What is the relation of metamorphic rocks and the San Andreas fault?
Read several of these articles/sections of books:
http://www.google.com/search?hl=en&source=hp&q=metamorphic+rocks+and+the+San+Andreas+fault&aq=f&aqi=&oq=
The second one looks promising, but is undoubtedly not the only place you'll find information.
Metamorphic rocks and the San Andreas fault are related in the sense that the fault zone has played a role in the creation and deformation of metamorphic rocks along its path. Allow me to explain how this relationship emerges.
The San Andreas fault is a prominent geological feature in California, stretching approximately 750 miles (1,200 kilometers) and marking the boundary between the Pacific Plate and the North American Plate. It is a transform fault, where the two plates slide past each other horizontally. This sliding motion causes stress and strain along the fault zone, resulting in earthquakes.
Metamorphic rocks, on the other hand, are a type of rock that has undergone significant changes in texture, mineral composition, or both due to high temperature, pressure, or both, deep within the Earth's crust. These changes occur over long periods of time and usually at depths several kilometers below the surface.
The San Andreas fault acts as a conduit for the movement of immense tectonic forces. As the Pacific Plate and North American Plate grind against each other, tremendous pressure and heat are generated along the fault zone. This intense geologic activity manifests as the uplift, folding, and shearing of rocks in the vicinity of the fault.
Within the San Andreas fault zone, as rocks experience the immense pressure and heat exerted by the tectonic forces, they can undergo metamorphism. The high temperatures and pressures enable the minerals in the rocks to recrystallize and rearrange themselves into new structures. Consequently, new minerals may form, and the rock's texture and appearance change. This process is known as fault zone metamorphism.
The types of metamorphic rocks encountered in the San Andreas fault zone vary depending on the pre-existing rock types and the specific temperature and pressure conditions experienced during the faulting event. Common metamorphic rocks found in the vicinity of the fault zone include schist, gneiss, and marble, among others.
In summary, the San Andreas fault creates the conditions necessary for the formation of metamorphic rocks through fault zone metamorphism. The intense pressure and heat generated by the tectonic forces along the fault zone cause pre-existing rocks to undergo structural and mineralogical changes, ultimately leading to the formation of metamorphic rocks.