[Cincinatus]

Look up Thomas Gold for an alternative theory of petroleum origins.

Yes, and while you're at it, be sure to check out bleeding as a way to fight disease, willow-witching as a technique to find water, and astrology as a way to predict the future. Oh, and if you go sailing, be sure not to fall off the edge of the Earth!

[JmyBryan]

I haven't followed it that closely, but I recollect that his theory may still have some viability.

[tpaine]

And be sure to ignore the fact that some of the planets are 'gas giants'. Methane is a common substance in our solar system, just as it is a common non biological substance on earth.

Methane + heat + pressure = petroleum...

Or, if you favor Golds theory, throw some micro-biological action into the methane soup of the deep hot bio-sphere.

[eno_]

I have not read The Deep Hot Biosphere and it could, of course, be total quackery. But microbes do live under the sea under incredible pressures and in termperatures, like 120C, that would readily sterilize anything on dry land.