Occurrence of phenylalkanes in some Australian crude oils and sediments

Evidence is presented to support the proposition that phenylalkanes in some Australian crude oils and sediments are of geochemical origin as opposed to resulting from contamination from byproducts of the petrochemical manufacture of surfactants. Evidence presented shows that: (1) an unexposed sediment core was found to contain phenylalkanes; (2) the molecular weight range of phenylalkanes in sediments and crude oils is usually wider than that found in surfactants, extending in some cases beyond C35; (3) abundant phenylalkanes were generated by pyrolysis of extracted sediments, and (4) phenylalkanes were found in the neutral lipid extract of extant Thermoplasma bacteria. Also, the presence of phenylalkanes and possibly phenylalkenes in the pyrolyzates of torbanites suggests that these compounds may also be formed from fossil algae.