Grain-size and mineral composition of the upper layer of sediments of the Barents Sea

2021 ◽  
pp. 398-415
Author(s):  
N.V. Politova ◽  
◽  
T.N. Alekseeva ◽  
N.V. Kozina ◽  
M.D. Kravchishina ◽  
...  

The paper presents data from grain size and mineralogical analyzes of surface bottom sediment samples obtained on several cruises of the R/V Akademik Mstislav Keldysh (2016–2018) from different parts of the Barents Sea. Pebble and gravel material is found in surface sediments in the form of impurities scattered throughout the sea. Such a chaotic distribution pattern is apparently associated with ice separation. Coarse material is most common in the Barents Sea off the coast of the Kola Peninsula, off the coast of Novaya Zemlya, Spitsbergen, where it accumulates due to coastal abrasion. In addition, a fraction >1 mm is widespread at depths where fine fractions are stirred and leached. The most common sediments in coastal shallow water are sands. Sands (0.1–1 mm) are widespread in the southern and southeastern regions of the sea, in the region of the Pechora polygon, the Kaninsky shallow water, the Kola Peninsula, and in the northwest, off the coast of Svalbard. With increasing depth, the sands are replaced by mixed sediments with a low admixture of pelite. Pelitic sediments are prevalent in the central part of the sea. Precipitation with a pelitic fraction (<0.01 mm) of more than 50% occupy about 70% of the Barents Sea. They are widespread in deep-sea hollows and trenches, as well as in the numerous fiords of the North Island of Novaya Zemlya and Franz Josef Land. Surface sediments have a predominantly terrigenous composition; only at the border with the Norwegian Sea the proportion of biogenic material increases. The mineral composition of sediments is dominated by quartz and feldspars, clay minerals are mainly represented by illite, smectite and kaolinite.

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 593
Author(s):  
Liudmila L. Demina ◽  
Olga Dara ◽  
Ramiz Aliev ◽  
Tatiana Alekseeva ◽  
Dmitry Budko ◽  
...  

A comprehensive examination of the elemental (including radionuclides and heavy metals), mineral, and grain-size composition of sediments from different areas of the Barents Sea was performed. Sediment cores were sampled in the Central Deep, Cambridge Strait (Franz Josef Land Archipelago), Russkaya Gavan’ Bay (Novaya Zemlya Archipelago), and Bear Island Trough. We aim to evaluate how the modern and more ancient environmental conditions are reflected in the elemental and mineral composition, as well as to test indicative elemental ratios. The applied methods include elemental analysis using gamma-ray spectroscopy, X-ray fluorescence (XRF), Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), and X-Ray Difractometry XRD analysis of minerals. Difference in sedimentation rates, grain-size composition, and sources of material, are reflected in downcore variation of Si/Al, Mn/Fe, P/Al, Ti/K, and quartz-feldspar ratios. At boundary Early Holocene/Late Deglaciation, intensive bottom currents from the West-Southern shelf areas contributed to increase of Si/Al and Zr/Ca ratios. Distinct growth of the Si/Fe ratio within the sediments deposited over Late Pleistocene to Mid Holocene may be caused by increased contents of the coarse sand material, as well as by abundant fluxes of clay-mineral-loaded glacial meltwater during the main deglaciation phase. The Mn/Fe ratio used as redox proxy, displayed peaks at different depths related to oxygen concentration growth in bottom water.


2021 ◽  
pp. 444-472
Author(s):  
A.V. Maslov ◽  
◽  
N.V. Politova ◽  
N.V. Kozina ◽  
A.B. Kuznetzov ◽  
...  

