A natural pyrolysis experiment — hopanes from hopanoic acids?

• Published in: Organic geochemistry Vol. 30; no. 12; pp. 1509 - 1516
• Main Authors: Bennett, Barry, Abbott, Geoffrey D.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.01.1999; Elsevier Science
• Subjects: Contact metamorphism; Decarboxylation; Earth sciences; Earth, ocean, space; Exact sciences and technology; Hopanes; Hopanoic acids; Hydrocarbons; Sedimentary rocks; Stratigraphy; Thermal maturation; Isle of Skye; Great Britain; Inner Hebrides; United Kingdom; Scotland; Hebrides; Western Europe; Hopanoic acids; Thermal maturation; Contact metamorphism; Hopanes; Decarboxylation; experimental studies; shale; Mesozoic; thermal maturity; hydrocarbons; Europe; contact metamorphism; hopanes; sedimentary rocks; Jurassic; pyrolysis; Phanerozoic; clastic rocks
• ISSN: 0146-6380; 1873-5290
• DOI: 10.1016/S0146-6380(99)00122-9

The formation or generation of hopanes are important processes during both the natural heating of organic-rich sediments and laboratory pyrolysis experiments. Molecular maturity parameters as well as the amounts (ng/g rock) of the C 31 hopanes and C 30–C 32 hopanoic acids were quantified in a Jurassic silty shale horizon (Isle of Skye, Scotland) as a function of distance from an igneous intrusion. The maturity profiles of the homohopanes and the hopanoic acids are comparable. There is also a correlation between the decreasing amounts of C 30–C 32 hopanoic acids and concomitant increases in C 29–C 31 hopanes suggesting that free hopanoic acids could be one potential source of hopanes in this particular horizon. Other possible sources could include hopanoic acids that are bound into the macromolecular fraction.