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Welina mai to the 40th Underwater Mining Institute, UMI 2011 - Marine Minerals: Recent Innovations in Technology. Since the first conference in Milwaukee, Wisconsin in 1970, the UMI Founder Professor Robby Moore always insisted on actively seeking the participation of industry, academia, and government. History has proven the wisdom of this approach, which is probably the key to its survival for so many years. The UMI is very much influenced by the cyclical pressures of the minerals commodity markets. When minerals demand and prices are rising rapidly, industrial participation in the Institute dominates the agenda, and participants share optimistic and aggressive views of the commercial prospects of the day. When metals prices are falling and world economies lethargic, academic experts continue to provide guidance and breakthroughs in the concepts and practices of exploration, technology, and environmental protection. Throughout the ups and downs, government participants provide a stabilizing force with conservative and environmentally sensitive policy statements, patient development efforts with long-term objectives, authoritative resource assessments and, sometimes, much needed regulatory clarity.

Jan 1, 2011

By Leonhard Weixler

The Bauer company was founded in 1790 by coppersmith Sebastian Bauer in Schrobenhausen, a small town north-west of Munich. The original workshop business carried out works including repairs to church roofs and brew kettles. Later the company expanded its operations to encompass water pipe installation, which it continued through to the 1980s. In addition to installing water pipes it then also began drilling wells, which were sometimes constructed using very simple methods, such as tripod frames (Figure 1).

Jan 1, 2011

By Sofia Martins, Anna Lichtschlag, Sven Petersen, Fernando Barriga, Bramley Murton, Adeline Dutrieux

"Sediments in the vicinity of the hydrothermal seafloor massive sulphide (SMS) mounds are characterized by high concentration of metallic particles. They result from a long process of weathering of the primary mineral deposits and have been accumulated in depressions by mass wasting and hydrothermal plume fall-out. We present here the first results obtained on pore waters analyses of such sediments in distinct geological seafloor environments (in low-temperature hydrothermally active zones, on extinct hydrothermal mounds and in a remote depositional channel). Vertical concentration profiles suggest that the pore fluid composition is affected more by seawater circulation compared with hydrothermal fluid flow in all environments. The composition of pore fluids is affected by diagenesis and redox processes in the distal depositional channel where Mn2+ is released at depth with Cu2+.IntroductionMarine hydrothermal fields, hosting seafloor massive sulphides, are potential resources for future deep-sea mining and might become economic reserves for the industries. They are widespread at mid-oceanic ridges, arcs and back-arc spreading centers (Hannington et al., 2011; German et al., 2016). Sediments in the vicinity of these fields can contain unusually high concentration of Fe, Mn, Zn and Cu among other metal elements (Shearme et al., 1983). These hydrothermal, or metalliferous, sediments result from a combination of processes such as collapsing and weathering of chimney material, filling of the channels by turbidite-like mass wasting, in situ authigenic mineralization and hydrothermal plume fall-out (Goulding et al., 1998; German et al., 1990). The sediments contain important indicators reflecting the development of the hydrothermal systems. Because of their widespread distribution and metal content, they themselves can be considered potential mineral resources. Circulation of seawater through these deposits, however, often modifies the sediment composition by oxidizing the sulphides into oxyhydroxides and clays causing mobilization of the metals. To address the importance of alteration and diagenesis of these hydrothermal sediments, including the result of seawater circulation, we investigated the post-depositional processes occurring in the hydrothermal sediments at the TAG Hydrothermal Field (Mid-Atlantic Ridge, 26°N), focusing on the mobility of metallic cations in a number of different seafloor environments."

