Hydrothermal Ore Genesis in the Sea of Japan

2021 ◽  
Vol 62 (9) ◽  
pp. 977-986
Author(s):  
N.V. Astakhova
Keyword(s):  
Sea Of Japan ◽  
Fault Zones ◽  
The Sea Of Japan ◽  
Hydrothermal Solutions ◽  
Ore Genesis ◽  
Ferromanganese Crusts ◽  
The Pacific ◽  
Deep Faults ◽  
Tectonically Active ◽  
Active Zones

Abstract —The Sea of Japan is a tectonically active region with rift-related destruction of the Earth’s crust and numerous volcanic edifices on the seafloor. Since the 1970s, numerous zones with ferromanganese crusts (FMCs) and phosphorite and barite ore occurrences have been discovered during the repeated expeditions of the Pacific Oceanological Institute, Vladivostok. Analysis of the distribution of these ore occurrences showed that all of them are confined to tectonically active zones of the seafloor: submarine volcanoes, tectonic scarps, or fault zones. In some zones, phosphorites occur together with FMCs, and in one zone, together with FMCs and barites. Ferromanganese hydroxides, phosphorites, or barites are found in the pores of basalts composing submarine volcanic edifices in the Sea of Japan. These data indicate that the ore matter in all zones is supplied with postvolcanic gas-hydrothermal fluids or hydrothermal solutions circulating along deep faults during the destruction of the continental crust in the southern and eastern parts of the sea. Thus, ferromanganese, phosphate, and barite ore occurrences in the Sea of Japan are related to low-temperature hydrothermal-sedimentary processes.

scholarly journals Long-term ocean acidification trends in coastal waters around Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroshi Ishida ◽  
Ryosuke S. Isono ◽  
Jun Kita ◽  
Yutaka W. Watanabe
Keyword(s):  
Pacific Ocean ◽  
Ocean Acidification ◽  
Sea Of Japan ◽  
Ocean Current ◽  
The Sea Of Japan ◽  
Marginal Seas ◽  
The Pacific ◽  
Activity Measurements ◽  
The Pacific Ocean

AbstractThis study examines long-term ocean pH data to evaluate ocean acidification (OA) trends at two coastal research institutions located on the Sea of Japan and the Pacific Ocean. These laboratories are located away from the influences of large rivers and major industrial activity. Measurements were performed daily for the past 30 years (1980s–2010s). The average annual ocean pH for both sites showed generally negative trends. These trends were – 0.0032 and – 0.0068 year–1 (p < 0.001) at the Sea of Japan and Pacific Ocean sites, respectively. The trends were superimposed onto approximately 10-year oscillations, which appear to synchronize with the ocean current periodicity. At the Sea of Japan site, the ocean pH in the summer was higher, and the rate of OA was higher than during other seasons. Our results suggest that seasonality and ocean currents influence OA in the coastal areas of open oceans and can affect the coastal regions of marginal seas.

scholarly journals Henricia djakonovisp. nov. (Echinodermata, Echinasteridae): a new sea star species from the Sea of Japan

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2863 ◽  
Author(s):  
Anton Chichvarkhin
Keyword(s):  
New Species ◽  
Sea Of Japan ◽  
Common Species ◽  
Sympatric Species ◽  
Variable Number ◽  
The Other ◽  
The Sea Of Japan ◽  
Sea Star ◽  
The Pacific ◽  
Russian Waters

A new sea star species,H. djakonovisp.n., was discovered in Rudnaya Bay in the Sea of Japan. This is a sympatric species of the well-known and common speciesHenricia pseudoleviusculaDjakonov, 1958. Both species are similar in body size and proportions, shape of skeletal plates, and life coloration, which distinguishes them from the otherHenriciaspecies inhabiting the Sea of Japan. Nevertheless, these species can be distinguished by their abactinal spines: in both species, they are short and barrel-like, but the new species is the onlyHenriciaspecies in Russian waters of the Pacific that possesses such spines with a massive, smooth, bullet-like tip. The spines inH. pseudoleviusculaare crowned with a variable number of well-developed thorns. About half (<50%) of the abactinal pseudopaxillae in the new species are oval, not crescent-shaped as inH. pseudoleviuscula.

