It is nice to see a post from someone who may well know what he is talking about, but in all fairness, you said:

"Sorry - absolutely incorrect" and immediately proceeded to give an explanation that is far from absolute. You state that oil comes from deep in the Earth and is produced by great heat and pressure, as I also said. You only disagree on the source of the material being acted upon.

Coal is, essentially, pure cabon. It is surely a "fossil fuel".

Crude oil, if sampled in various parts of the world, will contain every element known to man. At least leave the possibility open that the source is not directly from dead plants and animals. That has ben the common assumption for a long time, probably based only on the fact of high carbon content.