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By Georgy Cherkashov

Shallow-water formation of marine ferromanganese nodules as well as their deep-water analogues is found throughout the global ocean. The Baltic Sea is a key province for the shallow-water type of marine minerals. The following main distribution areas of Fe-Mn nodules have so far been discovered in the Baltic Sea: the Gulf of Bothnia, the Gulf of Riga, Central Baltic area (Gdansk- Klaipeda) and the Gulf of Finland. The last area (Gulf of Finland/Finnish Bay) is the best studied from all aspects including geological prospecting and environmental assessment.

Sep 14, 2011

By Sven Petersen, Berit Lehrmann, Bramley J. Murton, Paul A. J. Lusty

"INTRODUCTIONToday’s metal mining focusses on land based ore deposits which only consider one third of the Earth’s surface. Through an increasing global demand of strategic metals used in the electronic and green industry (Zepf et al. 2014), ‘uneconomic’ sites of lower grade in more technical challenging grounds such as greater depth and/or more remote areas are developed by the mining industry often resulting in higher environmental impact. However, considering the steady growth of the Earth population a shortage of certain metals may occur (Krausmann et al. 2009). In 2010, the United Nations allowed commercial exploration for seafloor massive sulphides (SMS) in international waters with currently six contractor licenses being granted.Although the number of discovered vent sites has steadily increased since the first discovery of hydrothermal venting at the Galapagos Rift in 1977 (Corliss et al. 1979) with more than 600 sites being known today, their economic potential is poorly constrained. So far Nautilus Minerals Inc., a Canadian mining company, is the only company having conducted a NI 43-101 resource estimate for the Solwara site, located in the territorial waters of Papua New Guinea. Other studies using bulk geochemical data from 95 sites published in literature do exist (Hannington et al. 2011, Monecke et al. 2016) suggesting a global resource potential for today’s known SMS deposits of 600 million tons with a median grade of 3 wt.-% copper, 9 wt.-% zinc, 2 g/t gold and 100 g/t silver. However, the geochemical data being used originated mainly from easily recoverable, mainly non insitu surface grab-samples and are under current mineral resource classification schemes such as JORC code or NI 43-101 not even accepted for resource estimations. Furthermore surface samples such as high-temperature sulphide chimney and talus material are not representative for the entire deposits with information regards thickness and continuity of individual sulphide layers obtained through drilling being scarce. In addition, it remains unknown what geological processes occur once hydrothermal activity ceases and whether metal tenor becomes enriched, depleted or disappears."

Jan 1, 2017

By Alexander Malahoff

The most exciting frontier in Ocean Technology is represented by a new class of Marine Bioproducts, the source of which lies in marine microorganisms. The microorganisms include microalgae, bacteria and archaea. These organisms represent very diverse, adaptive life forms and in their metabolic processes use carotenoids, polyunsaturated fatty acids, ultraviolet blockers, as well as a wide range of enzymes that are pivotal in the production of new pharmaceuticals and nutraceutical products. These organisms cover a wide spectrum of ocean environments, from the shallow to the deep, from the normal to the extreme. The technological challenge is in the identification of candidate organisms, in the screening for valuable enzymes, and in the industrial production. A whole new range of collecting strategies involving submersibles, ROVs and in situ ocean floor instrumentation is emerging. New non-polluting industrial chemical processes involving the use of photobioreactors and extremophile bioreactors for breeding and monitoring these organisms in neo-farming technology is emerging. The commercial value of these candidate products is immense, as is the range of potential organisms. The dimension of this new industry is global. The Marine Bioproducts Engineering Center (MarBEC), funded by the National Science Foundation (NSF), has been established at the University of Hawaii. The vision of MarBEC is to develop a seamless research system stretching from undergraduate education to industry for the purposes of producing valuable marine bioproducts outside of the normal chemical factory production. MarBEC is uniquely and strategically placed in the Pacific to explore, find, and adapt highly bioactive marine micro-organisms found in the tropical ocean. We have watched the increasing need by the ever-

