LSU Geologists Weigh In on Sinkhole Cause

The Advocate –  Company officials reject explanation of sinkhole’s formation

By David J. Mitchell

The sidewall of a Texas Brine Co. LLC salt cavern inside the Napoleonville Dome was dissolved through the dome’s outer edge, bringing the cavern into contact with surrounding sediment layers outside the dome before the cavern failed, an LSU geologist said Friday.

The assessment by Jeffrey Nunn, Ernest and Alice Neal professor of geology and geophysics and Pereboom professor of science, was a step beyond what other officials and scientists working on the sinkhole response have presented in public meetings and appeared to more closely lay the blame with Texas Brine, which mined the cavern by dissolving the salt.

Nunn spoke about factors leading to the sinkhole Friday during a luncheon talk at Mike Anderson’s restaurant to the Baton Rouge Geological Society. . . . .

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“What this indicates is that the bottom part of this abandoned cavern completely dissolved away the salt and the cavern was in direct contact with whatever formation is in the area,” Nunn said.

The seismic data indicates that the western side of the dome has an overhang, or bulge on its upper side, where the salt edge goes out but then curves back inward and possibly intersects with the Texas Brine cavity, exposing it to outer sediments.

AND –

Nunn told geologists Friday that one of the scientists’ worst-case fears is that the salt dome could continue to break up from its western edge and threaten other underground caverns.