Countless years earlier, the Earth looked significantly different from today. The continents were arranged in such a way that would be unknown to us, and one landmass dominated the others: Gondwana.
Gondwana used to be a supercontinent, from around 550 million years ago to around 180 million years ago, alongside Laurasia. Gondwana incorporated present-day South America, Africa, Arabia, Madagascar, India, Australia, and Antarctica.
But what happened to Gondwana, and what can it tell us about our worlds history?
How Gondwana broke away into smaller continents over millions of years.
Gondwana: The supercontinent that as soon as was
Be patient enough, and youll see the earth itself spring to life– it moves, breaking apart or coming together all over the planet. This is the story of the last in a type of geological titans, a supercontinent we called Gondwana.
The Earth is a world alive.
For many people, the world around us looks like an extremely steady place. Its shape appears, pardon the pun, set in stone. The continents we understand today are only a short-term plan, and they looked very different in Earths earlier history.
That shouldnt surprise anyone– after all, our planet is dynamic with life on the surface area. But it goes deeper than that, actually. The atmosphere, the electromagnetic field that avoids solar radiation from frying us alive, the terrain on which we live– these are all the product of lively procedures taking location under the surface.
A various Earth
Pangeas breaking-up stages.Image credits U.S. Geological Service.
More continents hit this early Gondwana gradually to form Pangaea, the “entire Earth,” roughly 300 million years earlier. It was enormous by any stretch of the imagination, all of the planets landmass was merged into one block dominating the southern hemisphere, surrounded by the biggest ocean in history. 20 to 70 million years later, throughout the Jurassic, lava plumes from the Earths core started burning through the crust like a blowtorch, producing a rift in between what we know today as Africa, South America, and North America.
The formation of Gondwana was a gradual process that took millions of years. The continental plates that would comprise Gondwana slowly merged and collided, pressed together by effective tectonic forces. As they did, they formed towering range of mountains, such as the Appalachian Mountains in North America and the Hercynian Mountains in Europe.
Convection cells associated with these plumes broadened the crack into a fully-fledged Tethys ocean, separating a northern supercontinent called Laurasia– todays North America, Europe, and Asia– from a southern one, our fully formed Gondwana. Dinosaurs are strolling about, many of the world is covered in lush rain forests, and the last supercontinents are poised to break up.
Some 540 million years back, during the late Ediacaran duration, tectonic movements brought todays Africa, South America, Australia, Antarctica, India, the Arabian Peninsula and Madagascar into a single, huge landmass. This was the early variation Gondwana, stretching from the Equator practically to the south pole, covering nearly one-third of the Earths surface area.
Its not you, its tectonics
Gondwana fragmented in phases. Sometime between 170 million and 180 million years earlier, modern-day Africa and South America began breaking apart from the rest of Gondwana.
Todays tectonic plates. Red arrows show main instructions of movement.Image credits U.S. Geological Survey.
Thats why South Americas eastern coast and Africas western coast appear like they d fit together snugly– at one point, they really did.
At this point basically all thats left of previous Gondwana is Australia and Antarctica– insufficient to be counted as a supercontinent. They did stay fused together until around 45 million years ago. After that, Antarctica moved south and froze over (due to a combination of the climate cooling off and shifting ocean currents around the brand-new landmasses) and Australia went adrift towards the north, hitting southern Asia. The accident is still taking place today, as the Australian plate is advancing north at a rate of about 3 centimeters (1.2 inches) a year.
At about the very same time as the South Atlantic Rift was opening up, the easternmost part of the continent, Madagascar and India, divided from the rest, opening the main Indian Ocean. The two stayed fused together up until the Late Cretaceous duration, after which India made a beeline for Eurasia– 50 million years back, the crash between the two was so violent it raised the Himalayas.
We still do not know precisely what triggered the continent to disintegrate. One theory holds that hot areas formed underneath it, producing rifts that broke the supercontinent apart. In 2008, however, University of London scientists suggested that Gondwana rather split into 2 tectonic plates, which then were then even more fragmented.
South America and Africa with the approximate place of their Mesoproterozoic (older than 1.3 Ga) cratons (steady and old parts of the crust.) Image credits Woudloper/ Wikimedia.
