DIAGENETIC TRANSFORMATION OF ORGANIC MATTER OF THE HOLOCENE BLACK SEA SEDIMENTS ACCORDING TO PYROLYSIS DATA
V.N. Melenevsky, S.V. Saraev, E.A. Kostyreva, V.A. Kashirtsev
A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
Keywords: Organic matter, diagenesis, pyrolysis, biomarker molecules, Black Sea
Abstract
We present results of pyrolysis (Rock Eval) and pyrolysis-gas chromatography-mass spectrometric methods of analysis of organic matter (OM) in the Holocene sediments of the Black Sea. The studied samples represent two parts of the sediment column: coccolith ooze with an average Corg = 2.8% at the top and sapropelic silts with an average Corg = 8.5% at the bottom. Sedimentation of the Holocene sediments might have proceeded in euxinic conditions, and in ancient Black Sea time they were more favorable for OM safety and the formation of sapropelic silt. The performed research has shown that the degree of diagenetic OM transformation is higher in the upper part of the core as compared with the lower one. This is probably due to the contemporary processes of anaerobic bacterial oxidation of methane supplied from deeper layers of the Black Sea deposits into the ancient Black Sea sediments.
|
