I wrote about the Bayou Corne sinkhole in Assumption Parish, Louisiana last September. This update is to fill our readers in on the latest developments in this ongoing environmental—and human—disaster. Residents have moved away from the area since this monster was discovered on August 3, 2012. At that time it was relatively small, but the 350 people living closest to it were evacuated. At that time, no one knew how big it would grow, but based on the Lake Peigneur experience, the Assumption Parish authorities were taking no chances. From what I am told, the local people did not have to be told twice to leave. They left, because they knew what happened at Lake Peigneur in 1980. Their homes near the sinkhole stand vacant. Those families are environmental refugees. So far, 45 of the 65 families who live there have agreed to sell their properties to Texas Brine.
Submitted by Charlton Stanley (aka Otteray Scribe), Guest Blogger
There are gigantic salt deposits under the state of Louisiana. Geologists tell us the salt dome under Assumption Parish is about the same size as Mt. Everest. Some of the deposits are as deep as 35,000 feet as shown in this not-to-scale drawing. In fact, huge salt deposits are under large patches of the North American continent along the Mississippi River valley all the way up to Lake Erie. The city of Cleveland is sitting on top of a large salt deposit.
Salt settled out of the water when these areas were part of the ocean as the continent of North America was forming. We have all seen what happens if you dissolve salt in water. It reaches a saturation point, where no more salt can be dissolved. At that point, the excess salt settles to the bottom. That process is still going on at the surface in places like the Great Salt Lake and the Dead Sea. Once the water evaporates, it leaves behind places like the famed Bonneville Salt Flats. The excess salt in the water in those formative years of this continent settled out into enormous deposits. The primary deposits of salt are deep underground, as far as ten thousand feet or more. However, like glacier ice, solid crystal salt becomes somewhat plastic under great pressure. At ten thousand feet, the overburden of rock and sediment creates pressures of thousands of pounds per square inch. Salt deposits find weak places in the rock, and start squeezing upward in plumes, called “salt domes.” These extrusions come nearer the surface, making the salt more accessible so it can be mined. When I lived in Louisiana as a kid, I remember the salt mines being an everyday topic of conversation. The salt is not only used for food, but has many industrial uses as well. During World War Two, the salt mines provided essential minerals used in the manufacture of ammunition and high explosives. Salt mining in Louisiana has been going on since before the Civil War. Some of the mine shafts go down as much as ten thousand feet, and some of the salt caverns that have been mined are enormous.