The Results of Stress

Stress & Strain Stress: A force that causes pressure in the rocks of the Earth’s lithosphere 3 Types: Compression: Rocks squeezed Tension: Rocks pulled apart Shearing: Rocks twisted or bent Strain: Caused by stress, change in shape or volume of rocks

Folding Folding: Rock becomes permanently deformed without breaking (higher temperatures and pressures) Wave-like structures

Three Types of Folds: Anticline: upcurved fold

Three Types of Folds Syncline: Downcurved fold

Three Types of Folds Monocline: gently dipping bends

Examples: With large folds, anticlines form ridges, synclines form valleys

Faulting Rock breaks under stress (lower temperatures and pressures) Fracture: rock breaks, but there is no movement to either side of the break Fault: rock breaks and move past one another

Faulting Fault plane: the surface of a fault Hanging wall: the rocks above the fault plane Footwall: the rocks below the fault plane

Types of Faults Normal Fault: The fault plane is steep/vertical, the hanging wall moves down relative to the footwall Divergent boundaries

Types of Faults Reverse Fault: Steep/vertical fault plane, hanging wall moves up relative to footwall Convergent boundaries

Types of Faults Thrust Fault: A special type of reverse fault, fault plane at a low angle

Types of Faults Strike-Slip Fault: The rock on either side of the fault plane moves horizontally Transform fault boundaries