Pat's Wildways

Pat’s Wildways: Salt and Pepper

Posted

Have you ever heard of a salt dome? Well, I never had either until I visited the Tabasco factory on Avery Island in southern Louisiana. Avery Island is a salt dome, one of five in Louisiana. Still, it is not an actual island surrounded by water, but instead a protruding hump of land that is higher than the surrounding areas, just like the Sky Islands of Arizona that rise above the deserts are not islands either. I learned about Sky Mountains recently at Cave Creek Ranch in southern Arizona, and now, I guess it is my turn to learn about these inland “islands” too.

I wasn’t expecting to learn more about geology when I recently did a road tour of southern Louisiana with my brother Ken. The weather was rainy and dismal, so my plans for a boat ride in the bayous were scrapped and we had to do something. Why not visit the Tabasco factory on Avery Island a couple of hours away from our temporary lodging at Da Boat House? “Sure, let’s do it,” says Ken, in his typical response.

Tabasco hot sauce was the invention of Edmund McIlhenny back in 1868 and has been produced from a factory on Avery Island ever since. The tabasco variety of hot peppers, named after Tabasco, Mexico, became popular in the New Orleans area around then and McIlhenny used them to produce his famous formula of tabasco peppers, salt and vinegar that is known the world over as Tabasco sauce. Our self-guided tour of the factory included stops at the barrel shop (where barrels are made), the aging area, (where tabasco pepper mash is aged for up to three years in white oak barrels covered with salt), the mixing area (where the mash is blended with vinegar and strained), and the bottling area where it all comes together. And, of course, there is the gift shop where tastes are offered of the many varieties of Tabasco sauce, and samples of things like Tabasco ice cream, followed by a Cajun lunch complimented with any Tabasco sauce your tongue desires.

 All that was interesting but really, it was the salt dome that the factory is built on that really captured my fancy. These domes occur worldwide and are associated with oil reserves that accumulate in the hollows beneath the solid salt. The northern Gulf Coast​ (including Louisiana) has a number of them, as well as the Middle East, Azerbaijan, and other areas known for oil production. There are upward of 4000 (!) oil platforms along the Louisiana coast, attesting to the predictive value of salt domes to oil exploration. As I discussed in last week’s column, the entire bayou area is bisected by deep channels that have changed the area's hydrology to enable the passage of large oil tankers and the intrusion of more saltwater into formerly freshwater habitats.

The rock salt under Avery Island is as close as 16 feet to the surface and a few thousand feet deep. From Native American times onward, this salt has been extracted. At one period up to 600 slaves​ worked the mine at one time. In more recent days, Cargill operated the salt mine on Avery Island, producing rock salt for road deicing, but it closed a few years ago.

Avery Island is a great place to visit for other reasons, too. Mr. McIlhenny and his heirs were nature lovers who protected Avery Island. Because this “island” rises above the swamp topography, its ecology is different from the surrounding area, and it supports a number of native species and animals. In the late 1800s, when snowy egrets were threatened with endangerment due to plume hunters seeking their feathers, one McIlhenny raised a few egrets, bred more, and released them. Now, hundreds of egrets and their kin have rookery at “Bird City” on Avery Island at certain times of the year. The McIlhennys also planted myriad camellias, azaleas, and other non-native flowering plants that also make Avery Island a great place to visit in the spring before the weather and insect activity heat up.

I never know what I will find when I go on a road trip. I am always on the lookout for new information and I am never disappointed. I hope you like coming along with me for the ride!

Pat Foster-Turley, Ph.D., is a zoologist on Amelia Island. She welcomes your nature questions and observations. patandbucko@yahoo.com