1. Constructive Plate Margins - Revision
Using the following key words, draw a constructive plate margin on your white board and label correctly
Sea floor spreading
Magnetic strips
Divergent
Basalt intrusion
Upper Mantle partial melting
Ocean ridge
High heat flow
Transform faults
Abyssal plain

2. Constructive Plate Margins - Revision
Using the following key words, draw a rift valley and label the parts
Normal faults
Basalt
Convection currents
Basalt intrusion
Upper Mantle partial melting
High heat flow

3. Plate Margins Three main types of plate margin: Constructive
Destructive
Conservative
Each type of plate margin has different rocks and types of hazard – why ?

4. Destructive Plate Margins
May also be called convergent plate margins. Why?
There are three types of destructive plate margins depending on what type of plates are involved:
Oceanic v Oceanic
Oceanic v Continental
Continental v Continental
Each will produce different hazards and rocks

5. Pre-Continent/Continent Collision Features
Partial melting of oceanic plate basalt and continental plate granite = andesitic/granitic magma
Where might we find andesitic rocks?
Subduction zone: describes the whole area where subduction is taking place
Ocean Trench: is the deep valley formed in the ocean floor as the subducted plate bends
Benioff zone: zone of earthquakes set off by the solid lithospheric plate forcing it’s way through the mantle

6. Oceanic v Oceanic Collision
Island Arc: An arc of islands running parallel to the trench/subduction zone created by volcanic activity fed by magma from the melting subducted plate
Label:
Trench
Island Arc System
Benioff Zone
Cold, Hot Regions
Why would one oceanic plate subduct beneath another ?
What type of rock would we find here ?

7. Continent/Continent Collision
Eurasian Plate
About 40 million years ago India collided with Asia and a huge mountain chain formed. Both plates were made of continental crust
When partial melting occurs beneath two continents colliding, what rock type would be produced ?
Indo-Australian
Plate
Why did they collide ?
What destructive zone features are missing ?
Granite
Subduction zone
Trench
Volcanoes

8. Homework
For Monday – see slip