The theory of plate tectonics added new information about plates vs. continents to the original theory of continental drift. Explain the difference.

Continental drift is a theory first presented by Abraham Ortelius (Abraham Ortels) in 1596. The concept was independently developed by German geologist Alfred Wegener in 1912. The theory states that the continents are moving slowly on the surface of the earth, and the majority of these large landmasses were together once, about 200 million years ago. This collection of continents is known as a super continent while Plate tectonics is the theory explaining the motion of the outer crust or the lithosphere of earth. Lithosphere is divided into tectonics plates. Two main types of tectonics plates are the oceanic crust and continental crust. Oceanic crust is mainly composed of Silicon and magnesium, hence called SIMA. Continental crust is made of Silicon and Aluminum and called SIAL. Each crust type is about 100km thick, but continental crust tends to be thicker. Below the crust lies the asthenosphere.