Slide 1

http://www.youtube.com/watch?v=7xWWowXtuvA&feature=related

Student to describe what is happening relate back to last lesson link with the structure asthenosphere and lithosphere1How the Earths surface movesBy the end of todays lesson all of you will:Identify evidence to prove continental driftKnow how the tectonic plates moveKnow what happens when convection currents rise or fall.Some of you will:Understand how density and viscosity affects plate movement.

Key terms: Convection currents, tectonic plates, plate boundaries. Continental driftToday I am looking for:Good collaborationClear communication in written and verbal form.

Starter True or FalseThe lithosphere consists of the Crust and upper mantle and is divided into tectonic plates. Convection currents are driven by the heat from the earths core

Heat and pressure cause stress in the crust and it breaks up

Basaltic rocks are less dense than granitic rocks The heat in the core is due to the pressure of overlying material and radioactivity TrueTrueTrueFalseTrueEnsure students know why. Use this slide to answer the question How do tectonic plates move?4

250 million years agoEvidence Position 250 ml years ago what is evidence all joined as Pangea Wegner continental drift5

Evidence

Same rocks found across ocean basins

Termination of mountain chainsGlacial deposits found at equatorCoral reefs in AntarcticaAny other evidence? Last evidence flies in7http://education.sdsc.edu/optiputer/flash/convection.htm

Explain plate movemtnIn pairs look at Figure 2 and in pairs explain to each other why the convection currents rise and why they fall back again.In books answer the followingidentify two processes that create convection currents (overlying material and radioactivity at the core). Discuss the responses.what might happen when a convection current rises and what is likely to happen when it sinks. By using Figure 2, students should be able to identify the features with which rising and falling convection currents are associated. (This could be illustrated using a lava lamp.)2)The creation of new crust takes place where rising convection currents are found. What else must be happening if new crust is being formed?. Ask them to complete Activity 1 on next slide to distinguish between different types of crustal material.

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(5 marks)Pupils to complete answer and self assess from next slide9Answer swap books peer assess

Continental rocks are lower in density (1 mark) and, having cooled slowly below the surface (1 mark), are made up of larger crystals (1 mark)of minerals such as quartz and feldspar (1 mark). The oceanic crust is denser (1 mark) and finer grained (1 mark), having cooled more rapidly on the surface (1 mark). Now self assess your own learning WWW/ EBI

Conservative marginWhat is happening at these plate boundaries in relation to convection currents kinesthetic RISING FALLING point and name boundary pupils to to the correct poster11Homework On VLE >geography>GCSE geography>restless earth > lesson 2 > A-C 0r foundation2 homeworks RisingFalling