1. Plate Tectonics
Key Question: What is plate tectonics and continental drift?
Key Words:
Plate Tectonics
Continental Drift
Sea Floor Spreading

2. From memory draw out the structure of the earth.

3. Characteristics of Plates C
Continental Crust
Oceanic Crust
Upper Mantle
Mantle
Lithosphere
Asthenosphere
Fold Mountains
Shield Areas
Continental Shelf
Continental Slope
Abyssal Plain
Root Zone
Basaltic
Granitic
2.7g/cm³
3.0 g/cm³

4. Characteristics of Plates
Fold Mountains
Continental Slope
Shield Areas
Continental Shelf
Abyssal Plain
Sial
Granitic
Continental Crust
Oceanic Crust
2.7g/cm³
Lithosphere
Upper Mantle
Basaltic
3.0 g/cm³
Sima
Asthenosphere
Root Zone
Mantle

5. Use the images below to write a sentence to explain what continental drift is and who proposed it.
Alfred Wegner
Continental Drift is …………
It was proposed by…………
1915
In …………

6. 1. Continental Fit Wegener, 1912 – idea of “continental drift”
WEGNER’S EVIDENCE
1. Continental Fit
Wegener, 1912 – idea of “continental drift”
Supercontinent- Pangaea
200 mya Pangaea began to break up into Laurasia & Gondwanaland
these continued to break up into smaller continents we recognise now

7. 2. Biological Fossil remains of the freshwater reptile Mesosaurus
Evidence for Plate
Tectonics
2. Biological
Fossil remains of the freshwater reptile Mesosaurus
small reptile with limited swimming ability
Fossil of fern Glossopteris
large seeds
fossil remains limited to freshwater areas
fossil remains widely distributed
associated with warmer climates

8. Evidence for Plate
Tectonics
3. Geological

9. Evidence for Plate
Tectonics
3. Geological

10. same trend, same age & rock types
Evidence for Plate
Tectonics
terminate at present coastlines
Appalachians, Scottish and Norwegian Mtns

11. Evidence for Plate
Tectonics
4. Climatological
Glacial till of same age in southern Africa, South America, India and Australia
Coal deposits in Antarctica
Permian Red Sandstone Beds in the British Isles – indicate deserts

12. Plate tectonics is …………
Plate Tectonic Theory
Plate tectonics is …………
the ……………………………………. that the Earth’s surface layer (the ………………………………) is made up of ……. major plates and many minor plates which ………………… relative to one another on top of a mobile layer below known as the ……………………………. They meet at plate boundaries.
Theory
lithosphere 7
move
asthenosphere
The plates move by ………………… currents in the
…………………………….. .
convection
Mantle

13. 1. Continental Drift 2. Sea-floor Spreading 3. Plate Tectonic Theory
History of Plate Tectonics
1. Continental Drift
Wegener, 1912 – Biological, geological, climatological & continental fit
Ewing, Discovery & study of Mid-Atlantic Ridge
1950’s – Study of palaeomagnetism
2. Sea-floor Spreading
Hess, 1962 – Age of rocks in Atlantic Ocean
1960’s - Discovery ocean trenches
Alaskan earthquake, Discovery of subduction zones
3. Plate Tectonic Theory
J. Tizo Wilson – hotspot theory for Hawaii and work on conservative margins