What evidence is there to suggest that the earth is composed of tectonic plates?

List of evidence:

1. The age and distribution of ocean sediments: the sediment in the ocean is thinner and younger than the age of the ocean indicates it should be.

2. The oceanic ridges: oceanic ridges are clear indicators of past events.

3. Terranes: oceanic plateaus that form by uplifting and mountain building as they strike a continent

4. Paleomagnetism: strips of alternating magnetic polarity at spreading regions.

5. The location of the mountains and Fossils, resemble continents, like the ancient mountains ( although many have eroded to their cores ) and location of the rock types and fossils, all of it match up.  With the fossil, tropical species found in the Antartic and similar fossils found in western Africa and Eastern South America.

6. Apparent polar wandering: plate movement caused the apparent position of the magnetic poles to have shifted  

7. Earthquakes and Volcanoes, if you check the map location of all the earthquakes recorded over time, almost all of them occur in plate boundaries. Hot spots: surface expression of plumes of magma

A volcanic island chain can form when a plate passes over a hot spot and a stationary mantle plume

8. Atolls and Guyots: coral formations and submerged volcanic mountains. Guyots were once volcanic peaks above sea level