Tectonic plates are giant slabs of Earth's lithosphere (the outer layer of the Earth ) that move in relation to each other. This movement can occur in one of three ways, toward one another (at convergent boundaries), away from one another (at divergent boundaries) or past one another (at transform boundaries). Please see this link for a related activity on convergent, divergent, and transform boundaries. Students should understand the content in the above activity ideally before this activity is competed. When the plates move in these ways, stress is placed on the rock. Stress in geological terms is the force applied to rock per unit area.
Three types of stress will be modeled in this activity:
- Compression
- Tension
- Shear stress
Key terms:
- Plate tectonics: The scientific theory that the Earth's crust is made up of plates that slowly shift position
- Deformation: Tilting, breaking and bending of rock
- Compression: Stress which causes rock to squeeze or push against other rock
- Tension: Stress which occurs when rock pulls apart or gets longer
- Shear Stress: Stress which occurs when tectonic plates move past each other causing rock to twist or change shape
- Fault: break in rock