide ores and Fe-Mn oxyhydroxide precipitates represent two extremes of a spatial continuum of hydrothermal deposition along oceanic ridges. Elemental variations across this continuum are of interest to economic geologists as a prospective geochemical exploration tool. Theoretical considerations suggest that certain physical and chemical parameters can be used to model compositional variations within the far-field (i.e., Fe-Mn oxyhydroxide) component as a function of distance from ridge axis; however, testing and verification of such models generally has been precluded because the few available distal hydrothermal sediment sequences have been sampled at low resolution and/or are highly diluted with biogenic components (e.g., siliceous and calcareous tests). Recent ocean drilling (ODP Leg 145; Sites 885/886) in the North Pacific successfully recovered an extensive record of "biogenic-free" distal hydrothermal precipitates from an area approximately 60 km south of the Chinook Trough at longitude 168.1 °W. Geophysical and geomorphological evidence suggests the Chinook Trough is the southern lithospheric scar marking initiation of late Cretaceous north-south rifting, implying that recovered hydrothermal materials record distal hydrothermal precipitation from the now-subducted Kula-Pacific spreading ridge. The Chinook Trough hydrothermal sequence is a continuous 15 my record of "biogenic-free" hydrothermal Fe-Mn oxyhydroxide precipitation mixed with eolian clays. It was deposited during the late Cretaceous, early Paleocene (80-65 Ma) as the perpendicular distance from ridge axis increased from 75 to 600 km. A high-resolution geochemical analysis of this hydrothermal sequence reveals distinct trends for the up-core (equivalent to increasing distance from ridge) distribution patterns of Fe, Sc, As, and rare earth elements (REE). Iron concentrations exhibit an S-shape distribution pattern with respect to increasing

Jan 1, 1994

By Michael J. Cruickshank

Marine minerals are more than an academic curiosity as they represent the most significant global source of mineral materials for economically and ecologically sustainable development for the future. Minerals research is traditionally carried out by industry and thus, in the United States at least, applied research in marine minerals may not get the share of government funding or attention that more exotic programs for space exploration or future global disasters engender. Two recent events have significantly changed the status of marine minerals. Discoveries made in the last thirty five years indicate that the potential for mineral occurrences in the oceans and seabeds, area for area, is as high as for terrestrial lands. On this basis the global mineral resource base has been recently increased by a factor of four of which three quarters is underwater. The recently enacted Law of the Sea has mandated what is probably the most far reaching re-distribution of natural resources in human history, and has resulted in a peaceful subdivision of seabed jurisdictions between the coastal nations of the world which should significantly affect future mineral markets and the balance of economic powers. Significant applied research efforts are ongoing for marine minerals as an adjunct to commercial production in southern Africa for diamonds; and in many other parts of the world for sands for beach and coastal protection. Forward planing, including research and development activities focussed on future commercial production of metalliferous oxides, continues in Korea, China, Japan, India, and with lesser activity, in the United States, United Kingdom, Germany and the CIS. Annual expenditures for this work amount to millions of dollars. In all cases the environmental aspects of commercial produc¬tion are a significant part of the research. Geologic studies on the occurence and distribution of metal sulfides at plate boundaries continue on a regional basis in the Pacific.

Jan 1, 1996

By Satya Nandan

• A review of the structure and mandate of the Authority – its main functions. • The different types of mineral resources found in the deep seabed – their global distribution. • The Development of Regulations for Prospecting and Exploration of Polymetallic Nodules, Cobalt-Rich Crusts and Polymetallic Sulphides including environmental regulations and guidelines. • Early constraints for deep seabed mining – Improving conditions for mining – Future prospects for mining.