On this water-logged island, adorned with numerous bays, lakes and bogs, it was a shock to encounter an isolated region of desert-like terrain. But the Tablelands, in the southern part of Gros Morne National Park, look like they belong in Arizona.
About 500 million years ago, the closure of an ancient ocean put the North American and Eurasian Plates on a collision course; while most of the ocean floor subducted beneath the Continents, a slab of ocean crust was pushed over the edge of North America. As the collision progressed, this edge was crumpled into a mountain range, now represented by the Northern Appalachians (the northern end of which rise along the northwest coast of Newfoundland). The oceanic crust segment was incorporated into this range and, after eons of erosion by streams and glaciers, has been sculpted into the Tablelands of Gros Morne.
Today, this flat-topped ridge has the look of a desert mesa. Despite the abundant rain and snow, the slab of perioditite (once at the interface of crust and mantle) does not retain moisture and supports only sparse vegetation. Indeed, this rust-colored formation sheds rocky debris across its slopes, creating a moonscape in the midst of Newfoundland's greenery. A Discovery Center, on the road to the Tablelands (Route 431), introduces visitors to the natural history of this fascinating landscape.
