The Elba 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.
Elba’s center stands about 200 ft above sea level. Within three miles the land runs from 190 ft to 400 ft, a difference of 210 ft: rolling country. The highest named summit within 15 miles is Coston Hill, about 460 ft, 10 miles north-northwest.
Under the town center the state geologic map shows Alluvial, coastal and low terrace deposits (sand), from the Holocene, less than 12,000 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 59×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sand. Age: Eocene, 34 to 56 million years old. About 8 mi of the line.
Claystone. Age: Eocene, 34 to 56 million years old. About 7 mi of the line.
Silt, clay. Age: Paleocene, 56 to 66 million years old. About 6 mi of the line.
Clay. Age: Eocene to Miocene, 5.3 to 56 million years old. About 2 mi of the line.
Sand. Age: Holocene, less than 12,000 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 Elba reaches Choctawhatchee Bay and the Gulf of America by way of the Pea and the Choctawhatchee: about 150 river miles.
90 miles of the trip are on the Choctawhatchee.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Elba; river miles along the main stem, rounded.