Basalt contains magnesium, calcium, and silica, among other components. When the rock is pulverized and applied to soils, magnesium and calcium are released from the silica and dissolve in water as it moves through the soil. The minerals in the soil react with the water and carbon that would otherwise go back into the atmosphere, forming bicarbonates, which can hang around in water for thousands of years, eventually making their way to the oceans where they can precipitate out as limestone and stay on the seafloor for millions of years.
How Adding Rock Dust to Soil Could Help Get Carbon into the Ground
Researchers are finding that when pulverized rock is applied to agricultural fields, the soil pulls far more carbon from the air and crop yields increase. More studies are underway, but some scientists say this method shows significant benefits for farmers and the climate.
e360.yale.edu