Deformation & Mountain Building

These flashcards cover key terms related to rock deformation and mountain building processes.

Deformation

Change in a rock’s position, shape, and/or volume from the application of stress.

Foliation

The alignment of mineral grains in a metamorphic rock due to pressure.

Stress

Forces acting on the surface of a material.

Strain

Measure of a rock’s change in shape or volume as a result of applied stress.

Tensional Stress

Forces that act outward on rock, causing it to become longer and thinner.

Compressional Stress

Forces that act inward on rock, causing it to become shorter and thicker.

Shear Stress

Forces that act parallel and opposite on different rock faces, causing tilting.

Elastic Deformation

Temporary change in position, shape, or volume that returns to original shape once stress is removed.

Plastic (Ductile) Deformation

Permanent bending, flowing, and smearing of rock when subjected to stress.

Brittle Deformation

Breakage of rock under stress that does not return to original shape.

Anticline

A type of fold where layers of rock are arching upward, with the oldest layers at the core.

Syncline

A type of fold where layers of rock flex downward, with the youngest layers at the core.

Orogeny

The process of mountain building by tectonic forces.

Hot Spots

Geological locations where plumes of hot material rise from the mantle, potentially creating volcanoes.

Subduction

The process where one tectonic plate moves under another and sinks into the mantle.

Terrane

A fragment of crustal material that has a different geology than the surrounding area.

Suture

The boundary between formerly separated continental plates due to collision.

Fault

A fracture in rock along which movement has occurred.