Pangea, right? Right? Not really. Despite the fact that most people have only ever heard of the one supercontinent, our planet has had a number of them. Earth's land masses - never content to just sit around and think deep thoughts - have been on the move. And like any massive, slow-moving behemoth, these babies are hard to steer. They crash into each other a lot (geologically speaking) and create these monstrous landmasses.
We are living through a relatively rare period of time in our planet's history, when the continents are comfortably spread out with plenty of elbow room, but there have been a number of periods when they were all smashed together in one configuration or another.What were earth's known supercontinents? Take a look here and you'll learn a thing or two about it.
Formed: 3.3 Billion Years Ago?
We know very little about the first continent (though, not exactly super, since there wasn't much land in those days), so the shape, size and scale of the theorized Vaalbara is pretty speculative. The two oldest cratons on the planet both have the oldest rock dated, so assumptions are made about what Vaalbara might have looked like based only on these two patches of oldness. It's named for the 'Brangelina' style mashup of the two cratons: the South African Kaapvaal Craton and the Australian Pilbara Craton. Paleomagnetic data from both these areas show that these two cratons could have been from the same supercontinent.The same evidence that shows the possible existence of Vaalbara also indicates that it started to break up after 2.5 billion years.
Formed: 3 Billion Years Ago
Ur is the first definitively known continent, despite being smaller at the time than Australia is now. Because it was the only one at the time, and because Vaalbara is still a theory, Ur is considered to be the first "super"continent. Ur would eventually join up with the continents Nena and Atlantica about one billion years later to form the supercontinent Rodinia. Ur actually survived for quite a while, making it through the breakup of Rondina and into the era of Pangaea, until it broke apart about 208 million years ago into Laurasia and Gondwanaland.You can now find the remains of Ur in parts of Africa, Australia, India, and Madagascar.
Formed: 2.7 Billion Years Ago
Kenorland is basically thought to have been made up from multiple smaller cratons (Zimbabwe, Kaapvaal, Gawler, Pilbara, and Yilgarn) , cratons being stable portions of continental crust from unstable geologic regions. Picture them as both shields - in which the basement rock crops out at the surface- and platforms - in which the basement is overlain by sediment.At this point in Earth's history, it was pretty much all volcanic/igneous activity all the time, until those cratons started to collide. When Kenorland started to break up, the oceans were just beginning to oxygenate and this is the point when the "snowball earth" theory takes place.
Formed 1.8 Billion Years Ago
The formation of Columbia (also known as Nuna and Hudsonland) was the result of global scale collision events. It consisted of the proto-cratons that had previously made up Laurentia, Baltica, the Ukranian and Amazonian Shields, Australia and possibly Siberia, North China and Kalaharia.When it began to break up, it is thought that its pieces began moving around independently for several hundred million years and then, about a billion years ago, the band got back together and formed our next super: Rodinia.