Everybody knows that oil and gas drilled out of the earth comes from the remains of plants and animals trapped underground millions of years ago. This received wisdom so dominates our thinking that it is enshrined in the very language we use–fossil fuels. They took eons to form, and we are using them up far faster than they can be replenished.

What if the whole theory is wrong?

That’s the premise of a small but passionate band of Russian and Ukrainian contrarians. They argue that oil and gas don’t come from fossils; they’re synthesized deep within the earth’s mantle by heat, pressure and other purely chemical means, before gradually rising to the surface. Under the so-called abiotic theory of oil, finding all the energy we need is just a matter of looking beyond the traditional basins where fossils might have accumulated.

The idea that oil comes from fossils “is a myth. … We need to change this myth,” says petroleum engineer Vladimir Kutcherov, at the Royal Institute of Technology in Sweden. “All kinds of rocks could have oil and gas deposits.”

Alexander Kitchka of the Ukrainian National Academy of Sciences brashly estimates that 60% of the content of all oil is abiotic in origin, and not from fossil fuels. He says companies should drill deeper to find it.

Kitchka says oil may be found in all sorts of geological structures such as volcanic rock or deep-sea thermal vents where companies aren’t looking today.

Kutcherov points to a handful of productive oil fields in Vietnam and elsewhere that lay in hard rock such as granite. Traditional theory says oil shouldn’t be present there. Certain wells in the Gulf of Mexico have produced more oil than expected. The abiotic crowd says they are slowly being refilled from a deeper source.

The abiotic oil theory goes back centuries and includes as its prominent champions Dimitri Mendeleev, best known for inventing the periodic table. It didn’t gain much visibility in America until the late Cornell University astronomer Thomas Gold championed it in the 1980s. He said that oil contains organic compounds not because it is derived from fossils but because giant colonies of deep-earth bacteria feed on deep hydrocarbon pools way down in the mantle.

In the 1980s, he convinced the Swedish government and investors to drill four miles through solid granite in central Sweden. They eventually recovered 84 barrels of oil. Gold considered it a scientific success, even though the project was a commercial failure.

To prove that abiotic oil is possible, in 2002 Kutcherov superheated calcium carbonate, water and iron in a pressure chamber and then cranked it up to produce 30,000 times atmospheric pressure, simulating the conditions present in the earth’s mantle. Sure enough, about 1.5% of the material converted into hydrocarbons, according to results in the Proceedings of the National Academy of Sciences. Most of it was methane and other gases, but about 10% was heavier oil components.

Since then, in work slated for publication, Kutcherov has shown that methane will convert into more complicated hydrocarbons under certain extreme conditions. Small amounts of natural gas that could be abiotic in origin have also been found in deep-sea vents. Kutcherov says methane is probably generated in the mantle, and depending on the conditions, it turns into heavier hydrocarbons as it bubbles up towards the surface.

Skeptics say that while traces of abiotic hydrocarbons may exist, little data support the idea of economically meaningful deposits. “Companies have been looking for oil for 100 years. If all this abiogenic stuff is there, why haven’t they found it?” asks geochemist Geoffrey Glasby, who spent nine months investigating the matter for a 2006 review paper in Resource Geology. He concluded the totality of the evidence did not support the concept.

“There is a difference between a few parts per million and tens of millions of barrels,” says Chevron geologist Barry Jay Katz, another skeptic. He notes that the theory fails to explain the wide variety of biological compounds found in oil from different parts of world. Oil from younger rocks contains compounds linked to flowering plants, but oil from older rocks formed before flowering plants existed contains only more primitive organic compounds.

“If you buy the theory, it says you will never run out of oil; there is an infinite supply, and don’t worry about anything,” says Katz. “That is not the way it seems to be working.”

American geologists might be convinced if the abiotic theorists can find big new oil fields using their methods. Kutcherov has developed a methodology for searching for deep migration channels where abiotic oil might rise to the surface. If he can raise money from investors, he hopes to begin searching for abiotic oil deposits in east Texas.