combustible fossils of organic origin, products of the transformation of plant, and more rarely animal, remains affected by geological factors. The term “caustobioliths” was proposed in 1888 by the German scientist H. Potonié, who divided caustobioliths into three groups according to origin: sapropelites, occurring as a result of the burial of lower organisms, primarily plankton algae, on the bottom of bodies of water (kero-gen of oil shales, boghead coal); humites, formed from the remains of higher plants, primarily marsh plants (lignite, coal); and liptobioliths, which are coals enriched with the components of plant matter that are most resistant to decay, such as pitches, waxes, and cuticles. Mixed types of caustobioliths are also found (saprohumites, liptosapropelites [cannel coal]).
Potonié also included petroleum (as a product of the underground distillation of sapropelites) and combustible natural gases among the caustobioliths.
REFERENCESPotonié, H. Proiskhozhdenie kamennogo uglia i drugikh kaustobiolitov. Leningrad-Moscow, Groznyi-Novosibirsk, 1934.
Muratov, V. N. Geologiia kaustobiolitov. Moscow, 1970.
N. B. VASSOEVICH