The rocks of St. Martins are Permian-Triassic age, about 250 million years old, and are composed of a red sandstone and coarse boulder conglomerate. The contact of the two formations is easily seen at the east end of the beach in front of the restaurants. Very few fossils are found in these rocks although some poorly preserved plant fossils were found in them many decades ago.
The Permian-Triassic rocks seen at St. Martins dip under the Bay of Fundy and emerge on the Nova Scotia side of the bay near Parrsboro and Blomidon. Nova Scotia’s fossil history includes the oldest dinosaurs in North America found in Triassic age rocks. We’re still looking for dinosaur fossils in New Brunswick!
The Triassic rocks in New Brunswick represent the oldest part of the time period, and may even extend back in geologic time to the Permian Period. Permian rocks in Prince Edward Island have produced reptile fossils.
Waves on the Bay of Fundy pound relentlessly on the coastal cliffs. The harbour at St. Martins has beautiful examples of sea caves, shallow features carved into sandstone and conglomerate. Sea caves are caused by physical coastal erosion processes. In sedimentary rocks like these the caves may form along rock layers. You can see this where the boulder conglomerate meets the red sandstone. The cave floor is on the same angle as the rock layers.
New discoveries of fossilized animal footprints were found by a local family near St. Martins. Although we do not know the exact animal that made the footprints, we do know that these types of footprints are only found in the youngest Permian Period; not in the Triassic Period. The red rocks of Prince Edward Island represent the oldest of the Permian Period (290 Ma.) and have produced reptile fossils and their footprints. The Permian-aged rocks at St. Martins represent the only known rocks from the youngest Permian period in Atlantic Canada. The fossil footprints they preserve were made by animals that lived just before the fossil record’s largest mass extinction event at the end Permian Period.