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Judi Lynn

(160,219 posts)
Tue Sep 18, 2018, 10:11 PM Sep 2018

Ancient Three-Way Collision Formed British Mainland


By Stephanie Pappas, Live Science Contributor | September 17, 2018 07:32am ET

Parts of Britain are a lot more like France than ever before realized.

In fact, Cornwall and south Devon on the British mainland are basically part of France — at least, geologically speaking. New research finds that these areas all derive from an ancient bit of continental crust called Armorica. Previously, the British mainland was thought to have been formed from only a piece of crust called Avolonia and a segment of the precursor to North America, Laurentia. The new research suggests that it was instead a three-way merger.

Understanding this process requires going back 400 million years ago, well before the formation of the famous supercontinent Pangea, which formed around 300 million years ago. It was the early Paleozoic, and most of the above-sea-level crust on Earth was divided into several continents, the largest being Gondwana, which contained the continental crust that would become the modern southern-hemisphere continents. The others were Avalonia (the precursor to Canada and much of Europe), Laurentia (the precursor to North America), Barentsia, Baltica, Siberia and North and South China. [Photo Timeline: How the Earth Formed]

Ancient collisions
Around 400 million years ago, Avalonia scrunched into a piece of Laurentia. This merger was previously thought to have created the land that would later merge into Pangea and then break up again into the modern-day British mainland.

More:
https://www.livescience.com/63599-ancient-formation-of-british-mainland.html
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Ancient Three-Way Collision Formed British Mainland (Original Post) Judi Lynn Sep 2018 OP
Facts About Pangaea, Ancient Supercontinent Judi Lynn Sep 2018 #1
... El Supremo Sep 2018 #2
The British must be quite displeased that part of their island belongs to France marylandblue Sep 2018 #3

Judi Lynn

(160,219 posts)
1. Facts About Pangaea, Ancient Supercontinent
Tue Sep 18, 2018, 10:15 PM
Sep 2018

By Tia Ghose, Associate Editor | February 22, 2018 07:30pm ET

About 300 million years ago, Earth didn't have seven continents, but instead one massive supercontinent called Pangaea, which was surrounded by a single ocean called Panthalassa.

The explanation for Pangaea's formation ushered in the modern theory of plate tectonics, which posits that the Earth's outer shell is broken up into several plates that slide over Earth's rocky shell, the mantle.

Over the course of the planet's 3.5 billion-year history, several supercontinents have formed and broken up, a result of churning and circulation in the Earth's mantle, which makes up most of planet's volume. This breakup and formation of supercontinents has dramatically altered the planet's history.

"This is what's driven the entire evolution of the planet through time. This is the major backbeat of the planet," said Brendan Murphy, a geology professor at the St. Francis Xavier University, in Antigonish, Nova Scotia.

More:
https://www.livescience.com/38218-facts-about-pangaea.html
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