Sinkhole risk in Robertson County, TN: Sinkhole country

Sinkhole country

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

On soluble rock: 92%
At or near the surface: 92%
Buried under cover: 0%

What this means before you buy

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

That works out to roughly 439 of Robertson County's 476 square miles on soluble rock, 439 of them with the rock at or near the surface. With about 78,459 residents (165 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 302 map points about 1.3 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Robertson County

The closest county with no soluble rock mapped is Hopkins County, KY, about 66 miles northwest. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Simpson County, KY 22 mi northeast · 99% at surface
Cheatham County, TN 23 mi southwest · 39% at surface
Logan County, KY 23 mi north · 93% at surface
Sumner County, TN 23 mi east · 70% at surface
Davidson County, TN 25 mi south · 75% at surface
Todd County, KY 28 mi northwest · 91% at surface

The rock underneath

The largest mapped soluble unit here is the St. Louis Limestone and Warsaw Limestone (limestone), Mississippian in age, covering about 89% of the county. Next is the St. Genevieve Limestone at 3%.

Against the rest of Tennessee

Robertson County ranks 10 of 95 in Tennessee for soluble rock at the surface, and sits above 97% of US counties on that measure.