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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 Thomas Pichler

In the past marine mining technology has focused on bulk mining of base metals from polymetallic massive sulfides. This has not been very successful because of the relatively low unit value of these metals and other reasons such as water depth, etc.. The process of gold enrichment in hydrothermal deposits is controlled through five different factors: (1) nature and source of the solution, (2) source of the gold, (3) a mechanism for mobilizing and transporting, (4) a mechanism for deposition, and (5) a mechanism to preserve the deposit. Gold has been identified in marine polymetallic massive sulfides from various locations on the ocean floor (e.g., spreading centers, seamounts) with contents ranging up to 5 ppm Au. This is within the current range of 1.0 to 7.0 ppm gold content which classifies gold ores. The gold appears to have been derived during hydrothermal alteration of the oceanic crust. Until the present there has been little attention to the possibility of mining gold or other precious metals in the marine environment. However, the magnitude of hydrothermal alteration (seawater can penetrates to a depth of 5 km into the oceanic crust) and primary gold contents of the rocks in the pathway of the fluid indicates that major gold deposits must have formed on or in the ocean floor, but they have not been found. To find a big deposit might only take an exploration model exclusively designed for gold exploration on the ocean floor.

Jan 1, 1993

By J. R. Hein

East Diamante is a submarine volcano in the southern Mariana arc that is a complex caldera about 10 km x 5 km (elongated ENE-WSW), and breached on its northern and southwestern sectors. A large field of barite-sulfide mounds was discovered in June 2009 and revisited in July 2010 aboard the R.V. Natsushima using the Hyper-dolphin ROV. The mound field occurs on the NE flank of a cluster of resurgent domes inside the caldera. The mound field extends for more than 100 m long and is about 30 m wide, and is aligned along a NE-SW rift valley. A sample of dacite yielded a 40Ar/39Ar age of 20,000±400 years. Individual mounds are typically 1-3 m tall and 0.5-2 m wide, with lengths from about 3 to more than 5 m. The mounds are composed of barite-dominant layers interbedded with Zn-sulfide-rich barite layers. Rare inactive spires and chimneys cap some mounds. Fe and Mn oxides are currently forming small (<1 m diameter, ~0.5 m tall) subsidiary mounds on the top of some of the sulfate/sulfide mounds and drape the flanks of others. Both diffuse- and focused-flow fluids emanate from the subsidiary oxide mounds. Ages of the basal sulfate/sulfide mounds cluster around 4,000 years old based on 226Ba/Ba, whereas the oxides are less than 5 years old based on 228Th/228Ra. Most mound and chimney samples are dominated by barite and amorphous silica; sulfides occur in variable amounts that in decreasing order of abundance include sphalerite, galena, pyrite, and chalcopyrite. Anglesite, cerrusite, and a Pb phosphate occur as late-stage interstitial phases. Some mound samples have fragmental textures; layered clasts composed of chalcopyrite and pyrite may have been derived from collapsed chimneys. Despite the abundance of barite, samples contain high concentrations of Zn (to 23 Wt.%), Pb (to 13 wt.%), Ag (to 500 ppm), and Au (to 15 ppm). Copper is enriched in a few mounds samples, up to 3 wt.%, but is typically <1 wt.%. Other significant metal enrichments include Sb (to 1320 ppm), Cd (to 1180 ppm), and Hg (to 55 ppm).

