Monday, October 22, 2007

Plate Tectonics...animations

More magnificent animations from Wycombe High School

Click here to view an animation showing how rift valleys develop into constructive plate margins leading to the development of new oceans. The Atlantic formed in this way about 200 to 250 million years ago.

Click here to see how plate tectonics provides the explanation for continental drift and the break-up of the super-continent of Pangaea about 225 million years ago. Click here(School Members only) for an alternative animation.

Click here to see an animation showing the convectional currents in the mantle which drive surface crustal plate movements.

Click here (School Members only) to see how constructive and destructive plate margins work together in the rock cycle.

Click here to see the formation of earthquake and volcanic activity at constructive plate boundaries.

Click here to see how the magnetic field of the earth reverses and how the pattern is recorded in the igneous rocks that are formed on either side of a mid-ocean ridge at a constructive plate margin.

Click here to see how basaltic lava enters the cold sea water at ocean ridges adding fresh rock to each crustal plate.

Click here to find out how oceanic crust is destroyed at destructive plate margins. These are also locations where there are ocean trenches, fold mountain ranges, volcanic activity and earthquake activity.

Click here to see how andesitic (or acidic) magma is created in a subduction zone which feeds intrusive and extrusive volcanic features.

Click here to find out how island arcs, such as the Aleutian Islands or the Japanese islands, form where a subduction zone forms between two oceanic crustal plates.

Click here to see how collision zones occur when two continents meet at a destructive plate margin, leading to major mountain ranges such as the Himalayas. The animation is in the form of a cross-section.

Click here (School Members only) for a further animation that shows the collision zone between India and Asia from a plan (map) view.

Click here (School Members only) to see how "foliated" metamorphic rocks can be formed at collision zones as a result of the intense pressure and heat.

Click here (School Members only) to see how transform faults form, such as those in California, Turkey or offset from the Mid-Atlantic Ridge. The animation includes maps of example locations.

Click here to see the creation of rock at constructive plate boundaries, and how the destruction of rock at subduction zones helps to complete the rock cycle.

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