Continental Drift

Continental Drift book page 182

1) Explain Continental Drift

Theory that explains that continents moved slowly to their current locations.

**Continental drift and new species ▶ Responsible for geographic isolation of populations

▶ Because of the separation of the continents,

organisms had to evolve to the new conditions, generating new species over time.

▶ The new species inhabit different areas but had a common ancestor.

Continental Drift book page 182

2) What is Pangea what does the word Pangea mean?

Pangea means “all land” and it is the name of the ancient mass of land that broke into the different continents

Continental Drift book page 183

3) What are the evidences of Continental Drift?

↖ The shape of the continents ↖ Rock structures↖ Fossils ↖ Climate Clues

Video:

▶Continental Drift

▶Michael Sammartano

▶https://www.youtube.com/watch?v=_5q8hzF9VVE

Continental Drift book page 183

3) What are the evidences of Continental Drift?

↖ The shape of the continents ( fit like a puzzle) pg 183

↖ Rock structures – similar rock structures are found in different continents suggesting that these continents were once connected.

Fossils – fossils of similar species ( animals or plants) are found in different continents, separated by oceans, suggesting that these continents were once connected. (page 183)

▶ Climate clues:A)Fossils of tropical plants and coal found in very cold areas show that the continents moved from the tropical zone to positions closer to the poles

B)Evidence of glaciers found in tropical areas, show that the continents were once covered in ice and could have moved from being closer to the poles to their actual position

▶ What causes Continental Drift?????

Continental drift is caused by the movement of the plates that form Earth’s lithosphere.

Layers of the Earth:to understand why continents move, we need to know more about the layers of the Earth

Layers of the Earth

The plates are pieces of the lithosphere that float in the asthenosphere

What are plate tectonics? Book page 190

▶ The theory of Plate Tectonics states that in the past all continents were part of a huge continent that broke into different sections

What are plate tectonics? Book page 190

▶ The lithosphere (the crust and the solid upper mantle ) is broken into the different plates, that move around on the asthenosphere.

▶ Fig 8 page 190 ▶ Fig 9 in the book shows different plate

tectonics

What causes continental drift?

▶ Tectonic plates move due to convection currents of the magma inside the Earth – fig 12 page 195

▶ Continental drift has continuously occurred throughout time, and continues to do so today.

( 1cm every year)