The distributions of polycyclic aromatic hydrocarbons (PAHs) in sediments o
f three Upper Triassic to Middle Jurassic sedimentary sequences from the No
rthern Carnarvon Basin, Australia have been investigated. Perylene was foun
d to be a major PAH component in the top Lower to base Middle Jurassic sedi
ments that are immature or at low maturity. Its depth/ age profiles are not
related to the combustion-derived PAHs that have been believed to be produ
ced during ancient vegetation fires before deposition. This suggests a diag
enetic origin for perylene. The concentration of perylene in the sediments
is proportional to the amount of terrestrial input, decreasing with distanc
e from the source of land sediments. Its carbon isotope composition is slig
htly heavier than higher-plant derived PAHs, but still in the range of the
terrestrially sourced PAHs including higher-plant PAHs and combustion-deriv
ed PAHs as suggested previously. Fungi are proposed to be the major precurs
or carriers for perylene in sediments based on the facts that (1) peryleneq
uinone structures have been previously suggested to be the natural precurso
rs for perylene; (2) perylenequinone pigments exist in many fungal bodies;
(3) fungi have played an important role during geological processes. (C) 20
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