The source geological map used is "Geologic Atlas of Texas, Dallas Sheet" - Bureau of Economic Geology, 1987.  The map was digitally distorted in some spots to align the roads with the more accurate modern map BUT there is still some distortions and alignment is not perfect.  Colors used here are arbitrary.

Geologic Atlas of Texas - Abilene  sheet descriptive booklet (PDF file - 517k)

[The best way to print the maps is to save each large image to your computer and then print because printing from a browser may cause clipping or resizing]