Reference

There is evidence suggesting the presence of oil and methane in non-sedimentary rocks, which challenges the traditional view that these hydrocarbons are exclusively formed from organic matter in sedimentary basins. Some key points from the search results include:

1. The Soviet school of thought proposed that oil reservoirs can exist in non-sedimentary rocks such as granite and metamorphic rocks, supporting the abiogenic hypothesis of petroleum origin Wikipedia.
2. Methane and oil are often found in geographic patterns related to deep-seated large-scale tectonic processes, suggesting a non-sedimentary origin [Harvard University Course].
3. Hydrocarbons can exist in semisolid or solid states in non-sedimentary rocks, as mentioned in Britannica's article on sedimentary rocks and oil Britannica.
4. The presence of methane hydrate deposits and the ambiguity in the geological record regarding the origin of oil and gas also support the possibility of their existence in non-sedimentary rocks Bionity.
5. Gaseous and liquid hydrocarbons, primarily methane, have been found in congealed magma on the Kola Peninsula in Russia, indicating an abiogenic origin Louisiana Department of Energy and Natural Resources.
6. Laboratory experiments have demonstrated the formation of methane from inorganic materials under high pressure and temperature conditions, supporting the abiogenic theory AGU Publications.

While the majority of oil and gas reserves are found in sedimentary rocks, these findings suggest that hydrocarbons can also be present in non-sedimentary rocks, indicating a more complex and possibly abiogenic origin for some petroleum reserves.