Sinkhole risk in Trousdale County, TN: Sinkhole country

Sinkhole country

Soluble rock at or near the surface across much of the county.

On soluble rock: 85%
At or near the surface: 85%
Buried under cover: 0%

The next step for one property

Get a sinkhole or geotechnical inspection before buying, building or adding weight to a foundation.

That works out to roughly 97 of Trousdale County's 114 square miles on soluble rock, 97 of them with the rock at or near the surface. With about 12,159 residents (106 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 545 map points about 0.5 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Trousdale County

The closest county with no soluble rock mapped is Morgan County, TN, about 86 miles east. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Macon County, TN 13 mi northeast · 24% at surface
Smith County, TN 15 mi southeast · 87% at surface
Sumner County, TN 18 mi west · 70% at surface
Wilson County, TN 18 mi southwest · 94% at surface
Allen County, KY 25 mi north · 51% at surface
Jackson County, TN 27 mi east · 58% at surface

The rock underneath

The largest mapped soluble unit here is the Nashville Group; Bigby-Cannon Limestone and Hermitage Formation (calcarenite), Ordovician in age, covering about 38% of the county. Next is the Ordovician [units] including Richmond Group (which includes Mannie Shale, Fernvale Limestone, Sequatchie Formation, and Arnheim Formation), the Maysville Group (which includes Leipers Formation), the Eden Group (which includes Inman Formation), and at 32%.

Against the rest of Tennessee

Trousdale County ranks 19 of 95 in Tennessee for soluble rock at the surface, and sits above 96% of US counties on that measure.