ESCI 1001 Lecture Notes - Lecture 5: Phanerozoic, Mass Spectrometry, Hadean
Document Summary
The process by which heat, pressure, chemical reactions in earth change the mineral composition and/or rock structure without melting it. Rocks are transforming from one state to another (not melting) Directed is smushed together and changes space during compression. Degree of temperature and pressure a rock is exposed to during metamorphism. Increasing p & t = low grade intermediate grade high grade. During progressive metamorphism: a shale/mudstone becomes a slate (low grade) Slate breaks into pieces naturally (used on rooftops: a slate becomes a schist (medium grade) If you see big minerals in the rock surface, it"s probably a schist: a schist becomes a gneiss (high grade) Bands in the rock/zones/bedding structures (not sedimentary rocks- these are heavier: partial melting metamorphism can no longer continue (very high grade) Eclogite = very high pressure- low temperature metamorphic rock. Blueschist = high pressure low temperature metamorphic rock.
