Abstract
Several series of unusual polycyclic alkanes (ranging from tricyclic to heptacyclic) have been identified as major components in extracts of Lower Cretaceous Ostracode Zone sediments of the Western Canada Sedimentary Basin. These compounds appear to be specific markers for the Ostracode Zone-sourced oils in the Lower Mannville Group reservoirs of the Provost area and may represent a new class of molecules whose natural distribution and biological significance remains to be determined. The stable carbon isotopic data of the tri-, tetra- and pentacyclic alkanes appear to be related to pristane and phytane, yet the significant isotopic depletion observed in the hexacyclic compounds suggests that they may be derived from different groups of organisms or different biosynthetic routes.