The article presents a brief lithological description of the modern bottom sediments of the Barents Sea, selected in the 67th voyage of the R/V “Akademik Mstislav Keldysh” at the polygons: 1) “Pechora Sea”; 2) “Western slope of Kaninskoe shoal”; 3) “Central Barents Sea (Shtokman area)”; 4) “Russkaya Gavan’ fjord”; 5) “Medvezhinsky Trench”; 6) in the area to the south of Spitsbergen; 7) “Kola meridian”; 8) “Spitsbergen – Franz Josef Land archipelago”; 9) “Cambridge Strait”. The distribution of Cr, Ni, Cu, Zn, Cd, and Pb in samples of bottom sediments (pelitic, aleurite-pelitic and sandy-aleuritic-pelitic ooze) is compared with the background concentrations and contents of these elements in the Post-Archean Average Shale (PAAS). The data obtained are consistent with the notion that the distribution of heavy metals and other elements in the bottom sediments is controlled primarily by the global geochemical background. The relationship of the Sc, V, Cr, Ni, Y, Zr, Nb, Mo, Hf, Th, U and rare-earth elements concentrations with content of fine pelite (< 0.001 mm) fraction and organic carbon (Corg) is considered. It was found that most of these elements are characterized by a moderate positive correlation with the amount of fine pelite fraction in samples. By the magnitude of the correlation coefficient with the Corg content, all elements are attributed into three groups: (1) with moderate positive correlation, (2) weak positive correlation, (3) practically not pronounced correlation. The distribution in the bottom sediments of the Barents Sea of the element-indicators of the source rocks composition (Sc, Th, Co, Cr, La and Sm), as well as of rare earths, make it possible to consider that the majority of bottom sediments is mature in geochemical terms material, the sources of which were rocks of the Kola Peninsula and Spitsbergen (?). The bottom sediments of the Cambridge Strait are represented by geochemically less mature material, which, apparently, entered the sea as a result of erosion of the Franz Josef Land archipelago rocks. The established isotopic characteristics (εNd, 207Pb/206Pb and 87Sr/86Sr) of 17 samples of surface sediments suggest that the main contribution to the formation of bottom deposits of the central regions of the Barents Sea is made by rocks of the mainland part located in the influence zone of the North Cape Current. Archipelagos and islands (Franz Josef Land, Novaya Zemlya, etc.) that frame the Barents Sea supply a relatively small amount of clastic material that is carried by Arctic currents. The values of εNd and 87Sr/86Sr in the surface sediments of the central part of the Barents Sea and in the ice-rafted sediments carried by the Transpolar Drift showed a significant difference. This suggests that the contribution of such material to the formation of surface sediments of the Barents Sea is relatively small


2020 ◽  
Vol 11 (5-2020) ◽  
pp. 116-125
Author(s):  
A.E. Noskovich ◽  

In the eastern part of the Barents Sea, there are 3 types of settlements of the bivalve mollusk Macoma calcarea. At low positive temperatures (from 0.6 to 1.3 оC),juveniles predominate on sandy-silty soils in settlements with low biomass, uneven growth and high mortality. In colder water masses (–0.4...–1.5 оC), M. calcareasettlements consist of long-lived, evenly growing large individuals that form high biomass values. In the settlement of group I, there was an increased elimination of certain size classes. The distribution of settlements depends little on the depth and salinity.


Author(s):  
I. G. Mindel ◽  
B. A. Trifonov ◽  
M. D. Kaurkin ◽  
V. V. Nesynov

In recent years, in connection with the national task of developing the Arctic territories of Russia and the perspective increase in the hydrocarbon mining on the Arctic shelf, more attention is being paid to the study of seismicity in the Barents Sea shelf. The development of the Russian Arctic shelf with the prospect of increasing hydrocarbon mining is a strategically important issue. Research by B.A. Assinovskaya (1990, 1994) and Ya.V. Konechnaya (2015) allowed the authors to estimate the seismic effects for the northern part of the Barents Sea shelf (Novaya Zemlya region). The paper presents the assessment results of the initial seismic impacts that can be used to solve seismic microzoning problems in the areas of oil and gas infrastructure during the economic development of the Arctic territory.


2015 ◽  
Vol 35 ◽  
pp. 9 ◽  
Author(s):  
Andrey Sikorski ◽  
Lyudmila Pavlova

<p>The species <em>Scolelepis finmarchicus</em> sp. nov. is described from the Norwegian and Barents Seas along the northern Norwegian coast and Kola peninsula. The occurrence of this species in the Kola Bay could be seen as a sign of climate warming in the area. Taxonomic issues existing in the genus <em>Scolelepis</em> within the area along the Norwegian coast and in the Barents Sea are briefly touched upon. Seven species belonging to <em>Scolelepis</em> have recently been recorded from the Atlantic sector of the Arctic. <em>Scolelepis</em> (<em>S</em>.) <em>matsugae</em> Sikorski, 1994 is newly synonymized with <em>S</em>. (<em>S</em>.) <em>laonicola</em> (Tzetlin, 1985). This article provides a brief review of <em>Scolelepis</em> together with an identification key for the genus from the Atlantic sector of the Arctic</p>


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3648
Author(s):  
Pavel R. Makarevich ◽  
Veronika V. Vodopianova ◽  
Aleksandra S. Bulavina ◽  
Pavel S. Vashchenko ◽  
Tatiana G. Ishkulova

