The Tablelands are where the Earth's mantle was pushed up to the surface by the convergence of tectonic plates. It is here at Gros Morne that the tectonic plates collided half a billion years ago and where a portion of the ocean crust was forced upward. The portion of the ocean floor contained part of the Earth's upper mantle. That has happened in very few other places on Earth with Gros Morne being the best example. Earth's exposed mantle here is mainly peridotite which contains several heavy metals and iron making it toxic to plants. A lecture at the visitor center given by Ranger Chris. She gave a wonderful PowerPoint lecture before we headed to the Tablelands to see the Earth's mantle first hand.
Chris shows us the topography of Gros Morne
Forget me Nots were blooming today
We had some time prior to heading to the Tablelands, so I hiked in the area of the visitors center to get a few views. We are on the west coast of Newfoundland right where the Gulf of St Lawrence becomes the Strait of St Lawrence. Although, many people here call it the ocean. Glaciers carved inlets, some of which became fjords. After the 2-3 mile thick ice sheet melted and the land rose up when the weight of the ice was no longer compressing it. So, some of these fjords became landlocked creating landlocked fjords of fresh water. We were told that when this happened some saltwater fish were separated from the ocean developing new freshwater species. Right where we were in Bonne Bay, we were told they had their own species of Cod in the salt water inlet.
I walked to a nearby cemetery where it appears everyone who ever died here was buried. The older section is being overtaken by Alder which is seemingly everywhere.
The Province flower - Pitcher plant
Finally, we are at the Tablelands. Here the peridotite is mostly barren rock. The orange color is due to the iron oxidizing. It looks like the Mars rover would be right at home here.
Through a process called hydrothermal metamorphism peridotite transforms to soapstone as seen here.
A few plants are able to make a living here. Moss campion is one. We saw several clumps of it.
Alpine chickweed
Serpentine sandwort
Wait! Did I not write that peridotite is toxic to plants. How did these get there? Above, Chris is explaining that eventually really hardy plants like lichen will begin growing on the rock. Then another hardy plant, moss will grow. In this case Grey wool moss. It looks like dirty wool. Chris is standing next to a rock almost completely covered in Grey wool moss. It turned green when she poured some water on it, reviving it. Over time, perhaps over a long period it exists by itself until a seed from somewhere is blown onto it or dropped by a critter. The seed gets snagged in the moss and then you begin to have a few hardy alpine plants eking out a living here. It takes a long time for this to happen. The peridotite has been here since the plates collided about 470 to 400 million years ago. And glaciations have occurred here since then, the last ending about 15,000 years ago. So, it has been a while yet it is still almost completely void of plants.
There is a trail which used to be a gravel road here. That trail has many invasive plants growing on its border making it a green ribbon through the barren Tablelands. When the road was built, gravel was put down and vehicles drove it and later we hike it. We inadvertently carry seeds and spores which get deposited along the road. That leads me to think that everywhere we have built paths and roads, we have provided the means to introduce a lot of plants that wouldn't be there otherwise.
Departing the Tablelands, we head to downtown Bonne Bay to await a water taxi. There are about a dozen commercial buildings here. The largest being a fish/shellfish processing plant. nOh, and there is this cute lighthouse right downtown.
From the water taxi
The blue and white boat is our ride to Norris Point from here. It is about a 30 minute ride across the inlet. From there, we head up the coast to the community of Cow Head where we will spend a couple nights.
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