SinkholeOdds

Sinkhole risk in Greene County, IN: Pockets of it

Pockets of it

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

On soluble rock
29%
At or near the surface
20%
Buried under cover
9%

The next step for one property

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 158 of Greene County's 542 square miles on soluble rock, 111 of them with the rock at or near the surface. With about 31,219 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 406 map points about 1.2 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and why the 9% under cover still counts.

Counties around Greene County

The nearest county rated sinkhole country is Monroe County, IN, about 27 miles east, 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.

The rock underneath

The largest mapped soluble unit here is the Stephensport Group (sandstone), Mississippian in age, covering about 15% of the county. Next is the West Baden Group at 11%.

The county also lies over the Illinois Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of Indiana

Greene County ranks 10 of 92 in Indiana for soluble rock at the surface, and sits above 75% of US counties on that measure.