Approximately 220 million years ago, during the late Triassic Period, the supercontinent Pangaea began to break apart.
The focus of the rifting began somewhere between where present-day eastern North America and north-western Africa were joined.
It is important to note that along these rifts, magmatic activity never stopped, as shown by the ongoing eruption of lava along the Mid-Atlantic Ridge.
It is a half-graben filled over time by characteristic red bed sediments, sediments eroded from the uplifted footwalls of the border faults that were deposited within the basin; they are red due to their abundance in oxidized iron oxide minerals.
A significant geological feature within the Newark Basin is the Palisades Sill.