Just when you think it can’t possibly get any worse, it does.
A Buried Volcano In Southeast Louisiana – A Paper Written in 1976
Pre-drilling seismic data had revealed the presence on this prospect of intrusive material with a density slightly higher than that of the surrounding sediments. Gravity data defined a weak maximum here, and no salt was believed to be present.”
More at link.
UPDATE: SOME ADDITIONAL LIGHT READING BELOW.
Why is BP so concerned about Volcanoes all of a sudden?
Here’s another -
Volcanic rifted margin along the Texas Gulf Coast