In spring 2016, the thermohaline characteristics of water masses and the distribution of chlorophyll-a concentration in the pelagic zone of the eastern part of the Barents Sea were studied. For the first time, in the conditions of an abnormally warm year and the absence of ice cover, a complex of hydrobiological works was carried out on a section crossing the Barents Sea from south to north along the western coast of the Novaya Zemlya archipelago. High concentrations of chlorophyll-a > 1 ˂ 6 mg/m3 at all stations of the transect indicate a stage of spring bloom in the successional cycle of microalgae. Significant differences in the content of chlorophyll-a in waters of various origins were revealed. The highest concentrations of chlorophyll-a corresponded to Arctic surface water (5.56 mg/m3). Slightly lower values were observed in the transformed Atlantic waters of the Novozemelskoe and Kolguevo–Pechorskoe currents (3.53 ± 0.97–3.71 ± 1.04 mg/m3), and the lowest was in the Barents waters (1.24 ± 0.84–1.45 ± 1.13 mg/m3).


Author(s):  
Denis V Zakharov ◽  
Igor E Manushin ◽  
Tatiana B Nosova ◽  
Natalya A Strelkova ◽  
Valery A Pavlov

Abstract This article investigates the diet of the snow crab (Chionoecetes opilio) and its feeding intensity in the Barents Sea. Data show that snow crab has a diverse diet that includes almost all types of benthic invertebrates living in the Barents Sea. There are differences between the diets of females and males and of juveniles and adults. Juveniles and females typically occupy shallow areas with communities of bivalve molluscs, while males typically live deeper on slopes and depressions where polychaetes and crustaceans are the most abundant groups. Stomach contents were analysed to determine the species composition and frequency of occurrence of various benthic taxa. Consumption of food was estimated and compared with data from the Russian seas of the Pacific region. The total annual consumption of macrozoobenthos by snow crab was calculated in accordance with its current distribution in the Barents Sea. Snow crab consumes at least 30 000 tonnes of benthos annually, which amounts to 0.1–0.2% of the total macrozoobenthic biomass in the investigated area. The population of snow crab causes the largest impact on the benthic communities in the northeastern part of the Barents Sea and near the south side of the Novaya Zemlya archipelago.


2019 ◽  
Vol 485 (2) ◽  
pp. 207-211
Author(s):  
A. V. Maslov ◽  
N. V. Politova ◽  
V. P. Shevchenko ◽  
N. V. Kozina ◽  
A. N. Novigatsk ◽  
...  

The Co, Hf, Ce, Cr, Th, and REE systematics are analyzed for modern sediments collected by a bottom grab during the 67th and 68th cruises of R/V “Akademik Mstislav Keldysh” and samples taken in the Barents Sea bays and inlets. Our results indicate that most modern bottom sediments are composed of fine silicoclastic material enhanced with a suspended matter of the North Cape current, which erodes the western coast of Scandinavia, and due to bottom erosion of some marine areas, as well as erosion of rock complexes of the Kola Peninsula, Novaya Zemlya, and Franz Josef Land (local provenances). Material from Spitsbergen also probably played a certain role. In the southern part of the Barents Sea, clastic material is supplied by the Pechora River.


2021 ◽  
pp. 25-43
Author(s):  
A.E. Rybalko ◽  
◽  
M.Yu. Tokarev ◽  

Hot questions in the modern Quaternary geology of the Arctic seas associated with their glaciation are discussed in this article. The questions of the history of the occurrence of the problem of shelf glaciation or “drift” accumulation of boulder-bearing sediments are considered in detail. The results of seismic-acoustic studies and their interpretation with the aim of seismic stratigraphic and genetic partition of the cover of loose sediments of Quaternary age are considered in detail. Arguments are presented in favor of the continental origin of glaciers (Novaya Zemlya, Ostrovnoy and Scandinavian), which in the late Neopleistocene spread to the shelf of the Barents Sea and occupied its surface to depths of 120−150 m. Further development of glaciation was already due to the expansion of the area of shelves glaciers. The facies zoning of glacial-marine deposits is estimated, which is related to the distance from the front of the glaciers. It is concluded that already at the end of the Late Pleistocene, most of the modern Barents Sea was free from glaciers and from the annual cover of pack ice. Data on the absence of the area distribution of frozen sediment strata within the modern Barents Sea shelf are presented.


Sign in / Sign up

Export Citation Format

Share Document