A 30-carbon triterpane biomarker indicative of higher plant contribution in the source organic matter. Oleanane has been linked to angiosperms (flowering plants) as its main source and has been found exclusively in Tertiary and Late Cretaceous oils and source rocks. It elutes immediately before C30 hopane in GC/MS (m/z 191) fragmentograms, but is better confirmed by GCMSMS.