Overview
Every introductory geology course teaches the same origin story. Marine organisms die, settle into oxygen-poor sediment, get buried, and over millions of years heat and pressure convert the organic material into kerogen and then into oil and gas. The hydrocarbons migrate upward until they meet an impermeable layer and pool beneath it. This is why exploration works: geologists look for the ancient basins and the trapping structures, and finding them predicts oil.
The abiogenic theory says this is backwards. Hydrocarbons, on this account, are primordial — present in the material the Earth formed from, generated at depth in the mantle under enormous pressure, and migrating upward through the crust, where they may pick up biological traces on the way rather than deriving from them.
Where It Came From
The idea has a serious scientific pedigree, which distinguishes it from most entries in this archive.
Nikolai Kudryavtsev set out a version in 1951, and a body of Soviet and Ukrainian work developed it over the following decades — a genuine research tradition, taught and published, sometimes described in the West as though it had guided Soviet exploration, though the extent of that is disputed.
In the West it is associated above all with Thomas Gold, an Austrian-born astrophysicist at Cornell of considerable standing, who had co-authored the steady-state cosmology and correctly identified pulsars as neutron stars. Gold argued in The Deep Hot Biosphere in 1999 that hydrocarbons rise from the mantle and that the biological markers found in oil come from a vast population of microbes living kilometres down in the crust, feeding on the hydrocarbons as they pass.
Gold was not a crank, and the deep biosphere part of his argument turned out to be substantially correct: subsurface microbial life is now an established field. That his most testable idea was vindicated is a large part of why the rest of it retains adherents.
The Siljan Ring
Gold got his test. The Siljan Ring in central Sweden is an ancient impact crater in granite — crystalline basement rock containing no sedimentary source material, so any hydrocarbon found there could not have come from buried organisms.
Drilling ran through the late 1980s and into the 1990s, to depths beyond six kilometres. It recovered hydrocarbons: small quantities of oil and gas, and a quantity of magnetite-bearing sludge. Gold treated this as confirmation.
The critical assessment was that the amounts were minute, far below anything commercially meaningful, and that the most likely explanation was contamination from the drilling lubricants — which were themselves oil-based. The wells were not economic and the project ended without establishing what it had set out to establish.
What the Mainstream Position Rests On
The biological origin is not an assumption; it is an inference from evidence that abiogenic theory has never accounted for.
Crude oil contains biomarkers — porphyrins derived from chlorophyll and haemoglobin, hopanes and steranes derived from cell membranes — molecules that are structurally specific to living organisms. Their distribution varies systematically with the age and depositional environment of the source rock, which is what a biological origin predicts and what a mantle origin does not. Oil also shows a carbon isotope ratio characteristic of biological fractionation, and its optical activity is a property of molecules built by living systems.
Small quantities of genuinely abiotic hydrocarbon do exist — methane in serpentinised rock, and in ultramafic settings — and this is uncontroversial. It is also nothing like the volumes in commercial reservoirs, and it is not what abiogenic theory claims.
The Conspiracy Layer
The suppression claim attaches at the economic end. If oil is abiotic it is effectively unlimited, and every projection of scarcity has been either a mistake or a fabrication designed to keep prices high. Reservoirs that appear to refill — the Eugene Island field in the Gulf of Mexico is the case most often cited — are read as evidence of resupply from below rather than as migration from adjacent compartments, which is the standard explanation.
The difficulty for the theory is one of motive. An oil industry that believed in abiotic oil would have every reason to drill for it: unlimited reserves in basement rock, accessible anywhere, would be worth more than any cartel. Exploration budgets go where the geology predicts oil, and the biological model predicts it well enough to have found essentially all of it. Suppressing a theory that would locate more of your product is a strange commercial strategy.
What keeps the idea alive is not the economics but Gold — a serious scientist, right about pulsars, right about the deep biosphere, and wrong, on the present evidence, about where oil comes from.