Theory of Plate Tectonics

What is the Theory Of Plate Tectonics?

• The Theory that the worlds Crust is cut in 7 Slabs named Plates.

What are Convection Currents?

• The movement of Plates from Rising Magma within the Core.

Explain how Convection Currents work?

• Magma Heats up and Rise due to the 5,000 Celsius Core.

• The Magma cools as it gets further away from the core and begins to fall

• Creates a Circle effect pulling on the plates.

What is the Heat of the Core?

• 5,000 Degrees Celcius

What can This Circle effect cause plates to do?

• Converge = Come Together

• Diverge = Pull Apart

• Transform = Move past eachother

What is the Theory of Continental Drift?

• The Theory that all of Earth’s Continents were once joined together on a super Continent Called “Pangea”

Who coined the Theory “Continental Drift” ?

• Alexander Wegner in 1912

How did Pangea break apart?

• Due to Convection Currents

How many Years ago did Pangaea Break Apart?

• 200 Million Years Ago.

What are the 3 Proofs to this theory

• Continental Fit

• Fossils

• Mountain Ranges

What is Continental Fit?

• That some parts of the world on a map can be fitted together.

• Was widely rejected

• Like a Puzzle Piece

How did Fossils prove his theory?

• Land based animals fossils could be found on different continents.

What had Mountain Ranges had to do with Wegener’s Theory?

• Mountain Ranges in Scandinavia were found in North America.

• Proving at one point they were on the same plate boundary.

What is Sea Floor Spreading?

• Plates diverging below the ocean.

Who Discovered Sea Floor Spreading?

• Harry Hess

What is the Mid Atlantic Ridge?

• A 16,000 KM Long

• Volcanic Mountain Range

What causes the creation of the Mid Atlantic Ridge?

• Sea Floor Spreading allows Magma to rise and cool above the crust in an ocean.

How do they know how old certain rock is ?

• The Depth of the Material