Sinkhole risk in Jackson County, AL: Sinkhole country

Sinkhole country

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

On soluble rock: 60%
At or near the surface: 60%
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 651 of Jackson County's 1,078 square miles on soluble rock, 651 of them with the rock at or near the surface. With about 53,780 residents (50 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 283 map points about 2.0 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: the signs to look for and how an inspection works, and how these percentages are measured.

Counties around Jackson County

The closest county with no soluble rock mapped is Cullman County, AL, about 67 miles southwest. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

DeKalb County, AL 23 mi southeast · 21% at surface
Dade County, GA 28 mi east · 39% at surface
Franklin County, TN 28 mi north · 66% at surface
Madison County, AL 32 mi west · 59% at surface
Marion County, TN 33 mi northeast · 39% at surface
Marshall County, AL 37 mi southwest · 29% at surface

What Jackson County is built on

The largest mapped soluble unit here is the Monteagle Limestone (limestone), Mississippian in age, covering about 20% of the county. Next is the Bangor Limestone at 14%.

Against the rest of Alabama

Jackson County ranks 2 of 67 in Alabama for soluble rock at the surface, and sits above 90% of US counties on that measure.