US, WASHINGTON (ORDO NEWS) — Pangea was the last supercontinent of the Earth – an extensive association of all the main land masses.
Before Pangea began to decay, the land we know today as Nova Scotia was tied to an unexpected neighbor: Morocco. Newfoundland was annexed to Ireland and Portugal.
About 250 million years ago, Pangea was still one continent, but the geological forces that formed the continents as we know them today have already begun to operate.
For many years, geologists have pondered why the continents diverged and how they eventually spread throughout the globe.
We know that Nova Scotia and Morocco were once united because their coastal areas are perfectly aligned. We can also trace their path from the structure of the ocean floor, which now separates them.
Today we are much closer to understanding the movement of continents, including the movement of land masses, but we still have a lot to learn.
The science of why they were at a distance of 5,000 kilometers from each other – and how the other parts of the continental mosaic diverged – was thoroughly investigated and discussed.
Some scientists believe that the continents were stretched by the movement of tectonic plates. Others say that hot material from deeper underground areas has made its way up and parted continents.
Whether one or the other theory is true, or some combination of both, is certain: no matter what happens, it did not happen quickly!
Plate tectonics is a continuous history that unfolds in millimeters every year. The changes were summed up over eons, placing us where we are today – still drifting, although almost imperceptible.
An area of particularly intense study and a long-standing mystery is the North Atlantic – an area bounded by Greenland, Eastern Canada and Western Europe – where the final stages of the breakup of Pangea are completed.
When the North Atlantic began to move away, the continent began to divide along the western side of Greenland. Then he stopped and continued to move between eastern Greenland and Europe. Why?
To solve this and related issues, my two colleagues and I gathered in the working group on the North Atlantic about 30 researchers from different fields of Earth science.
Our research group includes geophysicists, geochemists, and many others who study the structure and evolution of the Earth.
To date, the North Atlantic Working Group has held a number of seminars and published a number of documents that propose a new model for answering some long-asked questions about what happened in the North Atlantic.
The North Atlantic Working Group was able to collect many different types of data and study the problem from different perspectives. We concluded that the most important geological events were strongly influenced by an earlier activity — a process called “inheritance”.
Throughout the history of the Earth, continental land gathered together several times, and then diverged. This process of unification and subsequent divergence is known as the “supercontinental cycle.”
When Pangea was again stressed, she tore along the old structures. Although this process was proposed at the dawn of the theory of plate tectonics, it is only now becoming clear how important and far-reaching it is.
On the largest scale, the gap that formed the North Atlantic began first west of Greenland. There he struck the ancient mountain belts, which fell apart.
East of Greenland, the North Atlantic Ocean eventually formed.
In addition, relics from these previous plate tectonic cycles left traces deep in the Earth’s mantle, explaining most of the widespread molten rocks that accompanied the decay.
Alexander Lewis Mira, Associate Professor (Structural Geology), McMaster University.
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