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.
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.