Full Cycle Resource Evaluation of SMS Deposits Along the Arctic Mid Ocean Ridge

Author(s):  
Steinar Løve Ellefmo ◽  
Martin Ludvigsen ◽  
Erik Kristian Thon Frimanslund

Several hydrothermal vent sites have been discovered along the portion of the Arctic Mid-Ocean Ridge (AMOR) inside the extended Norwegian continental shelf (NCS). Seafloor massive sulfide (SMS) deposits are associated with these hydrothermal vent sites. These deposits contain significant amounts of valuable metals, such as copper, zinc, gold, and silver. Loki’s Castle is one of the most promising sites along the AMOR, with two 20–30 m high and 100 m wide mound-shaped SMS deposits. It is located at a water depth of 2,400 m. A production system concept is proposed for a deep-sea mining operation at Loki’s Castle based on the Nautilus Minerals’ Solwara 1 project. The overall cost structure and design of the Nautilus’ concept is in this study regarded feasible in AMOR in spite of the difference between the operating environment for the two locations. As the only relevant operational experience is De Beers’ shallow-water diamond mining off the coast of South Africa and Namibia, most of the environmental criteria used are taken from offshore drilling. Based on the net operating time, and accounting for scheduled maintenance and waiting-on-weather time, an estimate for annual average production rate and an annual production volume are estimated. Significant downtime is expected in January and July. Significant uncertainties are associated with early phases of projects. Probabilistic cost, grade and price estimates allow dealing quantitatively with uncertainties by giving input variables as probability distributions. Monte Carlo simulations are in this study run for different sets of variables, and the resulting key performance indicators are given as distributions. This paper adapts and presents a methodology normally used to assess technological and economic feasibilities of oil and gas projects. The methodology is adapted to the assessment of deep-sea mining projects and is illustrated through the assessment of the case based on Loki’s Castle ore characteristics and technologies planned for the Solwara 1 project with a cost structure adjusted according to AMOR conditions. Costs for processing, refining, waste disposal and logistics after ore arrival at onshore port is not included. The ore uncertainties are huge and the resources are with the present deposit knowledge speculative. Therefore, this study do not attempt to define any reserves.

Extremophiles ◽  
2014 ◽  
Vol 18 (3) ◽  
pp. 545-560 ◽  
Author(s):  
Andrea Jaeschke ◽  
Benjamin Eickmann ◽  
Susan Q. Lang ◽  
Stefano M. Bernasconi ◽  
Harald Strauss ◽  
...  

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 482 ◽  
Author(s):  
Przemyslaw Kowalczuk ◽  
Hassan Bouzahzah ◽  
Rolf Kleiv ◽  
Kurt Aasly

Simultaneous leaching of seafloor massive sulfides (SMS) from Loki’s Castle on the Arctic Mid-Ocean Ridge (AMOR) and polymetallic nodules (PN) from Clarion Clipperton Zone (CCZ) of the Central Pacific Ocean was studied. Leaching tests were conducted using sulfuric acid and sodium chloride, at a temperature of 80 °C for 48 h under reflux. The effect of PN-to-SMS ratio was examined. It was shown that simultaneous leaching of two different types of marine resources was possible resulting in high dissolution rates of metals. The proposed process has many advantages as it does not require pyrometallurgical pretreatment, and yields solid products (i.e., silica, barite, elemental sulfur, albite, microcline, muscovite), which might be utilized for various industrial applications.


Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 576 ◽  
Author(s):  
Ben Snook ◽  
Kristian Drivenes ◽  
Gavyn Rollinson ◽  
Kurt Aasly

Loki’s Castle on the Arctic Mid-Ocean Ridge (AMOR) is an area of possible seafloor massive sulphide (SMS)-style mineralisation under Norwegian jurisdiction, which, due to mounting social pressure, may be a strategic future source of base and precious metals. The purpose of this study is to characterise mineralised material from a hydrothermal vent system on the AMOR in detail for the first time, and to discuss the suitability of methods used; reflected light microscopy, X-ray diffraction (XRD), whole rock geochemistry, electron probe micro-analysis (EPMA), and QEMSCAN. The primary sulphide phases, identifiable by microscopy, are pyrite and marcasite with minor pyrrhotite and galena, but multiple samples from the Loki’s Castle contain economically interesting quantities of copper (hosted in isocubanite and chalcopyrite) and zinc (hosted in sphalerite), as well as silver and gold. This reinforces the notion that slow spreading ridges may host significant base metal deposits. Micro-textures (chalcopyrite inclusions and exsolutions in sphalerite and isocubanite respectively) are typically undefinable by QEMSCAN, and require quantitative measurement by EPMA. QEMSCAN can be used to efficiently generate average grain size and mineral association data, as well as composition data, and is likely to be a powerful tool in assessing the effectiveness of SMS mineral processing.


