Geo 401 Exam 2 2023 with 100% correct answers

Metamorphic Rock - correct answer -mineralogy, texture and/or composition has changed due to pressure, temperature and/or fluids (and enough time) Metasomatic Rock - correct answer -A metamorphic rock whose whole bulk chemical composition was altered during interaction with fluids Role of Pressure - correct answer -a result of overlying weight and/or horizontally oriented forces developed as the rocks are deformed. Greater weight tends to decrease space available for mineral growth, so the metamorphic minerals created at high pressures tend to be more dense. Role of Temperatures - correct answer -As a rock is subjected to different temperatures, original minerals become unstable and react. New minerals form at the expense of old ones Geothermal gradient - correct answer -increase in temperature with increasing depth What is the average rate at which temperature increases with depth in the Earth's crust? - correct answer -30 degrees C/km Role of Fluids - correct answer -Act as a catalyst during metamorphism; aids the exchange of ions between growing crystals High Metamorphic grade - correct answer -high temperature and pressure; e.g., continental collisions in plate boundaries; Himalayas Low Metamorphic grade - correct answer -low temperature and pressure; e.g, within plates, burial pressure & temperature Pressure (P) - correct answer -linearly proportional to depth Confining Pressure - correct answer -pressure in all directions, analogous pressure under water; high confining pressures change mineral equilibria, and so change the mineral assemblage