Jan 1, 2000

In 1983, the GEMINO research project (Geothermal Metallogenesis Indian Ocean) was initiated in order to locate and evaluate sites of recent or fossil hydrothermal activity in the largely unexplored Indian Ocean. During GEMINO cruises 1 and 2 with R/V SONNE in 1983 and 1986, the Central Indian Ridge between 21°S and 24°S was the subject of detailed exploration, including SeaBeam and magnetic mapping, hydrocasts, sediment coring, TV-grab sampling, and camera/video tows. Although hydrothermal sulfide mineralization was not located, a hydrothermal component in the sediment composition, hydrothermally altered basalts, and maximum concentrations of 27.5 nmol/kg Mn and 45.6 nl/l CH4 were discovered (Plüger and Herzig 1986; Herzig and Plüger 1988a). Leg 1 of the GEMINO-3 cruise in 1987/88 identified a neovolcanic ridge in the rift valley of a 30 km segment at 22°55'S as a site of weak hydrothermal activity and photographed smectite-like precipitates on basalt talus and a chimney structure on top of a ridge-parallel fault scarp. Water temperature data and the distribution of Mn and CH4 were interpreted as indicative of diffuse, low-temperature hydrothermal activity (Herzig and Plüger 1988b).

Jan 1, 1989

By Seung-Kyu Son

This study was investigated about physico-chemical parameter such as water temperature, salinity, inorganic nutrients and total organic carbon (TOC). CTD (Model: Sea-Bird 911 Plus) castings were carried out on two transects in the northeast equatorial Pacific Ocean. As a part of the Korea Deep-sea Environment Study (KODES), inorganic nutrients and TOC were determined at 41 stations located from 131° to 136°W along 10.5°N and from 17° to 5°N along 131.5°W (Fig. 1). We particularly chose KODES Long-term Monitoring Station (St. KOMO) to observe for the annually environmental baseline study in the contract area. [ ]

Jan 1, 2005

By Frank Manheim

The purpose of this presentation is to review the history of offshore non- fisheries resource development since World War II, as an introduction to a planned symposium on offshore resources scheduled for the 1996 UMI Conference. After World War II the United States became the leader in offshore oil and gas production, deep ocean drilling technologies, offshore terminals, platforms and production systems, and natural gas recovery and transport. Wartime skills in acoustic profiling and antisubmarine warfare were transferred into commercially important geophysical exploration techniques. The application of ocean drilling and geophysical techniques permitted the recognition and elucidation of plate tectonics patterns, development of seafloor spreading theory, and the transformation of our knowledge of seabed and subseabed strata. After John Mero's studies and recommendations for developing marine manganese nodules in the late 1950's interest in nonfuel minerals grew rapidly. The formation of international deep sea mining consortia in the 1960's was accompanied by a flurry of ocean engineering development, minerals prospecting and associated environmental studies The Santa Barbara Oil Spill of 1969 resulted in a moratorium on both offshore energy and minerals leasing by the Depart- ment Interior, and catalyzed the development of new Federal legislation in 1972. In 1973 the offshore energy moratorium was lifted in response to the Arab oil embargo, and offshore energy activities surged for a time. Minerals were reopened to leasing following President Reagan's 1983 executive order implementing a 200 mile EEZ. Although interest was spurred by

Jan 1, 1995

By David S. Cronan

The traditional method of deep sea manganese nodule exploration is to conduct grid survey and sampling on successively finer scales until a suitable deposit has been delineated. Clearly this is both time consuming and ultimately self-defeating if large areas of the ocean floor are to be explored on a human timescale. A conceptual deductive approach would be preferable if one could be found, as it would aim to outline areas of potentially economic nodules on the basis of easily measurable oceanographic parameters. An attempt to achieve this aim in the Central Pacific is outlined below. Nodule Distribution in the Central Pacific Ocean Maps of ore grade nodules in the Central Pacific show that they are confined to two zones trending roughly east-west which are well separated in the eastern Pacific but which tend to converge towards 170-180ºW. They follow the isolines of intermediate biological productivity in the surface waters, strongly suggestive of a biological control on their distribution. Within these zones the nodules preferentially occupy basin areas. Thus they are found in the Penrhyn Basin, Tokelau Basin, Central Pacific Basin, Clarion Clipperton Zone and Tiki Basin. Nodules in all these areas have features in common and are thought to have obtained their distinctive composition by similar processes.

