How Is Quartzite Formed?

Parent Rock

• The name of quartzite̵7;s parent rock is sandstone. When the quartz-filled sandstone transforms and recrystallizes, quartzite is the result. The higher the quartz content in sandstone, the purer the quartzite will be after it transforms into a new state.

Transformation

• Rocks undergo a process the Idaho Museum of Natural History calls the ̶0;rock cycle.̶1; The rock cycle is a ̶0;model that describes the formation, breakdown and reformation of a rock as a result of sedimentary, igneous and metamorphic processes.̶1; Quartzite forms during a metamorphic process when sandstone undergoes heat and pressure.

Controlling Forces

• Pressure and temperature changes impact the stability of the sandstone̵7;s quartz. The processes that create the necessary changes transform sandstone into quartzite. Professor Stephen Nelson of Tulane University identifies these processes as cataclastic, burial and contact metamorphism.

Metamorphism

• Cataclastic metamorphism occurs when ̶0;two bodies of rock slide past one another along a fault zone.̶1; Burial metamorphism takes place when ̶0;sedimentary rocks are buried to depths of several hundred meters̶1; causing high temperatures, even in the ̶0;absence of differential stress.̶1; Contact metamorphism occurs when hot magma makes contact with the sandstone.

  One or more of these processes create the conditions necessary for the transformation of sandstone̵7;s quartz into quartzite.

Time

• Professor Nelson shares that metamorphism is an ̶0;extremely slow process.̶1; The key chemical reactions behind the recrystallization of sandstone̵7;s quartz may span millions of years.