What type of geological structure results from cracks in the Earth's crust?

Cracks in the Earth's crust create faults, which are fractures along which movement has occurred. When stress builds up in the Earth's crust due to tectonic forces, it can exceed the strength of the rocks, causing them to break. This results in a fault line, where the rocks on either side of the crack can move relative to one another. Faults can vary greatly in size and can lead to significant geological events, such as earthquakes, when they slip.

In contrast, mountains typically form due to the folding and uplift of the Earth's crust rather than from cracks. Basins are depressions that may accumulate sediment, while plains are generally flat, expansive areas and do not directly result from the presence of cracks. Therefore, the development of faults is the direct geological consequence of the cracks resulting from the stresses in the Earth's crust.