Are flat lying sedimentary and volcanic rocks are often bent into a series of wave like undulations. Two most common folds are anticlines and syncline. Anticline is formed by upfolding or rock layers and syncline is the limb on the anticline.

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Force and stress

Stress is the amount of porce applied on a single area, types of stress

- differential stress: is unequally applied in different directions

- tensional stress: it tends to elongate or pull appart a rock

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Strain an irreversible change in the shape and size of a rock body when stress is caused.

temperature and confining brittle failure or deformation is when a rock close to the surface where there are low presures and temperatures fracture after exceeding their strength.

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Joints are fractures along which no appreciable displacement has occured

- two types of joints, columnar rorm wheningneous rocks cool and develop shrinkage

- most joints are produced when rocks in the outermost crust are deformed many rocks are roken by two or three sets of intersecting joints.

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