Plate Tectonic Theory Flashcards
What is Plate Tectonics?
- The Earth’s crust is made up of a number of large plates moving in constant, slow motion.
How do Tectonic Plates move?
Convection currents in the mantle move the plates. The source of heat driving the convection currents is radioactive decay which is happening deep in the earth.
On what part of the plate do earthquakes occur and volcanoes form?
At the edges of these plates (plate boundaries).
Explain how convection currents move the plates.
The magma is heated to 5,500°C in the mantle and rises to the crust where they cool and descend only to be heated again. This was powerful enough to move the Earth’s plates.
Explain how fossils contribute evidence to support Plate Tectonics.
Similar fossils are found on different continents, showing that these regions were once very close or joined together. Such species could not have crossed oceans, so they must have lived on the same land mass.
Explain how Geological Patterns contribute evidence to support Plate Tectonics.
Similar patterns of rock layers on different continents is evidence that the rocks were once together or joined.
Give an example of the evidence of Geological Patterns.
Coal has been found in Antarctica. Coal requires warm climates to form. This indicates that it was once near the equator.
Explain how the Jigsaw fit contributes evidence to support Plate Tectonics.
Some continents fit together like a geological jigsaw puzzle, meaning all the rocks were formed when the land was a single continent - Pangea.
List the main evidence that supports Plate Tectonices
Jigsaw Fit, Convection currents, Study of Fossils, Geological Patterns, and Palaeomagnetism
