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By Robert Corcoran, Piotr Jasiobedzki, Roy Jakola, Michael Jenkin

Vast mineral resources of copper, zinc, cobalt and gold have been identified off the coast of Papua New Guinea at depths exceeding 2,000 meters. Accessing them in a cost effective manner and without destroying the marine habitat requires overcoming numerous technical and operational challenges. Although there are a number of deep-sea mining operations underway worldwide, the depths encountered are significantly less than will be required to mine these ore deposits. To date, only the oil industry has developed technologies for successfully accessing reserves at depths of 3,000m.

By Lee Sung-rock

KIGAM (Korea Institute of Geoscience and Mineral Resources) has been doing various kinds of research works in marine minerals and energy resources exploration and utilization since early 1990s in Korea. In the presentation, the authors will introduce the recent research and development activities mainly focusing on the rare earth metals of the Pacific deep seabed Mn-nodules and gas hydrates which occur from Korean deep waters. KIGAM has been participating in the polymetallic manganese nodule exploration, mining and metal-extraction project, which is modulated by KIOST (Korea Institute of Ocean Sciences and Technology, formerly KORDI). Now KIGAM puts more focus on extracting precious and rare earth metals from the Mn-nodule as well as underlying sediments. The rare earth elements (REE) from seabed mineral deposits also draw attention to those countries including Korea which are lack in natural resources. KIGAM is doing several kinds of leaching experiments using various kinds of reagents under the different experimental parameters. Extraction of rare earth metals from deep sea nodule using H2SO4 and HCl solution showed good leaching effect. As the gas hydrates are to be evaluated as a new future energy resource globally, Korean government has initiated national R/D program covering fundamental exploration survey for resources assessment in Korean deep waters and production technology development. KIGAM plays a key role in seismic exploration, resources assessment, experimental

Sep 14, 2011

By Gary J. Massoth

Are hydrothermal emissions from subduction-related volcanic arcs important to the total hydrothermal burden of the oceans? While historical observations of hydrothermal venting of fluids at mid-ocean ridgecrests, intra-plate hotspots, and backarc spreading centers are numerous, we remain poorly informed regarding the contributions from hydrothermal systems associated with oceanic submarine arcs. Here we report the chemical results from the first systematic assessment for hydrothermal activity at an intra-oceanic arc front. We discovered that 7 of the 13 submarine volcanoes that define a 260-km-long segment of the southern Kermadec arc north of New Zealand are hydrothermally active. Most significant here is that the chemical compositions of the various hydrothermal systems, inferred from back-extrapolation of observations of hydrothermal plumes, are diverse, and in many instances enriched in the concentrations of gases (e.g., CO2 and H2S) and metals (e.g., Fe and Mn) compared to effluents commonly discharged from mid-ocean ridges. If our results are generally representative of submarine arcs, whose global extent may equal one-third that of ridgecrests, the answer to our leading question could be a resounding yes in terms of both volume and chemical composition.

Jan 1, 2001

By S. Jeffress Williams

Continental shelf margins are dynamic sedimentary environments that contain important benthic habitats and support many functions such as navigation, national defense, cables, pipelines, trawling, and oil and gas and mineral extraction. Coastal margins also contain resources such as sand and gravel aggregates, which are becoming increasingly important for beach nourishment to mitigate coastal erosion and enhance recreation and to restore degraded coastal ecosystems. Existing geologic maps of the seafloor and sub-bottom sedimentary character, morphology, texture, composition, and other seafloor properties are not available for some regions, are out of date and not inclusive of the massive data collected during the past several decades, and are not in GIS-based digital formats. New geologic maps, based on unified and integrated national digital datasets, showing the sedimentary character of continental margins are critical tools for both research to better understanding the geologic history and processes of continental margins as well as the distribution of habitats and resources and for managing coastal-marine resources. The majority of existing seafloor maps are decades old and do not include recent data from mapping surveys, seabed sampling and observation carried out by federal agencies, universities and industry. Because continental margins are increasingly important, comprehensive and integrated databases are needed to produce GIS-based digital maps displaying information such as seafloor geology, sediment character, texture and distribution. To meet the need for a unified database of seafloor sedimentary character, the USGS is conducting the Marine Aggregate Resources and Processes project, a national assessment of marine sand and gravel with federal, state, and academic partners.

