| Blackjack Formation | |
|---|---|
| Stratigraphic range: | |
| Type | Formation |
| Underlies | Apache Group |
| Overlies | Yankee Joe Formation |
| Thickness | 600 m (2,000 ft) |
| Lithology | |
| Primary | Argillaceous quartzite |
| Location | |
| Coordinates | 33°42′N 110°43′W / 33.70°N 110.71°W |
| Region | Arizona |
| Country |  Arizona |
| Type section | |
| Named for | Blackjack Mountains, Arizona |
| Named by | D.E. Livingston |
| Year defined | 1969 |
  Blackjack Formation (the United States)  Blackjack Formation (Arizona) | |
The Blackjack Formation is a geological formation exposed in the Blackjack Mountains, Arizona, US. The age of the formation is between 1474 and 1436 million years, and detrital zircon geochronology of its sediments provides clues for reconstruction the supercontinent, Rodinia.