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

6. OC Transitway at Roosevelt Ave

Stromatolite fossils in cross-section

North wall of the OC Transitway

Footbridge over OC Transitway at Roosevelt Ave., Ottawa, Ont.


Flat-lying stromatolite unit exposed along the OC transitway north and south wall between Churchill Ave. and the Sir J.A. Macdonald Parkway

Stromatolites are biosedimentary structures built up during sedimentation by cyanobacteria (blue-green algae). Layers were built up as the cyanobacteria grew up through successive depositions of lime muds to create rounded, domed structures. The limestone wall of the Transitway bedrock shows vertical cross-sections through these fossils. Gull River Formation.

Stromatolites can also be seen in plane view near the Québec side of the Champlain Bridge.

Stromatolite laminae