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Luke Wren Inglês 7 flashcards

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1How do metamorphic rocks form? By what system is this?Under heat or pressure or both.
Occurs in a solid state without melting. Usually without loss or addition of elements.
Isochemical (closed system)
2What is contact metamorphism? How would it occur?Low pressure high temperature.
By the flow of heat from an igneous intrusion.
3What is regional metamorphism? Where would it occur?High pressure and high temperature.
Deep within the crust during plate collisions.
4What is dynamic metamorphism? Where would it occur?Low temperature and high pressure.
Along major fault zones.
5Give two sources of heat.Internal heat from the mantle (geotherm 25-30° per km)
Igneous intrusion.
6Give two sources of pressure.Weight of overlying rocks (lithostatic pressure)
Horizontal movement of plates (lateral pressure)
7What factors affect the degree of metamorphism?-Temperature and pressure
-Original composition of rock
-Presence of pore fluids
(speeds up chemical reactions)
-Time
(very slow, 1mm per 1myr)