Final answer:
Differential stress on a rock means the stress is unevenly distributed, leading to deformation such as folding or fracturing.
The type of deformation depends on factors like the rock type and environmental conditions. This concept is essential for interpreting geological structures.
Step-by-step explanation:
When a rock is subjected to differential stress, it means that the stress applied to the rock is not equal in all directions.
This can lead to various types of deformation, depending on the kind of differential stress acting on the rock. The three main types of stress are compression, tension, and shear.
Compression stress pushes rocks together, tension stress pulls them apart, and shear stress results in rocks sliding past one another horizontally.
Under differential stress, rocks first undergo elastic deformation, where they can return to their original shape upon removal of stress.
Once the rock's elastic limit is exceeded, it will experience either plastic deformation, resulting in bending and folding, or brittle deformation, leading to fracturing. This behavior is influenced by factors such as the type of rock, depth, and the environmental conditions of pressure and temperature.
Understanding the response of rocks to differential stress is crucial for interpreting geological features like folds and faults, and can provide insights into the history and dynamics of Earth's crust.