Jan 1, 2003

By James M. Cairns

Deep Sea Minerals Inc. (DSM) is a high technology marine minerals and biotechnology corporation. The corporation is currently engaged in a worldwide leasing program to acquire exclusive rights in specific Economic Exclusive Zones (EEZ?s) that DSM?s marine geologists have identified as prospective targets for seabed mines of copper, zinc, gold, and silver. In the last two years the corporation has assembled an international team, including some of the world?s leading marine research scientists and engineers, and has created strategic partnerships and alliances with world-class engineering and mining groups. Development of a marine mining venture has key requirements in common with most other mining ventures. These include financing, deposit location, property acquisition, deposit delineation, and permitting, as well as the collection, transportation, processing and marketing of the ore itself. DSM has made progress on all of these fronts, which is outlined in a general way in this presentation. Financing for the venture is clearly the first big hurdle to overcome. Deep seabed mining involves new technologies and significant up-front capital investment. Less than fifteen years ago, such financing would probably have impossible to achieve, given classical business models. However, with the spectacular success of high technology ventures in the areas of electronics, software, and biotechnology, new business models and investment strategies have evolved which put relatively high evaluations on intellectual property and exhibit relatively high confidence in new ways of doing things. DSM is taking full advantage of these changes in venture capital markets in its financial planning.

Jan 1, 2000

By G. Rehder

The release of methane as free gas from the seafloor into the water-column well within the hydrate stability field is a natural process observed today in various ocean settings, such as the Cascadia margin, the Black Sea, the Guayamas Basin, and the Gulf of Mexico. The subsequent dissolution of gas bubbles into the water-column determines the vertical distribution of aqueous methane in the water-column and the upwards methane flux. Understanding this process not only is essential to describing the impact of natural deep-sea gas seepage, but also to assessing the hazard potential from blowouts and offshore exploitation activities, which are steadily expanding to greater ocean depths. Furthermore, the fate of methane from seeps contributes to scenarios of global change in the past and future involving the large scale destabilization of gas hydrates on a. We recently reported on the extended lifetime of methane bubbles within the hydrate stability field due to the formation of a hydrate skin (Rehder et al., 2002), based on in situ measurements of methane and argon bubble dissolution in the depth range 400 to 800 m. More recently, these observations were extended to depths from 900 to 1500 m. Single bubbles were injected from the ROV Ventana into an attached, back-illuminated, flow-through imaging box. The ascent of individual bubbles within the imaging box was recorded with Ventana?s HDTV camera system by piloting the 3-ton ROV upward, at the bubble rise velocity, for up to 400 m of vertical transit. Observed rise velocities were approximately 30cm/sec for all depths. Post-dive analysis of the HDTV video allowed detailed measurements of the bubble shrinking rates. The results of the earlier and new experiments lead to the following conclusions: (A) Methane bubbles released below the hydrate stability field showed markedly enhanced lifetimes, attributed to hydrate skin formation. The change in radius with time, dr/dt, varied from -7.5 micrometer/s above the hydrate stability field to about -1 micrometer/s at the deepest release depth. (B) Bubble lifetime within the hydrate stability field increased with distance in P-T space from the hydrate phase boundary. (C) Before hydrate skin nucleation, dr/dt for CH4 bubbles was comparable to dr/dt above the hydrate stability field. Although variable, the onset time for the hydrate skin effect to occur generally decreased with distance from the hydrate phase boundary (super-pressurization and super-cooling with respect to hydrate formation). (D) Even before the onset of the hydrate skin effect, a slight decrease of dr/dt with increasing depth was observed.

Jan 1, 2005

By Arturo Carranza Edwards

Sedimento II oceanographic cruise, on board of the B/O El Puma, shows a new high anomaly or phosphate associated with shelf sediments from the south Mexican Pacific. Recently, were found two anomalies in the Gulf of Tehuantepec, that are located to the east of this new anomaly, that is related to muddy sands and rock fragment debris. The latter shows values of 17% P205. The phosphate occurrence is probably associated with red tides locations that usually are found in sites where sediments are phosphates enriched. These findings suggest that south Mexican Pacific is of potential interest for P205, in waters with high nutrients values. The possibility of a more regional occurrence of phosphate, from California to Chile is suggested.

