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The Grenville mountains

1.10 billion yrs ago – 980 million yrs ago

A Himalaya where the Adirondacks now sit as stumps

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In depth

The Grenville province is a belt of deeply altered rock running from Labrador to Texas, the remains of a mountain range pushed up around a billion years ago. The Grenville province runs from Labrador to Texas and shows wherever younger layers have been stripped away. The rocks are metamorphic and formed at twenty to thirty kilometres depth — what you see in the Adirondacks is not the mountain but its underside. That Rodinia existed at all was only established in the 1990s, largely by correlating Grenville rocks with equivalent belts in Scandinavia and Amazonia.

For children

When the supercontinent Rodinia was assembled, continents collided where eastern Canada and New York State lie today. The mountains pushed up were probably as high as the Himalaya. All that remains are the deep roots, worn down over a billion years.

Sources

  • Li m.fl., Precambrian Research 160 (2008)
  • Geological Survey of Canada: Grenville Province

Connects to

  • Rodinia1.10 billion yrs ago – 750 million yrs ago

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Part of Terra Saga — the story of Earth on a timeline. terrasaga.org · Last changed 2026-08-16