Jan 1, 2017

By Raymond A. Binns

The Eastern Manus Basin (EMB) contains three major active hydrothermal zones and a number of smaller occurrences of hydrothermal deposits, and can be considered as a regional-scale modern analogue for volcanic-hosted mineral fields on land. Unlike the central Manus Basin, a back-arc spreading zone with some MORB-like basalt-hosted massive sulfide deposits, the EMB is a pull-apart rift zone between two transform faults, where a basement of Eocene-Oligocene arc crust is being thinned by extension, with rapid sedimentation on the tilted fault blocks. Present-day submarine igneous activity in the EMB, with which hydrothermal activity is associated, has arc geochemical affinities and is related to subduction of the Solomon Sea Plate at the New Britain Trench. Overall, hydrothermal deposits in EMB are found with lavas ranging from picritic basalt to rhyodacite in composition, although the two major occurrences of massive sulfide are hosted by the more siliceous dacite and rhyodacite variants. Some volcanic edifices are central eruptions, mostly of porphyritic lavas or domes, while others are elongate ridges formed by fissure eruption in which the typically aphyric lavas were very fluid. Evidence for shallow-level fractional crystallisation controls of lava chemistry implies presence of subjacent differentiated intrusions or former magma chambers. Seismic tremor at one site during the nearby 1994 Rabaul eruption suggests magma movement in the chamber.

Jan 1, 1998

By Akira Usui

The details in small-scale variability of the geological occurrence and chemical composition of ferromanganese crusts are not yet well understood, although the northwestern Pacific seamounts are believed to be among the most promising areas for rare metal resources. Our belief is that geological observations and geochemical analyses are still insufficient for economic evaluation or for discussion of depositional processes and environments. Our team, composed of geologists, mineralogists, geochemists, physical engineers, and microbiologists has attempted to utilize an ROV for in-situ measurement and for sampling of undisturbed and uncontaminated ferromanganese crusts at three typical seamounts in the NW Pacific near the Japanese Exclusive Economic Zone. The first ROV geological survey of ferromanganese crusts was successfully completed, and the ROV proved to be the most powerful, efficient and elegant method to date. The collected samples (more than total 1 ton of crusts, at more than 100 sites along a total of approximately 10 km of survey lines) were most suitable to analyze water-depth dependency and secular variation of their composition. The intact surfaces of crusts, collected without the usual abrasion caused by dredging, were also valuable for microbial study of Mn oxidizing bacteria. The ROV sampling devices, however, can be improved with further sophisticated drills or rock saw blades in the future.

Jan 1, 2011

By Gregory Abramov

Borehole Mining (BHM), a remotely-operated waterjet mining method (Figure 1), has recently achieved two major milestones. It was, for the first time, applied to the extraction of manganese ore and at temperatures below freezing. The 1St stage is a demonstration test that is now underway just north of Emily, Minnesota, where the manganese ore is located 100-160m below the surface and its reserves are estimated to be in excess of 500,000 tons. The deposit was discovered over 60 years ago but, due to the fragile and sensitive nature of this Land of 10,000 Lakes (nickname for the State of Minnesota) and strong environmental restrictions, the iron/manganese reserves were deemed unrecoverable and remained untouched until late 2010 when permission for a single-hole demo-test was issued by the local Department of Natural Resources.

Jan 1, 2011

By Stephen J. Juras

The Myra Falls deposits comprise a complexly metal-zoned polymetallic volcanogenic massive sulfide district located 90 km from Campbell River in central Vancouver Island, British Columbia, Canada. The massive sulfide deposits are hosted by subaqueously-deposited rocks of the Devonian age Myra Formation of the Sicker Group volcanic assemblage. The deposits comprise many individual massive sulfide lenses grouped into several major zones within two main felsic volcanic stratigraphic intervals - the upper Lynx-Myra-Price Horizon and the lower H-W Horizon. The largest of these zones, the H-W and Battle, occur within the H-W Horizon. The first claims in the area of what is now Boliden-Westmin?s Myra Falls Operations were staked in 1917. Early prospecting resulted in the discovery of three massive sulfide showings which eventually became the Lynx, Myra and Price mines. Sporadic exploration was carried out until 1961 when Western Mines Ltd. (now Boliden-Westmin Ltd.) acquired the claims. Subsequent ore definition outlined 1.9 million tonnes of ore (approximately 5 years of mine life) in the Lynx deposit, and mining began in 1966. Pre-mining geological reserves (to January 1, 1997) comprised 6.7 million tonnes grading 3.3 g/t Au, 130.6 g/t Ag, 2.0 % Cu, 1.4 % Pb and 10.2 % Zn for the Lynx-Myra-Price deposits, 17.1 million tonnes grading 2.3 g/t Au, 32.7 g/t Ag, 2.3 % Cu, 0.3 % Pb and 4.2 % Zn for the H-W deposits and 4.2 million tonnes grading 1.1 g/t Au, 27.0 g/t Ag, 2.2 % Cu, 0.5 % Pb and 12.0 % Zn for the Battle deposits. Property-wide production to January, 1996 has been 15.7 million tonnes grading 2.1 g/t Au, 58.7 g/t Ag, 1.9 % Cu, and 5.2 % Zn.

