Occurrence of proteinaceous moieties in S- and O-rich Late Tithonian kerogen (Kashpir oil Shales, Russia)

The polar fraction, isolated from the off-line pyrolysate at 400 degreesC o f a Late Tithonian, sulphur- and oxygen-rich, kerogen was examined via Rane y Nickel desulphurization and TMAH thermochemolysis. Important information on this kerogen, not accessible via conventional pyrolysis, was thus obtain ed: (i) its structure is not simply based on alkyl skeletons cross-linked b y ether and (poly)sulphide bridges, (ii) TMAH thermochemolysis afforded dir ect evidence of the survival of proteinaceous moieties in this 140 million years old kerogen and (iii) encapsulation within an aliphatic organic matri x was probably the main pathway reponsible for such a conspicuous preservat ion, also possibly favoured by the presence of numerous sulphur links. (C) 2001 Elsevier Science Ltd. All rights reserved.