Some geochemical features of the major element composition of the surface bottom sediments of the Barents sea

Abstract

The results of determination of the major element composition of 34 surface bottom sediment samples of the Barents sea are presented in this chapter. The main sources of sedimentary material supply to the sea – river discharge, aeolian input and other – were considered. It was shown that the available own and literature data did not allow to obtain an adequate estimation of entering sedimentary material balance in the sea. The comparison of the compositions of bottom sediments (sands, aleurites, pelites) and of predominated in the sea basin rocks has demonstrated the prevailed terrigenous material input. The interdependences between all major elements in bottom sediments and their grain-size composition were considered in details. It was established that the well-known interrelationships with the politic sediment fraction took place for all elements except Mn – increasing their contents along with growth of pelitic fraction. The exception is SiO2 and CaO, they demonstrated the highest content in the coarse fractions. The Mn behavior is unusual one. Mn concentrations in the sediments of the south-western part of the sea is almost independent on the share of the pelitic fraction that is very unexpected. At the same time the sediments from the north-eastern part of the sea are very enriched by Mn – up to 1.0−1.5%. The probable reasons of such type of this metal distribution in the sediments are discussed. On a base of the results available the fragmental maps of Al, Fe and Mn oxides distribution in the bottom sediments were constructed. The conclusion was made that our new data supported the classical type of the prevailed terrigenous sediment formation in the Barents Sea.

Diatom and Dinocyst Production, Composition and Flux from the Annual Cycle Sediment Trap Study in the Barents Sea

“…Islandinium sp., optical section, March 2018. (3)(4)(5)(6). Three Echinidinium karaense, high and mid-focus, (3,4) August 2017, optical section, (5) November 2017 and (6) August 2017.…”

“…The NAC provides a substantial advection of heat, salt, nutrients and biomass [5]. The main source of freshwater runoff into the Barents Sea is the Pechora River (70%), which freshens the southeastern part of the sea [6]. Annually, firstyear ice can cover up to 90% of the sea surface in the winter and the ice-edge zone crosses most of the Barents Sea shelf during the spring bloom [7,8].…”