Jan 1, 1998

By S. Rajendran

The area of the Exclusive Economic Zone (EEZ) of India is about 2.014 million km2 and the resource evaluation of placer deposits is one of the objectives of Government of India. Placers are detrital metallic minerals found on beaches and in the near shore areas. Quantitatively more important are placer deposits of light heavy minerals such as zircon, ilmenite and rutile. Rivers and other drainage channels are the main carriers of the placers which contain heavy minerals like magnetite, ilmenite, garnet, zircon, monazite, rutile etc. The present beach as well as part of the shelf was land during Pleistocene as a result of the world wide lowering of the sea levels. The coast line shifted a number of times. Hence, the heavy mineral placers on the beaches are expected to extend to offshore areas chiefly with Pleistocene lowered sea level strands. India has extensive deposits of heavy mineral placers along the beaches. Placer deposits of heavy minerals occur in discontinuous patches on the beaches along many parts of the east and west coasts. Along the central west coast of India (12??N - 19? N lat.) the placer containing 14 - 17% ilmenite form an estimated reserve of 4 million tons. On the Ratnagiri coast of Maharashtra, the proportion of heavy mineral varies between 54 and 70% in the bulk samples, consisting mainly of 14 - 39% magnetite and 16 - 30% ilmenite. The National Institute of Oceanography (NIO) surveys show that the sediments off the central west coast consist largely of silty sand, sand silt and clay. The core samples show that a reddish brown clay overlay olive gray clay which in turn overlay heavy mineral rich sands. The heavy mineral concentration ranges upto 90% and has mainly ilmenite and magnetite with minor quantities of apatite, rutile, zircon, kyanite etc. Siddiquie et al. reported 42 - 75% TiO2 in the ilmenite.

Jan 1, 1998

By Karsten Hagenah, Tor Jensen, Jens Laugesen, Øyvind Fjukmoen, Lucy Brooks

"The methods and technologies to be used for environmental monitoring of seabed mining activities are a key issue. Due to the large water depths, there are special challenges with respect to the monitoring equipment that is suitable. DNV GL has built up substantial experience of environmental monitoring from oil & gas projects in deep waters in the Norwegian Sea.Monitoring equipment and experiences from the oil & gas sector can to a large extent be applied to seabed mining.BackgroundThe International Seabed Authority is currently developing an environmental management strategy for the Area (ISA, 2017) as a part of the work on the regulations for exploitation for mineral resources in the Area.The draft environment strategy contains provisions related to monitoring and reporting of the activities. An Annex (Annex III) of the draft document describes the format and content of the environmental management and monitoring plan.The monitoring plan should contain, inter alia: ?Technology to be deployed.?Monitoring frequency of respective elements/components of the Marine Environment.?Monitoring procedures required to implement the Monitoring programme.?Details of the environmental monitoring stations across the Environmental Impact Area.?Monitoring specifics e.g. water quality; sedimentation rates; sound; plume extent; etc., as well as relevant Environmental Targets.?Monitoring of Mining Discharges.?Processes for Monitoring reviews and Environmental audits."