Jan 1, 2011

By Peter Halbach

Within the frame of the German-Indonesian cooperative Bandamin research project two short cruises (7 station days each) were carried out which led to the Flores-Banda basin located north of the active volcanic arc. This basin is part of a large island-arc subduction-collision system resulting from a complex plate tectonic situation in which three major plates collide with each other. The eastern part of the Sunda-Banda convergent margin also includes the transition from subduction of oceanic lithosphere to collision of the Australian continental crust with the arc. This transitional part is cut and displaced by various large obliquely striking fault systems. Thus, the south eastern and eastern arc segments represent geological conditions which are suitable for the development of hydrothermal convection and potential mineral precipitation. Our study area lies north of the transitional section between Flores and Wetar. We started with a high-resolution bathymetric mapping of 240 km2 in a region some 36 km north of the island of Lomblen. A small submarine neovolcanic ridge was discovered striking approximately NW-SE and consisting of several submarine volcanic structures. In the northwest of the study area, the active subaerial Komba Volcano (Batu Tara) marks the youngest continuation of the ridge system examined. From the ridge we collected fresh and hydrothermally altered volcanics with disseminated sulfides (pyrite, pyrrhotite, markasite, and chalcopyrite), together with ferrugenous gossans.

Jan 1, 2004

By Igor E. Mikhaltsev

The goal of investigation of the midwaters and of the bottom of the world - ocean versus technological possibilities. Manned vehicles and maximum depth decision. The methods of solving of the problem. The science and technology alloy. Mutual venture of Academy of Sciences of the USSR and, Rauma-Repola Oy of Finland. MIR-1 and MIR-2 - as twins. No reasons of copy "Sea Cliff" and "Nautilus". Six landmarks of specificity of "MIR"-type submersibles. The manned spheres and three ballast spheres are made of maraging steel; the electric power resource (100 kwh) and maximum underwater speed (5 knots) is two times more than of the analogous vehicles while the batteries are of NiFe type; the MIR submersibles have the seawater ballast (and trim) system which means practically unlimited vertical manoeuvrability ; and the weight in air is equal to "Nautilus" - 18,6 tons (in case of equal energy resource the weight of MIR-1 or MIR-2 would be 17 tons). Some remarks on standard life support (248 man-hours) safety systems and specificity of launch & recovery system.

Jan 1, 1988

By Brian D?Olier

Much of the aggregate that is being exploited at present from these areas is a ?relic? deposit. It was originally eroded from primary source rocks and transported to a depositional centre by processes that are now either greatly reduced in effectiveness or are largely absent at the present time. Following the retreat of the Devensian ice sheet, the subsequent rise of sealevel and the drowning of large areas of the continental shelf along with the lower reaches of many rivers, a fresh sequence of sediment sources, pathways and sinks now exist. Sediment is being eroded from several, pre-existing source areas and transported along different, well - defined pathways to a number of new depositional sinks. Some of the present, licenced, aggregate dredging areas lie close to these sources, pathways and sinks with the consequent dredging activity being perceived by some as interfering with the ?natural process? that links the offshore and the coastal / littoral zones. With this perception in mind, the principal, sources, pathways and sinks between Flamborough Head and Beachy Head will be highlighted and the relationship of dredging activity upon them, evaluated. It will be demonstrated that offshore dredging activity has no effect upon supplies of sediment to coastal beaches.

Jan 1, 2004

By Kira Mizell, James R. Hein

Ferromanganese (FeMn) crusts form by precipitation of iron and manganese oxides from seawater onto a rock substrate and are therefore considered hydrogenetic in origin. Diagenesis does occur however, through the process of phosphatization. During phosphatization, abundant dissolved phosphate in seawater replaces carbonate in the detrital fraction as well as directly precipitates within the FeMn matrix as carbonate fluorapatite (CFA). This process is likely accompanied by the partial dissolution or replacement of the oxide phases [1]. As a result of these diagenetic processes, trace elements adsorbed on the oxides are released and can either be depleted or enriched in the phosphatized FeMn crust layers. Pb, for example, has been shown in sequential leaching experiments to associate with the iron oxyhydroxide (FeOOH) phase in purely hydrogenetic layers, while >95% of Pb in phosphatized crust layers is found in the CFA fraction [2, 3]. However, previous sequential leaching studies analyzed bulk layers of phosphatized crusts and only a few crusts, from the Pacific Ocean. Here we present concentration data for Pb and other trace elements in the CFA fraction leached from thin stratigraphic intervals of the phosphatized portion of FeMn crusts from the Pacific and Atlantic oceans to confirm consistency of trace metal association with CFA both throughout the phosphatized section and in two ocean basins. The Pb and trace element concentration data from this study will also be compared with data from non-phosphatized crusts from the global ocean. We can then determine the effect of phosphatization on the concentration of Pb and other elements of greater economic interest in FeMn crusts, specifically whether there is overall enrichment, depletion, or possibly even phase transfer of each metal in the phosphatized layers.

