Jackson Volcano, Extinct volcano beneath Jackson, Mississippi

Jackson Volcano is an extinct volcano resting roughly 2900 feet beneath the ground of the Mississippi capital, forming a geological dome structure. Gravity measurements have mapped the extent of this formation, which lies beneath several city neighborhoods.

Scientist E.W. Hilgard published the first study about the anticline beneath the city in 1860, leading to decades of geological investigations. Later research over the following century helped scientists understand how ancient volcanic activity shaped regional geology.

The name Jackson Dome comes from the uplifted rock around the buried volcano, which is visible in local gravity measurements. The dome holds relatively pure carbon dioxide used in oil production in Gulf Coast oil fields, and over a hundred oil wells stood on its crest in 1934. The Mississippi Coliseum, whose sign faces the parking area, stands directly above the volcano.

The volcano has no surface trace to visit; the Mississippi Coliseum, marked by its sign, stands directly above it, and the surrounding parking area sits on the Jackson Dome. Gravity surveys, not outcrops, reveal the dense rock below. Look for the Coliseum's shallow segmented dome roof and glass lower section as the only visible marker of the site.

The carbon dioxide deposits within the volcanic formation are harvested commercially and fed into oil production processes along the Gulf Coast. These gas reserves make the extinct volcano a practical resource for regional industry.