Jan 1, 2017

By Manfred Krutein

Ocean mining has a number of problems which are critical to its development: ? Political hurdles on national and international stages ? The worldwide economic situation, with the possibliity of a recession ? Financial difficulties in funding further work ? Technical problems for the development of ocean mining and transport subsystems ? Demands for technology transfer This paper touches the last two points and provides some thoughts for discussion and creative objectification. The many technical problems of ocean mining will be identified and some proposed solutions will be investigated relative to the state-of-the-art technology of ocean mining and nodule transport. An outlook into the future attempts identification of the steps necessary to eventually develop components for workable systems that are not only technically but also economically feasible.

Jan 1, 1978

By Grigori Abramov

Borehole Mining (BHM) is a remotely operated underground and underwater method of extracting (mining) mineral resources by high-pressure water jets. It can be carried-out from the land surface, open pit floor, underground mine and floating platform or vessel. The method is currently in use in mining and exploration of such natural resources and industrial materials as: uranium, iron ore, quartz sand, gravel, coal, poly-metallic ores, phosphate, gold, diamonds, rare earths, amber and several more. Yet another application of Borehole mining technology is construction of subsurface collectors, ground walls and storage for compressed or liquefied gases, oil and other products.

By Andrea Koschinsky, Sophie Paul

"INTRODUCTIONOnce again deep-sea mining has been receiving a lot of attention in recent years. Industrial and political advancements also call for environmental baseline studies and analyses to aid the development of standards and monitoring protocols. As part of the EU research project “JPI Oceans: Ecological Aspects of Deep-Sea Mining”, the RV Sonne cruise SO242 to the Peru Basin revisited the DISCOL area that had been artificially disturbed in 1989. This offered the unique opportunity to study a deep-sea site 26 years after a disturbance similar to manganese nodule mining had been carried out (Figure 1). A comparison of a variety of undisturbed and disturbed sites shed light on the re-establishment of a geochemical equilibrium and a range of baseline values. This information can help to inform standard development for monitoring and mining purposes.Heavy metal data and its applicationResearch findingsDuring the cruise, disturbed and undisturbed surface sediment was sampled. The pore water analyses show that the 26 years old disturbance is not visible in the metal profiles and that the pore water reaches equilibrium through diffusive fluxes relatively quickly. The sediment, however, shows some differences between disturbed and undisturbed sites in the upper 20 cm, even after 26 years. Lower concentrations in the usually manganese-oxide rich top layer, variations and “unnatural” peaks in the manganese profiles, for example, suggest removal or mixing of the top layer (Figure 2)."

Jan 1, 2017

By Charles L. Morgan

In June 1996, the United Nations International Seabed Authority opened shop in Kingston, Jamaica as an autonomous international organization charged with the administration of seabed mineral developments in all areas beyond national jurisdictions. The Authority is a consequence of the 16 November, 1994 entry into force of the 1982 United Nations Convention on the Law of the Sea (UNCLOS) and the 1994 Agreement relating to the Implementation of Part XI of UNCLOS. The total seabed area included within the Authority?s purview has yet to be assessed accurately, but clearly constitutes the largest single jurisdiction on the planet. The Authority is governed by legislative bodies called the Assembly and the Council and an administration called the Secretariat. The Assembly includes representatives of the 132 member states which are currently parties both to UNCLOS and to the 1994 Agreement. These member states directly fund the operations of the Secretariat. They include most of the world?s developed nations, island nations, and others among the 188 independent countries which are members of the United Nations. Notably absent are the United States and Canada, which are the only developed coastal states not represented. The Council is a 36-member subset of the Assembly representatives selected through a somewhat involved process designed to achieve a balanced representation of the specific interests of the members. Ultimate responsibility for the Authority?s actions resides in the Assembly, but most initiatives originate in the Council. Also included in the Authority are two subsidiary advisory bodies, the Finance Committee, which reviews the Secretariat?s budget, and the Legal and Technical Commission, which evaluates claims and drafts technical regulations. The Secretariat itself includes a staff of about 30, including 15 highly qualified and competent attorneys, accountants, engineers, and scientists. Details describing the composition and activities of these bodies can be found at the Authority?s website (http://www.isa.org.jm).

