|MadSci Network: Earth Sciences|
Dear Hannah, The website for you is the Paleomap Project, located at http://www.scotese.com/ Use the “Earth History” hotlink on the Paleomap Project website which lets you select and view maps of where the continents were for each geological period going back to the Late Proterozoic, 650 million years ago. There are other fascinating things you can do on the Paleomap Project website too. See what you can learn by exploring it. Pangea was not the first supercontinent in the Earth’s history. There was a much older supercontinent called Rodinia which formed about 1.1 billion years ago, and which broke up in the Late Proterozoic. The continents which split away from Rodinia drifted during the Paleozoic Era until they collided to form the southern supercontinent called Gondwana and the northern supercontinent called Laurasia. Gondwana and Laurasia then came together by the end of the Carboniferous Period to form Pangea. The Paleomap Project will take you back to the time when Rodinia was breaking up. Our knowledge of where the continents were and what they looked like is pretty good for Pangea and the more recent geological past since Pangea broke up. Our knowledge becomes less good before Pangea because the geological evidence on which we base reconstructions of the movements of the ancient continents becomes less reliable the further back in time we go. But we still have a pretty good idea of how the continents wandered over the Earth back as far as Rodinia. Before Rodinia we do not know what the continents looked like. We think that the land masses that existed in these very early times were smaller and more numerous than the continents after Rodinia. Going back as far as 4 billion years ago or more, I imagine the Earth covered by a global ocean, with volcanic island chains as the only land. Over hundreds of millions of years these island chains, which would have moved around on the Earth’s surface as the tectonic plates moved, collided to form larger land masses. Finally these collisions created Rodinia. I hope this answers your question, and I hope you enjoy using the Paleomap Project. Kind regards, David Scarboro
Try the links in the MadSci Library for more information on Earth Sciences.