IGCSE Geography: Natural Environments: Plate Tectonics

Slide 1: Plate Tectonics

Slide 2: Global Distribution of Volcanoes

Slide 3: Global Distribution of Earthquakes

Slide 4: Tectonic Plates > Plate Boundaries

Slide 5: If we can provide proof that Pangaea existed – what else can we prove?

Slide 7: The Future ...

Slide 8: What is the evidence that Pangaea existed? 1. Geological Evidence 2. Biological Evidence 3. Climate Evidence

Slide 9: 1. Geological Evidence

Slide 10: Fit of South America and Africa

Slide 11: The continents of South America and Africa look like they should fit together like a jig- saw puzzle. There are patterns in the structure of the mountains in North East USA and North West Europe that would suggest they should join together.

Slide 13: 2. Biological Evidence

Slide 15: Could Mesosaurus have swum from South America to Africa? Researchers say no.

Slide 17: The fossils of Mesosaurus has been found in both South America and Africa. Looking at the skeleton of Mesosaurus tells us that it could not have swam from one continent to the other therefore the continents, at one time, must have been closer.

Slide 18: 3. Climate Evidence

Slide 19: Coal Think about the climate in which coal forming vegetation grows.

Slide 20: Limestone > Coral

Slide 22: Limestone is found France and the UK > Must have been located in a warmer region of the world.

Slide 23: So what are the mechanisms that makes this happen? Sea Floor Spreading

Slide 24: Plates are like rafts ‘floating’ onto top of the mantle.

Slide 26: We know about the structure of the earth from the study of the behavior of waves as they pass through the earth.

Slide 27: Exploring the Ocean Floor

Slide 28: Ranges of submarine mountains in the middle of the Atlantic.

Slide 29: The crust gets older with distance from the Mid-Oceanic Ridge. There are strips of crust that show alternating polarity.

Slide 30: Convection currents.

Slide 31: Convection currents in the mantle.