Jan 1, 2000

By Samantha Smith

Nautilus Minerals (Nautilus) is following the lead of the petroleum industry as it strives to tap vast offshore resources. Planning is well underway for the Solwara 1 Project in the Bismarck Sea, Papua New Guinea (PNG) to recover high-grade seafloor massive sulphide deposits in 1600 m water depth. The deposit contains an average copper grade >10 times higher than a typical land-based porphyry copper mine. The high grades combined with a relatively small amount of overburden ensure the Solwara 1 Project will have a significantly smaller physical footprint than its land-based counterparts. Offshore minerals production also has the advantage of minimal social disturbance. Nautilus is dedicated to setting a high environmental and social responsibility standard. Nautilus recognises the importance of transparent and inclusive stakeholder engagement and has taken a proactive approach to involve as many key stakeholders as possible. One of the first steps in the permitting process in PNG is the preparation of the Environmental Inception Report, which describes the project, its envisaged impacts and the proposed studies for the Environmental Impact Assessment (EIA). Local (PNG-based) and international environmental scientists, anthropologists, NGOs and other experts were involved in the definition of studies conducted for the Solwara 1 EIA and a team of world-leading experts was involved with carrying out the studies, culminating in the preparation of the Environmental Impact Statement (EIS). To ensure transparency, collaborating researchers are free to publish their findings. Following its submission, the EIS was made available for public review and public hearings were held at several locations. The EIS has also undergone a rigorous independent review by PNG government-engaged consultants. Outside the permitting process, Nautilus works alongside government officials to carry out ongoing community consultations. Information dissemination and feedback acquisition has also occurred through the Nautilus website and attendance at a number of international conferences, workshops, and meetings. This paper will outline the leading edge approach Nautilus has taken in completing the environmental impact statement for the world?s first deep seafloor copper-gold mine. In addition, this paper will review the permitting process and the government and stakeholder engagement undertaken as part of Nautilus? desire to ?do it right? in this exciting new industry.

Jan 1, 2010

By Carsten Rühlemann, David Friedmann, Bernd Friedrich, Thomas Kuhn

"This paper explores the option of direct reduction smelting of the nodules from the German license area in the equatorial NE Pacific in a submerged arc furnace (SAF). An optimized slag design is proposed to separate the larger Mn-bearing stream from the valuable metals (i.e. Ni, Cu, Co, Mo). The slag optimization allows a maximum of Mn to be retained in the manganese-silicate slag on the one hand and a maximized metal recovery in a FeNiCuCo alloy on the other. This way, the goal is to make use of the complete nodules (“zero-waste”) instead of extracting only the metals Ni, Cu, and Co, which make up about 3 wt%. The process closely relates to the “Inco Process” by the Ocean Management Inc. (OMI) of the late 1970s, which was a consortium of INCO (International Nickel Company, CAN; today Vale Canada), Preussag AG & Metallgesellschaft AG (GER), DOMCO (JPN), and Sedco (USA). However, the manganese containing slag is investigated in more detail to recover FeMn, FeMnSi and/or SiMn. To optimize the process modern tools such as thermo-chemical modeling in FactSage™ have been used. [1,2]Polymetallic deep-sea manganese nodules may offer a decreased dependency of raw material imports for Germany and the EU. Currently, four European countries (United Kingdom, Belgium, Germany, and France and an Eastern European consortium (InterOcean Metal)) hold exploration licences for these nodules in international waters in the equatorial NE-Pacific. The license areas each cover 75 000 km2 of the seafloor and are located in the Clarion Clipperton Fracture Zone (CCZ) south east off Hawaii at water-depths between 4000 and 6000 m. The nodules may be used as a resource for industrially important metals such as Cu, Ni, Mn as well as for technology metals like Co, Mo, V and Zn. The average chemical composition of nodules from the German license area is presented in Table 1. [3,4]"

