Earthquake zone may have been where continents collided

Colliding continents explains the unique geology of an area stretching from north of the Great Lakes along the northern shore of the St. Lawrence River to Labrador. According to an article appearing in January 2010 in the Canadian Journal of Earth Sciences, the Grenville Orogen, as it is known to geologists, shows several hallmarks of an ancient continent collision. Authors Andrew Hynes of McGill University and Toby Rivers of Memorial University of Newfoundland compare the zone to the Himilayas, where a small continent collided with the larger Asian continent.
The continents Amazonia and Laurentia are thought to have collided along this area starting 1100 million years ago, and slowly moving together over 100 million years. Metamorphic rock in the Ottawa area — including the area of yesterday’s earthquake — has a much higher pressure than rock in other areas of eastern Canada, as a result of the forces at work in the collision. While the geological history does not directly explain recent earthquakes, it sheds light on a section of the earth’s crust unique in the world, that we are still attempting to understand.

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