Types of Faults and Folds

Types of Faults and Folds• Faults: when rocks break due to force.

– Normal FaultCaused by tension (pulling apart)

– Reverse FaultCaused by compression (pushing together)

– Strike-Slip FaultCaused by shear (lateral) forces (sideways)

• Folds: when rocks bend due to force.– Anticline

Caused by compressionFolded up like an "A"

– Syncline Caused by compression Folded down like a "U" - Monocline

- Caused by compression, a gently dipping bend.

Stress and Strain

• Stress is the applied force (The pushing and pulling on the rock layers).

• Strain is the bending & twisting that happens to the rock also known as deformation.

3 Types of Stress

• Compressional stress pushes matter (rock layers) together.

• Tensional stress pulls matter (rock and dirt layers) apart.

• Shear stress is rotational. The stress is parallel to a face of the material

Normal Fault Before After

Reverse FaultBefore After

Strike-Slip Fault Before After

FoldsAnticline

Syncline

Monocline