Jan 1, 2017

By James M. Franklin

Research on modern hydrothermal systems provides quantitative measures of the processes of formation of hydrothermal fluids and of precipitation mechanisms from them. Studies of ancient deposits provide new information regarding volcanological processes that are related to the deposits, as well as data on their spatial and temporal compositional variations. Mew exploration guidelines result from both aspects of research. The most fundamental requirement for large metalliferous hydrothermal systems is an abundant heat supply for the upper two kilometers of the crust. This heat may come from a focused heal source (shallow-level subvolcanic intrusion), but ambient heat also may have provided enough energy for the reactions necessary to effect leaching of metals, especially where heat flow is particularly high (i.e. very large or high-temperature magmatic source, such as ultramafic environments). For most VMS systems, the majority of the metals were derived through leaching from footwall strata; in addition interstratal fluids may enter subvolcanic intrusions during episodes of magma a chamber "cracking," engendering some '?magmatic" component in the hydrothermal system. Direct contributions of metalliferous magmatic fluid also may be significant from arc-related or back-arc felsic or alkalis systems. These latter contributions may form exceptionally high - grade portions in some deposits. Subvolcanic intrusions, which are excellent indicators of high heat flow and may have been the direct driving mechanisms for some stems undergo two stages of alteration: On intrusion emplacernent. fluids may rapidly enter and react with their mesostatic portions, evident in the sills in the Middle Valley. High temperature interactions caused albitization and destruction of oxides and sulfides, releasing metals. During terminal hydrothermal stages, the metalliferous fluid collapsed into the intrusions, forming disseminated and vein sulfides.

Jan 1, 1998

By Jan M. Peter

Many massive sulfide deposits and districts around the World contain rocks that are variously referred to as ?exhalites?, banded iron formation (IF), ?Algoma-type? IF, ferruginous chert, jasper, jasperoid, cherty tuff, tuffite, tuffaceous exhalite, chloritic IF or sulfide IF. With few exceptions, such rocks are thought to be (in part) fossil hydrothermal sediments deposited from hydrothermal fluids vented into a submarine rift environment. Such hydrothermal sediments are associated with a wide variety of ancient base-metal sulfide deposits (e.g., Cyprus-, Besshi-, Kuroko-, and Broken-Hill-type deposits), and hydrothermal sediments are commonly associated with some of the largest base metal sulfide deposits in the world. Analogs of ancient hydrothermal sediments can be found around many modern seafloor hydrothermal deposits which themselves precipitate from high-temperature (350°-400°C) hydrothermal fluids. Hydrothermal fluids are quenched on contact with ambient seawater, and most of the metals are immediately precipitated to form the mound and chimney deposits. However, for kinetic and solubility reasons, not all metals and other species are immediately precipitated at the vent site. Fine particles (up to several hundred microns in diameter) of sulfides, sulfates, carbonates, oxides, silica, Fe-oxyhydroxides, clays, and other phases are precipitated from the hydrothermal fluids in the water column above the deposits. These particles or "particulates" are carried upward for several hundred meters in a buoyant hydrothermal plume (which is typically several hundred meters thick) until it reaches a neutral density, and disperses laterally from the vent site. Modelling of plume dynamics has shown that the majority of particulates are deposited by gravitational settling a few hundred meters from the vent site, and Å99% of particulates are deposited within 3 kilometers. However, signals from modern plumes have been detected even hundreds of kilometers from their source. Factors which can affect the morphology of the plume (and the resultant fallout pattern) include: particulate size, shape and density, bottom topography, and the direction and velocity of bottom currents.

