How did this island that is Newfoundland, come into existence millions of years ago.

As for every place on earth, this island also came about as a result of the evolution of earth’s landmasses. However, this place has some fascinating and unique features. And it is also because of what I saw and heard here, I started researching these topics, mostly online.

Let me explain a few general pieces I gathered from several different sources. As one can imagine, no one knows for sure what really happened billions of years ago. What we know is based on evidence that is seen and then interpreted to generate theories. Based on these theories, plausible models of what may have happened are created. There are still many uncertainties about some aspects related to ancient locations, timelines and sequences of some geological events, but there is also consensus on many important aspects.

Movement of landmasses made continents

The age of our earth is assumed to be around 4.6 billion years. About a billion years after that, land mass started to appear. Over millennia, land masses have expanded. They have come together, bumped into each other, remained together for many millennia sometimes as super continents and then have split apart to form smaller continents. This split was not necessarily where they initially came together. And then they have drifted away for several millennia, to come together again millennia later. Awesome to think that this is still happening. This is an interesting link to a video which shows movements which happened and prediction for what will happen in the future. https://www.youtube.com/watch?v=YwL9nOJ_AoU. I come from India and was fascinated to learn and see how the Indian subcontinent came about as well.

So, landmasses have been coming together and then moving apart for millions of years, at a very slow pace of about a few cm every year. This is called the continental drift and is due to plate tectonics.  This splitting of land masses to form continents was suggested many years ago simply by looking at the edges of continents on maps. But now, we have evidence in the form of similarities in fossils and rocks, between edges of different continents (see picture below). We also have better understanding of how this has been happening over millions of years to give rise to the continents and geography we now have.  It is continuing to happen and so, if we come back after another million years the continents will look different from what they are now. There are many resources on line to learn more, but here are two I found interesting.

https://www.youtube.com/watch?v=ZCvkwG-W8pU https://www.britannica.com/place/Pangea.

Why am I saying all these? It is because Newfoundland has had an interesting evolution in relation to continental drift over millions of years and carries many lines of evidence that contribute to our understanding of these major events that happened millions of years earlier. Based on continental collisions and separations, this island appears to have three distinct geographical areas – west, central and east. Each of these areas have still visible features to support theories of their ancient affiliations and origins.  

There are several institutions and individuals in this part of the world devoted to research in these areas and new knowledge keeps evolving.

What happened in Newfoundland

Around 600 million years ago, ancient north America, was part of a much bigger continent, which then split.  The part containing the current north America was called Laurentia. Western Newfoundland was along the eastern most part of this continent. During that period, there was an ocean called the Iapetus Ocean almost where the Atlantic Ocean is now. Interestingly, Iapetus is named after the father of Atlas from Greek mythology and the Atlantic is after Atlas. The Iapetus Ocean separated Laurentia from the other land masses of those times including the supercontinent Gondwana. All these continents were mostly in the southern hemisphere or around the equator.

Millennia later, the Iapetus Ocean floor east of ancient Newfoundland sank, and volcanic island arcs appeared. Remains of these island arcs are still visible in the central zone of Newfoundland. Continental movements continued and Laurentia moved towards Gondwana. As they came together, the ocean crust and mantle were pushed onto the continental margins of Laurentia. This started around 470 million yrs ago and by 410 million yrs ago, these continents collided into each other, raising a mountain range where the Iapetus Ocean was. Halfway along this mountain was ancient Newfoundland. Following this collision and other collisions of land masses around this time, a single large continent called Pangea, containing most of the land masses of earth surrounded by one ocean was formed.

The continents then stayed together as Pangea, which incidentally is the most recent supercontinent, – meaning there were supercontinents before that and likely to be more later on-, for the next several millennia. Again, around 200 million years ago, Pangea split, opening the Atlantic Ocean.

This split was not along where Gondwana initially joined and so some parts of Gondwana remained attached to the eastern the side of ancient Laurentia, and these parts are now in eastern Newfoundland, Nova Scotia, New Brunswick and north-eastern United States. The rest of the original Gondwana split to form the current south America, Africa, India and Australia.

https://en.wikipedia.org/wiki/Iapetus_Ocean Fossil evidence showing similarities (blue on one side and green on the other) suggesting the land was once connected but an ocean separated the two sides of the red line

So, Newfoundland

shares geological and early life ancestry with the Americas, Africa and Europe. Western Newfoundland was part of current N American continent for at least a billion years. The eastern part, now known as the Avalon, came from Gondwana, remainder of which is in Africa and S America. The central plateaux are mostly Iapetus Ocean floor, developed from opening and closing of the Ocean and collision between super continents resulting in changes in the earth’s crust and mantle and then weather effects over millennia. Huge slabs of ocean floor brought up onto the surface of the earth when Iapetus Ocean closed are still preserved in the mountains in western Newfoundland.

One of the few places on earth where the crust and mantle of the earth are exposed and visible above the surface of the earth is at the Table Lands of Gros Morne national park. The mountains that Iapetus Ocean closure caused is now the Appalachian Mountains which stretch from Alabama to Newfoundland. Further north, these ranges continue under the ocean to Scotland and Scandinavia. Many different types of rocks, based on their origins, structure etc remain exposed in different parts of the island especially around its long coastline.

In addition to these events, the Newfoundland landscape was also created by a series of glaciation and deglaciation and erosion over millennia. There were a few ice ages when most parts of the earth were covered with ice, followed by thawing when the ice glaciers retreated.  A well-documented ice age which covered most of the earth, named Gaskiers, occurred around 580 million years ago and lasted about 340 thousand years – this was apparently the shortest of the three major glaciations that occurred around that period. (There were a few more in the latter periods.) Deposits attributed to deglaciation of Gaskiers are found in very few places, one being Newfoundland. A town here bears the name of Gaskiers.

All these together gives Newfoundland many unique features in its land scape including fjords and lakes and a very thin soil layer over the rocks throughout the island.

So, geologically speaking, this island is remarkable. And is a big attraction for those interested in geology. A lot of what we know about earth and its origins come from these and similar areas.

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