Geochemical fractions and indicators of sedimentation conditions in the Barents sea

2021 ◽  
pp. 431-444
Author(s):  
L.L. Demina ◽  
◽  
D.F. Budko ◽  
N.V. Politova ◽  
T.N. Alexeeva ◽  
...  
Keyword(s):  
Trace Elements ◽  
Chemical Weathering ◽  
Barents Sea ◽  
Sediment Cores ◽  
Total Content ◽  
The Core ◽  
Geochemical Fractions ◽  
The Barents Sea ◽  
Liquid Phases ◽  
Mobile Fraction

Research results of geochemical fractions and distribution pattern of the major and trace elements in the sediment cores of the Barents Sea are presented. In the sediment core AMK- 5193, located in the central part of the sea, Al, Cr and Ni were detected predominantly in the lithogenic form (75−97% of the total content) throughout the core. A large or a noticeable portion (from 65% to 30% from total contents) of Pb, Cd, Cu, Ni, Co, Mn, and As was found to be accumulated due to hydrogenous processes, such as adsorption on amorphous Fe-Mn oxyhydroxides and clay particles. In the uppermost oxidized layer (0−6 cm) of St. AMK-5193, where the most intensive exchange processes between the solid and liquid phases of bottom sediments happen, a significant increase in the proportion of geochemically mobile fraction of most metals was found. In this part of the core, the maximum content of Fe and Mn in the form of authigenic oxy-hydroxides which serve an effective sorbent of most trace elements, including heavy metals, was recorded. At st. 5194, the downcore rythmic covariation of the Si/Al, Ti/Al and Fe/Al ratios reflecting contribution of terrigenous matrix, as well as Al/Ca ratio (indicator of physical and chemical weathering) was revealed. Moreover, the Al/Ca ratio exhibited an asynchronous change with the Si/Al and Fe/Al ratios. Also, the downcore variation in the Ti/Al ratio was opposite to that of Mn/Fe (an indicator of geochemically mobile fraction). Variation of the Ti/Zr ratio, reflecting the range of aerosol transport of clastic material, is weakly expressed in the AMK-5194 core, which supports the proximity of the terrigenous source.

Rare and Trace Elements in the Modern Bottom Sediments of the Barents Sea

2020 ◽  
Vol 55 (1) ◽  
pp. 1-23
Author(s):  
A. V. Maslov ◽  
N. V. Politova ◽  
N. V. Kozina ◽  
V. P. Shevchenko ◽  
T. N. Alekseeva
Keyword(s):  
Trace Elements ◽  
Bottom Sediments ◽  
Barents Sea ◽  
The Barents Sea

Postglacial paleoceanography and paleoenvironments in the northwestern Barents Sea

2019 ◽  
Vol 92 (2) ◽  
pp. 430-449 ◽  
Author(s):  
Elena Ivanova ◽  
Ivar Murdmaa ◽  
Anne de Vernal ◽  
Bjørg Risebrobakken ◽  
Alexander Peyve ◽  
...  
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Sediment Cores ◽  
Ice Cover ◽  
Atlantic Water ◽  
The Arctic ◽  
High Productivity ◽  
Surface Warming ◽  
The Barents Sea ◽  
Suitable Location

AbstractThe Barents Sea offers a suitable location for documenting advection of warm and saline Atlantic Water (AW) into the Arctic and its impact on deglaciation and postglacial conditions. We investigate the timing, succession, and mechanisms of the transition from proximal glaciomarine to marine environment in the northwestern Barents Sea. Two studied sediment cores demonstrate diachronous retreat of the grounded ice sheet from the Kvitøya Trough (core S2528) to Erik Eriksen Trough (core S2519). Oxygen isotope records from core S2528 depict a two-step pattern, with lower δ18O values prior to the Younger Dryas (YD), and higher values afterward because of advection of the more saline, 18O-enriched AW. At this location, subsurface AW penetration increased during the Allerød and YD/Preboreal transition. In the study area, foraminiferal and dinocyst data from the YD interval suggest cold conditions, extensive sea-ice cover, and brine formation, along with the flow of chilled AW at subsurface and the development of a high-productivity polynya in the Erik Eriksen Trough. Dense winter sea-ice cover with seasonal productivity persisted in the Kvitøya Trough area during the early Holocene, whereas surface warming seems to have occurred during the middle Holocene interval.

scholarly journals Paleo Cruise 2018

2020 ◽  
Author(s):  
Katrine Husum ◽  
Ulysses Ninnemann ◽  
Tom Arne Rydningen ◽  
Elisabeth Alve ◽  
Naima E B Altuna ◽  
...  
Keyword(s):  
Sea Ice ◽  
Time Scales ◽  
Barents Sea ◽  
Sediment Cores ◽  
Ice Cover ◽  
Atlantic Water ◽  
Natural Variability ◽  
Argo Float ◽  
The Barents Sea ◽  
Through Flow

