The Monroeville 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.
Monroeville’s center stands about 420 ft above sea level. Within three miles the land runs from 130 ft to 430 ft, a difference of 300 ft: rolling country.
Under the town center the state geologic map shows Miocene Series undifferentiated (sand, clay), from the Miocene to Pliocene, 2.6 to 23 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 49×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Clay, limestone. Age: Eocene, 34 to 56 million years old. About 6 mi of the line.
Sand. Age: Holocene, less than 12,000 years old. About 6 mi of the line.
Sand, clay. Age: Miocene to Pliocene, 2.6 to 23 million years old. About 5 mi of the line.
Limestone. Age: Oligocene, 23 to 34 million years old. About 4 mi of the line.
Sand. Age: Eocene, 34 to 56 million years old. About 3 mi of the line.
Claystone. Age: Eocene, 34 to 56 million years old. About 0.2 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 Monroeville reaches Mobile Bay and the Gulf of America by way of Limestone Creek, the Alabama and the Mobile: about 140 river miles.
75 miles of the trip are on the Alabama.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Monroeville; river miles along the main stem, rounded.