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By Hunsoo Choi, Sang-Mo Koh

Manganese nodule, the aggregate of fine grained manganese oxide minerals, is very brittle and fragile. In exploitation of manganese nodule, manganese nodules are easily broken into small pieces or powder during collecting and lifting from the sea floor. The broken manganese nodule under few millimeters and bottom sediment pumped up with manganese nodule affect to the lifting process. In this study, we tried to understand the physical properties of the powdered manganese nodule and bottom sediment, and to know the effect which may be rised to the actual mining of manganese nodules.

By Curtis Clement

Williamson & Associates, Inc. has developed a marine mineral exploration tool using an induced polarization technology (IP) under license from the US Geological Survey. Developed by Jeff Wynn at the USGS, this method has gone through several prototyping stages and is now in commercial use to map offshore ilmenite deposits. Preliminary results of a recent resource mapping program are discussed as well as potential applications in the detection and quantification of other minerals in marine sediments.

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 Nobuyuki Okamoto

Ferromanganese crusts on the seamounts in the Pacific Ocean are potential resources of cobalt, nickel, platinum and REEs. Particularly, those of the Republic of Marshall Islands and the Federated States of Micronesia (FSM) waters are believed to be of the highest resources potential area in the Pacific Ocean. The total six cruises using the Japanese Research Vessel Hakurei Maru No. 2 were carried out in the seamounts of the Marshall Islands in 1996, 1998 and 2002, and of the FSM in the 1997, 1998 and 2005 for evaluation of economic potential for cobalt-rich ferromanganese crusts as part of the Japan-SOPAC joint project. During these cruises numerous data such as bathymetric, geological, geophysical and environmental data were obtained. Geophysical exploration with backscatter mapping and side scan sonar, visual imaging using towed TV camera and geological sampling using dredge bucket and/or benthic multi-coring system (BMS) were conducted on these seamounts. In this presentation, we will report the mode of distribution of the crusts and calculated resource estimation based on the results of these geological and geophysical shipboard survey and land-based analyses. Keywords: ferromanganese crusts, Marshall Islands, Micronesia, resource potential

Jan 1, 2011

By Samantha Whisman, James R. Hein

Hydrothermal marine manganese-oxide deposits (HMMD) are cemented and variously replaced volcaniclastic and biogenic sediments that were mineralized by distal, low- temperature, hydrothermal fluids. HMMD predominantly form below the seabed as sediment-hosted statabound deposits but can also form on the seabed. These deposits form at oceanic and back-arc basin spreading centers, volcanic arcs, and mid-place hotspot volcanoes. HMMD have traditionally not been considered to have an economic potential because they were considered to be devoid of economically valuable critical elements. This contrasts with their non-hydrothermal counterparts, ferromanganese crusts and nodules, which are enriched in many critical elements. However, manganese is now one of the critical metals and HMMD have the highest manganese contents (up to 55% Mn, so- called battery-grade Mn) of all the types of deep-ocean mineral deposits. There is a growing demand for this critical metal and an upward trend exists in the price of manganese on the global market. Also, other critical elements can occur in high concentrations in some HMMD and their economic potential has not been considered, especially for lithium (up to 0.17%) and molybdenum (up to 0.24%), but also vanadium (to 820 ppm), chromium (to 346 ppm), and nickel (to 0.45%), among others. Which of these critical elements are enriched and their concentrations depend on the types of rocks leached at depth by the hydrothermal fluids, the composition of hydrothermal minerals precipitated in the higher temperature parts of the circulation system, and the types of sediments mineralized by the manganese oxides. For example, mineralization of a carbonate sediment resulted in the highest lithium contents, whereas leaching of ultramafic rocks at depth as a rule results in the highest chromium and nickel contents in the HMMD. These deposits are known to be widespread, especially in volcanic arcs, but their lateral and vertical extents and consequently size, tonnage, and grade have not been determined. Most samples of hydrothermal deposits have been collected by dredging and therefore the in situ relationships often are not known. One sample from the Mariana volcanic arc, west Pacific, was collected by ROV at 1274 m water depth from a layered outcrop 6.6 m thick that may be a sequence of pervasively mineralized volcaniclastic layers and offers the first clue as to the potential vertical extent that these deposits may attain. However, only the top ~0.4 m-thick layer was sampled, so it is not known whether the mineralization extents throughout the outcrop. Although large manganese deposits of various origins occur on the continents, they consist of manganese carbonates, silicates, or complex mixtures of manganese minerals. In contrast, marine hydrothermal HMMD exhibit relatively simple mineralogy that would make processing of this potential ore much simpler.

