# Fossil fuels or mantle derived hydrocarbons?

Andre
This question has biologic, chemical and geophysic elements but the question is for chemical specialists. Hence my choice to post it in "chemistry".

There is a consistent idea about fossil fuels - petroleum not being biotic but "mantle derived hydrocarbons". It has most probably been discussed before but:

http://www.gasresources.net/

This paper argues:

The H-C system does not spontaneously evolve heavy hydrocarbons at pressures less than approximately 30 kbar, even in the most favorable thermodynamic environment. The H-C system evolves hydrocarbons under pressures found in the mantle of the Earth, and at temperatures consistent with that environment.

So what would be the current scholar view about the origin of earth oil? Fossil / biotic or abiotic?