EVSC 2800 Study Guide - Midterm Guide: Metamorphic Facies, Convergent Boundary, Thrust Fault

• School: University of Virginia
• Department: Environmental Sciences
• Course: EVSC 2800
• Professor: Mary Theresa Howard

Document Summary

Chemical composition unaltered, texture drastically different: heat, pressure, and fluid composition are the three principal factors that drive metamorphism. Heat can transform a rocks chemical composition, mineralogy, and texture by breaking chemical bonds and altering the existing crystal structures of the rock. When rock is moved from the earth"s surface to its interior, where temperatures are higher, the rock adjusts to the new temperature. Its atoms and ions recrystallize, linking up in new arrangements and creating new mineral assemblages. Pressure, like temp, changes a rocks chemical composition, mineralogy, and texture. Solid rock is subjected to two basic kinds of pressure, also called stress: Confining pressure is a force applied equally in all directions. Directed pressure or differential stress is force exerted in a particular direction (when you squeeze a ball of clay between your fingers) Fluids: metamorphic processes can alter a rock"s mineralogy by introducing or removing chemical components that are soluble in heated water.