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By C. H. Hobbs

A recently completed series of projects funded by the Commonwealth of Virginia and the U.S. Minerals Management Service was designed to assess the distribution of heavy minerals on the inner continental shelf adjacent to Virginia. These projects indicate that a suite of minerals of both strategic and economic interest is present. Analysis of several hundred grab and core samples shows that zircon, monazite, and titanium minerals (ilmenite, rutile, and leucoxene) occur in quantities that probably warrant further study by the mineral industry. Furthermore, side-scan sonography and shallow seismic profiles have provided information on the thickness and areal extent of the mineral-bearing sands. Possible development of the resource is enhanced by a potential use of offshore sand for beach nourishment. The results of the preliminary studies have been presented in open-file publications and oral reports in order that the mineral industry might have an up to date basis upon which to consider more exploratory work. Much of the effort south of the mouth of Chesapeake Bay was made in cooperation with and enhanced by an independent study of sand resources for beach nourishment and other needs. Preliminary review of the quantitative analyses of the heavy-mineral content of several hundred samples demonstrates that the distribution of high concentrations is non-uniform. From core data, the greatest abundances of some economic heavy minerals (ilmenite, rutile, leucoxene, monazite, and

Jan 1, 1988

By Daisuke Monoe, Kisaburo Nakata, Rika Takeuchi, Tetsuo Yamazaki, Tomoaki Oomi, Tomohiko Fukushima

There are generally two methane passes in conjunction with the seafloor natural cold seepages, as is schematically shown in Fig. 1. The first pass consists of the coupled anaerobic oxidation of methane and anaerobic sulfate reduction, as well as sulfur oxidation in the bacterial mats and immobilization thereafter in the sediment layer and on the seafloor. Through the first pass, calcium and organic carbonates are formed in biological and chemical processes from the methane (Luff and Wallmann, 2003; Luff et al., 2004). The detailed structure of the seafloor methane consumption process unit and its biological and chemical processes were introduced in Yamazaki et al. (2005). The other pass consists of direct bubbling into the water column. Through this pass, organic carbonate is formed with biological oxidation, and a small amount of the methane escapes into the atmosphere. Methane flux is supplied to these two passes through the sediment layer from the deeper structures. The structure of the methane supply process unit was introduced in Yamazaki et al. (2006).

Sep 24, 2006

By C. W. Devey, K. S. Lackschewitz

The mineralogy and geochemistry of hydrothermally altered wall rocks from different modern basaltic- and felsic-hosted hydrothermal fields at seafloor spreading centers and convergent margins have been studied to determine the characteristics of different types of alteration and to calculate the magnitudes of elemental exchanges between seawater and wall rock.

Aug 24, 2006

By Evgeny G. Gurvich

While direct study of high temperature hydrothermal activity and the associated mineral formation as well as study of their scales are possible in the modern ocean, researchers are deprived of such opportunity for past geologic time. Even in cases where hydrothermal deposits that formed in the geological past are preserved they have been covered by sediments or overlain by lava and have become inaccessible after a time for obser-vation and sampling. Rarely are these buried hydrothermal deposits found during deep-sea drilling or coring operations, and their direct study on an ocean scale is impossible at present. Even within hydrothermal fields, without special preliminary detailed surveys, the probability of intersecting hydrothermal edifices that are covered by sediments becomes a rare event.

Aug 24, 2006

By Yoshio Masuda

Cobalt-rich crust in rich Co, Ni, Mm and Pt will be a potential resources for island country such as Republic. Marshall Islands. This study was conducted for Marshall Islands by the President Kabua?s request. It covers crust resources, CLB mining, processing, and economic estimation, and study concluded feasible veiw.

Jan 1, 1991

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 Yanis Miezitis, Gerald Mueller, Timothy F. McConachy, Ronald G. Sait, Keith R. Porritt, William J. McKay

In November 2004, Australia lodged with the United Nations Commission on the Limits of the Continental Shelf possible new maritime boundaries in relation to Australia’s continental shelf extending beyond 200 nautical miles from the Territorial Sea Baseline (Colwell and Symonds, 2005). If agreed by the commission, just over half of Australia’s land mass will lie below the sea, and Australia will have one of the largest marine jurisdictions in the world (14.41 million km2). With this jurisdiction comes a responsibility to manage and sustain the marine environment (McConachy, 2006). Knowledge of minerals and their resource potential is part of this responsibility but is generally poorly known (McConachy, 2005).

Aug 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 Takashi Ito

Numerous studies have examined the distribution of deep-sea manganese deposits throughout geologic history. Here I summarize the recent results, focusing on the frequency of occurrence, burial age and mechanism, and the paleoceanographic implications.

