| Blackshare Formation | |
|---|---|
| Stratigraphic range: Miocene, | |
| Type | Formation |
| Unit of | Santa Fe Group |
| Underlies | Tuerto Formation |
| Overlies | Tanos Formation |
| Thickness | Over 1,260 m (4,130 ft) |
| Lithology | |
| Primary | Sandstone, conglomerate |
| Other | Mudstone |
| Location | |
| Coordinates | 35°25′05″N 106°18′25″W / 35.418°N 106.307°W |
| Region | New Mexico |
| Country |  United States |
| Type section | |
| Named for | Blackshare Ranch |
| Named by | S.D. Connell and S.M. Cather |
| Year defined | 2002 |
  Blackshare Formation (the United States)  Blackshare Formation (New Mexico) | |
The Blackshare Formation is a geologic formation exposed in the Hagan Basin west of the Ortiz Mountains of New Mexico. It is estimated be to of Miocene age.[1][2][3]