Jan 1, 2018

By Valcana Stoyanova

Data and information for this study were collected in June-July 2009 onboard the RV Yuzhmorgeologiya in the area covers about 7000 km2 in the eastern part of the CCFZ between 10º05? - 10º55?N and 119º25? ? 121º08?W. In accordance with the IOM research program the cruise was intend to acquire both geological and environmental data and information necessary for delineation of nodule deposits and also data for identification of the baseline of benthic ecosystem. Having implementation of its 15-year plan of work for exploration under the contract with ISA, current activities of IOM were focused on nodule fields within prime areas that could be mined in the future. Bottom photographs obtained by towed deep-sea vehicle NEPTUN along 6 profiles with common length about 300 km (Fig. 1). In total, about 11,500 digital photographs (what cover approximately 40,000 m2 of the ocean floor) were analyzed for assessment of nodule coverage and investigation of megafauna (animals, visible in photographs, the dimension more than 2 cm). The giant single-cell organisms Xenophyophorida were the most multiple animals in seabed photographs. Their number on the site area averaged 1187 ind/ha. However, the vertical camera position does not allow counting all xenophyophorids, therefore their valid number is represented 10 times more. According to all available information these protozoans play the relevant role in assemblage of deep-water environment, giving for other animal groups an [ ] additional source of nutrition and a substratum for settlement and attachment. The ophiuroids are found in assemblage with xenophyophorids in many cases, standing on a sediment at their base.

Jan 1, 2010

In early 1990s, the Korean government has launched a deep-sea research program to secure the stable long-term supply of strategic metallic minerals including Cr, Cu and Ni. Through the pioneering surveys, Korea registered 150,000 km2 of Mn-nodule field in the Clarion-Clipperton area, the NE equatorial Pacific to the international sea-bed authority (ISA) in 1994. Following the ISA exploration code, the final exclusive exploration area of 75,000 Km2 was assigned in 2002, based on results of eight-year researches of chemicophysical properties of nodules, bottom profiles and sediment properties. Since that time, environmental studies, mining technical developments including robot miner and lifting system and establishment of smelting systems were accompanied with the detailed geophysical studies to decipher the priori mining area until 2009. Major points of the recent Korea Mn-nodule program are deployed on a commercial scale until 2015. In order to meet the goals, detailed 25,000 scaled mining maps in the priori area will be prepared, which can provide operation roots of the miner. In addition, an environmental-friendly mining strategy will be pursued based on the environmental impact test and environmental monitoring.

Sep 14, 2011

By D. S. Cronan

Based on analogy with the Clarion-Clipperton zone, three main factors appear to influence the occurrence of potentially economic nodules in the study area, (i) elevated biological productivity, mainly above 50gCm-2y-l, (ii.) sea floor depth near or below the CCD, (iii) an absence of turbidite sedimentation. These conditions are fulfilled in parts of the following basins, where available data indicate that high grade and sometimes abundant nodules occur. i) The East Central Pacific Basin west of the Line Islands extending to the East Central Pacific Basin north and east of the Phoenix Islands ii) The West Central Pacific Basin west and northwest of the Phoenix Islands iii) The North Penrhyn Basin north of Penrhyn Island Notwithstanding the similarities between the environmental conditions under which potentially economic nodules occur in the Clarion-Clipperton zone and in the areas listed above, such similarities may relate only to present day conditions. During the possibly long periods of nodule formation, environmental conditions may have varied, and the deposits formed under conditions different from those prevailing at the present day. However, the fact that both present day conditions and the deposits in the two areas do show similarities suggests that applying the same genetic model to them has some validity. Possibly, any changes in environmental conditions during the period of formation of the deposits has been similar in both areas. Such uncertainties can only be resolved by a much fuller evaluation of the evolution of nodule deposits in both areas throughout recent geological time.

