Search SEDIS
| Data sets | Publications | Expeditions | Thesaurus |
Portland Formation  | |
|---|---|
| BT | Chronostratigraphic Units |
| .Phanerozoic | |
| ..Mesozoic | |
| ...Jurassic | |
| ....Lower Jurassic | |
| .....Portland Formation | |
| RT | Massachusetts |
| Connecticut | |
| Newark Supergroup | |
| SN | In Newark Supergroup. Previously thought to be Upper Triassic in age. Added to Thesaurus in 1989. |