Jan 1, 2000

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 Julian Malnic

The emerging marine minerals exploration and mining industry is currently focused mainly on the technical elements for its success such as developing exploration and mining technologies. However, in one sense, the technical challenges are quite soluble whereas those arising in the fields of the environment and public opinion could present this new generation of miners with problems that are far more difficult to overcome. One need only look at the issues currently faced by mining projects on land to see how powerful the new forces of so-called ?civil society? are in stopping mineral developments in many countries. From the geographic viewpoint, there are many countries but there is just one ocean, so the impacts experienced by any one operation are likely to have pervasive repercussions throughout the industry. A well-oiled NGO development protest lobby will see leverage in resisting this new industry and will seize on the single-ocean angle. The Australian Minerals Industry has established a voluntary Code for Environmental Management that provides an active and valuable model for satisfying the ?court of public opinion? and in delivering economic results to industry that are in current jargon, sustainable. An explanation of the Code for Environmental Management, and the reasons behind 44 companies representing more than 300 operations and 85% of Australia?s sizeable mineral production being signatory to it will be given. Participants see it as a means to future shareholder wealth.

Jan 1, 2000

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 Sang-Mook Lee

The Manus back-arc basin behind the New Britain Trench is one of the major sites of active seafloor hydrothermal vent-fields which are considered to be modern-day analogue of felsic volcanic-hosted polymetallic massive sulfide deposits abundant in ancient geological record. Many of these deposits represent multi-million dollar resources, and yet very little are known about the fundamental processes leading to their formation. In November 2000 January 2001, the PACMANUS hydrothermal system in this region will be targeted by the Ocean Drilling Program Leg 193 to investigate the internal anatomy. A number of observations that suggest that the tectonic, magmatic and hydrothermal processes in the eastern Manus basin spreading center are unusual in that they can not be explained by a simple back-arc opening due to subduction of the New Britain Trench. Geochemistry of submarine volcanoes in the eastern Manus basin, for instance, shows affinity to arc rather than back-arc type volcanoes. Yet these submarine volcanoes lie too faraway from the Benioff-Wadati zone. One hypothesis is that the magmatic and subsequent hydrothermal activity of this region is a direct result of the irregularities in the deep crust and upper mantle structure and that the tectonic process is controlled by the sharp inflection of the New Britain Trench. According to this hypothesis, the two major southeast-trending strike-slip faults in the eastern Manus Basin, Djaul and Weitin Faults, should extend farther down and join to the New Britain Trench. They would form a transform arm of the triple junction with the New Britain Trench southeast of New Britain Island and southwest of Bougainville Island forming the other two arms. A trench-trench-transform triple junction can not be stable over time, and therefore a slight change in the plate velocity may lead to a dramatic change in the configuration of the plate boundaries. If so, the instability of the triple junction may cause large tectonic deformations, such as mantle uplift under the Manus basin due to mantle rupturing by transform faults, and therefore may explain the arc-style volcanism and unusual compositions of hydrothermal deposits in the eastern Manus basin.

Jan 1, 2000

By Derek V. Ellis

This article is a summary, with documentation and references, of recent global developments in identifying environmental issues affecting the marine mining industry. It is recognised that marine mining for various products occurs at various depths from shallow water (e.g. aggregate and diamond mining) potentially to great depths (e.g. metalliferous muds, and manganese crusts and nodules). Nevertheless there are environmental issues in common, even though the options for resolutions will vary greatly. The point of this review is to identify the issues, so that where site-specific resolutions are considered, it is possible to draw on experience with the issues elsewhere. Related mining issues, e.g. tailings effluent quality, orebody geochemistry, are mentioned where relevant but are not detailed in this article, although obviously they are a part of there solutions to the environmental issues. The environmental issues and their resolutions are important - on the basis of the ethic of not creating more impact than is inevitable, and the long-term financial and social costs at a mine-site of not getting the resolutions right.

Jan 1, 2000

By Mikhail D. Ageev

The paper concerns with some questions of Autonomous Underwater Vehicle (AUV) control system design, which allows a motion at rough undersea terrain. The AUV advantages reveal itself completely during exploration of such objects as seamounts and reefs area. These objects are characterized by steep slopes (30 degrees and above) and chaotic situated obstacles (rock debris, pinnacles, escarpments). Uses of other technical facilities for operating in such formations are difficult, dangerous or impossible. These regions take an interest due to the presence of iron-manganese crusts. Modern AUV can estimate density of mineral by means of still camera or video recorder. For this reason the vehicle has to move with the distance of 3-5 meters from seabed. Under such conditions micro- and mesorelief presents a considerable danger for AUV. The AUV can bypass underwater obstacles in the various ways. However, in any case AUV motion will be characterized by intensive maneuvering on various speeds (from 0 up to 1.5 m/s), circular change of tractive force vector and, hence, a circular flow about the hull. So, AUV is equipped with the propulsion system, which provides free modes of motion.

