13 - Plate Tectonic Theory

What do these maps show?

TaskTaskProduce an annotated world Produce an annotated world

map to show the location and map to show the location and distribution of earthquakes, distribution of earthquakes,

volcanoes and volcanoes and fold fold mountainsmountains

Use pages 8+9 from the AtlasUse pages 8+9 from the Atlas

You have 15 minutesYou have 15 minutes

Structure Structure You should be able toYou should be able to Describe the general distribution of fold Describe the general distribution of fold

mountains, volcanoes and earthquakes mountains, volcanoes and earthquakes Explain how this distribution is related to Explain how this distribution is related to

movements at plate boundaries. movements at plate boundaries. Understand the processes leading to the Understand the processes leading to the

formation of rift valleys and block mountains.formation of rift valleys and block mountains. Show a basic understanding of plate Show a basic understanding of plate

tectonics, describing the global pattern of tectonics, describing the global pattern of plates, their structure, and be aware of plate plates, their structure, and be aware of plate movements - plates moving away from each movements - plates moving away from each other (sea floor spreading), plates moving other (sea floor spreading), plates moving towards each other (subduction) and plates towards each other (subduction) and plates sliding past each other.sliding past each other.

The Structure of the

Earth

Crustal PlatesCrustal Plates

Types of CrustTypes of Crust

Oceanic crust that lies under the ocean, Oceanic crust that lies under the ocean, is mainly basalt and 5-7km thickis mainly basalt and 5-7km thick

Continental crust 20-50km thick and Continental crust 20-50km thick and composed mainly of granite; it makes composed mainly of granite; it makes up the large land masses – the up the large land masses – the continentscontinents

Continental crust is low density and Continental crust is low density and “floats” on top of the mantle whereas “floats” on top of the mantle whereas oceanic crust is much higher densityoceanic crust is much higher density

ConvectioConvection n

CurrentsCurrents

Destructive (Convergent) Destructive (Convergent) Plate Boundary (Margin)Plate Boundary (Margin)

subduction

Constructive Constructive (Divergent) Plate (Divergent) Plate

Boundary (Margin)Boundary (Margin)

Sea floor spreading

Cross section of the Atlantic Cross section of the Atlantic

Other Plate Boundaries - Other Plate Boundaries - CollisionCollision

India colliding with Asian subcontinent

Other Plate Boundaries - Other Plate Boundaries - ConservativeConservative

San Andreas fault California

Rift Valley and Block Rift Valley and Block MountainsMountains

The end resultThe end result

But is it all bad?But is it all bad?

TaskTask Produce an A3 summary sheet to show the Produce an A3 summary sheet to show the

4 plate boundaries (destructive, 4 plate boundaries (destructive, constructive, collision and conservative)constructive, collision and conservative)

You need a cross-sectional diagram of eachYou need a cross-sectional diagram of each

For each boundary you should;For each boundary you should; describe what is happening, describe what is happening, give a real example of a place in the world give a real example of a place in the world

where this boundary can be found,where this boundary can be found, outline the type of tectonic (volcanic and outline the type of tectonic (volcanic and

earthquake) activity linked with each earthquake) activity linked with each boundary. boundary.