The Big Lake 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.
Chance of showers
Chance of showers
Mostly cloudy; cooler
Partly cloudy
Partly cloudy
Partly cloudy
Partly cloudy
Big Lake’s center stands about 2,680 ft above sea level. Within three miles the land runs from 2,620 ft to 2,740 ft, a difference of 120 ft: gently rolling country.
Under the town center the state geologic map shows Buda Limestone, from the Late Cretaceous, 66 to 100 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 51×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Coarse-detrital, fine-detrital. Age: Quaternary, less than 2.6 million years old. About 9 mi of the line.
Limestone. Age: Late Cretaceous, 66 to 100 million years old. About 8 mi of the line.
Limestone. Age: Early Cretaceous, 100 to 113 million years old. About 5 mi of the line.
Sand, fine-detrital. Age: Pleistocene, less than 2.6 million years old. 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.
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.
