What is the effect of applying stress over a long period of time to rock?

When stress is applied to rock over an extended period, the rock is more likely to undergo deformation in a ductile manner rather than a brittle manner. Ductile behavior refers to the ability of the material to bend and deform without fracturing, which typically occurs under prolonged stress, allowing for gradual changes in shape.

In geological terms, this means that when rocks experience continuous forces, they do not break or shatter immediately but instead can flow or change shape over time, especially when influenced by factors such as temperature and pressure. This is particularly relevant in environments like tectonic boundaries where rocks may be subjected to significant stress for long durations, leading to mountain-building processes or the formation of folds in sedimentary layers.

In contrast, brittle behavior usually occurs under high stress over a short time or when the material reaches its elastic limit. Immediate fracturing is associated with sudden stress application, making ductility the prevailing behavior when stress is applied gradually over long periods.