| Bandelier Tuff | |
|---|---|
| Stratigraphic range: Pleistocene, | |
 Kwage Mesa, a typical finger mesa eroded out of the Bandelier Tuff in the Pajarito Plateau | |
| Type | Geologic formation |
| Unit of | Tewa Group |
| Sub-units | La Cueva Member, Otowi Member, Tshirege Member |
| Overlies | Tschicoma Formation, Paliza Canyon Formation |
| Thickness | 330 m (1,080 ft) |
| Lithology | |
| Primary | Ignimbrite |
| Other | Pumice |
| Location | |
| Coordinates | 35°45′50″N 106°19′19″W / 35.764°N 106.322°W |
| Region |  New Mexico |
| Country |  United States |
| Type section | |
| Named for | Bandelier National Monument |
| Named by | Harold T.U. Smith |
| Year defined | 1938 |
 Map of Bandelier Tuff exposures | |
The Bandelier Tuff is a geologic formation exposed in and around the Jemez Mountains of northern New Mexico. It has a radiometric age of 1.85 to 1.25 million years, corresponding to the Pleistocene epoch. The tuff was erupted in a series of at least three caldera eruptions in the central Jemez Mountains.
The Bandelier Tuff was one of the first ignimbrites recognized in the geologic record, and has been extensively studied by geologists seeking to understand the processes involved in volcanic supereruptions.