ESCI 1101 Lecture Notes - Lecture 6: Phyllite, Source Rock, Kyanite
Document Summary
Rock metamorphism: the process of changing the characteristics of a rock by changes in pressure and temperature not changing rock composition. No melting, but fluids (h2o) can be important in the pore space. Rocks formed at or near the surface are not in equilibrium at depth. Metamorphic grade: the combination of pressure and temp. Low grade: less than or equal to 10km lower pressure, lower temperature. High grade: greater than or equal to 20km higher pressure, higher temperature. Facilitates mineral growth by easing movement of ions. When water moves through the system, composition can change. Metasomatism: change in the composition of a rock as the result of the introduction or removal of chemical constituents. Produces important resources (sulfides, ore bodies, origin of life) Based on minerals textures and source rock (protolith) Foliation: sets of flat or wavy parallel planes in rock. Formed by alignment of platy minerals (micas and clay) Slaty cleavage: planes along which rock easily cleaves.
