Forty-eight years ago, Dan McKenzie honored us with his first article on “lower mantle viscosity”, or better known as name plate tectonics theory. This theory states that the Earth is divided into plates that move in different directions and speeds. The movement is caused by convection in the asthenosphere. Lower, hotter magma rises upward and pushes the plates outward, then cools and sinks. Additionally, in places like the mid-ocean ridge, there are cracks in the Earth's crust where magma rises up and replaces old rocks, pushing them to one side or the other. (Richardson) This theory is supported by irrefutable facts. Here are some of them: the shapes of many continents appear to have been connected at some point, there are similar fossils on almost every continent, and the oldest parts of ocean plates are only about 200 million years old . This theory is as close to the facts as possible. When our Earth's tectonic plates are viewed separately, there's nothing spectacular about them, but when they're viewed together in a different arrangement, it's almost impossible not to see how they fit together. It is believed that the continents were once all connected until 260 million years ago, when a giant natural event separated them. (The Geological Society) This is a separate hypothesis known as Pangea, which means all the earth. Scientists have worked tirelessly to build a giant landmass where the continents stay in their current general area and fit together. With erosion as the opposing force, it's impossible to get an exact picture of what it looked like, but what we have now comes extremely close. There are even fossils on the edges of plates that match fossils on the edges of other plates. T...... middle of paper ...... because the sea floor is expanding. He proves this by saying that the continents all seem connected at one point, that there are similar fossils on different continents that are now separated by hundreds of miles, and that the oceanic crust is made up of different rocks of different ages. . Dan McKenzie was an underpaid and underappreciated geophysicist who wrote a phenomenal paper in 1966. He is now considered the man who solved one of Earth's greatest mysteries, the man who discovered the plate tectonics. “Dan McKenzie.” State of Pennsylvania. Penn State, 2014. Web. February 19, 2014 “Dan McKenzie”. Plate technology. The Geological Society, nd Web. February 19, 2014. “Continental Drift.” Continental drift. Enchanted learning. Internet. February 19 2014. .