GEOL 1001 Chapter : Metamorphic Rocks
Document Summary
Transition of one rock into another by temperatures and or pressures unlike those in which it formed. Metamorphic rocks are produced from: igneous rocks, sedimentary rocks, other metamorphic rocks. Bonding of these atoms is dependent on most efficient way for them to combine, if unstable, metamorphism will allow it to change it"s atomic composition and become stable. Changes in heat, pressure, and the chemical environment of rocks can alter mineral compositions and crystalline textures. Metamorphic changes occur in the solid state, so there is no melting. Heat: most important agent, recrystallization results in new, stable minerals, two sources of heat, 1. Contact metamorphism heat from magma, rocks being changed due to close proximity to a magma chamber: 2. An increase in temperature with depth geothermal gradient. Pressure and differential stress: increases with depth, confining pressure applies forces equally in all directions, differential stress- unequal in different directions, usually caused by tectonic forces. Texture size, shape, and arrangement of mineral grains.
