Chapter 7a Structural Geology: Stress & Strain

Question 1

What is Stress & Strain?

Answer 1

Stress = Force per unit area acting on a solid
Strain = any change in shape or volume of a body that is a result of a stress

Question 2

What are the 4 Earth Forces that contribute to stress and strain?

Answer 2

1. Body
2. Surface
3. Pressure
4. Viscous

Question 3

Construct the Anderson Classification of tectonic regimes & Discuss the in-situ stress magnitude order for each tectonic regimes

Answer 3

Tectonic regimes are defined in terms of the relationship between :
- vertical stress (Sv)
- 2 mutually perpendicular horizontal stresses (SHmax, Shmin)

1. Normal Fault
   - Sv > SHmax > Shmin
2. Reverse Fault
   - SHmax > Shmin >sV
3. Strike-slip Fault
   - SHmax > Sv > Shmin