Sources of gallium in ferromanganese crusts from the Sea of Japan

2015 ◽  
Vol 56 (8) ◽  
pp. 1148-1153 ◽  
Author(s):  
P.E. Mikhailik ◽  
E.V. Mikhailik ◽  
M.G. Blokhin ◽  
N.V. Zarubina
Keyword(s):  
Sea Of Japan ◽  
The Sea Of Japan ◽  
Ferromanganese Crusts

Geotraverse across the Sikhote Alin ? The Sea of Japan ? The Honshu Island ? The Pacific

1985 ◽  
Vol 7 (3) ◽  
pp. 379-387 ◽  
Author(s):  
A. G. Rodnikov ◽  
A. G. Gainanov ◽  
B. V. Yermakov ◽  
V. M. Kovylin ◽  
V. A. Seliverstov ◽  
...  
Keyword(s):  
Sea Of Japan ◽  
The Sea Of Japan ◽  
Sikhote Alin ◽  
The Pacific ◽  
Honshu Island

Marine reservoir correction for the Pacific coast of central Japan using 14C ages of marine mollusks uplifted during historical earthquakes

2007 ◽  
Vol 67 (2) ◽  
pp. 286-291 ◽  
Author(s):  
Masanobu Shishikura ◽  
Tomoo Echigo ◽  
Heitaro Kaneda
Keyword(s):  
Radiocarbon Dating ◽  
Pacific Coast ◽  
Historical Earthquakes ◽  
The Sea Of Japan ◽  
Central Japan ◽  
South Central ◽  
Kanto Earthquake ◽  
The Pacific ◽  
Tectonically Active ◽  
Mollusk Assemblages

AbstractIn this study we utilize marine shell samples from two levels of historically uplifted sessile mollusk assemblages and raised wave-cut benches to evaluate the marine reservoir correction (ΔR) for the Pacific coast of central Japan. Elevation measurements of the uplifted marine shells indicate that the lower assemblage emerged during the 1923 Taisho Kanto earthquake (M7.9), whereas uplift of the upper assemblage is most likely but less confidently ascribed to the 1703 Genroku Kanto earthquake (M8.2). Radiocarbon dating of carefully selected samples from the upper and lower assemblages yielded very similar ΔR values of 82 ± 33 and 77 ± 32 yr, respectively. We regard the former ΔR value as a representative and more reliable value given the uncertainty in correlation of the upper assemblage with the 1703 earthquake. This result is consistent with previously reported ΔR values for the Pacific coast of south-central Japan and areas around the Sea of Japan that are influenced by warm ocean currents. Radiocarbon dating of coseismically uplifted shells can aid in estimating marine reservoir ages in the tectonically active Japan Islands.

scholarly journals Gold in Ferromanganese Deposits from the NW Pacific

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 979
Author(s):  
Pavel Mikhailik ◽  
Evgenii Mikhailik ◽  
Vladimir Ivanov
Keyword(s):  
Sea Of Japan ◽  
Solid Phase ◽  
Marshall Islands ◽  
The Sea Of Japan ◽  
Gold Content ◽  
Electron Microscopic ◽  
Gold Particles ◽  
North West ◽  
Ferromanganese Crusts ◽  
West Pacific Ocean

Ferromanganese crusts from four different areas of the North-West Pacific Ocean—the Detroit (northern part of the Imperial Ridge) guyot, the Zubov (Marshall Islands) guyot, the “Gummi Bear” seamount (an intraplate volcano near the Krusenstern FZ), and Belyaevsky volcano (the Sea of Japan)—were studied. Samples from the Detroit and Zubov guyots and the “Gummi Bear” seamount have similar chemical and mineral compositions of hydrogenetic cobalt-rich ferromanganese crusts. Crust from the Sea of Japan seems to reflect a hydrothermal influence. The gold content in most samples from the Detroit guyot was 68 ppb and from the Zubov guyot varied from 180 to 1390 ppb, which is higher than the average for the Pacific crusts (55 ppb). Gold content in two other samples was less than 10 ppb. Based on the electron microscopic studies, aggregation of gold particles with a size of 680 μm were identified in the Detroit guyot crust. The sizes of the Au particles are up to 10–15 μm, which has not been previously noted. Gold particles similar in morphology and size were also found in the Zubov guyot crust, which is located far from the Detroit guyot. The largest particle of gold (≈60 μm), represented by electrum, was found in the clay substrate from the “Gummi Bear” seamount. The lamellar, rudaceous morphology of the gold particles from the Detroit and Zubov guyots reflects their in situ formation, in contrast to the agglutinated, rounded with traces of dragging gold grain found in the substrate of the sample from the “Gummi Bear” seamount. Three-component (Ag-Au-Cu) gold particles were found in the hydrothermal crust from the Belyaevsky underwater volcano. Grains similar in composition were also found in Co-rich crust. The research results show that the gold was probably added to by hydrothermal fluid in the already-formed hydrogenetic ferromanganese crusts during rejuvenated volcanic stages. Biogeochemical processes may have played a major role in the formation of submicron solid-phase gold particles.

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