DBPapers
DOI: 10.5593/sgem2012/s14.v3006

STUDY OF SEDIMENTATION RATES AND OIL COMPONENTS’ ACCUMULATION IN THE SEDIMENT CORES OF THE SEA OF AZOV AND THE DON RIVER USING THE METHOD OF RADIOISOTOPES

A. KUZNETSOV, Y. FEDOROV, P. FATTAL
Wednesday 1 August 2012 by Libadmin2012

References: 12th International Multidisciplinary Scientific GeoConference, www.sgem.org, SGEM2012 Conference Proceedings/ ISSN 1314-2704, June 17-23, 2012, Vol. 3, 973 - 978 pp

ABSTRACT

The present work is devoted to the analysis of results of investigations carried out in the
Russian sector of the Sea of Azov and in the lower part of the Don River during the
period from 2006 to 2010. In several scientific expeditions for the first time in the Sea
of Azov investigation history 48 sediment cores from 20 to 100 cm thick were taken and
studied layer-by-layer in order to determine the distribution of oil components and
radioisotopes Cs-137 and Pb-210. The radioisotopes’ specific activities were measured
by gamma-spectrometry in order to assess the sedimentation rates and to date different
sediment core layers. The concentrations of oil components were obtained with the use
of thin layer and column chromatography, optical and gravimetric methods making
possible to determine separately the sum of aliphatic, naphthenic, mono- and diaromatic
hydrocarbons, the sum of polycyclic aromatic hydrocarbons and the asphaltic
components as well as the presence of hydrocarbons of contemporary biological origin.
According to the results of radiological analysis, the highest sedimentation rates are
obtained for the delta and the near-delta part of the Don Rive (5 to 14 mm of wet matter
per year). The lowest rates are characteristic for the shallow eastern part of the Gulf of
Taganrog (1 to 2 mm of wet matter per year) in spite of considerable sediment runoff of
the Don River. That’s because of low depths (2 to 5 m) and high hydrodynamic activity
of water column favoring regular stirring-up and carrying out of sediments. In the
deeper central and southern parts of the Sea of Azov the sedimentation rates rise up to 4
mm per year. The study of oil components distribution in the sediment cores shows that
the most of them are concentrated in the upper layer formed in the last 50 to 70 years,
i.e. in the period of the most important anthropogenic pressure.

Keywords: Sedimentation rates, oil components, radioisotopes, sediment cores.