2. Rock Deformation

3. rock deforms (changes shape) because of stress put on the rock stress is a force that acts on a body (rock in this case) differential stress is a force which is not equal in all directions when a rock is stressed differentially it can undergo 3 stages of deformation: elastic, plastic, rupture  elastic: returns to original shape if the stress is removed  plastic: when stress is beyond the return point and the rocks does not return to original shape - folding  rupture: stress is so great that the rock breaks - faulting

4. different rocks behave differently depending upon the chemistry of the rock - different minerals, and especially crystal structure rocks generally fit into 2 categories with respect to deformation: brittle and ductile brittle rocks rupture before any plastic deformation occurs ductile rocks have a large range of plastic deformation between elastic deformation and the rupture point generally speaking, more crystalline rocks have a greater rupture strength, that is, they resist rupturing longer but have little plasticity

5. stress deformation elastic deformation rupture point Brittle Rock As stress increases so does deformation. If the stress is removed, the rock will return to its original shape unless it reaches the …. The rock is faulted.

6. stress deformation stress deformation elastic deformation rupture point elastic deformation plastic deformation rupture point Brittle Rock The rock is folded irreversibly during plastic deformation. Eventually,the stress leads to... faulting Ductile Rock