The Oilton 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.
Oilton’s center stands about 850 ft above sea level. Within three miles the land runs from 720 ft to 890 ft, a difference of 170 ft: gently rolling country.
Under the town center the state geologic map shows Goliad Formation (clay, sandstone), from the Miocene, 5.3 to 23 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 54×. 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, sandstone. Age: Miocene, 5.3 to 23 million years old. About 13 mi of the line.
Clay. Age: Late Eocene to Early Oligocene, 28 to 38 million years old. About 9 mi of the line.
Clay. Age: Oligocene, 23 to 34 million years old. About 0.8 mi of the line.
Mudstone, sand. Age: Oligocene, 23 to 34 million years old. About 0.6 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.