Ch08_Outline

Ch08_Outline - Chapter 8 Metamorphism and Metamorphic Rocks...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Chapter 8 Metamorphism and Metamorphic Rocks Metamorphism ± The 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 Metamorphism ± Metamorphism progresses incrementally from low-grade to high-grade ± During metamorphism the rock must remain essentially solid ± Metamorphic settings Contact or thermal metamorphism –driven by a rise in temperature within the host rock
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Metamorphism ± Metamorphic settings Hydrothermal metamorphism –chemical alterations from hot, ion-rich water Regional metamorphism Occurs during mountain building Produces the greatest volume of metamorphic rock Rocks usually display zones of contact and/or hydrothermal metamorphism Agents of metamorphism ± Heat Most important agent Recrystallization results in new, stable minerals Two sources of heat Contact metamorphism – heat from magma An increase in temperature with depth due to the geothermal gradient Agents of metamorphism ± Pressure and differential stress Increases with depth Confining pressure applies forces equally in all directions Rocks may also be subjected to differential stress which is unequal in different directions
Background image of page 2
3 Pressure in metamorphism Figure 8.4 Agents of metamorphism ± Chemically active fluids Mainly water with other volatile components Enhances migration of ions Aids in recrystallization of existing minerals Agents of metamorphism ± Chemically active fluids Sources of fluids Pore spaces of sedimentary rocks Fractures in igneous rocks Hydrated minerals such as clays and micas
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Agents of metamorphism ± The importance of parent rock Most metamorphic rocks have the same overall chemical composition as the parent rock from which they formed Mineral makeup determines, to a large extent, the degree to which each metamorphic agent will cause change Metamorphic textures
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/17/2008 for the course GS 121 taught by Professor Leavell during the Fall '07 term at Ohio State.

Page1 / 15

Ch08_Outline - Chapter 8 Metamorphism and Metamorphic Rocks...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online