Geochemical features of the diagenesis of the holocene deposits in the area of the Spitsbergen Archipelago

Quantitative characteristics for the rates of diagenetic processes in the u pper (0-30 cm) layer of the sedimentary deposits in the area of the Spitsbe rgen Archipelago (78 degrees-80 degrees N) were obtained by lithologo-geoch emical, radioisotopic (S-35, C-14), and stable-isotopic (delta(34)S, delta( 13)C) studies. It was proved that the rates of diagenetic processes in the polar deposits at 123-395 m depth, affected by the East Spitsbergen "warm" current, are mostly determined by bioproductivity and are commensurate with the rates of the processes in the shelf deposits of temperate latitudes. H igh contents of migratory methane (up to 263 ml/dm(3)) and isotopically-lig ht organic carbon (C-org, delta(13)C = -30 parts per thousand) are found in the 1-m layer of shelf deposits (at 123-m sea depth) with a low bacterial in situ production of methane. It was shown that methane is not utilized in the deposits by the methanotrophic bacterial community and it may be suppl ied to the water mass and, probably, to the atmosphere.