Astrophysics (index)

Carbonate-Silicate Cycle

(reversible carbon/silicon chemical reaction)

The Carbonate-Silicate Cycle is a naturally-occurring chemical (Geochemistry) change:

CaSiO3 + CO2 ⇔ CaCO3 + SiO2


Calcium (Ca) Silicate + Carbon (C) Dioxide → Calcium Carbonate + Silicon (Si) Dioxide

At the surface of the Earth, the balance is in favor of carbonates (dissipating carbon dioxide), but at Temperatures of 300k, the balance is toward silicates. The surface of Venus tends toward the latter as do subsurface conditions of Earth.

The cycle helps stabilize climate in that rain with carbon dioxide hitting rocks causes the reaction, which dissipates carbon dioxide. Volcanic eruptions eventually replenish it.

The ability to operate this cycle affects an Extra Solar Planet's ability to maintain liquid water.