The Afton plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
Sunny
Partly cloudy
Sunny
Partly cloudy
Partly cloudy
Partly cloudy
Partly cloudy
Afton’s center stands about 790 ft above sea level. Within three miles the land runs from 760 ft to 830 ft, a difference of 70 ft: gently rolling country. The highest named summit within 15 miles is Timber Hill, about 970 ft, 11 miles northwest.
Under the town center the state geologic map shows Keokuk and Reeds Spring Formations and St. Joe Group (chert, limestone), from the Carboniferous, 324 to 359 million years old.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Chert, limestone. Age: Carboniferous, 324 to 359 million years old. About 12 mi of the line.
Shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 4 mi of the line.
Shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 4 mi of the line.
Limestone, shale. Age: Carboniferous, 324 to 359 million years old. About 3 mi of the line.
Coarse-detrital, fine-detrital. Age: Pleistocene, less than 2.6 million years old. About 0.7 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Afton reaches the Gulf of America by way of Horse Creek, the Neosho, the Arkansas and the Mississippi: about 1,110 river miles.
Lakes on the way: Murray Lake and Ozark Lake.
600 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Afton; river miles along the main stem, rounded.