Jan 1, 2004

By Richard H. T. Garnett

Large scale, profitable, offshore mining of cassiterite started in 1907 around the coast of south Thailand and continues today in Indonesia. The more complex marine mining of diamonds commenced in the early 1960?s and is now an established industry off the coast of Namibia in southern Africa. The activities have involved many diverse organisations, and have required the development of new marine mining equipment. De Beers Marine, more recently as contractor to Namdeb, has been the dominant producer since 1989. Smaller, public, mining companies, registered in South Africa, Canada and the U.K., have achieved mixed performance results, but the total annual revenue from offshore diamonds now exceeds about US$ 180 M. With the benefit of hindsight, there are some useful lessons to be learned from the experiences. Mining of placer deposits at sea is more difficult and more costly than on land. It justifiably commences in response to a market demand for a product that cannot be supplied in sufficient quantity from onshore sources, not because the marine resource exists. The high costs can be offset in places by submarine grades so high that they have not been seen on land for a century. Technical and commercial success requires a combination, and a sufficiency, of ore reserves, capital, experienced people, and technology. Economic viability is not achieved easily and some diamond mining companies have experienced a very short productive life, terminating in their acquisition or liquidation. The reasons for failure in marine mining, regardless of whether the product is diamonds, gold, or tin, invariably are similar and fall into two categories. Those outside a company?s control include the sea conditions, taxation and fiscal climate, security of lease tenure, and the diamond market. The others, assignable to the company, provide important instructions for those who may aspire to advance the cause of marine mining.

Jan 1, 2004

By H. L. Gibson, U. Schwarz-Schampera, Mark Hannington

Ancient ore deposits provide important clues for the understanding of the origin and distribution of modern submarine hydrothermal systems. An analysis of the formation conditions, tectonic settings, and preservation of ancient seafloor mineral deposits from the recent geological past to the late Archean sheds light on the time-space relationships and diversity of mineral deposit types likely to be found in the modern oceans. Microplate tectonics that characterized ancient ore-hosting greenstone belts were strikingly similar to those active in volcanic arc environments of the western Pacific today. In such complex settings, oblique collisions, opposing subduction zones, and rapid changes in stress regimes (e.g., from compressional to tensional and back to compressional) were common, causing juxtaposition of diverse styles of mineralization. The world-class base metal deposits of the late Archean Abitibi greenstone belt of Canada, for example, were formed within a relatively short time span of ~20 m.y., in response to successive arc rifting, back-arc basin development, and exhumation of accretionary complexes along major arc-parallel crustal-scale faults. Similar processes and environments are important settings for metallogenesis in modern submarine volcanic arcs. Active marginal basins of similar size and representing similar stages of evolution are well represented in the western Pacific today and contain a similar suite of mineral deposit types. Examples from the eastern Manus Basin and adjoining New Ireland Basin (PNG) and in the Lau-Tonga-Kermadec arc-backarc system illustrate these similarities. Certain gold-rich volcanogenic massive sulfide deposits at the southern margin of the Abitibi greenstone belt (e.g., Bousquet and LaRonde deposits in the eastern Blake River Gp.) may be important ancient analogs of newly discovered gold-rich black smoker deposits found along the active fronts of today's submarine volcanic arcs.

Sep 24, 2006

By Sup Hong

Herein, concept designs of two different types of mining robots are concerned, which are aimed for developments of deep seabed mineral resources: polymetallic nodules (PMN) and seabed massive sulfides (SMS), respectively. Continuous mining concepts are presented based on technical and environmental feasibility, where the environmental and functional differences for commercial productions are investigated. Needs and roles of versatile mining robots are explained as a key of continuous mining system. The functional requirements and design characteristics of mining robots to satisfy the top requirements from customers are described comparatively. Schemes of axiomatic design and quality function deployment (QFD) are utilized: functional requirements (FR) are defined, technical requirements (TR) are figured out, design parameters (DP) are derived, and degrees of importance of design parameters are evaluated. Analogy and discrepancy in remote operation methods are put side by side. A pilot scale mining robot for PMN and a commercial scale one for SMS are suggested in form of concept designs. PMN mining robot is shaped as a multiple configuration of unit robot modules in side dimension, in which the unit robot module consists of two tracks and two pick-up modules. SMS mining robot is based on a four-tracked vehicle. Main platform is mounted on the vehicle through turn-table. Excavation device consists of two-articulated boom and cutter tool. Crushing-and-pumping units are placed same in both robot platforms.

