The radiation effects of uraninite on hydrocarbons is believed responsible for both the corrosive nature and the polymerization of petroleum fractions. Irradiated hydrocarbons are activated by fragmentation and ionization of molecular groups. The resulting unsatisfied bonds become satisfied either by recombining with other ionized groups (i.e., polymerization or condensation) or by reacting with metallic compounds to form metallo-organic complexes. The nature of such bitumens is further diversified by hybrid humic-asphaltic complexes.