Its name comes from Latin. It means “oil of stone”. But what is the true origin of oil? We know that it is the product of a transformation process over millions of years. However, there are many misconceptions about its origin.
It is estimated that about 70% of today’s crude oil deposits were formed in the Mesozoic Era. That is when the dinosaurs had their heyday. That may be the reason for the strange theory that oil comes from dinosaurs.
The protagonists are actually tiny beings. The most accepted theory is the so-called organic one. The decomposition of the remains of animals and microscopic algae at the bottom of the waters originated petroleum.
That theory indicates that fine sediments and organic remains are deposited in a basin. After a long time, pressure and temperature increase, forming hydrocarbon chains. Other superimposed geological layers generate pressure and temperature conditions. The organic matter slowly turns into hydrocarbons. It is like a pressure cooker.
Petroleum can also come from the transformation of organic material from old-growth forests. The type of hydrocarbon rich in terrestrial plant matter is associated with gas fields.
Some scientists argued in the past that petroleum has an inorganic origin. It would form in the depths of the Earth without the need for the remains of living organisms. They argue that in the interior of the Earth’s mantle, carbon can exist as hydrocarbon molecules, mainly methane. These hydrocarbons may migrate out of the mantle into the Earth’s crust until they escape to the surface. Or they remain in impermeable strata, forming oil reservoirs. The theory of the inorganic origin of petroleum is not accepted by most scientists.
So, the organic theory of the origin of petroleum is the most accepted. What about dinosaurs? They lived at the same time as the formation of oil in the Mesozoic. Perhaps their remains fell to the bottom of the sea or lagoons. And compression transformed them into oil.
“Any organic matter could be present in the generation of petroleum,” said the UNAM experts. “But very large volumes of matter are required. They were only possible to achieve by the large volumes of plankton in the sea. That is the true origin of oil,” they concluded.