It's really the alkalinity (e.g. the Mg++ or Ca++), which silicate rocks often have (but technically not limited to silicates).
As an aside, we need to dissolve roughly one large mountain into the mix layer (top ~50m) of the ocean to have it fully take up atmospheric CO2. Without dissolving, the reaction is very slow (co2 in atmosphere => slightly lower pH rain => reaction with mostly passivated rock + erosion).
TIL about silicate weathering https://en.wikipedia.org/wiki/Carbonate%E2%80%93silicate_cyc...
silicate rocks basically traps co2 over millions of years and causes temperatures to fall
It's really the alkalinity (e.g. the Mg++ or Ca++), which silicate rocks often have (but technically not limited to silicates).
As an aside, we need to dissolve roughly one large mountain into the mix layer (top ~50m) of the ocean to have it fully take up atmospheric CO2. Without dissolving, the reaction is very slow (co2 in atmosphere => slightly lower pH rain => reaction with mostly passivated rock + erosion).
There are various companies/projects set up around that idea:
https://www.lithoscarbon.com/
https://en.wikipedia.org/wiki/Carbfix
https://co2crc.com.au/
https://sgeas.unimelb.edu.au/research/carbon-trap-lab
Paper in Proceedings of the National Academy of Sciences: https://www.pnas.org/doi/10.1073/pnas.2525919123