| Passaic Formation | |
|---|---|
| Stratigraphic range: Late Triassic, | |
 | |
| Type | Geological formation |
| Unit of | Newark Supergroup |
| Underlies | Orange Mountain Basalt |
| Overlies | Lockatong Formation |
| Thickness | maximum of over 19,685 feet (6,000 m)[1] |
| Lithology | |
| Primary | Siltstone, Mudstone, Shale |
| Other | Sandstone, Conglomerate |
| Location | |
| Region | Newark Basin of Eastern North America Rift Basins |
| Extent | ~200 miles (320 km) in New York, New Jersey, and Pennsylvania |
| Type section | |
| Named for | Passaic, New Jersey[1] |
| Named by | Paul E. Olsen, 1980[1] |
The Passaic Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and New York. It was previously known as the Brunswick Formation since it was first described in the vicinity of New Brunswick, New Jersey. It is now named for the city of Passaic, New Jersey, which is near where its type section was described by paleontologist Paul E. Olsen.[1]