Kerogen from lagoonal mats and from a coastal marine sediment was extracted, mixed with known minerals, and heated in sealed pyrex tubes for periods extending from 1 to 100 hours over a temperature range of 50 to 500°C. The minerals used were calcite, kaolinite, illite, and two different montmorillonites. Methane and carbon dioxide were separated, quantitatively determined, and their ¹³C/¹²C isotope ratio measured. Rock Eval was used on the bulk residual material after pyrolysis to determine amount of hydrocarbon formed and the thermal changes in the kerogen. These results were compared with data obtained from bitumen extraction by organic solvents.

The results suggest that minerals can have either catalytic or inhibitory effects. These effects are displayed at lower temperatures only. At higher temperatures, thermal effects dominate. Calcite and montmorillonite C were found to be inhibitory to production of bitumen, whereas kaolinite, illite, and montmorillonite B were found to be catalytic. The inhibitory effects were interpreted as being due in part to direct interaction between mineral and kerogen, but also to entrapment of bitumen within interlayer spacing and prevention of its escape due to mineral-organic molecular configuration.

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