Chapter 10, Problem 1GST

To determine

The environment within the Earth in which the rocks to experience ductile deformation can be located and the scenario in which brittle rather than ductile deformation might occur.

Answer to Problem 1GST

The shallow depths or near-surface areas are the environment within the Earth in which the rocks to experience ductile deformation and the brittle rather than ductile deformation could be seen in the areas of deeper depths in the Earth’s crust.

Explanation of Solution

A rock body undergoes various geological processes during a long span of geologic time. The physical changes that occur in a rock body are collectively called as deformation.

Brittle deformation happens when a rock body exceeds its strength to deform elastically, and it breaks into small pieces like glass objects, ceramic plates. It mainly occurs when a material loses its ability to hold together due to the breakage of chemical bonds by stress.

Ductile deformation happens when a rock body or any material changes their shape without any breakage or fracture. Clayey materials are deformed in a ductile manner. Ductile deformation enables the materials to remain in solid state; folds are the examples of ductile deformation.

The brittle deformation normally occurs at shallow depths and the ductile deformation occurs at greater depths. The four factors that influence the deformation of rocks are temperature, confining pressure, rock type and time.