Jan 1, 1986

By Benoît Waquet

In a context of scarce mineral resources, coupled with an increasing global demand in metals due to the exponential growth of newly industrialized countries, the mining industry will inevitably have to deal with tomorrow?s resources: underwater deposits. Three types of offshore deposits are known to date: polymetallic nodules, cobalt-rich crusts and hydrothermal sulphides. The latter, regarding the political-economic context, is now considered most likely to be exploited in a near future. Operating a mine critically requires accurate knowledge on geotechnical properties of the ore. A question is thus to be asked: Is there a particular spatial organization of geotechnical properties in a hydrothermal sulfide mound? In the present study, geotechnical properties have been measured for 29 sulfide samples of known origin, completed by 14 measurements on Western Pacific specimens from Yamazaki et al. (1990) and Yamazaki and Park (2003). From these geotechnical data on 43 sulfide samples, we can provide some answers to this question above, crucial for future exploitation of underwater mines.

Jan 1, 2010

By James R. Hein

Low- to intermediate-temperature, diffuse-flow hydrothermal fields and associated mineral precipitates have been found at many locations along oceanic spreading centers, back-arc basin spreading axes, and midplate hot-spots. However, this type of hydrothermal field has not been found in oceanic fracture zones until recently. We mapped and collected samples from an active hydrothermal field in the Blanco Fracture Zone (BFZ) located in the northeast Pacific. The BFZ connects the Gorda and Juan de Fuca spreading centers and is divided into east and west segments by Cascadia Depression, a small spreading center. Small pull-apart basins occur along both the east and west segments. A complex set of basins near the western end of the BFZ includes from east to west, Surveyor Depression, East Blanco Depression (EBD), and West Blanco Depression. The hydrothermal field described here is located in the EBD.

Jan 1, 2001

By Alexander Malahoff

Field observations and sampling of land-based and submarine hydrothermal and geothermal sites show a definite link between the geological setting, fluid geochemistry and specialized assemblages of microorganisms found at these settings. Three initial sites have been chosen as a basis for these studies. The first site is located on hydrothermal vents in pit craters on the submarine volcano Lo?ihi (Hawai?i) at a water depth of 1,300 meters. The second site is within the geothermally active vents, ponds and lakes of the Taupo Volcanic Zone of New Zealand. The third site extends along the chain of volcanically and hydrothermally active volcanoes of the Kermadec-Tonga arc and back-arc system. To focus our work in New Zealand, a geomicrobiology field and experimental center has been established in Wairakei, New Zealand, with the relevant genomics, proteomic and bioinformatics work being conducted at the University of Hawaii. As part of a partnership between the University of Hawai?i, the Institute of Geological & Nuclear Sciences (GNS) and Victoria University of Wellington, a new interdisciplinary graduate course in geomicrobiology will be taught at Victoria University beginning next year. Since mineral-microbial interactions have been occurring for the past few billion years and these interactions have led to where one generates the other, a metal-bacteria research program has been initiated at GNS using arsenic-gold and other metal-bacterial interaction processes as a research objective. In this research program, we have completed the full genome of a new species of marine bacterium Idiomarina loihiensis from the Lo?ihi hydrothermal vents and identified specialized microorganisms living in pH 0.3 geothermal vent waters of White Island, New Zealand. The multidisciplinary approach to study the process of accumulation of metals in the hydrothermal systems clearly shows the path of how bacterial-mineral interaction can precipitate metal deposits. These studies will lead to new avenues for biomining, bioremediation and the understanding of the origins of life.

