EAS210 Lecture Notes - Lecture 4: Metamorphic Rock, Continental Crust, Arenite
5 Dec 2018
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Chapter 7, p. 162-182 earth: an introduction to physical geology 4ce. Definition:- metamorphic rocks are pre-existing rocks of any type that. Dr. clark undergo recrystallization without melting in response to changed physical conditions; the mineralogical and textural changes are stable at the new conditions: mineralogy the mineralogy of a metamorphic rock reflects three principal factors, namely, original mineralogy. ; this is higher grade than slate, but still low grade: schist - grain size continues to increase, with larger micas growing, so that the rock splits or even crumbles along very irregular surfaces. Also develops at first in low grade metamorphism, but eventually something appears: various porphyroblast minerals appear, embedded in biotite or muscovite matrix , characterizing medium grade metamorphism. Given that appearance/disappearance of minerals in response to changing conditions is neither isothermal nor isobaric, individual minerals occupy stability fields in a p-t diagram. We also note skarn; process described: with silicate fluids flushing carbonate country rocks.
