11/9

During this unit in geoscience we learned a lot about plate tectonics and the theory of continental drift. There are five pieces of evidence in favor of continental drift. These are 1. Continents fit together like a puzzle. 2. They have similar geological features. 3. They have similar fossil records. 4. Volcanoes and earthquakes follow the ridges along the continents. 5. People are monitoring the distance between continents and it shows that the seafloor is spreading. These are all very solid pieces of evidence to prove the theory of continental drift. There are three different types of continental drift. One type is divergent. This type of continental drift most often only happens with oceanic plates. This is when the plates are moving away from each other, such as seafloor spreading. When this happens this creates underwater mountains because magma gets pushed up from underneath the ocean and solidifies creating matter and then creating mountains. This is what creates the underwater oceanic ridges. Another type of continental drift is convergent. There are two different types of convergent continental drift; collision and subduction. The first kind happens when a continental plate and another continental plate collide with each other. This forms mountains. The second kind, subduction, happens when one plate goes underneath another plate. This forms volcanoes and trenches on the ocean floor. The third type of continental drift is called transform plate boundaries and this happens when plates grind against each other. This creates earthquakes.