>>28630967
We don't really know where it comes from. The tar lake in Trinidad refreshes itself to the old level no matter how much is extracted.
Living origin is one theory but there is so much of it it seems unlikely and who wouldn't the plants just rot down? Why do they turn to oil?
One theory by Immanuel Velikovsky is that it is of celestial origin. He said that every nation with oil reserves today had legends of a rain of fire in their past.
Another theory is that it is generated within the earth by means we do not understand. But seeing as the deepest anyone has drilled into the earth is seven miles anything beyond that is pure conjecture and abiotic origin is no worse than other theories.
It is better to call it mineral fuel really than fossil fuel. It isn't as though the fossil theory is proven or even lab replicable. Fortunately there is so much of it that there is no meaningful way to run out.