patrick.net

Another breakout discussion from a long thread. What are the origins of terrestrial petroleum deposits, biotic or abiotic?

The abiotic case is that carbonate rocks and water get subducted by plate tectonics and changed by the deep heat and pressure into petroleum spectrum molecules.

This is often brought up by people holding cornucopian pro-petroleum positions, suggesting that because it's an abiotic process, oil is endlessly renewable. Proponents never take the hypothesis further and detail processes, timelines, and specific deposits showing clear evidence of abiotic origin. Furthermore, they never seem to recognize that even if petrogenesis proves 100% abiotic and as described, it's STILL too slow of a process to provide limitless energy resources to humans for limitless time.

The biotic case is that extant petroleum deposits consist of metamorphosed ancient biological deposits like algal mats in lakes. Much of the coal on earth was originally jungle land that existed before cellulose eating bacteria evolved, resulting in very long term in-situ accumulation of carbon.

Accessible oil shale deposits contain identifiable fossils and chemical signatures of biological processes. A particularly good example is the Messel Pit in Germany, an ancient lake which formed in a deep volcanic vent with chronically low oxygen below the surface waters. The pit was believed to release intermittent clouds of CO2 that caused mass die-offs of larger animals, whose bodies sank to the hypoxic depths to become preserved in remarkably excellent condition. The contents of this pit were estimated to represent over a million years of accumulation, from a time period approximately 47 million years ago. Therefore, this pit is not only proof that oil CAN form biotically, it gives a lower bound of 47 million years needed for that to become oil under those specific conditions since. The location is believed over time to have drifted 10 degrees further North in latitude in addition to gaining up to a few hundred feet of overburden above the shale deposits. https://www.age-of-the-sage.org/evolution/messel_pit.html

Proponents of abiotic petrogenesis, are you aware of any specific oil deposits that can be conclusively proven to have formed only by abiotic processes?