Sinkhole risk in Marion County, KY: Pockets of it

Pockets of it

Soluble rock at the surface or under thin cover in part of the county.

On soluble rock: 45%
At or near the surface: 45%
Buried under cover: 0%

What this means before you buy

Check the parcel against your state survey sinkhole map, and ask for an inspection if cracks, depressions or sticking doors show up.

That works out to roughly 155 of Marion County's 344 square miles on soluble rock, 155 of them with the rock at or near the surface. With about 19,851 residents (58 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 615 map points about 0.7 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 Marion County

The nearest county rated sinkhole country is Nelson County, KY, about 20 miles northwest, close enough that the same rock may run under the county line. 2 of the 6 closest counties land in the same band; the ground changes quickly around here.

Taylor County, KY 13 mi south · 49% at surface
Washington County, KY 15 mi north · 42% at surface
Nelson County, KY 20 mi northwest · 56% at surface
Boyle County, KY 22 mi east · 54% at surface
Larue County, KY 23 mi west · 78% at surface
Green County, KY 24 mi southwest · 88% at surface

What Marion County is built on

The largest mapped soluble unit here is the Drakes Formation (dolostone (dolomite)), Ordovician in age, covering about 16% of the county. Next is the Ashlock Formation, Grant Lake and Calloway Creek Limestones, and Fairview Formation, undivided at 12%.

Against the rest of Kentucky

Marion County ranks 47 of 120 in Kentucky for soluble rock at the surface, and sits above 86% of US counties on that measure.