Jan 1, 2003

By T. Schoening

The exploration of the seafloor regarding the abundances of poly-metallic nodules has received growing attention recently. Image-based exploration using cameraequipped deep-sea observation systems has been introduced successfully to increase spatial resolution in the exploration process but the evaluation and interpretation of the huge amount of image data creates a serious bottleneck. In this paper we present a new software solution to the problem of automatic detection and segmentation of poly-metallic nodules in underwater images, which is not only accurate but so fast that real time image analysis is definitely in reach. Thus, an application on an AUV (Autonomous Underwater Vehicle) seems possible in the near future.

Sep 14, 2011

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 Raymond A. Binns

Drilling into an active hydrothermal system linked to convergent-margin felsic magmatism is a listed priority of the Ocean Drilling Program that addresses several fundamental geoscience issues. Solid and fluid products of felsic rock-water interaction, and the consequences for global chemical fluxes and for ore deposition, should differ from those in basaltic mid-ocean ridge environments already successfully tested by Legs 106, 139, 158 and 169. So, too, will fracturing controls on fluid pathways, and sources for metals and ligands. Researching the subsurface volcanic, structural/hydrologic, and mineralisation/alteration architecture of a drilled felsic-hosted system also has economic implications, especially for land¬based mineral exploration. A first-order hypothesis to be tested states that fluids derived from volatile-rich magmas are more important than recirculated seawater in convergent-margin hydrothermal systems - economic geologists increasingly appeal to this for creating "world-class" massive sulfide orebodies. Another hypothesis proposes "subhalative" massive sulfide deposition within hydraulically expanded volcanic products as a factor in generating large orebodies. Many second-order hypotheses such as leaching fractionated volcanics to cause gold enrichment in back¬arc systems also need testing. The thoroughly surveyed, active, PACMANUS hydrothermal field in the Eastern Manus back-arc basin of Papua New Guinea will be the site for ODP Leg 193 commencing in November 2000. It lies near the crest (1655-1750 m) of high-standing Pual Ridge, a 40 km-long edifice of dacite/rhyodacite with basal andesite all having geochemical and isotopic affinities with modern arc volcanoes of nearby New Britain. PACMANUS includes at least three focussed, high-temperature "smoker" sites with Cu+Au-rich massive sulfide deposits, and a field of diffuse, lower temperature venting through intensely altered dacite where modelling indicates significant subsurface mineralisation. Isotopic characteristics of deposits and vent fluids suggest magmatic contributions to the mineralising fluids.

Jan 1, 2000

By L. B. Khershberg

According to geochemical specialization, cobalt-manganese crusts (CMC) of the Magellan Seamounts are rich in cobalt and manganese and are complex in composition. Besides cobalt, manganese, and nickel, they contain such components, as platinum, copper, molybdenum, and rare earth elements, which enhance the value of this material. Factors and conditions responsible for Co-Mn ore-genesis and processes of cobalt-manganese crust formation are described in a number of Russian and foreign geological papers. The study of ore-concentrating processes in the Magellan Seamounts helped to solve an important applied problem, namely to reduce the time needed to reveal the factors of CMC formation mechanism. The authors of this research found seawater over the described area of Magellan Seamounts to be stratified and to contain high concentrations of manganese, iron, cobalt, nickel, copper, lead, and zinc. Diagrams of suspended Co, Mn, Ni, and other components in seawater (0-5500 m), as well as medium concentrations of basic elements (Co, Mn, and Ni) in ore deposits of metallogenic levels of Magellan Seamounts, were found to coincide both on guyots and abyssal plains. Detailed geological study of guyots in the Magellan Seamounts (Dalmorgeo, IOAN, Roskomnedra, and others) revealed that medium Co-Mn crusts cover bedrock rocks in narrow ribbon-like bodies along the edges of bathymetric intervals 1300-1600 m, 1400-2000 m, 2000-2500 m, and 2500-3000 m.

Jan 1, 2004