Deforming the Earth’s Crust

Deforming the Earth’s Crust

DeformationDeformationThis is the process where the shape of rocks change.

Caused by:

Compression- Objects are squeezed; when 2 plates collide

Tension- Objects are stretched; Occurs at divergent plate boundaries.

FaultingFaulting

Faults are cracks in the Earth’s crust.

Each side of the fault are called fault blocks.

They are named either a hanging wall or a footwall.

Hanging WallHanging Wall

Foot WallFoot Wall

Normal FaultsNormal Faults

A normal fault occurs when the hanging wall moves down relative to the footwall.

Normally occurs when tectonic forces cause tension that pulls rocks apart.

Normal FaultNormal Fault

Reverse FaultsReverse FaultsReverse faults causes the hanging wall to move up relative to the footwall.

These normally occur when tectonic plates cause compression that push rocks together.

Reverse FaultReverse Fault

Strike Slip FaultsStrike Slip Faults

Here the rocks break and move horizontally past one another.

The San Andreas Fault is a great example of this.

Strike Slip FaultStrike Slip Fault