National Geographic : 2009 Jun
We are in a newly discovered branch of Jag- uar Cave, a maze of mad plumbing doglegging down through a thick layer of limestone beneath the farms and wooded ridges of north-central Tennessee. As pocked with holes as Swiss cheese, Tennessee is part of what cavers refer to as TAG, an acronym for Tennessee-Alabama- Georgia. ese three states compose the south- ern end of a belt of limestone laid down hun- dreds of millions of years ago when the region was covered by an ancient sea. Where there s limestone there are bound to be caves, be- cause limestone is susceptible to corrosion by slightly acidic water. Over millions of years this slow dissolution has riddled the bedrock with tunnels and chambers, creating a subterranean world in which the potential for exploration is almost limitless. ere are more than 14,000 known caves in TAG---9,200 in Tennessee, 4,800 in Alabama, and 600 in Georgia---and there is a subculture of single-minded cavers eager to probe them all. People have been exploring Jaguar Cave since prehistoric times, but the system is so vast that unknown conduits and million-year-old pip- ing are still being discovered. Moving again, we crawl and climb and pull and push, eventually peeping out into a large cavern. Smith has a say- ing that "caves either drop, pop, or stop." is one pops. Even with our headlamps on high Marion "the Goat" Smith wriggles into an unexplored Tennessee cave.