The Jurassic in Pennsylvania, US

Paleontology and geology

During the Jurassic, rift basins were developing in eastern Pennsylvania as plate movement continued to pull apart the supercontinent of Pangea, creating the beginnings of the modern Atlantic Ocean. Reddish sand, silt, and clay accumulated in rivers and lakes in these rift basins. Molten rock rose up along fractures in the crust, and some of it flowed out onto the surface as lava. Fern spores and pine pollen are common in the red and gray mudstones of the Newark Rift Basin in the eastern part of the state. Dinosaurs roamed the landscape, leaving behind some footprints but few bones.