Sinkhole risk in Seminole County, GA: Sinkhole country

Sinkhole country

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

On soluble rock: 100%
At or near the surface: 86%
Buried under cover: 14%

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 237 of Seminole County's 238 square miles on soluble rock, 204 of them with the rock at or near the surface. With about 9,274 residents (39 per square mile), there is effectively nowhere in the county off the soluble rock, town or country. The figures come from 246 map points about 1.0 miles apart, so a pocket smaller than that can be missed or overstated.

Counties around Seminole County

The closest county with no soluble rock mapped is Randolph County, GA, about 58 miles north. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Decatur County, GA 17 mi east · 55% at surface
Miller County, GA 18 mi northeast · 100% at surface
Jackson County, FL 23 mi southwest · 87% at surface
Early County, GA 27 mi north · 81% at surface
Gadsden County, FL 29 mi southeast · 33% at surface
Houston County, AL 30 mi northwest · 84% at surface

Which formation it is

The largest mapped soluble unit here is the Ocala Limestone (limestone), Eocene in age, covering about 89% of the county. Next is the Suwannee Limestone and its residuum at 5%.

Against the rest of Georgia

Seminole County ranks 5 of 159 in Georgia for soluble rock at the surface, and sits above 96% of US counties on that measure.