Geobiology ◽  
2012 ◽  
Vol 10 (6) ◽  
pp. 548-561 ◽  
Author(s):  
A. Jaeschke ◽  
S. L. Jørgensen ◽  
S. M. Bernasconi ◽  
R. B. Pedersen ◽  
I. H. Thorseth ◽  
...  

2019 ◽  
Vol 69 (4) ◽  
pp. 975-981 ◽  
Author(s):  
Sven Le Moine Bauer ◽  
Andreas Gilje Sjøberg ◽  
Stéphane L'Haridon ◽  
Runar Stokke ◽  
Irene Roalkvam ◽  
...  

A bacterial strain, designated BAR1T, was isolated from a microbial mat growing on the surface of a barite chimney at the Loki’s Castle Vent Field, at a depth of 2216 m. Cells of strain BAR1T were rod-shaped, Gram-reaction-negative and grew on marine broth 2216 at 10–37 °C (optimum 27–35 °C), pH 5.5–8.0 (optimum pH 6.5–7.5) and 0.5–5.0 % NaCl (optimum 2 %). The DNA G+C content was 57.38 mol%. The membrane-associated major ubiquinone was Q-10, the fatty acid profile was dominated by C18 : 1ω7c (91 %), and the polar lipids detected were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid, one unidentified lipid and one unidentified phospholipid. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain BAR1T clustered together with Rhodobacterales bacterium PRT1, as well as the genera Halocynthiibacter and Pseudohalocynthiibacter in a polyphyletic clade within the Roseobacter clade. Several characteristics differentiate strain BAR1T from the aforementioned genera, including its motility, its piezophilic behaviour and its ability to grow at 35 °C and under anaerobic conditions. Accordingly, strain BAR1T is considered to represent a novel genus and species within the Roseobacter clade, for which the name Profundibacter amoris gen. nov., sp. nov. is proposed. The type strain is Profundibacter amoris BAR1T (=JCM 31874T=DSM 104147T).


1992 ◽  
Vol 6 ◽  
pp. 190-190
Author(s):  
Richard A. Lutz ◽  
Rachel M. Haymon

An abundant and unusual fauna is associated with deep-sea hydrothermal vents on the crest of the global mid-ocean ridge system. Precipitation of metal sulfides, silica, iron-oxyhydroxides and other minerals at these vents encrusts and replaces the remains of dead organisms to form fossils that may be preserved in the geologic record. For example, molds and casts of tubiculous polychaete and vestimentiferan worms are abundantly preserved in Recent hot spring deposits on the mid-ocean ridge crest, and similar worm molds also have been found in Tethys ophiolite sulfide mineral deposits of mid-Cretaceous age. The aragonitic and calcareous shells and tests of other vent species are also good candidates for fossilization by encrustation and replacement of their carbonate constituents with hydrothermal minerals.Recent and ongoing studies of the ecology and mineralization of vent organisms at active hot spring sites on the mid-ocean ridge in the eastern Pacific provide knowledge needed for gleaning paleoecological information from fossiliferous marine hydrothermal deposits in the geologic record. At modern vents, intact larval shells (prodissoconchs or protoconchs) are present on the surfaces of many juvenile molluscs. Preservation of these larval shells by hydrothermal mineralization may provide a powerful paleoecological tool for interpretation of the life history strategies of many sessile invertebrates associated with ancient submarine hydrothermal vents. Bacterial mats that grow on the outer surfaces of sulfide mineral structures have been preserved by silica deposition in inactive deposits on the East Pacific Rise (EPR) axis at 9°27'N. Studies of the ecology and growth history of this bacterial species at active vents are in progress.Preservation of ridge crest vent fauna within volcanic rock units can occur when lava erupts on the ridge crest near hydrothermal vent communities. Along the axis of the EPR at 9°50.6'N, vent mussels and vestimentiferan worms were found partially buried by lava flows and volcanic collapse rubble. Animals trapped beneath eruption-associated rubble may be coated or replaced by hydrothermal minerals precipitating from fluids circulating in the cooling rocks. In addition, worm-tube molds were created at the EPR 9°50.6'N site where lava quenched around living vestimentiferans (analogous to the formation of tree-molds in Hawaiian lava flows). These lava molds contained pyritized remnants of the chitinous tubes of the vestimentiferans.


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