Question

Where does brittle deformation generally occur, and where does ductile deformation happen?

A) Brittle: Deep beneath the surface, Ductile: Near the surface
B) Brittle: Near the surface, Ductile: Deep beneath the surface
C) Brittle: High pressure and heat, Ductile: Low pressure and heat
D) Brittle: Low pressure and heat, Ductile: High pressure and heat

Answer 1

Brittle deformation occurs near the Earth's surface, while ductile deformation happens deep beneath the surface. The high conditions of pressure and temperature at depth facilitate the ability of rocks to change shape in a plastic manner without fracturing.

Step-by-step explanation:

Brittle deformation generally occurs near the Earth's surface, where pressure and temperature conditions are relatively low, causing rocks to fracture and break. Conversely, deep beneath the surface, under high temperature and pressure conditions, rocks tend to undergo ductile deformation; they bend and flow rather than break. This ductile behavior is facilitated by the capacity of rocks to recrystallize and change shape without fracturing, a process associated with deeper geologic environments, such as the asthenosphere or regions undergoing metamorphism in subduction zones.

The correct answer to the question is Brittle: Near the surface, Ductile: Deep beneath the surface, which corresponds to option B. The question lies within the realm of geological processes, specifically regarding how rocks deform under different pressure and temperature conditions, which is critical in understanding the geodynamics of Earth's crust and mantle.