CO2 in Earths Crust

[nautica]

Which has the most CO2. The Earths Crust or the Earth's atmosphere. I know the atmosphere contains only .035%, but I can find any info on the amount of CO2 in the earths crust.

thanks
Nautica

[Andre]

Well, its basically about the element carbon, not gasseous carbon dioxide. The bulk of the carbon is stored on Earth, as forms of limestone or marble, chemically a bond of carbon dioxide and calcium oxide: CO2 + CaO -> CaCO3

This may be a very informative page (http://www.oznet.ksu.edu/ctec/Carbon/carboncycle.htm)

However it overlooks one big carbon store: the clathrate on the ocean bottoms, estimated about 11,000 gigatons.

Curiously enough is that the total amount of carbon in the CO2 of the atmosphere of Venus is about the same as all the carbon in the Earth crust.

[nautica]

I have seen the numbers on carbon and I understand the relationship. But, I am looking for actual numbers on CO2 in the Earths crust.

thanks
nautica

[Bystander]

Might help if you state your definition of "crust" for this question, and that for carbon dioxide. Including ground water and gases in solution, or not? Including hydrocarbon reservoirs and associated gases, or not? Including gases in soil pore volume, or not?

Physically, the distinction between carbon dioxide in limestone as a distinct chemical species from carbon dioxide dissolved in crustal rock (with a hell of a large heat of solution) doesn't exist.

You're going to be limited to making distinctions among oxidation states of carbon, reduced, elemental, sub-, mon-, or di-oxide --- "free" carbon dioxide in solution in this, that, or the other rock type? Parts per million --- try degassing anything completely, and you'll see. You want to do an assay and MAKE the distinctions among carbon dioxide that is chemically (salts, adsorbed), or physically (whatever that means in this context --- trapped in inclusions) present in rock samples?