Ottawa-Bonnechere Graben
Ottawa-Bonnechere Graben | |
|---|---|
Map of the Ottawa-Bonnechere and Timiskaming grabens | |
| Location | Ontario and Quebec, Canada |
| Part of | Saint Lawrence rift system |
| Age | Late Proterozoic to Early Paleozoic |
| Geology | Graben |
| Dimensions | |
| • Length | 700 km (435 mi) |
The Ottawa-Bonnechere Graben (also known as the Ottawa Graben) is a geological structure that coincides with a 55 km (34 mi) wide topographic depression extending from near Montréal through Ottawa. It is part of the Saint Lawrence rift system that also includes the seismically active Saguenay graben. This rift valley was formed when the Earth's crust moved downward about a kilometre between two major fault zones known as the Mattawa and Petawawa faults.