Jan 1, 2018

By S. Rajendran

Gas Hydrates (Methane Hydrates) are solid, ice-like substances composed of water and natural gas. They occur naturally in areas of the world where methane and water combine at appropriate conditions of temperature and pressure and are found in ocean bottom sediments and in some permafrost areas. Besides temperature and pressure, factors like bathymetry, sediment thickness, sedimentation rates, and total organic carbon content (TOC) also control gas hydrate formation in the ocean basins. The stability of gas hydrates depends on the critical combination of high pressure and low temperature (0 - 17 bars, 0 - 25°C), which in turn is dependent on the mix of gases from which the mineral is formed. As the critical parameters can be altered by deposition, erosion, slumping, formation or melting of ice cover, rise and fall of sea level, and sudden temperature changes induced by tectonic activities, current flow, or volcanisms, the gas hydrates tend to be very unstable. The Indian offshore is promising for the occurrence of gas hydrates in a total of about 80,000 km2 area in the bathymetry range of 700 to 3000 m as reported in earlier surveys. A gas hydrate stability zone thickness map was prepared using bathymetry and sea bottom temperatures along the continental margins of India. This map is expected to provide the depth window while searching for Bottom Simulating Reflectors (BSR). The study indicates that a minimum water depth of 750 m is required for the formation of gas hydrates, above which the chances for gas hydrate occurrence appear minimal despite other favorable conditions like organic-rich sediments, etc. Single-channel seismic analog records (Gupta et al., 1998) indicate that the Western Continental Margin of India (WCMI) offers a greater promise for gas hydrate occurrences, particularly with regard to the number of BSRs traced on the analog records as compared to earlier surveys.

Jan 1, 2005

By Andreas Kaede

INTRODUCTION Due both to the political history of UNCLOS and the sensitivity of the ocean floor and environment to man made impacts, both the Convention (including also the 1994 Amendment) and subsequent codification (such as the ISA draft code on Exploitation of Mineral Resources in the Area) put a focus on information about, and conveyance of, technology employed by interested deepsea mining companies, to inter alia the Authority and developing countries. In contrast, companies usually are (or by their nature should be) interested in safeguarding their technology and business secrets in order to secure unique selling propositions in a competitive environment. On the background of the meanwhile maturing regulatory régimes on deep sea mining, the presentation will look into some of the key regulatory provisions mirroring these apparently antagonistic interests, how the players involved could deal with them, and how they might in some cases be reconciled. Progress of Presentation The presentation will start by briefly examining some classical methods of protection of technology, such as patents, copyrights, and (not the least) secrecy. It will be found that some of the statutory means of protection due to their territorial character may face problems in being implemented in areas outside national jurisdiction, such as the Area, but that, thinking globally, they nevertheless retain much of their value for the purpose of protection. Depending on available presentation time, a model case may be used to illustrate the above – and also some of the following – findings.

Jan 1, 2018

By E. Moriguchi, K. Tamaki, A. Okuda, K. Iizasa, C. Honsho

The northern Izu-Ogasawara Arc is characterized by an abundant distribution of submarine calderas along the volcanic front to the back-arc rift zones. In many of these calderas hydrothermal activities are observed. Among these calderas, hydrothermal ore deposits with economically feasible quality and amounts are hosted at two calderas, the Myojin Knoll Caldera and Beyonnaise Knoll Caldera. We conducted two research cruises in 2005 and 2006 to investigate further hydrothermal activities and ore deposits in these calderas and to complete the geological and geophysical mapping in the area. We discovered a strong signature of hydrothermal activity in the Myojin-sho Caldera using AUV capabilities. Newly obtained geological and geophysical data clarified the relationship between back-arc rifting tectonics and hydrothermal activities in the area. Five calderas (two of them newly found) and numerous (>200) volcanoes are mapped in the area. Complete SeaBeam coverage showed a distinct feature of the back-arc rifting activity and its relationship to the submarine calderas on the volcanic front. The back-arc rift zones composed of four segments separated by E-W trending volcanic ridges. Three of the calderas are located in the rift zone and are heavily deformed by the rift normal faulting that typically trend NNW-SSE. As the Beyonnaise Caldera is located in a swarm of faulting zones at the eastern end of the back-arc rift, the formation of the hydrothermal ore deposits found in the Beyonnaise Caldera are apparently affected by these faulting activities. Newly found submarine calderas are located in the rifting zone and are heavily faulted.

