Find out more about The Open University's Science courses and qualifications
Rodinia - the first supercontinent
Between one billion and 620 million years ago, the continental crust that would one day be known as Britain formed tiny parts of a giant supercontinent called Rodinia (approximately 500 million years before the formation of Pangaea, a later supercontinent). All of Britain was south of the equator, with some parts as far as 60 degrees, further than Australia and the southernmost tip of South America today. The rifting or splitting apart of this supercontinent began around 760 million years ago to form a second supercontinent continent known as the ‘Vendian’ supercontinent.
Britain in two parts
Rifting of this second land mass caused the formation of a small ocean called the Iapetus. The split was complete by 550 million years ago. On the west side of the Iapetus Ocean was the continent Laurentia (now North America) and on the east side was a land mass called Gondwana (South America, Africa, Asia and Australasia). Split between these land masses was ‘Britain’. The northern part of Britain including Scotland was on the continent of Laurentia, and the Southern part of ‘Britain’ was on the continent of Gondwana. It was another 100 million years before Southern Britain and Scotland would finally meet…
A segment of Gondwana including Britain and Ireland, split away from the main body of Gondwana 475 million years ago. This land called Avalonia made its way across the newly formed Iapetus Ocean, eventually meeting with Laurentia about 440 million years ago. During parts of this transition, the continental crust, which makes up Britain, was underwater. By this time the continents had migrated across the globe and Britain was now approaching the equator.
Following in the wake of Avalonia was the giant landmass Gondwana, slowly approaching Laurentia and closing up the Iapetus Ocean. When this was complete 300 million years ago, Pangaea, the most recent Supercontinent was formed. Britain was fully enclosed in the middle of Pangaea by 250 million years ago. There was an ocean separating most of Africa from Europe and Asia called the Tethys. Up until now the continents were unrecognisable, but following the break up of Pangaea 140 million years ago, just as the dinosaurs were reaching great diversity, the earth started to resemble something we might recognise today. Britain, however, was part of an archipelago or series of islands. It was once again mostly under water. The Atlantic Ocean began to form as North America broke away from Europe, and by 80 million years ago South America and Africa separated too. At the same time, Africa and Europe became conjoined closing up the Tethys Ocean.
Study a free course
-
Life in the Palaeozoic
Learn more to access more details of Life in the PalaeozoicFossils are a glimpse into the distant past and fascinate young and old alike. This free course, Life in the Palaeozoic, will introduce you to the explosion of evolution that took place during the Palaeozoic era. You will look at the many different types of creatures that existed at that time and how they managed to evolve to exist on land.
-
An introduction to geology
Learn more to access more details of An introduction to geologyIn this free course, An introduction to geology, you will explore basic geological processes, focusing on how, where and why different rocks and natural resources form across the Earth.
-
Geological processes in the British Isles
Learn more to access more details of Geological processes in the British IslesThe landscape of the British Isles has undergone dramatic changes during the history of the Earth, from shallow sea to desert to the familiar terrain of the 21st century. In this free course, Geological processes in the British Isles, you will explore the processes that have shaped the British landscape over time, gaining insight into the ...
Rate and Review
Rate this article
Review this article
Log into OpenLearn to leave reviews and join in the conversation.
Article reviews
In the wake of this event, the Rheic ocean opened and eventually closed during the Devonian.
Why is there no mention of the Rheic Ocean?
You may wonder about the question mark after ocean.
I attempted to find the difference between an Ocean and a Sea.
More confusion, generally these terms are interchangeable. (I swam in the sea/ocean)
But, geographically Seas are smaller than oceans and they are partially enclosed by land (i.e. the Mediterrean Sea, Baltic Sea).
More confusion wnen large water bodies are land-locked and are partially saline. i.e. Caspian sea
Is it a Lake? Even the freshwater Great Lakes, have evidence of rising salinity, Great Seas?
I think this problem needs to be clarified.
Possible answer: Oceans are large, saline and contain internal spreading ridges, all the rest are seas.
EXCEPT lakes. These are low salinity bodies of land-locked water. A limit of salinity to be ascertained until it becomes a sea, 2%?
There is a problem with lakes because the salinity is variable, depending of the input of freshwater, and its elevation.
Food for thought.