Sinkhole risk in Sequatchie County, TN: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 21%
At or near the surface: 21%
Buried under cover: 0%

What this means before you buy

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 56 of Sequatchie County's 266 square miles on soluble rock, 56 of them with the rock at or near the surface. With about 17,620 residents (66 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 442 map points about 0.8 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Sequatchie County

The nearest county rated sinkhole country is Hamilton County, TN, about 19 miles southeast, close enough that the same rock may run under the county line. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Grundy County, TN 17 mi west · 21% at surface
Hamilton County, TN 19 mi southeast · 70% at surface
Bledsoe County, TN 19 mi northeast · 25% at surface
Marion County, TN 20 mi southwest · 39% at surface
Van Buren County, TN 23 mi north · 27% at surface
Warren County, TN 30 mi northwest · 81% at surface

The rock underneath

The largest mapped soluble unit here is the Wells Creek Formation and Knox Group (above Copper Ridge Dolomite) (limestone), Ordovician in age, covering about 8% of the county. Next is the Bangor Limestone and Hartselle Formation at 5%.

Against the rest of Tennessee

Sequatchie County ranks 67 of 95 in Tennessee for soluble rock at the surface, and sits above 75% of US counties on that measure.