What is the process by which rocks change shape under stress?

The process by which rocks change shape under stress is known as "deformation." Deformation occurs in response to applied forces, and it can lead to various changes in the rock's shape or structure. There are three main types of deformation:

1.Elastic Deformation:

Rocks initially undergo elastic deformation when subjected to stress.

In this stage, the rocks deform temporarily but return to their original shape once the stress is removed.

This is similar to stretching a rubber band and having it return to its original form when released.

2. Plastic Deformation:

If the stress applied exceeds the elastic limit of the rock, it enters the plastic deformation phase.

During plastic deformation, rocks undergo permanent changes in shape without fracturing.

This process involves the rearrangement of mineral grains within the rock.

3. Brittle Deformation:

When stress continues to increase and exceeds the rock's strength, it may undergo brittle deformation.

This involves the actual breaking or fracturing of the rock, leading to the formation of faults and fractures.

Earthquakes often result from the release of accumulated stress during brittle deformation.

Factors influencing the type of deformation include the type of rock, temperature, pressure, and the rate of applied stress. Rocks subjected to high temperatures and pressures, such as those found deep within the Earth, are more likely to undergo plastic deformation. Additionally, the geological setting and tectonic forces in an area play a crucial role in shaping the deformation characteristics of rocks.