The Snellville 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.
Snellville’s center stands about 1,070 ft above sea level. Within three miles the land runs from 890 ft to 1,130 ft, a difference of 240 ft: rolling country. The highest named summit within 15 miles is Stone Mountain, about 1,670 ft, 8 miles west-southwest.
Under the town center the state geologic map shows Granitic Gneiss undifferentiated, from the Precambrian to Paleozoic.
The section below crosses 9 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 45×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Gneiss. Age: Precambrian to Paleozoic. About 9 mi of the line.
Gneiss, amphibolite. Age: Precambrian to Paleozoic. About 3 mi of the line.
Quartzite, mica-schist, amphibolite. Age: Precambrian to Paleozoic. About 3 mi of the line.
Metagraywacke, mica-schist. Age: Precambrian to Paleozoic. About 3 mi of the line.
Age: Precambrian to Paleozoic. About 2 mi of the line.
Amphibolite, biotite-gneiss, mica-schist. Age: Precambrian to Paleozoic. About 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. 3 smaller units along the line are not listed.
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 Snellville reaches the Atlantic Ocean by way of Big Haynes Creek, the Yellow, the Ocmulgee and the Altamaha: about 420 river miles.
Lake on the way: Jackson Lake.
240 miles of the trip are on the Ocmulgee.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Snellville; river miles along the main stem, rounded.