Contents and Molecular Composition of Alkane-Naphthenic Hydrocarbons, Lignin, and Its Destruction Products-Phenols- in the Bottom Sediments of the West European Basin

摘要

In three cores of the bottom sediments samled from the top, slope, and foot of a small rise located near the foot of the West European continental slope in the Porcupine abyssal plain in the area of the wreck of the Bismarck battleship, by means of high-performance gas-liquid chromatography, the content and molecular composition of the alkane fraction of hydrocarbons (HC) and phenolic compounds of lignin were studied. The concentrations of n-alkanes and phenols in the bottom sediments of all the studied cores were low both in abso-lute values per sediment mass unit and in the organic matter composition, which is characteristic of the pelagic sediments of the World Ocean: the alkane contents varied from 0.07 to 2.01 mug/g of dry sediment or from 0.0001 to 0.01% of C_org, while that of phenols ranged from 1.43 to 11.1 mug/kg of dry sediment or from 0.03 to 0.6% of C_org. The pronounced variations in the contents of n-alkanes and lignin throughout the cores were caused mainly by the irregular supply of terrigenous matter onto the bottom under the conditions of changes in the sedimentation mode during different geological epochs. Lignin and its derivatives make the principal contribution to the formation of the organic matter composition in the bottom sediments of the West European Basin is composed of terrigenous residues of higher plants and autochthonous organic matter of marine vegetation; i.e., it exhibits a mixed terrigenous and autochthonous (terrigenous and planktonogenic) orgian.