[DuncanWaring]

Denbury’s 320-mile Green Pipeline changes that. It transports carbon dioxide, mined in Mississippi, ...

What the heck is a "carbon dioxide mine"?

[thackney]

Denbury currently uses carbon dioxide (CO2) from our underground natural source at Jackson Dome located near Jackson, Mississippi. Such natural sources are rare, and to our knowledge, we have the only large natural source of CO2 in the Gulf Coast region.

http://denbury.com/index.php?id=16

Mined, like Natural Gas is “mined”.