Polycyclic Aromatic Hydrocarbons (PAHs) as Geochemical Signatures of Petroleum Discharge in Sedimentary Strata

The distinction between petrogenic and pyrogenic origins of polycyclic aromatic hydrocarbons is well established in organic geochemistry (Blumer, 1976; Yunker et al., 2002; Peters et al., 2005). While high-temperature, open-air biomass combustion causes extensive dealkylation, yielding predominantly unalkylated parent PAHs, low-temperature thermal maturation under high-pressure, anoxic sedimentary conditions generates a characteristic predominance of C1-C4 alkylated homologues—the unambiguous molecular signature of crude oil and reservoir fluids.