Yeah I wondered the same thing. I suspect that it has a part to play at least. There are a lot (LOT) of pretty pure magnesium/iron silicate minerals in the cr

Yeah I wondered the same thing. I suspect that it has a part to play at least. There are a lot (LOT) of pretty pure magnesium/iron silicate minerals in the crust (olivine) that can be ground up and reacted with co2 dissolved in seawater to give magnesium/iron carbonate. Check these folks out: https://www.projectvesta.org/ https://www.projectvesta.org/