Pyrolytic and spectroscopic study of a sulphur-rich kerogen from the "Kashpir oil shales" (Upper Jurassic, Russian platform)

The kerogen of an organic-rich sample, termed f top, from the Gorodische se ction (Russian platform) was studied using a combination of microscopic, sp ectroscopic and pyrolytic methods so as to examine its chemical structure, source organisms and formation pathway(s). This kerogen, which is mainly co mposed of orange gel-like, nanoscopically amorphous organic matter, exhibit s a relatively high aliphatic character; organic sulphur is mainly present as di(poly)sulphides and alkylsulphides. The f top kerogen was chiefly form ed via intermolecular incorporation of sulphur in algal or cyanobacterial l ipids and carbohydrates. However, its formation also involved oxidative con densation via ether linkages. Comparison of f top sample with other S-rich kerogens points to a closer similarity with Monterey kerogens rather than w ith a kerogen from the bituminous laminites of Orbagnoux. (C) 2000 Elsevier Science Ltd. All rights reserved.