Re: Geothermal Energy Controls Earth's Climate
Not far south of me in Pitenweem on the southern Fife coast (The East Neuk to be precise) if you clamber over the bay at low tide you come to a place close to the low cliff where the fossilised stump of a cycad is exposed. Nearby are some rocks with the trackways of giant centipedes across them.
But to destroy your contention we simply need to turn our eyes upwards (i.e. to later time periods) and see a line of hydrocarbon in the form of coal in the cliff face.
Oh and oil companies employ electron microscopists to examine oil samples for micro fossil fragments (bits of leaf, pollen grains) of the sort you find not uncommonly in coal.
I have as a souvenir of my PhD days a sweatshirt with a penguin in a scarf using an electron microscope and the legend 'South Campus EM Unit: the most Southerly EM unit in the World". That status was briefly threatened by plans to put an EM (on very sensitive dampeners) on an oil prospecting ship around Antarctica. But then the Big Ice got made a Science Park and it didn't happen. Which is how I know about that stuff as I wondered why an oil company might want to do that and looked it up.
The precise organism bits they find tell them how old, from which epoch, the deposit dates. If it is too early or too late (Carboniferous is favoured, clock the name) then the deposit is unlikely to be large.
Note too that evidence of early life in the form of carbon grains means it probably got going not very long after the crust cooled enough. When exactly did this fission occur then?