In 1596, Abraham Ortelius was the first man to provide the theory of how continents were once close together. It was not until 1912, when Alfred Wegner revisited that theory. Alfred Wegner was born on November 1, 1880 and was most notable for the continental drift theory. This theory stated that continents were slowing drifting towards the earth. In the 20th century scientists realized that the Earth crusts is not made up of one piece but are made up of plates. When we looked at the maps we saw that South America and Africa look like they could be put together. Scientists believe that Pangea existed about 150 million years ago. All of the continents were once one big continents called Pangea. Then it started to break apart to make the continents we see today. The crust of the earth is broken into tectonic plates. Tectonic Plates are plates that float around on a layer of molten rock called the outer mantle.When the the plates move, continents shifts along with them, this is called continental drift. This explains why fossils of historic animals were found on the Northeast coast of South America and South West coast of Africa.When the continental drifts shift you can hardly feel the ground moving because they only move one to ten centimeters every year. Volcanoes, earthquakes and mountains are a result of active plate boundaries. Earthquakes are when plates are moving against each other. Places like California have a lot of earthquakes because they are right on the edge of the plates. Divergent boundaries are where plates are moving apart. Therefore new crust is formed from the liquid rock pushing up against the outer mantle. Convergent boundaries are where plates are moving towards each other. Sometimes plates are subducted. Subduction Zones is a region of the Earth’s crust where the plates meet. Transform plates are where plates slide horizontally towards each other and make friction. These plates are always moving and gradually changing. A craton is a large stable block of the earth’s crust forming the nucleus of a continent. The seven main plates are the African plate, Antarctica, Eurasia, Pacific, and South America plates.