Sinkhole risk in Ashley County, AR: No soluble rock mapped

No soluble rock mapped

No soluble bedrock mapped.

On soluble rock: under 1%
At or near the surface: under 1%
Buried under cover: 0%

The next step for one property

No soluble bedrock is mapped here, so natural sinkholes are unlikely. Collapses from broken pipes or old mines are a separate risk.

That works out to roughly 3 of Ashley County's 925 square miles on soluble rock, 3 of them with the rock at or near the surface. With about 17,984 residents (19 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 350 map points about 1.6 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 how these percentages are measured.

Counties around Ashley County

The nearest county rated sinkhole country is Oktibbeha County, MS, about 168 miles east. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Morehouse Parish, LA 26 mi south · 0% at surface
Drew County, AR 28 mi north · 18% at surface
Chicot County, AR 28 mi east · 0% at surface
Bradley County, AR 30 mi northwest · 12% at surface
West Carroll Parish, LA 33 mi southeast · 0% at surface
Union Parish, LA 43 mi southwest · 0% at surface

The rock underneath

The largest mapped soluble unit here is the Jackson Group (mixed clastic/carbonate), Late Eocene in age, covering about under 1% of the county.

The county also lies over the Gulf Coast salt domes, 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 Arkansas

Ashley County ranks 34 of 75 in Arkansas for soluble rock at the surface, and sits above 51% of US counties on that measure.