Strain (mechanics)

Episode 7 of Structural Geology delves into the concept of strain. Building upon our understanding of stress, faults, folds, and joints, we will explore how rocks deform in response to applied forces. We will differentiate between different types of strain, including elastic, plastic, and brittle deformation. This episode will also cover how strain is measured and represented, and its relationship to stress. Understanding strain is crucial for interpreting geological structures and understanding the tectonic history of an area.

Check your understanding

These are the same multiple-choice questions you will see in the Quiz section after you listen to the episode. Use them here to preview or review the answers.

Strain is defined as:

  1. The force acting on a rock
  2. The resistance of a rock to deformation
  3. The deformation of a rock caused by stress
  4. The temperature of a rock

Which type of deformation is permanent?

  1. Elastic
  2. Plastic
  3. Brittle
  4. Both plastic and brittle

Brittle deformation results in:

  1. Folding
  2. Faulting and jointing
  3. Elastic stretching
  4. No change in shape

Engineering strain is a measure of:

  1. Change in angle
  2. Change in length
  3. Change in volume
  4. Change in temperature

What do strain ellipses or ellipsoids represent?

  1. The stress field
  2. The temperature field
  3. The deformation of a rock body
  4. The chemical composition of a rock

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