Chapter: Formation of Mountain Ranges

Events on the Plate Borders

1. Divergent boundaries

This means that two plates are moving away from each other through the pressure of a growing rift. Here you can see how such a rift is formed.

2. Horizontal displacement/Transform Boundaries

This is an aerial photo of a horizontal displacement caused by an earthquake near Las Vegas. You will certainly understand what happened here after you have taken a closer look at the following two graphics.

3. Convergent boundaries

a) Chile-type: This graphic shows you with the example of the Chile-type how oceanic crust is subducted (pushed) underneath the continental crust. Here this happens with a relatively fast movement.

b) Mariana-type:

The movement here is quite slow, the crust is subducted at a steeper angle, a deep-sea trench forms and the continent is retreating. In this process islands are formed between retreating continent and deep-sea trench.

The types also indicate where these phenomena can best be observed.