Answer 1:
This is an interesting question. There is a good web site where you can look at different maps, in different periods of time about the continents evolution. In these maps, you will be able to compare by yourself the actual shape of the continents and their past form:
Maps of pangaea
Rodinia was a super continent formed about 1.1 billion years ago (that's 1,100,000,000 years). 750 million years ago, Rodinia broke into three pieces that drifted apart as a new ocean formed between the pieces. Then, about 600 million years ago, those pieces came back together with a big crunch known as the Pan-African orogeny (mountain building event). This formed a new super continent, with the name of Pannotia. By about 550 million years ago, Pannotia was breaking up into several small fragments, Laurentia (the core of what is now North America), Baltica (northern Europe), and Siberia, among others, and one very large piece. This large piece, containing what would become China, India, Africa, South America, and Antarctica, was called Gondwana. It is considered a super continent in its own right because it is so big, but it is only part of the earlier super continents.
Over the next 200 million years many of the small pieces came together to form another large continent called Laurasia. Laurasia and Gondwana joined approximately 275 million years ago to form the super continent of Pangaea. The breakup of Pangaea is still going on today and contributes in the formation of the Atlantic Ocean. Eventually a new super continent will form and then it will break apart and so on.
As you can see, the earth's continents have seen a lot of action over time. There were probably some super continents formed in the 4300 million years of earth's history that came before Rodinia was formed, however, we have a much harder time understanding the history of rocks that old because there were not very many life forms to help determine the age of the rocks and because so much has happened to the rocks since they formed that the record of the original events is not very clear any more (imagine that five different people each taped over different parts of your favorite video and then from the little pieces that were left of the original, you had to go back and try to put the whole story together) - geologists who do this work are a lot like detectives. Click Here to return to the search form.
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