undifferentiated rock units

Paleontology and geology

In the Early Devonian, the collisions of multiple landmasses caused the Acadian Orogeny. Mountains were pushed up as magma intruded underneath and melted some of the continental crust. This process created the South Mountain Batholith and many other smaller intrusions. Older rocks were heated, folded, and faulted as they were crushed together. Large faults developed, pushing some areas up and others down into basins. Devonian igneous rocks along the fault zone record this complex history of intrusion, volcanism, and deformation.

Most of the Devonian rocks in Nova Scotia are igneous and do not contain fossils. However, in the highlands, fossils of early land plants are found in shales and sandstones that were deposited by rivers flowing through the basins. Along the northern coast, a few beds of deep water siltstones and shales contain fossils of extinct fish. These fish look different than the ones we know today: some had jaws, some did not, but most had bony armor or spines.