Geologists Map CO2 Soaking Rocks

Here's a bit from physorg.com about geologists mapping the whereabouts of rocks that can sip-up massive amounts of CO2:

A new report by scientists at Columbia University's Earth Institute and the US Geological Survey points to an abundant supply of carbon-trapping rock in the US that could be used to help stabilize global warming.

To slow global warming, scientists are exploring ways to pull carbon dioxide from the air and safely lock it away. Trees already do this naturally through photosynthesis; now, in a new report, geologists have mapped large rock formations in the United States that can also absorb CO2, which they say might be artificially harnessed to do the task at a vastly increased pace.

To slow global warming, scientists are exploring ways to pull carbon dioxide from the air and safely lock it away. Trees already do this naturally through photosynthesis; now, in a new report, geologists have mapped large rock formations in the United States that can also absorb CO2, which they say might be artificially harnessed to do the task at a vastly increased pace.

[...]

Ultramafic rocks generally form in earth's mantle, starting some 12 miles under the surface and extending down hundreds of miles. Bits of these rocks—peridotite, dunite, lherzholite and others-- may be squeezed to the surface when continental plates collide with oceanic plates, or, less often, when the interiors of continents thin and develop rifts. Because of their chemical makeup, when the rocks are exposed to carbon dioxide, they react to form common limestone and chalk. A map accompanying the report shows that most such rocks are found in and around coastal mountain ranges, with the greatest concentrations in California, Oregon and Washington, and along the Appalachians from New England to Alabama. Some also occur in the interior, including Montana. Worldwide, other formations are scattered across Eurasia and Australia.

[...]

The major drawback to natural mineral carbonation is its slow pace: normally, it takes thousands of years for rocks to react with sizable quantities of CO2. But scientists are experimenting with ways to speed the reaction up by dissolving carbon dioxide in water and injecting it into the rock, as well as capturing heat generated by the reaction to accelerate the process. "It offers a way to permanently get rid of CO2 emissions," said Juerg Matter, a scientist at Columbia's Lamont-Doherty Earth Observatory, where a range of projects is underway.

- Brewskie