Plate Tectonics

The links below will take you to really useful places!
So much has been posted on the web by others! Plate tectonics is a popular subject. You do need to be a bit wary of some sites - they may not be totally factually correct. Below is a list of links to some really useful sites that cover what you need to know about plate tectonics.


Plate Tectonics - An Introduction - a brilliant overview of all the necessary material
Evidence for Plate Tectonics - the best site I've found on the evidence
Plate Tectonics Notes and Pics - this has some really good pictures of the different types of plate margins (but the text is a bit 'high level' for GCSE purposes).
The material on these sites is so good that I'm not going to add to them. Click away!


Here is what the syllabus says you need to know...

The jigsaw pattern fit of the continents and fossil distributions across the continents caused Wegner to come up with the theory of continental drift in 1915.

The detection of magnetic stripes either side of mid-ocean ridges leading to the age of the ocean floor being shown to get older as you go further from the mid-ocean ridges made Hess (1960), Vine and Matthews (1963) realise that the ocean areas must be continuously be being added to.

J. Tuzo Wilson (1965) found the process that stopped the Earth needing to get bigger as the ocean areas grew - what we now call 'Plate Tectonics'

and direct laser measurements tracking the movement of the plates using satellites has been used to confirm that the movements do take place.

There is a range of evidence supporting the theory of plate tectonics and the direction and rate of plate movement such as mountain ranges, subduction zones, rocks showing that continents must have moved through different climatic zones...

We no know that the lithosphere  is a cold, rigid outer shell that is composed of the crust and the uppermost part of the mantle. It is underlain by the asthenosphere, a weaker layer. The lithosphere is divided into a number of rigid plates which move relative to one another due to thermal convection in the mantle.

The relative movements between plates produce different effects at different types of plate boundary.

• Divergent (constructive) plate margins: [basalt extrusion, sea floor spreading, the

origin of basaltic magma by partial melting of the upper mantle, ocean ridges, high

heat flow, rift valleys, abyssal plain]

• Conservative plate margins: [earthquake activity, transform faults] (San Andreas

fault zone)

• Convergent (destructive) plate margins :

1. oceanic-oceanic: [island arc/trench systems] (Java-Sumatra/Caribbean) 2. oceanic-continental: [active continental margins; subduction zones Benioff

zone, partial melting producing andesitic and granitic magmas] (the Andes) 3. continental – continental: [mountain building, folding, thrust faulting, partial melting of the crust producing granites, associated regional metamorphism]

You need to be able to Use maps to interpret the global distributions of earthquakes, igneous rocks and mountain belts in the context of processes at or near to plate boundaries.

Interpret the relative movement of plates from their plate boundary context shown in maps/diagrams.

Interpret the type of magmatism and seismic activity associated with different plate boundaries from data provided in text, diagrams, photographs or maps.