Jan 1, 1998

By Julian Malnic

Transplanting the steps used in exploring and developing mineral deposits on land into the marine environment will help developers. While familiar to oil and gas explorers and many other sea-based industries, the marine environment is so alien to the 90s terrestrial miner that the phrase ?terrestrial mines in the sea? is useful for reinforcing the fundamental parallels in mining sulphides at sea and on land. As on land, the processes of ?pre-feasibility study? and ?feasibility study? will determine the economics of mining a deposit. For many, the step into the sea can detract from the need to follow these familiar and recognised steps used when any new deposit is found on land. The technology to mine sulphides in the 1500 to 2000 m depth range exists. Currently, it is not found in a single, integrated and commercially available system but every element available to build such as system is. Transplanting the thinking of the leaders of the terrestrial mining industry into the sea will perhaps be the greatest challenge and reinforcing the basic steps of discovery - pre-feasibility through to feasibility is the best way to achieve this. After all on land one doesn?t ask ?Can we profitably mine it?? before one can authoritatively answer ?What have we found??. Research by Nautilus Minerals Corporation suggests that the mining of seafloor massive sulphides (SMS) will not only be profitable but potentially lower in both capital and operating costs than prevail in most terrestrial deposits. Nautilus is also acutely aware that with the first SMS deposits under title, it will be setting the standards for seafloor mining into the new millenium. Indeed, we have trained on us not only the eyes of the mining industry waiting to see if SMS deposits really do offer radically better returns, but other stakeholders of the sea and the capital markets. Mistakes by any SMS developer could land all developers in ?hot water?. The rush to exploit our deposits for economic gain will be tempered by ensuring there is adequate public debate and consultation for our environmental code. Failure in any facet of a marine mining development could set back the move to the ocean floor.

Jan 1, 1998

By Irina Dobretsova, Anna Sukhanova, Anatoly Kondratenko, Svetlana Babaeva, Sergey Andreev

"With the acceptance of an application and a signed contract for prospecting deep-sea sulfides (2012) between the Russian Federation and the ISA, at present it is particularly important to assess the quality of oceanic sulfide minerals and to reliably estimate their resources.Some procedures of geochemical classification (chemical analyses, mineral composition of SMS) and calculations (density of ore, density of the mineral part of the ore, porosity and moisture contents) were used for estimation of mineral resources potential.The key characteristics for estimating the predicted resources of hydrothermal ore fields are the metal contents and the density of wet and dry sulfide ores. However, in the future it is impossible to provide an estimate of the predicted resources without taking into account the following important factors:- the quantitative ratio of main sulfide minerals;- proportion of non-metallic components (opal, quartz, talc);- the replacement of primary minerals by copper sulfides;- texture-structural features of sulfide ores.The offered mineral classification of the SMS is based on the prevalence of minerals in the ores and partly on their composition. The main ore-forming minerals of SMS are pyrite, chalcopyrite and sphalerite. Sulfide mineralization is accompanied by the presence of nonmetallic minerals, where quartz and opal prevail, and where we also meet aragonite, talcochlorite and anhydrite."

Jan 1, 2017

By Alexander Malahoff

The summit of L_ihi submarine volcano changed dramatically after seismic activity beneath L_ihi during the month of August 1996. Bathymetric re-surveys of the L_ihi edifice using SeaBeam, Simrad and deep-towed Reson-Focus multibeam systems showed the presence of new north-south striking fissures, normal faults and a new pit crater located at the site of a former 300-meter high volcanic cone. Comparisons between the pre-1996 SeaBeam data and the new bathymetry show a net loss of about 100 million cubic meters of rock volume on the summit. This loss is localized at a new pit crater -- the 300-meter deep by 1,300-meter wide Pele's Pit. Submersible observations with Pisces V show the northern edge of Pele's Pit to be bounded by a normal fault located north of the site of the former Pele's Vents cone that has disappeared into the new pit crater. A new hydrothermal field, the Ikaika Vents, extending from a water depth of 1,311 meters to 1,287 meters has formed at the northeastern edge of the floor of Pele's Pit. Submersible observations of these new Ikaika Vents during September 1996 showed vigorous venting at the site with extensive white-colored bacterial mats hanging off the rock face above the vents. Follow-up mapping and sampling of the vent sites during August 1997 showed vent temperatures of up to 198°C, dense populations of vent shrimps around the vents and a centimeters-thick veneer of fine-grained polymetallic sulfide mineralization along the rock walls above individual vents. The mineralogy of the sulfides shows a barite, chalcopyrite, sphalerite, and pyrite composition.

Jan 1, 1998