HUMIFICATION OF THE ORGANIC MATTER IN THE SURFACE BOTTOM SEDIMENTS OF THE EAST SIBERIAN SEA

New data on the content of humic substances (HS) in the East Siberian Sea are presented. The results of the studies showed that the degree of humification of organic matter (OM) in the studied samples of the upper layer of bottom sediments of the sea varies from 21 % to 9 % and averages 15 %, which is typical of low-productivity Arctic seas. It was found that the average HA values (for the considered profiles) were 0.16 and 0.20 %, which is typical of oxidized marine sediments. The concentration of organic carbon (Corg) varied from 0.34 % to 1.89 % depending on the granulometric type of sediment. It is shown that the total Corg consists of 10–40 % HS, the HS themselves consist of 12–30 % humic acids (HA) and 70–88 % fulvic acids (FA), which indicates early humification of sediments. НAs were determined only in the sediments of the coastal part of the sea. FAs were determined in all studied bottom sediments.