The San Andreas Fault is the most striking physical feature to traverse California. Berkeley's stadium was built on the the Hayward Fault.
Cracks show the effects of earthquakes.
As the rock on both sides of the tectonic lines is very resistant, the major part of this movement is held back for a long period of time and is, instead, conserved in the form of elastic tension. Once the limit of elastic tension is surpassed, this form of energy, conserved for decades, is released in the form of a tectonic earthquake. This dextral movement began about 20 - 30 million years ago, after the Pacific Plate had come into contact with the North American Plate. As a result of the constant subduction of the Farallon Plate, a deep rift was formed which was filled up with eroded sediments from the eastern continent over a period of several million of years. This way the mainland was extended in a westerly direction.