Jan 1, 2011

By Takafumi Kasaya, Katz Suzuki, Yoshifumi Kawada

"INTRODUCTIONThe area beneath the seafloor preserves valuable resources that are inevitable to sustain our industrial society. Hydrocarbon resources such as petroleum and natural gases are one of the representative examples, which have been mined over a century (Brandt et al. 1998). In addition, submarine resources such as methane hydrates, ferromanganese crusts, and metal deposits of hydrothermal origin have long been known (Rona 2003; Kvenvolden and Rogers 2005), although methods of their mining have not yet been developed. All of these resources are distributed heterogeneously, and various exploration techniques have been developed and examined. The Japan Agency for Marine-Earth Science and Technology (JAMSTEC) is conducting a project on the development of exploration methods of these unexploited resources (Urabe et al. 2015; also see http://www.jamstec.go.jp/sip/images/pamphlet_e.pdf). The present study particularly focuses on our attempt on the developing an exploration method of hydrothermal ore deposits.Seafloor hydrothermal ore deposits are associated with submarine volcanoes of mid-ocean ridges, hot spots, and island arcs, and back arcs (Hannington et al. 2010). Active hydrothermal systems discharging high-temperature fluids can be detected above the seafloor as anomalies of temperature, turbidity, and acoustic impedance (e.g. Kasaya et al. 2015). However, because of the temperature limitation of mining (Boschen et al. 2013), the target of mining may be extinct and probably buried. To explore buried hydrothermal ore deposits from the vast seafloor area, geophysical surveys that can obtain information below the seafloor must be required. Several techniques including magnetic, electrical, and gravitational methods have been developed (e.g. Jones 1999; Kowalczyk 2008). Although physical properties taken by these methods are sensitive to the presence of hydrothermal deposits, difficulties are sometimes encountered. For example, anomalies of magnetic susceptibility and electrical conductivity, which characterize the presence of ore deposits, may be found above non-hydrothermal bodies such as volcanic bodies and reservoirs of hydrothermal fluids (e.g. Honsho et al. 2016). Thus, combinations of multiple methods must be used to specify the existence of buried hydrothermal ore deposits"

Jan 1, 2017

By Yuta Yamamoto

Seafloor massive sulfides (SMS) which contain Au, Ag, Cu, Zn, and Pb have been interested in as a target of commercial mining these 15 years. Japan has large potential of SMS and a national R&D project for the mining has been active these 5 years. However, the economy of SMS mining is very bad, because the waste tailing disposal cost is very expensive in Japan. A slurry flushing method is experimentally examined in this study for the improvement of the economy. During the flushing, because of density difference between the metal-rich ore and the waste rock, a kind of gravity separation is possible. The results suggest a possibility of the actual application.

Sep 14, 2011

By Tetsuo Yamazaki

Natural methane hydrate has been scientifically studied as a carbon reservoir globally. However, in Japan, the potential for energy resource has been industrially highlighted. There is less domestic oil and natural gas resources in Japan, but many potential deposition areas for methane hydrate in ocean around Japan are the reasons. Less CO2 discharge from methane compared with coal, oil and conventional natural gas when the same calorie value we get is considered as the advantage for energy resource. However, because methane hydrate distributes in shallower sediment layer in ocean floor, accidental leakage of methane may occur while we utilize methane hydrate. Methane itself has 21-times impact on the greenhouse effect, if it reaches the atmosphere. Therefore, it is necessary to estimate the behavior in the environment after the leakage, if we want to use methane hydrate as energy resource. The mass balance after leakage of methane on seafloor and in water column is numerically studied through the analyses of methane emissions from natural cold seepages and hydrothermal activities in this research. The outline structure of mass balance ecosystem model shown in Fig. 1 is introduced. A numerical early diagenetic model CANDI (Carbon And Nutrient Diagenesis) developed by Boudreau (1996) for simulating the biogeochemical processes such as organic matter, oxidant, nutrient, bi-product, and pH diagenesis in aquatic surface sediments and C. CANDI improved by Luff and Wallmann (2003) for describing the formation process of calcium carbonates in CANDI are used as bases of the ecosystem modeling in surface sediment layer around seafloor methane emission. Two functions such as methane bubble dissolution and bacterial methane oxidation in water column are added to an existing physical plume dispersion model by Doi et al. (1999).

