Pieces that support Continental Drift
There are four ideas that help support Alfred's theory of continental drift that were found after his death. The same freshwater animal fossil was found on different continents separated by salt water. There are also the same temperate plant fossils that were found on all the continents, even Antarctica. On the coastlines, there are similar rock layers where the continents would have joined. In places with warm weather, there are glacial deposits that shouldn't be there. These are theories that help support Alfred's hypothesis.
My opinion of Continental Drift
I do think continental drift happened mainly because of glacial deposits being found in warm climate areas, and they wouldn't be there if continental drift didn't happen.
About plate tectonics.
Plate tectonics is the moving of plates. The plates move because of convention currents and also hold up the continents. Sometimes these plates collide and cause mountains, trenches, or volcanoes. Other times, they move away from each other and cause rift valleys or new seafloor. They also can move continents away from each other.
My opinion of Plate tectonics
I do not think the theory of plate tectonics is valid, because I do not believe the Earth's core is hot enough to move the plates because they are just too big.
Information of Seafloor Spreading
Harry Hess came up with this theory of seafloor spreading. His theory is that hot, less dense material rises from the Earth's crust to the surface of the ocean, cools and settles, and then creates new seafloor. Which can be underwater mountains, ridges, and volcanoes. The new seafloor pushes the older seafloor sideways.
My opinion of Seafloor Spreading
i think seafloor spreading is valid because there is actually evidence. Magnetic pole reversals and younger rocks being closer to the mid-ocean show that the seafloor has been moving.