| Petrified Forest Member | |
|---|---|
| Stratigraphic range: late Triassic, | |
 Petrified Forest Member at its type location, north of Tiponi Point, Petrified Forest National Park | |
| Type | member |
| Unit of | Chinle Formation |
| Underlies | Rock Point Formation |
| Overlies | Poleo Formation |
| Lithology | |
| Primary | Mudstone |
| Other | Sandstone, siltstone |
| Location | |
| Coordinates | 35°04′26″N 109°46′48″W / 35.074°N 109.780°W |
| Region | New Mexico |
| Country | United States |
| Type section | |
| Named for | Petrified Forest, Navajo and Apache Counties, AZ[1] |
| Named by | Herbert E. Gregory |
| Year defined | 1947 |
  Petrified Forest Member (the United States)  Petrified Forest Member (Arizona) | |
The Petrified Forest Member is a stratigraphic unit of the Chinle Formation in Arizona, Colorado, New Mexico, Nevada, and Utah.[2] It preserves fossils dating back to the Triassic period.