Earth Sciences 1022A/B Lecture Notes - Lecture 7: Calcite, Phyllite, Mica
7 Dec 2015
School
Department
Course
Professor
Document Summary
Earth sciences 1022a lecture 7 metamorphic rocks. Heat: most important, drives chemical reactions and recrystallization of host rock o o. Geothermal gradient - going below the ground it gets hotter and hotter, and that"s from the residual heat from the mantle that is radiating. Pressure: increases with depth (confining pressure and directed pressure) o o. Confining - rock experiences pressure from all sides. Directed - pressure that is lined up coming from either direction (it changes the look of the rock, so the rock deforms and the new features that develop develop perpendicular) Chemical activity: ions in solution exchange with ions in minerals of the parent rock to form new minerals o o o. With chemical activity, that water is driven off. Largely related to heat but pressure as well. There are minerals that develop that are unique to metamorphic rock. Larger scale in the cores of mountains built by colliding plates. Most intense in the roots of mountain belts.
