Transcript Chapter 5 Deformation of the Crust

Chapter 5
Deformation of the Crust
5.1
How is the crust deformed?
Deformation the bending, tilting, and
breaking of the earth’s crust
Turn to text page 83
Isostatic adjustment
Isostasy – the balance between
the forces of the crust pressing
down on the mantle, and the
mantle pressing up on the crust
Isostatic adjustments cause the
crust to bend up and down
Why do isostatic adjustments constantly occur in areas with mountain ranges?
Mountain ranges erode.
As the crust lightens, area rises
Rivers can carry large amounts of mud, sand, and gravel.
Glaciers melt, so crust rises
Stress
Stress – force that causes pressure in the rocks of the crust
Compression
Rocks are squeezed together
Tension
Force that pulls rocks apart
Shearing
Push rocks in opposite directions
Turn to text page 84
Identify the stress forces on the rocks below...
Identify the stress forces on the rocks below...
Shearing
Identify the stress forces on the rocks below...
Tension
Shearing
Identify the stress forces on the rocks below...
Tension
Shearing
Tension
Identify the stress forces on the rocks below...
Tension
Shearing
Tension
Compression