The Porum 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.
Porum’s center stands about 580 ft above sea level. Within three miles the land runs from 530 ft to 970 ft, a difference of 440 ft: hilly country. The highest named summit within 15 miles is Blu Mountain, about 1,370 ft, 13 miles south-southwest.
Under the town center the state geologic map shows McAlester and Hartshorne Formations (shale, sandstone), from the Carboniferous, 299 to 324 million years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 36×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 9 mi of the line.
Shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 6 mi of the line.
Shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 3 mi of the line.
Coarse-detrital, fine-detrital. Age: Pleistocene, less than 2.6 million years old. About 3 mi of the line.
Fine-detrital. Age: Holocene, less than 12,000 years old. About 3 mi of the line.
Shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 0.3 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 Porum reaches the Gulf of America by way of South Fork Dirty Creek, Dirty Creek, the Arkansas and the Mississippi: about 1,000 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 Porum; river miles along the main stem, rounded.