Overlooking the warm waters of Nova Scotia's Northumberland Strait, Arisaig offers a fascinating window to life on Earth from 448 to 401 million years ago. One of North America's most continuously exposed sections of Silurian rock is found here. The 4 kilometres (2.4 miles) of coastline from McArras Brook to Arisaig Point, including Arisaig Provincial Park, exposes 47 million years of earth history. This is not much in geological time - the Earth itself is older than 4.5 billion years.

The rocks and fossils of Arisaig have been studied by geologists from around the world for over 150 years. They represent a continuous record of conditions in a warm, shallow, storm-frequented sea from the Late Ordovician Period through the entire Silurian Period to the Early Devonian Period.

From Arisaig Point southwestward to McArras Brook, thirteen rock units are exposed in the cliffs with a total thickness of 1.6 km (1 mile). The oldest rocks are found at Arisaig Point and consist of dark and light coloured lava and pyroclastic flows. The sedimentary rocks of the Arisaig Group begin at the Point and continue toward McArras Brook. Most of these rocks are siltstones and sandstones with uncommon shales. Almost all show an abundance of fossils.

Important Sites Home	Interpreting Arisaig's Fossils