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 Timothy F. McConachy, Christopher J. Yeats, Ray Binns

Various kinds of sediment-hosted polymetallic sulfide deposit are known on land in ancient marine sequences, many tending to be larger and more valuable than massive sulfide deposits genetically associated with volcanic host rocks. Often such deposits are attributed to subhalative or shallow sub-seafloor precipitation processes, and structural control by faulting is commonly evident. Apart from the famous but anomalous Red Sea metallic oozes and several NE Pacific sites (Middle Valley, Escanaba Trough, Guaymas Basin), however, modern analogs of the sediment-hosted polymetallic sulfide category are lacking. Some deposits hosted by volcaniclastic rocks, such as JADE (Okinawa Trough) and Suzette (Eastern Manus Basin) are strictly sediment-hosted, but their formation is associated with the igneous activity and they are better considered a variant of the more abundant volcanic-associated polymetallic sulfide deposits.

Aug 24, 2006

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

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 Sang Bum Chi

In order to better predict and manage benthic disturbance by deep seabed manganese nodules mining, we needed to conduct a benthic disturbance experiment at the selected area, which has a similar environmental condition as the preservation reference area. Therefore, we have performed environmental baseline studies from 2003--not only to select the benthic environmental impact testing site but, also to detect any environmental changes before and after mining activity. Since then, a large dataset of various parameters ranging from physical (e.g. temperature, salinity, current, weather), chemical (e.g. dissolved oxygen, nutrients, dissolved and particulate organic carbon), biological (e.g. bacteria, plankton, benthos), geological (e.g. Mn-nodule abundance, sediment shear strength) and others (e.g. bathymetric profile and slope, mass flux) have been accumulated. Using this dataset, descriptive statistics and cross-correlations were performed to select the benthic environmental impact testing site. Outcome of this analysis suggests that the potential benthic impact testing site would be a rectangular-shape area (10 km × 10 km) and located at 10°27'~10°33'N, 131°53'~131°58'W, which is latitudinally the same as the preservation reference area.

Jan 1, 2011

By S. W. McCandless

Since the mid 1970's, the science of remote sensing has invented and demonstrated sensors that hold unique promise for users that operate in the marine environment. Earlier, visible and infrared sensors provided images and temperature maps of surface conditions, but the 1970's introduced active (radars) and passive (radiometers) microwave sensors capable of penetrating clouds and operating day or night over the world's oceans. Space-based observation satellites permit these systems to span the globe many times each day, providing a view of the world's oceans and Arctic areas consistent with daily and, sometimes, hourly changes in the marine environment. Experimental satellites launched by NASA proved that such systems had great scientific merit, but, even more importantly, they could produce information valuable to marine transportation, fishing, and resource exploration and extraction. This latter subject includes the off-shore search and production of petroleum and natural gas resources and ocean mining as well. A few early satellites, such as GEOS-3, Nimbus-7, and most notably Seasat established that global wind fields, all weather sea surface temperature, ocean topography and sea state, and fine scale images of wave patterns, surfactants,

Jan 1, 1986

By Darryl Thorburn

The Cook Islands are 15 islands located in the Southwest Pacific (between 8-23°S latitude and 156-167°W longitude). The total land area is about 200 km2. However, because its islands are widely scattered, the EEZ of the Cooks encompass an area about 2 million km2. The Cook Islands government exercises sovereignty and jurisdiction over its EEZ according to international law and convention as a member state under UNCLOS1. Accordingly, the Cook Islands government exercises full control over resources in its EEZ, including minerals on the seabed. Decision making on allocating licences for exploration and ultimate mineral recovery is by the Cook Islands government and will be set out in relevant statutes. Seabed minerals investigations within the EEZ of the Cook Islands and adjacent waters were first carried out by, USSR, US, and New Zealand research vessels in the late 1960 early 1970?s and indicated the presence of high concentrations of manganese nodules. This early work was followed by a number of Government funded surveys in and adjacent to the Cook Islands EEZ These surveys have identified a world class resource of manganese nodules within the Cook Islands EEZ (CI EEZ), containing significant

Sep 14, 2011

By Eric J. Foell, Hjalmar Thiel, Gerd Schriever

Environmental studies for the mining of polymetallic nodules (PN) from the deep sea may be traced back for some 35 years.

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.

By Simon McDonald

The Neptune Group was established in 1999 to apply for exploration permits within New Zealand’s 200nm EEZ. These applications were to investigate and commercialise hydrothermal Seafloor Massive Sulphide (SMS) deposits identified by international researchers and to locate others. SMS are volcanically related seafloor accumulations of copper, lead and zinc with high levels of gold and silver. Neptune has three granted exploration licenses within the New Zealand EEZ and has application in other jurisdictions. Neptune undertook the world’s first commercial drilling exploration work of SMS in December of 2005.

Aug 24, 2006

By Kokichi Iizasa

Modern Kuroko-type deposits have been much reported in submarine calderas and cauldrons in the EEZ of Japan since 1988. Some of them have been found based on heavy mineral analysis of sediments in which sulfide particles may be derived from hydrothermal sources in the ambient areas. From the end of August to early September 2007, in the middle Izu-Ogasawara arc south of Tokyo, ROV expeditions were carried out in submarine calderas in order to examine mineralogical features between intact heavy particles spouting out from sulfide chimneys and heavy minerals such as sulfides in sediments around sulfide mounds in Kuroko-type deposits, and to find more newly formed hydrothermal sulfide fields in those areas. Some preliminary results from the ROV expeditions are reported here.

Oct 15, 2007