The end of the Triassic Period saw large-scale rifting during the break-up of Pangaea. What is now eastern North America began to separate from what is now north-western Africa, creating the young Atlantic Ocean. Magma was generated through decompression melting, and a portion of it was intruded into the sandstones and arkoses of the Stockton Formation within the Newark Basin, one of the Eastern North America Rift Basins. The magma would eventually solidify and, after millions of years, the overlying rocks would be uplifted and eroded, exposing the Palisades Sill as we know it today.