STRESSES, FOLDS AND FAULTS.pptx
- 2. STRESS the force applied to a rock that causes deformation
- 4. TENSION force that pulls on crust in opposite direction causes crust to stretch and become thin in middle
- 5. COMPRESSION force that pushes rock in together causes crust to rise
- 6. SHEAR force that pushes rock in 2 opposite directions causes masses of rock to break, slip, or change shape
- 7. FOLD a bend in rock that is the response to compressional forces. most visible in rocks that contain layering.
- 9. MONOCLINE involves a slight bend in otherwise parallel layers of rock. form by vertical movement and generally found fault below monocline
- 10. ANTICLINE a fold that arches upward. The rocks dip away from the center of the fold. The oldest rocks are found at the center. The youngest rocks are draped over them at the top of the structure Also called the “dome”.
- 11. SYNCLINE a fold where the rock layers are warped downward. Both anticlines and synclines are the result of compressional stress. the youngest rocks are at the center. The oldest rocks are at the outside edges. Also called the “basin”.
- 12. FAULT are cracks in the earth's crust where movement occurs on at least one side. are formed in the Earth's crust as brittle response to STRESS. Earthquakes occur along faults because of the sliding
- 14. PARTS OF A FAULT
- 15. TYPES OF FAULT Normal Fault Reverse Fault Strike-Slip Fault
- 17. NORMAL FAULT happen in areas where the rocks are pulling apart (tension stress) so that the rocky crust of an area is able to take up more space.
- 18. REVERSE FAULT the rocks are pushed together (compression stress), and the hanging wall moves upward along the fault relative to the footwall. This is literally the 'reverse' of a normal fault. Sometimes called “Thrust fault”
- 20. STRIKE – SLIP FAULT a fault on which the two blocks slide past one another caused by shearing stress.