The Allenport 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.
Mostly cloudy
Mostly cloudy
Partly cloudy
Sunny
Sunny
Mostly sunny
Mostly sunny
Allenport’s center stands about 700 ft above sea level. Within three miles the land runs from 530 ft to 2,100 ft, a difference of 1,570 ft: steep hill country. The highest named summit within 15 miles is Butler Knob, about 2,340 ft, 7 miles southwest.
Under the town center the state geologic map shows Hamilton Group (black-shale), from the Early Devonian to Middle Devonian, 384 to 422 million years old.
The section below crosses 12 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 11×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Age: Early Devonian to Middle Devonian, 384 to 422 million years old. About 6 mi of the line.
Limestone. Age: Silurian to Devonian, 359 to 445 million years old. About 5 mi of the line.
Black-shale. Age: Early Devonian to Middle Devonian, 384 to 422 million years old. About 4 mi of the line.
Quartzite. Age: Silurian, 422 to 445 million years old. About 4 mi of the line.
Shale, sandstone. Age: Silurian, 422 to 445 million years old. About 0.9 mi of the line.
Shale. Age: Silurian, 422 to 445 million years old. About 0.8 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 6 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 Allenport reaches Chesapeake Bay and the Atlantic Ocean by way of the Juniata and the Susquehanna: about 170 river miles.
Lake on the way: Lake Aldred.
80 miles of the trip are on the Juniata.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Allenport; river miles along the main stem, rounded.
