Types of Folds

Anticline – upfolded, or arched, rock layers
Syncline – downfolded rock layers

Deformation – general term that refers to all changes in the original form and/or size of a rock body
Most crustal deformation occurs along plate margins

Factors that influence the strength of a rock
Temperature and confining pressure
Rock type
Time

Rocks bent into a series of waves
Most folds result from compressional forces which shorten and thicken the crust

Anticlines and synclines can be
Symmetrical – limbs are mirror images
Asymmetrical – limbs are not mirror images
Overturned – one limb is tilted beyond the vertical
Where folds die out they are said to be plunging