Faults

Faults in the Earth surface are of three basic types:

• strike/slip- top picture, also known as a transform plate boundary, the slabs of the crust slide past one another in the horizontal plane.
• reverse/thrust - top right picture, the hanging wall is forced up and over the footwall. In a reverse fault the dip angle is > 45 degrees, a thrust fault dip angle < 45 degrees, compressional stress.
• normal- bottom left picture, hanging wall drops below footwall, dip angle about 60 degrees, tensional stress.