Sep 24, 2006

By Chris Castle

Following the recent award of a prospecting license by the New Zealand Government, Widespread Energy Ltd. (Widespread) is focused on the acceleration of its exploration program in order to bring a potential phosphorite deposit to market in the near future. Rock phosphate is the primary constituent of most fertilizers that are manufactured and distributed in New Zealand. Field trials in the 1980s demonstrated that direct application of rock phosphate can result in a more effective fertilizer (than super-phosphate) with less environmental damage from run-off. At present virtually all of the rock phosphate used by the New Zealand fertilizer industry (approximately 1 million tonnes a year) is imported from Morocco. In recent years price increases of up to 12 fold (peak of $500/t) with massive increases in freight costs have bought to the forefront the economic opportunity to in part replace foreign imports with a local source of phosphate. The Chatham Rise phosphate deposits are relatively well understood, having being discovered during the 1950?s and it is estimated that approximately 100 years supply (at current requirements) is present at shallow depths. An estimated 100 million tonnes of rock phosphate is present within the license area based on previous private and publicly funded research. Widespread has engaged several parties to assist in the exploration planning to confirm the resource potential. Widespread has commenced investigating the feasibility of recovering the phosphorite nodules off the sea floor, and presently has several conceptual technical solutions under consideration and will advance the discussions with potential contractors during the exploration phases. Widespread is acutely aware of its responsibilities to conduct both the exploration program and extraction of the rock phosphate, in a manner that causes minimal disruption to the marine environment. To this end, the National Institute of Water and Atmosphere (NIWA) ? a New Zealand Crown Research Institute has been engaged to assist in designing sampling and extraction methods that will minimize disruption to the seabed. All sampling and extraction activities are planned to be conducted with reference to the environmental guidelines published by the International Marine Minerals Society ?Code for Environmental Management of Marine Mining.? Widespread is conducting its project with a background of changing regimes to both the allocation and environmental management of its activities.

Jan 1, 2010

By Akira Usui

Fine-scale geochemical, mineralogical, and structural variations in ferromanganese crusts are believed to be the long-range records of paleoceanographic conditions and geological events on the small to global scales in the world oceans, which is useful in reconstructing marine environment. The chemical profiles of thick hydrogenetic ferromanganese crusts and nodules were determined by ICP/ES at 2-3 mm intervals at several locations over the Japanese Islands, Magellan Seamounts, Marshall Islands, and South Pacific Basins, together with Be-10 dating. We found general trend of Co enrichment (or high ratio of Co/Mn) in the upper layers of crusts, or outer layers of nodules, which formed in younger period probably after the late Miocene. This general trend of higher Co concentration in the surface may be true over the western to the Pacific, but local variations in growth patterns and shorter-range fluctuations in chemistry and structure were found as well. The growth rate is sometimes three times faster at the shallower depth even in a single seamount. The in-depth fluctuation of Co is well correlated with the ratios Mn/Fe ratio and Ce/La, suggesting changes in redox conditions during the growth of hydrogenetic ferromanganese crusts.

Jan 1, 2002

By James R. Hein

A new data set of cobalt-rich ferromanganese (Fe-Mn) crust chemistry has been completed for the first detailed sampling of a latitudinal crossing of the Pacific equatorial zone of high biological productivity. Samples were collected in January-March, 1999, during the AVON 2 cruise aboard the R.V. Melville, Scripps Institute of Oceanography. Samples were collected from 4.6° N to 9.2° S latitudes along two ridges, the Marshall Islands-Gilbert Islands ridge (4.6° N to 3.5° S) and the Howland Island-Tokelau Islands ridge (1° N to 9.2° S). The two ridges are offset east-west in the region of overlapping latitudinal sampling by about 466 km. We determined the concentrations of 48 elements for 147 samples from 39 dredge hauls taken on 33 seamounts and island flanks that occur between the Marshall Islands to the northwest and Samoa to the southeast. Element concentrations can be examined as varying spatially and with water depth in the ocean and we examine those relationships based on statistical analysis of the chemical and spatial data. The mean Fe/Mn ratio of 1 and mean Co content of 4645 ppm are typical of West Pacific hydrogenetic crusts; but the mean Co content is low compared to those of some equatorial North Pacific sites, such as the Marshall Islands and Johnston Island EEZs. In contrast, the mean Cu concentration (1540 ppm) is 35% higher than the mean concentration for Pacific Ocean Fe-Mn crusts (998 ppm). Another striking difference is the 40% higher Ba concentrations (mean 3107 ppm) compared to typical Central and West Pacific crusts (mean 1876 ppm); but Ba concentrations are lower than those in California continental-margin Fe-Mn crusts (mean 4085 ppm). A final significant difference in Fe-Mn crust chemistry is Zr concentrations, mean 921 ppm (maximum 1523 ppm), which is about 30% higher in this data set compared to the previously determined mean value of 613 ppm for Central and West Pacific crusts. Zirconium has a strong positive correlation with Ba and a weak positive correlation with Mn.

