Jackson Volcano is an extinct volcano 2900 feet (884 meters) beneath the city of Jackson, Mississippi, under the Mississippi Coliseum. The uplifted terrain around the volcano forms the Jackson Dome, an area of dense rock clearly noticeable in local gravity measurements. E.W. Hilgard published his theory of an anticline beneath Jackson in 1860 due to his observations of surface strata.The dome contains relatively pure carbon dioxide which is used in oil production in Gulf Coast oil fields. The noble gas data suggests mantle origins with a date of 70 million years for the Jackson Dome intrusion. Geologists have evidence of repeated uplifts accompanied by dike intrusions and volcanic extrusions, erosion, and sedimentation with one coral reef having developed during a submergence. Much of the