Ottawa Gatineau Geoheritage

The Ottawa-Gatineau Geoheritage Project promotes greater public knowledge and appreciation of the geology and related landscapes in and around Canada's National Capital Region

7. Tunney's Pasture

Gloucester Fault

Tunney's Pasture

Scott St., west of Parkdale Ave., Ottawa, Ont.

Park on the south side of Scott St., cross to the north side, about 80 m west of Parkdale, and look through the fence to the opposite wall of the transitway

Section of the Gloucester fault splay at Tunney's Pasture showing the displacement across the fault.

Photo by J. Aylsworth

The OC Transpo western transit way shows excellent exposures of the Ordovician bedrock in the region. Along Scott St. near the Tunney's Pasture entrance on Parkdale Ave. the Gloucester Fault can be seen through the fence. Look for the statue of a large hand. Faults are breaks in the bedrock. Frequently faults are areas of weakness where erosion will occur. Throughout the transit way many of these eroded areas are unstable so they have been cemented over to re-enforce and stabilize the faulted rock. However, parts of the fault spray are still visible here. The upturned layers on the east side of this break indicate that the eastern block has moved downward with respect to the west side. There is actually 30 m of vertical displacement here. There are different rocks on either side of this fault. The Gull River Formation is found on the west side: the Bobcaygeon Formation on the east. Both belong to the Ottawa Group.