The result is that the crust lengths as it is pulled apart. This generally results in the formation of a normal fault . The block resting on the fault drops downward. This can be seen by comparing rock units on either side of the fault. Of course, older fault scarps are gradually eroded.
Fault scarps can show vertical displacement of hundreds of meters.
Normal faults may extend over great linear stretches, such as the eastern front of the Sierra Nevada - over 400 miles long. Tension can produce multiple sets of normal faults, with alternating blocks of crust rising and falling relative to its neighbors. Uplifted blocks are called horsts , dropped blocks are called grabens . This is how the mountains ranges of the Basin and Range in Nevada were formed. Normal faulting, like all faulting, is accompanied by earthquakes or tremors.