- the bituminous matter in oil shale, from which shale oil is obtained by heating and distillation.
- the solid organic material found in some rocks, such as oil shales, that produces hydrocarbons similar to petroleum when heated
- A fossilized mixture of insoluble organic material that, when heated, breaks down into petroleum and natural gas. Kerogen consists of carbon, hydrogen, oxygen, nitrogen, and sulfur and forms from compacted organic material, including algae, pollen, spores and spore coats, and insects. It is usually found in sedimentary rocks, such as shale.