Sinkhole risk in Moore County, TN: Sinkhole country

Sinkhole country

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

On soluble rock: 65%
At or near the surface: 65%
Buried under cover: 0%

What to do about a house in Moore County

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

That works out to roughly 84 of Moore County's 129 square miles on soluble rock, 84 of them with the rock at or near the surface. With about 6,773 residents (52 per square mile), much of the land is open, and the mapped rock may sit far from where people actually live. The figures come from 403 map points about 0.6 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Moore County

The closest county with no soluble rock mapped is Cullman County, AL, about 85 miles south. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Bedford County, TN 17 mi north · 93% at surface
Lincoln County, TN 17 mi southwest · 62% at surface
Franklin County, TN 17 mi southeast · 66% at surface
Coffee County, TN 21 mi northeast · 74% at surface
Marshall County, TN 26 mi northwest · 94% at surface
Grundy County, TN 37 mi east · 21% at surface

Which formation it is

The largest mapped soluble unit here 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 (shale), Ordovician in age, covering about 48% of the county. Next is the Nashville Group; Bigby-Cannon Limestone and Hermitage Formation at 11%.

Against the rest of Tennessee

Moore County ranks 38 of 95 in Tennessee for soluble rock at the surface, and sits above 91% of US counties on that measure.