Jan 1, 2005

By M. E. Williamson

A seafloor based robotic drilling system is being developed for the National Institute of Ocean Technology in Chennai, India to support a National initiative for marine methane hydrate research. The system will be capable of core sampling to 150m below the seafloor in 3000m of water under telemetric control of an operator onboard a research vessel at the surface. Unlike previous robotic drilling systems, this unit (designated the ACS) will use wireline methodology to reduce the number of tool handling operations required to complete the borehole (conventional rod drilling requires 2025 tool handling operations to complete a 100m hole, while wireline requires only 48 operations to reach the same depth).

By H. Oda, L. E. Fong, K. K. McBride, B. P. Weiss, F. J. Baudenbacher, A. Usui

Fine-scale dating is a key parameter in characterizing the growth history of hydrogenetic ferromanganese crusts. We once compared several dating methods, micropaleontological (calcareous nanofossil), radiometric (10/9Be), and paleomagnetic (step-wise measured inclination) methods on single samples, but these independent methods were not consistent with each other (Joshima & Usui, 1999). For example, a 4-cm thick crust was dated as 3Ma by the fossil-paleomagnetic combined method, while it dated older than 5.5 Ma by Be-10 dating. This discrepancy suggests a question if the Be-10 radiometric method can give us false ages or growth rates (Usui et al., 2002) because of post-depositional change, diffusion or other reasons. In order to answer the question, we conducted ultra-fine magnetostratigraphy with a SQUID microscope on the same hydrogenetic Mn crust sample. Rock magnetic measurements revealed that the main magnetic mineral is well dispersed single domain grains, which is typical to magnetite but not yet specified (Oda, 2005).

Aug 24, 2006

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 Ning Yang, Yuxiang Chen, Ming Chen

An ultraviolet laser Raman spectrometer was developed to detect and analyze material components of seawater, seafloor sediment and rock at a depth of 7000m maximally. Wave length of the excitation resource of the spectrometer is set to 355nm, which can enhance eigen scattered intensity and detecting sensitivity, and avoid fluorescence interference. Miniaturization design was adopted for deep-sea application. Design of the optical system and pressure cartridge, material selection and seal design of the observation window, and design of the Lithium batteries are the key technologies in the procedure of research and development. The spectrometer was carried by a Lander sank to sea bottom of the Pacific's Mariana Trench for verification. During the sea trials, data acquisition for Raman spectra was conducted for analyzing seawater in the detection area, and the spectrometer was verified synthetically. According to the data, the spectrometer is stable and practicable with high resolution and precision, and it is appropriate to detect and analyze composition of substance under the tremendous ocean.

Jan 1, 2017

By Winston Rocher Anda

Traditionally, mining activities have been developed in firm land, but technological advances and human needs have opened in the last year?s new opportunities in the maritime field. This has happened not only in the oil or hydrocarbons industries, but also in relation to the exploration or exploitation of other minerals, metallic and non-metallic. This has forced several countries to complement or create legal rules that make possible its own development and the International Law, through the United Nations Convention on the Law of the Sea, to regulate this activity in the space of its own, the calling area. Chile, as country with a long experience in mining and great advances in large deposits exploitation, possesses a special juridical frame that regulates this economic activity according if it is the geographical or territorial area in which is realizes, and it has been complemented lately with the international normative.