The Nansen Legacy paleo cruise was carried out from September 26 to October 20, 2018 with RV “Kronprins Haakon”. The cruise took place in the northern Barents Sea and the Nansen Basin, and it went through the sea ice to 83.3 N. The overriding objective of the cruise was to reconstruct the natural variability and range of sea ice cover and Atlantic Water through flow in the Barents Sea on longer time scales. During the cruise four ocean moorings were deployed in northwest Barents Sea, where one ARGO float was also deployed. Twelve “paleo stations” were identified using multibeam and sub bottom profilers. At these stations, short and long sediment cores were obtained. This cruise report gives an overview of methods used and samples taken. 

scholarly journals Geochemical Fractions of Heavy Metals in Bottom Sediments of the Pobeda Hydrothermal Cluster in the Mid-Atlantic Ridge (17°07′–17°08′ N)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 591
Author(s):  
Liudmila Demina ◽  
Irina Gablina ◽  
Dmitry Budko ◽  
Olga Dara ◽  
Aleksandra Solomatina ◽  
...  
Keyword(s):  
Bottom Sediments ◽  
Sediment Cores ◽  
Total Content ◽  
Total Carbon ◽  
Residual Fraction ◽  
Carbonate Sediments ◽  
Core Sediment ◽  
Metalliferous Sediments ◽  
Geochemical Fractions ◽  
Fe And Mn

In this study, to better understand the influence of hydrothermal processes on ore metal accumulation in bottom sediments, we examined distribution of Fe, Mn, Cu, Zn, As, and Pb in core of metalliferous sediments from the Pobeda hydrothermal cluster, and in core of non-mineralized (background) carbonate sediments (located 69 km northwards). Mechanisms of Fe, Mn, Cu, and Zn accumulation in sediments (12 samples) were evaluated based on sequential extraction of geochemical fractions, including a conditional mobile (F-1, exchangeable complex; F-2, authigenic Fe-Mn oxyhydroxides and associated metals; F-3, metals bound to organic matter/sulfides), and residual (F-4), fixed in crystalline lattices ones. The element contents were determined by the XRF and AAS methods, total carbon (TC) and total organic carbon (TOC) were determined using a Shimadzu TOC-L-CPN. Mineral composition and maps of element distribution in sediment components were obtained using the XRD and SEM-micro-X-ray spectrometry methods, respectively. In metalliferous sediments, according to our data, the major Fe mineral phase was goethite FeOOH (37–44% on a carbonate-free basis, cfb). In the metalliferous core, average contents (cfb), of Fe and Mn were 32.1% and 0.29%, whereas those of Cu, Zn, Pb, and As, were 0.74%, 0.27%, 0.03%, and 0.02%, respectively. Metalliferous sediments are enriched in Fe, Cu, Zn, Pb, and As, relatively to background ones. The exception was Mn, for which no increased accumulation in metalliferous core was recorded. Essential mass of Fe (up to 70% of total content) was represented by the residual fraction composed of crystallized goethite, aluminosilicates, the minerals derived from bedrock destruction processes mineral debris. Among geochemically mobile fractions, to 80% Fe of the (F-1 + F-2 + F-3) sum was determined in the form of F-2, authigenic oxyhydroxides. The same fraction was a predominant host for Mn in both metalliferous and background sediments (to 85%). With these Fe and Mn fractions, a major portion of Cu, Zn, and Pb was associated, while a less their amount was found in sulfide/organic fraction. In the metalliferous sediment core, maximal concentrations of metals and their geochemically mobile fractions were recorded in the deeper core sediment layers, an observation that might be attributed to influence of hydrothermal diffused fluids. Our data suggested that ore metals are mostly accumulated in sediment cores in their contact zone with the underlying serpentinized peridotites.

Method application of optimal multi-parameter analysis to assess the distribution of water masses as an example of CTD data of the Barents Sea in summer 2017

2019 ◽  
pp. 38-51
Author(s):  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova
Keyword(s):  
Barents Sea ◽  
Field Measurements ◽  
Structural Similarity ◽  
Water Masses ◽  
Parameter Analysis ◽  
Water Dynamics ◽  
Phosphorus Concentration ◽  
Nitrogen And Phosphorus ◽  
The Barents Sea ◽  
Expert Assessments

Identification of water masses in areas with complex water dynamics is a complex task, which is usually solved by the method of expert assessments. In this paper, it is proposed to use a formal procedure based on the application of the method of optimal multiparametric analysis (OMP analysis). The data of field measurements obtained in the 68th cruise of the R/V “Academician Mstislav Keldysh” in the summer of 2017 in the Barents Sea on the distribution of temperature, salinity, oxygen, silicates, nitrogen, and phosphorus concentration are used as a data for research. A comparison of the results with data on the distribution of water masses in literature based on expert assessments (Oziel et al., 2017), allows us to conclude about their close structural similarity. Some differences are related to spatial and temporal shifts of measurements. This indicates the feasibility of using the OMP analysis technique in oceanological studies to obtain quantitative data on the spatial distribution of different water masses.

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