Jan 1, 2004

By Sukumar Bandopadhyay

The Marine Minerals Technology Center (MMTC) was authorized by an act of the United States Congress in 1996. The act established several marine minerals research centers in the U.S., including one at the University of Alaska Fairbanks. The Alaska MMTC is funded through the Minerals Management Service of the Department of the Interior and concentrates its research in the Arctic seas region. Recent research projects at the MMTC include, among others, application of a geographic information system (GIS) to the gold placer deposits offshore Nome, Alaska, development of a marine gold placer reserve definition model using a neural network, and development of an expert system model for submarine tailings disposal (STD) planning and decision-making. Although geostatistics remains the most prevalent method used today for ore grade estimation, researchers have made numerous improvements over the years for accurately predicting grades of ore using other estimation techniques. One such technique, the neural network, has recently emerged as an alternative to geostatistics for grade estimation purposes. A neural network is a non-linear, model-free estimator that is well-suited for noisy and/or sparse data environments. Neural networks perform best with non-linear spatial data, contrary to the stationary assumption of ordinary Kriging techniques. In the marine placer ore reserve definition model, the neural network technique was used to estimate placer gold reserves offshore Nome. This study demonstrated the utility of neural network modeling over other traditional ore reserve estimation methods, especially for high cut-off grades. Some of the relevant issues of neural network modeling were also addressed in the study. In testing, the neural network produced results that were close to those from geostatistical techniques including Kriging, polygonal, and inverse distance methods.

Jan 1, 2005

By Sukumar Bandopadhyay

The Marine Mining Technology Center (MMTC) was authorized by an act of the United States Congress in 1996. The act established several marine minerals research centers in the U.S., including one at the University of Alaska Fairbanks. The Alaska MMTC is funded through the Minerals Management Service of the Department of the Interior and concentrates its research in the Artic seas region. Recent research projects at the MMTC include, among others, a geographic information system (GIS) application to the gold placer deposits offshore Nome, Alaska, a marine gold placer reserve definition model using a neural network, and development of an expert system model for submarine tailings disposal (STD) planning and decision-making. Although geostatistics remains the most prevalent method used today for ore grade estimation, researchers have made numerous improvements over the years for accurately predicting grades of ore using various other estimation techniques. As a result, the neural network has recently emerged as an alternative to geostatistics for grade estimation purposes. A neural network is a non-linear, model-free estimator that is well-suited for noisy and/or sparse data environments. Neural networks perform best with non-linear spatial data, contrary to the stationary assumption of ordinary Kriging techniques. In the marine placer ore reserve definition model, the neural network technique was used to estimate placer gold reserves offshore Nome. This study demonstrated the utility of neural network modeling over other traditional ore reserve estimation methods, especially for high cut-off grades. Some of the relevant issues of neural network modeling were also addressed in the study. In testing, the neural network produced results that were close to those from geostatistical techniques including Kriging, polygon, and inverse distance methods.

Jan 1, 2004

By Fred C. Dobbs

To effectively manage the potential environmental impacts of deep-sea mining of manganese nodules, we need to know substantially more about the effects of sediment redeposition on abyssal communities and the time scales of recovery from such effects. As an initial step towards a predictive understanding of mining impacts on abyssal benthos, we are conducting a series of biological studies within the framework of the Benthic Impact Experiment (BIE). Mining operations will cause resuspension of sediments across extensive areas of the abyssal Pacific Ocean. The resultant plumes likely will produce redeposition layers, ranging from a few sediment grains in thickness to > 1 cm, over thousands of square kilometers of the seafloor. The impact of such redeposition on abyssal benthic communities is exceedingly difficult to predict. While there has been speculation that redeposition of 1 mm or less will exert deleterious effects, there has been very little testing, and the BIE will provide the first in situ test of redeposition impacts. In a series of cruises before and after controlled resedimentation, we are collecting biological samples to determine the undisturbed state of the ecosystem, the immediate effects of disturbance, and the time-course of recovery resulting from quantified levels of resedimentation.

