The Crosby 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.
Crosby’s center stands about 1,960 ft above sea level. Within three miles the land runs from 1,910 ft to 2,040 ft, a difference of 130 ft: gently rolling country.
Under the town center the state geologic map shows Cannonball Formation (shale, sandstone), from the Paleocene, 56 to 66 million years old.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 43×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Claystone, siltstone. Age: Paleocene, 56 to 66 million years old. About 14 mi of the line.
Shale, sandstone. Age: Paleocene, 56 to 66 million years old. About 7 mi of the line.
Siltstone, claystone, sandstone. Age: Paleocene, 56 to 66 million years old. About 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.