How we figured all of this out
This sealed the theory of plate tectonics, and furthermore helped us understand how these enormous landmasses moved in the past– consisting of how Gondwana happened and ultimately broke up. Basically, Gondwana was broken up by the exact same tectonic forces that had actually previously brought Gondwana together in the very first place.
The remarkable similarity between the shape of western Africa and eastern South America was first officially noted by Sir Francis Bacon in 1620 as accurate maps of the two continents became available. In 1912, Alfred Wegener, a German meteorologist, proposed that the 2 continents formed a single body at one point– in fact, he was the first to envision the great supercontinent Pangaea.
Nevertheless, the theory of plate tectonics became extensively welcomed by the 1960s when the Vine– Matthews– Morley hypothesis was formed following paleomagnetism (or fossil magnetism) measurements of the oceans floor. These measurements tape-recorded the magnetic homes saved in ocean-bottom rocks as they formed with time, showing that rift locations include brand-new product to oceanic plates, pressing continents apart.
How magnetic stripes form on the sea floor.Image credits Chmee2/ Wikimedia.
Alexander Du Toit, a South African geologist, additional elaborated on the theory in his 1937 book Our Wandering Continents. Seeing the opposition Wegeners theory encountered, he thoroughly collected proof of the 2 continents past link– the incident of glacial deposits (or tillites) and rock strata on both sides of the Atlantic, in addition to similar fossil plants and fauna discovered solely on southern continents, specifically the fern species Glossopteris. His theory acquired traction with scientists from the southern hemisphere however was still commonly criticized by geologists in the northern hemisphere. They envisioned land bridges spanning from continent to continent to explain how one types might be discovered on both sides of an ocean, even to the point where these bridges would circle whole continents.
Life in Gondwana
The breakup of Gondwana likewise had an extensive impact on the distribution of species around the globe. As the continents separated, the plants and animals that survived on them were also separated. This resulted in the advancement of distinct ecosystems and the evolution of distinct species on each continent.
The formation of Gondwana was a progressive procedure that took millions of years. Convection cells associated with these plumes widened the fissure into a fully-fledged Tethys ocean, separating a northern supercontinent called Laurasia– todays North America, Europe, and Asia– from a southern one, our fully formed Gondwana. At some point between 170 million and 180 million years earlier, modern Africa and South America started breaking apart from the rest of Gondwana. Gondwana was home to a diverse range of plant and animal life, much of which was unlike anything discovered on Earth today. The same tectonic procedures that shattered and made Gondwana and the supercontinents prior to it functions just the very same, powered by the big amount of heat caught in the depths of the Earth.
Today, the remains of Gondwana are scattered around the globe, but its tradition survives on. When made up, the mountains, deserts, and other landscapes that were formed throughout the supercontinents presence can still be found on the continents that it.
Gondwana was house to a varied variety of plant and animal life, much of which differed from anything discovered on Earth today. Scientists have actually uncovered fossils of ancient reptiles, amphibians, and even early mammal-like creatures that resided on the supercontinent. The discovery of these fossils has provided valuable insight into the advancement of life on Earth.
The fossils of the ancient creatures that resided on Gondwana give us a glance into the remote past and provide important insights into the evolution of life on Earth. And the coal deposits formed from the ancient glossopterids continue to be a major source of energy all over the world.
Among the most substantial discovers from Gondwana is the discovery of ancient, tree-like ferns. These ferns, known as glossopterids, were incredibly large and are believed to have been one of the dominant types of greenery on the supercontinent. Scientists think that they may have played an important function in the development of coal deposits, which are now a significant source of energy all over the world.
In general, Gondwana was a vital action in the Earths history, its research study can supply an understanding of plate tectonics, environment, and life advancement and how they formed our world. Gondwanas story is still unfolding, its a suggestion of how much more there is to learn more about our planet and its history.
Gondwana is the last of the supercontinents the world has actually seen– so far. The very same tectonic processes that made and shattered Gondwana and the supercontinents before it works simply the exact same, powered by the huge quantity of heat caught in the depths of the Earth.
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