Jan 1, 1992

By Se-Won Chang

This is a part of the joint KIGAM-GNS-NIWA 3-year study of ferromanganese nodules on the Campbell Drift, east of Campbell Plateau to determine age distribution, growth rates and geochemical evolution in relation to geographic setting. During the research voyage SAA3 by R/V Tangaroa (TAN 9909) in July-August 1999, seafloor sampling and camera towing were conducted along the two transects across the known flow path of the Deep Western Boundary Current (DWBC) perpendicular to the lowermost margin of the Campbell Plateau and Bollons Seamount. The four major nodule facies, SHH (slope hydrogenetic nodules with high density), AHH (abyssal hydrogenetic nodules with high density), ADH (abyssal diagenetic nodules with high density), and ADL (abyssal diagenetic nodules with low density) were identified. Two additional minor nodule facies, SIB (slope irregular nodules with ice-rafted boulders) and SHB (slope hydrogenetic nodules with boulders and crust), of localized distributions are also identified.

Jan 1, 2003

By Youngtak Ko

The northeastern Pacific shows the highest nodule abundance among the oceans in the world, and thus has been drawing international attention for deep-sea manganese nodule development. The objectives of this study are to construct database using geostatistics and geographic information system (GIS), to quantify rating value using probability and statistical methods, to suggest suitable sites for manganese nodule development, and to verify results using three statistical approaches. The copper and nickel contents of the nodules were determined by chemical analysis. Factors related to slope, aspect, water depth, and topography were obtained from multi-beam echo sounding data. The transparent layer thickness was determined using a sub-bottom profiler. The probability method was used to calculate each factor&apos;s rating, and the layers for different factors were summed to produce the development potential index (DPI). Result maps were constructed for manganese nodules development. The distribution pattern of DPI showed to be controlled of nodule abundance and metal contents. Verification was performed by comparing the results with sampling data in three ways: success and prediction rate, linear regression, and test of independence.

Sep 14, 2011

By V. K. Banakar, R. P. Rajani, A. R. Chodankar

The Afanasiy-Nikitin Seamounts (ANS) in Eastern Equatorial Indian Ocean (Figure 1) are shown to be the exposed part of the presently buried 85°E Ridge system under the Bengal Fan sediment and were emplacement around 75-80 m.y. ago (Krishna, 2003). The first recovery of ferromanganese crusts from the ANS was made during 1994, and the samples (Figure 2) provided important clues on the evolution of this seamount (Banakar et al., 1997).

By Kiseong Hyeong

The Intertropical Convergence Zone (ITCZ), where the southeast and northeast trade winds converge, is the effective climatological barrier that separates the southern and northern hemispheres in terms of dust budget. Asian and N. American dusts dominate in the Pacific north of the ITCZ, while Central and S. American dust prevails south of the ITCZ. In order to understand the nature of latitudinal and depth-related variations of mineral composition in terms of position relative to the ITCZ, deep-sea core sediments were collected from 9°N to 17°N at a 2° intervals along the 131.5°W meridian and analyzed for mineral composition. The amount of illite in surface sediments decreases gradually from 65% at 17°N to 31% at 9°N. In contrast, smectite increases from 11% to 56% southward. The observed mineralogical variation toward the ITCZ is attributed to the increased supply of volcaniclastic material transported via the southeast trade winds from the Central and South America source regions. Smectite-illite transition, a phenomenon that the amount of smectite increases over illite, occurs at around 10°N, the northern margin of the ITCZ. This result indicates that the change in latitudinal position of the ITCZ in the geological past could be recorded by the smectite-illite transition in deep-sea cores. The cores studied show down-core variation of mineral composition from illite-rich at the surface to a smectite-rich clay suit at depths, similar to the latitudinal variation. The smectite-illite transitions observed in these cores are likely the records of changes in latitudinal position of the ITCZ. The depth and age of the smectite-illite transition is getting shallower and younger towards the equator, implying that the ITCZ was located farther north during late Tertiary and has shifted southward to the present position of 5°N~10°N.

Jan 1, 2004