El Paso Formation
| El Paso Formation | |
|---|---|
| Stratigraphic range: | |
| El Paso Formation in road cut near Lake Valley, New Mexico, USA | |
| Type | Formation | 
| Sub-units | See text | 
| Underlies | Portal Formation, Montoya Group | 
| Overlies | Bliss Formation, Coronado Sandstone, Precambrian basement | 
| Thickness | 137–300 meters (449–984 ft) | 
| Lithology | |
| Primary | Limestone, dolomite | 
| Other | Siltstone | 
| Location | |
| Coordinates | 31°54′N 106°29′W / 31.90°N 106.49°W | 
| Region | Texas, New Mexico, Arizona | 
| Country | United States | 
| Type section | |
| Named for | El Paso, Texas | 
| Named by | G.B. Richardson | 
| Year defined | 1904 | 
The El Paso Formation is a geologic formation that is exposed from the Permian Basin of New Mexico and Texas to southeastern Arizona. It preserves fossils dating back to the Ordovician period.