The Norristown 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
Mostly sunny; warmer
Partly cloudy
Mostly sunny
Mostly sunny
Mostly sunny
Mostly sunny
Norristown’s center stands about 260 ft above sea level. Within three miles the land runs from 190 ft to 340 ft, a difference of 150 ft: gently rolling country.
Under the town center the state geologic map shows Neogene undifferentiated (sandstone, claystone), from the Tertiary Neogene, 2.6 to 23 million years old.
The section below crosses 2 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.
Sandstone, claystone. Age: Tertiary Neogene, 2.6 to 23 million years old. About 24 mi of the line.
Sand. Age: Quaternary, less than 2.6 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 Norristown reaches the Atlantic Ocean by way of the Ohoopee and the Altamaha: about 160 river miles.
90 miles of the trip are on the Altamaha.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Norristown; river miles along the main stem, rounded.
