Sinkhole risk in Marion County, MO: Pockets of it

Pockets of it

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

On soluble rock: 85%
At or near the surface: 0%
Buried under cover: 85%

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 373 of Marion County's 437 square miles on soluble rock. With about 28,425 residents (65 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 327 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why the 85% under cover still counts, and the signs to look for and how an inspection works.

Counties around Marion County

The nearest county rated sinkhole country is Calhoun County, IL, about 68 miles southeast. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

Ralls County, MO 19 mi south · 4% at surface
Lewis County, MO 20 mi north · 0% at surface
Shelby County, MO 24 mi west · 0% at surface
Adams County, IL 26 mi northeast · under 1% at surface
Monroe County, MO 29 mi southwest · 7% at surface
Knox County, MO 35 mi northwest · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Osagean Series (limestone), Early Mississippian-Osagean Series in age, covering about 65% of the county. Next is the Kinderhookian Series at 20%.

Against the rest of Missouri

Marion County ranks 100 of 115 in Missouri for soluble rock at the surface, and sits above 0% of US counties on that measure.