If you like big rocks, I got just the place for you! Roughly half an hour north from Peterborough you can visit the town of Buckhorn in the Kawartha region of Ontario which has three easily accessible glacial erratics.

What are glacial erratics?

Glacial erratics are large boulders that have been carried by ice sheets, often smoothing, and scouring them in the process as they are carried underneath the ice sheets along with other eroded materials. They can then be deposited a distance away their source region making them a great example of the erosive power of ice sheets which have defined the landscapes of southern Ontario during past glaciations. Ontario is littered with glacial erratics originating from when ice sheets scoured the Canadian Shield and transported their igneous or metamorphic rocks southward. These boulders can be massive in size, with the largest known erratic in southern Ontario being the Bleasdell Boulder (search site 32) which is 8 meters tall and weights 33000 tons!.

Check out the virtual field trip about the Bleasdell Boulder here!

On the edge!

Right next to the home hardware and the bridge through Buckhorn on Route 23 you can find the Balancing, or ‘Teetering’, Rock (search site C44) which is a large granite erratic (Figure 1). Aside from being quite large this erratic has the appearance that it is precariously balanced on the edge with a noticeable large gap underneath. It makes for a great photo op if you aren’t unnerved by the teetering appearance.

Figure 1-Standing next to the Balancing Rock

A matching pair!

What’s better than one erratic, it must be two erratics! Just off Lakehurst Rd in Buckhorn, you can find Adam & Eve Rd which is where you can find the Adam & Eve Glacial erratics (see site C45). After passing the signpost and heading up the short steps you will find the matching pair of glacial erratics (Figures 2-4). The pair of large granite boulders perched upon the Canadian Shield sure was a scenic site to behold.

Figure 2- Signpost at the Adam & Eve Rocks

Figure 3- A short climb up the steps leads to the glacial erratics

Figure 4- Adam & Eve erratics standing side by side

Fun Note: Watch for the transition

Buckhorn isn’t exciting just because of the erratics, it is also interesting because it lies on the frontier of the Canadian Shield which extends northwards and defines much of Northern Ontario’s landscape. You will undoubtedly notice the pink felsic rocks of the Canadian shield exposed throughout Buckhorn as you travel through. However, just south of Buckhorn you can witness where the Canadian Shield transitions to Paleozoic bedrock at the surface. Travelling a minute south down Buckhorn Road, Route 23, you will notice a transition from the bright pink outcrops peppered throughout the town to grey layered Paleozoic Limestones in the roadside outcrops. Buckhorn’s geologic position makes its an interesting stopping point on your journey through Ontario that will hopefully give you appreciation for the vastly different geology you can find in the province and the desire to explore more of it.

If you are in the Greater Toronto Area and unable to travel to Buckhorn you still find some erratics closer to home. The Rock Walk at the University of Toronto Scarborough Campus has glacial erratics on display notably a large marble erratic stemming from the Peterborough region, although these are unfortunately not as large as the ones found at Buckhorn.

Want to find more interesting places in Ontario to explore?

Check out the Planet Rocks website to find sites of geologic significance across Ontario!