Great Canadian Parks / Newfoundland

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The Parks / Newfoundland & Labrador / Gros Morne National Park



 

From the highway above Norris Point, you can look across Bonne Bay and see a piece of the earth's history rising before you. These are the Tablelands, a striking 600 metre-high plateau of rock from the earth's upper mantle, an anomaly on the landscape that has given scientists valuable information about the theory of Plate Tectonics, in which continents do not stay put, but move about on the surface of the earth's fiery liquid core.

 

During this ‘continental movement’ over 450 million years ago, the earth's crust split beneath the ocean and, as the plates moved closer together, the oceanic crust and mantle layer of the Eurasia/Africa plate was thrust on top of the sedimentary rock of the North American Continental Shelf. By the time the plates had finished their collision course, a huge chunk of the ocean floor and the upper mantle rock, usually buried beneath it, was exposed. When the continents broke apart again, the rift was 500 kilometres further east, leaving this piece of the Eurasian/African Plate stuck to North America, and providing Gros Morne National Park with a unique cross section of the ocean floor.

 

The mantle rock is called peridotite; a dark greenish brown in its natural state, it becomes a golden tan as it oxidizes or weathers. Under extreme heat and pressure, water has altered some of this material to form serpentine, a marbled green rock common to the oceanic lithosphere. The rock is so rich in magnesium and iron that it supports little vegetation; however, botanists are discovering a fascinating community of arctic alpine species that have somehow managed to survive in isolated pockets of the Serpentine Barrens.

 

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