What are the typical minerals formed as a result of contact metamorphism?
Typical minerals formed as a result of contact metamorphism include hornblende, garnet, wollastonite, andalusite, and biotite. These minerals are formed due to the high temperature and low-pressure conditions associated with igneous intrusions.
What are the main differences between contact metamorphism and regional metamorphism?
Contact metamorphism occurs when rock is heated by proximity to magma or lava, affecting a localized area, while regional metamorphism results from large-scale tectonic pressures and temperatures that affect extensive areas. Contact metamorphism often produces non-foliated rocks, whereas regional metamorphism typically leads to foliated rocks.
How does contact metamorphism affect the surrounding rock structures?
Contact metamorphism affects surrounding rock structures by causing changes in mineral composition and texture due to high temperatures from nearby magma intrusions. This localized heat alters the rock, forming non-foliated metamorphic rocks like hornfels, without the pressure-induced foliation seen in regional metamorphism.
What factors influence the intensity of contact metamorphism?
The intensity of contact metamorphism is influenced by the temperature of the adjacent magma, the duration of heat exposure, the composition of the original rock, and the presence of fluids. These factors determine the degree of mineralogical and textural changes in the affected rocks.
What are some real-world examples of contact metamorphism?
Real-world examples of contact metamorphism include the formation of hornfels around the edges of igneous intrusions, such as the contact zones of granite intrusions in Scotland, the metamorphosed limestone known as marble in the Carrara region of Italy, and the aureoles around the Palisades Sill in New York and New Jersey.