Некоторые геохимические особенности макроэлементного состава поверхностного слоя донных осадков Баренцева моря

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.