Liquid crude oil is predominantly composed of the diogenic products of marine single cell organisms such as algae and cyanobacteria with a much smaller amount from fresh water algae and diatoms. Under very special geological conditions terrestrial biomass such as peat bogs and swamp deposits can under go petrogenisis but it’s very rare. There is a whole field of geochemistry devoted just to the study of petrochemical geosystems. Effectively ZERO of any hydrocarbon is from an animal source the amounts of biomass was simply too small and deposited upon death in an environment that was not conducive to petrogenisis. Dinosaur Fossil fuel is a myth. I have a 300 page workbook from the last petrol geochemistry continuing education I had to take to keep my PG cert I’m a geochemist and a petroleum geologist by first master’s and third. You can devote a 20 year career to just type classing oils by the geochemical markers in them.
so oil is the earth’s renewable energy?
Thanks for the heads up.