Karami, A., Golieskardi, A., Keong Choo, C. et al. The presence of microplastics in commercial salts from different countries. Sci Rep 7, 46173 (2017). https://doi.org/10.1038/srep46173
“Our brine is naturally sourced from an ancient, untouched sea called the Iapetus Ocean (predating the Atlantic) trapped below the Appalachian mountains. Our salt is free of contaminants and heavy metals that may be found in other oceans. Gleaned from the earth by an underground brine aquifer, the salt is then processed naturally using the power of the sun and gentle mountain breezes.”
If that isn't a fantastically deceptive piece of marketing then I don't know what is. It writes as if other salt deposits didn't originate in some kind of ancient body of water, and it uses the fact that they're harvesting a brine to imply that the entire bloody ocean is still hiding under the Appalachians, so that by buying their salt you're buying "sea salt" (and all the naturalist voodoo that might entail) but without any of the contaminants of modern oceans. Being low in mercury and whatnot seems like a good thing, and their salt is probably fine, but that marketing is something else.