Types of stress
Tension: pulls rock apart
Compression: squeezes rock together
Shear: forces act parallel to each other, but in opposite directions

Types of deformation:
elastic: rock returns to original shape after stress is removed
plastic: rock changes shape permanently
brittle: rock fractures

Type of deformation depends on:

• temperature
• timing
• type and amount of stress
• rock type
• pressure

syncline: opens upwards
anticline: opens downwards
Most folds are plunging (their axis is not horizontal)
 

Fractures: brittle deformation of rocks
joints: fractures with no movement
faults: fracture with movement

Normal fault: hanging wall moves down.
due to tension

Reverse faults: hanging wall moves up. Due to compression.
Thrust faults are low-angle reverse faults.

Strike-slip faults: blocks move horizontally past one another
Right lateral: movement is to the right
Left lateral: movement is to the left

How mountains form:
1. Compression 2. Tension 3. Erosion around plutons 4. Volcanism