Jan 1, 2003

By Kioshi Mishiro, Pratima Jauhari, Walter Williams

INTRODUCTION The UN-General Assembly adopted an Agreement on 28 July 1994 entitled ‘Agreement relating to the implementation of Part XI of the United Nations Convention on the Law of the Sea ((UNCLOS) of 10 December 1982’. The Agreement came into force on 16 November 1994, and consequently, the inauguration of the International Seabed Authority (ISA, or the Authority), located in Kingston, Jamaica. The Authority is the organization through which States Parties to the Convention (168, as of 25 July 2017) shall, in accordance with the regime for the seabed and ocean floor and subsoil thereof beyond the limits of national jurisdiction (the Area) established in Part XI and the Agreement, organize and control activities in the Area, particularly with a view to administering the mineral resources of the Area. The legal regime for the administration and development of the mineral resources of the Area as it now exists are available in Part XI of the Convention1 which contains the legal framework governing “activities in the Area” and in Annex III to the Convention which contains the “Basic Conditions of Prospecting, Exploration and Exploitation” with respect to the resources of the Area2. The 1994 Agreement relating to the Implementation of Part XI of the UNCLOS is the so- called ‘parallel system’; as elaborated in article 153 of the Convention. The essential elements of the ‘parallel system’ include assured access for States parties and their nationals to seabed mineral resources along with a system of site-banking, whereby ‘reserved areas’ are set aside for the conduct of activities by the Authority through the ‘Enterprise’ itself or in association with developing States or in joint venture with the contractor who provided the particular reserved site2.

Jan 1, 2018

By Ning Yang, Sup Hong

INTRODUCTION Metal components contained in deep-seabed mineral resources are being highlighted as “energy metals”, which are widely utilized in the entire fields of energy: harvesting and generation, storage and transportation, and saving. Those are mostly trace and rare metals, and rare earth elements as well: manganese, nickel, cobalt, copper, molybdenum, tellurium, selenium, platinum, etc. Toward low carbon society, for global sustainability, the role of metals and minerals is growing up in industries of energy and transportation [1]. In this context, the production and supply of energy metals from deep seafloor have to be approached also based on sustainable development. In deep-seabed mining activity, the sustainability is focused on potential impacts on ecosystems in benthic area and water column. The environmental impacts in deep-seabed mining are caused basically by intervention in benthic zones and transportation of materials. Those are, in particular, removal of benthic habitats, generation and dispersion of sediment plumes, surface transportation of seawater and sediment, tailing from mining vessel, sound and light noises, and chemical leakage, etc. This paper is aiming at fundamental guidance towards sustainable mining of polymetallic nodules.

Jan 1, 2018

By Daniel Brutto

Environmental considerations are a key driver within the marine mining consenting process across different national and international legislative regimes and are critical in shaping the global public perception of the industry. As a result, it is vital that mining companies seeking to operate within marine environments establish a robust understanding of the sensitivities of the seabed environments in which they are active, the impacts of their activities and the ability of the environment to recover from these impacts. The significant risks of failing to do so include an inability to either obtain or maintain operating permits. The risks can be mitigated by the common application of existing seabed biological expertise in baseline assessment and monitoring. The key ingredients of a fit-for-purpose, cost-effective seabed ecological assessment include early consideration of ecological issues within the project life-cycle through undertaking detailed desk-top studies as-wellas the multiple-use of data that have been acquired as a consequence of prospecting processes, with such data including remote acoustic data, seabed imagery and sediment samples. These data can be used to inform the design of robust benthic baseline surveys which provide adequate information on the ecological character of the environment in question and habitats and species of conservation importance - decreasing project risk and increasing the likelihood of securing consent.

Sep 14, 2011

By Valery M. Yubko

"The conceptual basis of the developed model is based on the ideas that evolution of geological-geomorphological structure of the CCZ is controlled by four types of geologic factors: geodynamic, sedimentary, volcano-tectonic and erosion-lithodynamic. In terms of time span two factors (geodynamic and sedimentary) can be considered as permanent and the other two as sporadic.The geodynamic factor is responsible for two interrelated geological processes. One is going under conditions of the axial zones of spreading centers and results in formation of the CCZ basement. Historically this process is considered as a starting point for each of the heterochronous fragments of the CCZ. The second one controls gradual shifting towards the Pacific Plate (Hawaiian direction) and subsidence to greater depths of the neogenic fragments (basement). Thus, those processes control basic topography, geomorphology and the seabed depth within the CCZ.Volcanogenic-hydrothermal activity of the EPR is one of the main sources of the ore components, which finally compose manganese nodules as a result of complicated processes of their dissemination and transportation to the bottom in dissolved and organically bound forms.The role of the other constant factor (sedimentary) is displayed in two ways. Firstly, initial relief is smoothed under the influence of this factor, which, subsequently, makes favorable conditions for manganese nodules formation. Secondly, it favors transportation of the majority of the ore components, participating in manganese nodules formation into zones of active nodules formation."

Jan 1, 2017