Here's the abstract to the scientific paper:
http://www.pnas.org/content/early/20...
I'm not sure, but I think you misunderstood what that "million times" refers to. It's possible that we could artificially increase the rate of carbonation of peridotite to around a million times the natural carbonation rate. The reaction produces rocks that could indeed hold a significant mass of carbon dioxide, but the reaction can only occur one time. Moreover, the product rock is weaker, and has a higher volume than the parent peridotite. This would place surrounding rock under potentially significant stress, perhaps resulting in fault slippage, made easier by the loss of strength in these rocks themselves.
The whole ROF area is heavily faulted. You would not want to be underground anywhere within the entire region, if carbon dioxide was being injected into it. The paper mentions that localized earthquakes could result.
Perhaps when and if the ROF is mined out, it might then be feasible to use the carbon dioxide sequestering capacity of the peridotite deposits, but I don't think you'd proceed with that while there are any mineable metal deposits. Maybe the barren peridotites of Oman or Papua New Guinea can host such activity, but I think it's not suitable for the McFauld's region, at this time. Just my opinion.
Lar