Jan 1, 2011

By Kaihui Yang

Volcanogenic massive sulfide deposits are generally considered to have been formed by hydrothermal fluids that leach ore metals out of footwall rocks. However, the necessity for a metal-rich magmatic component in the ore-forming fluid of "giant" ore deposits has been debated over the decades. The solution to this issue is important not only for metallogenic models but also for the mineral exploration. In the hydrothermal leaching model, massive sulfides at mid-ocean ridges are deposited from hydrothermal fluids containing 80 ppm Fe, 6 ppm Zn, 2 ppm Cu, 350oC, and 0.7 g/cm3 density (average data for 21oN East Pacific Rise). A simple calculation demonstrates that such a dilute fluid is unlikely to have been responsible for the formation of the largest ancient massive sulfide ores of greater than 100x106 tonnes, such as Kidd Creek, Brunswick No. 12, Neves Corvo, and Rio Tinto. For such a deposit consisting primarily of pyrite, sphalerite, galena and chalcopyrite (other minerals, including gangue, might account for an additional 10-20%) and even assuming 100% precipitation and retention of the sulfides, more than 790 km3 of vent fluid would be required. For typical water-rock reaction ratios of about 2, this fluid would have to have reacted with about 395 km3 of rock to acquire its metals by conventional leaching processes. This estimate, however, conflicts with the observation that even a giant massive sulfide ore body is usually underlain only by a few cube kilometers of obviously altered rocks. Moreover, this model is not consistent with the observation of hanging wall alteration in many large massive sulfide deposits. The close spatial association between massive sulfides and volcanic rocks, in both ancient and modern sea floors, suggests that direct magmatic contribution should be taken into account in the genetic model. Magmatic fluids, capable of carrying abundant ore metals and volatiles and escaping from magma by depressurization, are well known from modern active volcanoes on land. High concentrations of metals occur in CO2-rich magmatic fluid trapped in felsic volcanic rocks nearby large presently-forming VMS deposits in the eastern Manus Basin (Pacmanus, Suzette) and also in the footwall rocks of Ordovician giant Brunswick #12 deposit in the Bathurst district, New Brunswick. Only 1% of such metal-rich magmatic fluid mixed with heated sea water, that has leached its metals from rocks, would contribute 85% of the total metals to form an orebody. Such magmatic fluids are most likely to be formed from volatile-rich felsic magmas that are prevalent in back arcs, and, if added to the normal circulation system, the fluids could be responsible for the formation of "giant" ore deposits. If this is true, then the study of magmatic fluids in the seafloor volcanic rocks may provide criteria for the exploration of large ore deposits.

Jan 1, 2011

By Will Roberts, M. E. Williamson

After verification of methodology and testing of prototype systems during 2005/06, Nautilus Minerals expanded their Papua New Guinea (PNG) operations to a full commercial exploration program in 2007. Included was the deployment of sensors and survey systems to locate, characterize and verify massive sulfide deposits with potential as mine sites within the tenements held by Nautilus in PNG. This presentation discusses some of the gear developed and operated during the 2007 PNG investigation.

By J. Robert Woolsey

This paper provides certain Southeastern coal-burning utilities with an economic strategy for complying with the sulfur dioxide emission standards set firth by the Clean Air Act Amendments of 1990. The strategy takes advantage of the occurrence of vast quantities of manganese nodules on the Blake Plateau offshore Georgia and the Carolinas, a commodity which as been proven to be a highly effective dry sorbent of sulfur dioxide. Using existing technology, manganese nodules could be mined and transported via barge directly to power plant sites, where they would be used as filter material for cleaning sulfur dioxide from the effluents of coal-fired power plants. Completely sulfated filter material could be treated for the extraction of by-product metals such as cobalt, copper, nickel, and manganese. The strategy may well be enhanced by the occurrence of ore grade phosphate rock in the same area of the Blake Plateau. This phosphate rock could be simultaneously mined to effect a reduction in production costs if it is found to be suitable for use as either a direct application fertilizer or as an acidulated superphosphate fertilizer. The manganese nodule-based strategy offers a retrofitting solution for existing power plants that would minimize the capital costs for compliance with the Clean Air Act Amendments and has the added advantage of providing a number of other metal or fertilizer by-products.

Jan 1, 1992

By Steven D. Scott

Several polymetallic sulfide deposits (copper, zinc, f lead, silver, f gold) presently exposed at the surface of the ocean floor are of sufficient size and apparent grade that they will someday be seriously considered as mineable resources. Responsible ocean mining may have some real environmental advantages over land mining, although they both share the same downstream problems caused by smelting and refining. The area of disturbance for an ocean mine would be much less than for an equivalent sized deposit on land around which considerable rock has to be excavated in order to get at the ore. Acid mine drainage, a very serious problem in land ming, would not be a concern in the alkaline and oxygen deficient environment of the deep ocean. There would undoubtedly be loss of habitat for some marine organisms but this could be minimized by mining deposits that are no longer hydrothermally active and therefore support little life. The risk of severe corrosion and thermal damage to the mining equipment at hydrothermally active sites would probably preclude their recovery in any event. The scientific community and environmental advocates should take advantage of the long lead time before ocean mining commences to insure that the environmental mistakes of the past, as encountered in some land mining, are not repeated. In order to fully understand and thereby mitigate the consequences of recovering seafloor sulfides, test mining of a small deposit using the German-designed high capacity television grab, preceded and followed by detailed observations of the mining site from a submersible, is proposed.

Jan 1, 1992

By Allan Spencer

In March 2007, Nautilus Minerals Inc. announced that they had commenced their 2007 exploration and development program with the mobilization of the Research Vessel Wave Mercury and the Survey Vessel Aquila onsite Papua New Guinea.