geo

Stress

The force applied to a rock.

Strain

The rock's response to stress (change in shape or volume).

Compression

Squeezing stress.

Tension

Pulling apart stress.

Shear

Stress that causes rocks to slide past each other.

Elastic Deformation

Temporary deformation; rock returns to original shape.

Ductile Deformation

Permanent bending or flowing.

Brittle Deformation

Permanent breaking or fracturing.

What determines if a rock will deform ductile or brittle?

Temperature, Pressure, Rate of Stress.

Anticline

Upward arching fold.

Syncline

Downward trough-like fold.

Tight Fold

Fold with a small angle between limbs.

Overturned Fold

One limb is tilted beyond vertical.

Recumbent Fold

Fold is lying on its side; horizontal orientation.

Fault

Breaks in rock where movement has occurred, caused by brittle deformation.

Hanging Wall

Rock above the fault plane.

Footwall

Rock below the fault plane.

Strike-Slip Fault

Horizontal movement caused by shear stress; found at transform boundaries.

Reverse Fault

Hanging wall moves up caused by compression; found at convergent boundaries.

Normal Fault

Hanging wall moves down caused by tension; found at divergent boundaries.

Horst

Block of rock uplifted between normal faults.

Rift Valley

Block of rock that sinks between normal faults.

Orogeny

Formation of mountains through tectonic processes.

Convergent: Oceanic-Continental

Forms volcanic mountains; example: Andes Mountains.

Convergent: Oceanic-Oceanic

Forms volcanic island arcs; examples: Japan, Aleutian Islands.

Convergent: Continental-Continental

Forms non-volcanic mountains; example: Himalayas.

Divergent

Forms fault-block mountains; example: Basin and Range Province, Western U.S.

Isostasy

The balance between Earth's crust and mantle.

How does the crust interact with the mantle in isostasy?

The crust 'floats' on the denser mantle like an iceberg in water.