scholarly journals Biosignatures in chimney structures and sediment from the Loki’s Castle low-temperature hydrothermal vent field at the Arctic Mid-Ocean Ridge

Extremophiles ◽  
2014 ◽  
Vol 18 (3) ◽  
pp. 545-560 ◽  
Author(s):  
Andrea Jaeschke ◽  
Benjamin Eickmann ◽  
Susan Q. Lang ◽  
Stefano M. Bernasconi ◽  
Harald Strauss ◽  
...  
Keyword(s):  
Low Temperature ◽  
Hydrothermal Vent ◽  
The Arctic ◽  
Mid Ocean Ridge ◽  
Loki’S Castle ◽  
Ocean Ridge ◽  
Hydrothermal Vent Field

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

2017 ◽  
Author(s):  
Steinar Løve Ellefmo ◽  
Martin Ludvigsen ◽  
Erik Kristian Thon Frimanslund
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
Operating Time ◽  
Cost Structure ◽  
The Arctic ◽  
Operational Experience ◽  
Production Volume ◽  
Mid Ocean Ridge ◽  
Loki’S Castle ◽  
Ocean Ridge

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.

scholarly journals Simultaneous Leaching of Seafloor Massive Sulfides and Polymetallic Nodules

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 482 ◽  
Author(s):  
Przemyslaw Kowalczuk ◽  
Hassan Bouzahzah ◽  
Rolf Kleiv ◽  
Kurt Aasly
Keyword(s):  
Industrial Applications ◽  
The Arctic ◽  
Central Pacific ◽  
Massive Sulfides ◽  
Central Pacific Ocean ◽  
Polymetallic Nodules ◽  
Mid Ocean Ridge ◽  
Different Types ◽  
Loki’S Castle ◽  
Ocean Ridge

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.

scholarly journals Characterisation of Mineralised Material from the Loki’s Castle Hydrothermal Vent on the Mohn’s Ridge

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 576 ◽  
Author(s):  
Ben Snook ◽  
Kristian Drivenes ◽  
Gavyn Rollinson ◽  
Kurt Aasly
Keyword(s):  
Hydrothermal Vent ◽  
Precious Metals ◽  
The Arctic ◽  
X Ray Diffraction ◽  
Reflected Light ◽  
Average Grain Size ◽  
Association Data ◽  
Loki’S Castle ◽  
Ocean Ridge ◽  
Multiple Samples

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.

scholarly journals Microbial diversity of Loki's Castle black smokers at the Arctic Mid-Ocean Ridge

Geobiology ◽  
2012 ◽  
Vol 10 (6) ◽  
pp. 548-561 ◽  
Author(s):  
A. Jaeschke ◽  
S. L. Jørgensen ◽  
S. M. Bernasconi ◽  
R. B. Pedersen ◽  
I. H. Thorseth ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
The Arctic ◽  
Mid Ocean Ridge ◽  
Black Smokers ◽  
Loki’S Castle ◽  
Ocean Ridge

scholarly journals Profundibacter amoris gen. nov., sp. nov., a new member of the Roseobacter clade isolated from Loki’s Castle Vent Field on the Arctic Mid-Ocean Ridge.

2019 ◽  
Vol 69 (4) ◽  
pp. 975-981 ◽  
Author(s):  
Sven Le Moine Bauer ◽  
Andreas Gilje Sjøberg ◽  
Stéphane L'Haridon ◽  
Runar Stokke ◽  
Irene Roalkvam ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
The Arctic ◽  
Rrna Gene ◽  
Unidentified Phospholipid ◽  
Content Type ◽  
Link Type ◽  
Mid Ocean Ridge ◽  
Novel Genus And Species ◽  
Loki’S Castle ◽  
Ocean Ridge

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).

scholarly journals A subduction influence on ocean ridge basalts outside the Pacific subduction shield

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
A. Y. Yang ◽  
C. H. Langmuir ◽  
Y. Cai ◽  
P. Michael ◽  
S. L. Goldstein ◽  
...  
Keyword(s):  
Upper Mantle ◽  
The Arctic ◽  
Mantle Flow ◽  
Mantle Heterogeneity ◽  
Gakkel Ridge ◽  
The Pacific ◽  
Mid Ocean Ridge ◽  
The Pacific Ocean ◽  
Back Arc ◽  
Ocean Ridge

AbstractThe plate tectonic cycle produces chemically distinct mid-ocean ridge basalts and arc volcanics, with the latter enriched in elements such as Ba, Rb, Th, Sr and Pb and depleted in Nb owing to the water-rich flux from the subducted slab. Basalts from back-arc basins, with intermediate compositions, show that such a slab flux can be transported behind the volcanic front of the arc and incorporated into mantle flow. Hence it is puzzling why melts of subduction-modified mantle have rarely been recognized in mid-ocean ridge basalts. Here we report the first mid-ocean ridge basalt samples with distinct arc signatures, akin to back-arc basin basalts, from the Arctic Gakkel Ridge. A new high precision dataset for 576 Gakkel samples suggests a pervasive subduction influence in this region. This influence can also be identified in Atlantic and Indian mid-ocean ridge basalts but is nearly absent in Pacific mid-ocean ridge basalts. Such a hemispheric-scale upper mantle heterogeneity reflects subduction modification of the asthenospheric mantle which is incorporated into mantle flow, and whose geographical distribution is controlled dominantly by a “subduction shield” that has surrounded the Pacific Ocean for 180 Myr. Simple modeling suggests that a slab flux equivalent to ~13% of the output at arcs is incorporated into the convecting upper mantle.

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