1. METAMORPHIC ROCKS Rocks that form from other pre-existing rock (sedimentary, igneous, or metamorphic) that have been changed from high temperature and/or high pressure

2. Metamorphic Rocks

3. Metamorphic Rocks Formation

4. Conditions that cause rock to undergo metamorphism include: Heat - Under conditions of high temperature from magma contacting pre-existing rock. Pressure - Deep burial and pressure from mountain formation.

5. Types of Metamorphism 1. Contact Metamorphism 2. Regional Metamorphism

6. Contact Metamorphism  Deep burial and pressure from mountain formation.  The main metamorphic agent is heat.  Also forms when pre-existing rock comes into contact with molten lava or magma. The heat from the molten material is hot enough to cause the minerals in the original rock to re-crystallize, but not melt.

7. Regional Metamorphism  Covers large areas typically associated with mountains  Deep burial and pressure from mountain formation.  Heat and Pressure change the rock

8. Types of Metamorphic Rocks  Foliated: rocks with mineral crystals arranged in cable-like distorted layers/structures  Mineral Alignment  Banding  Animation: Foliation Animation: Foliation  Nonfoliated: rocks with recrystallized minerals; no layering  Recrystallization: This is the growth of new mineral crystals from other rocks.

9. TextureComposition Type of Metamorphism CommentRock Name Mica Regional (Heat and Pressure increase w/ depth) Low-Grade metamorphism of SHALE Mica, Quartz, Feldspar, Amphiboles, Garnet Foliation surfaces shiny from microscopic mica crystals Mica, Quartz, Feldspar, Amphiboles, Garnet, Pyroxene Platy mica crystals visible Mica, Quartz, Feldspar, Amphiboles, Garnet, Pyroxene Compact, may split easily FOLIATED MINERAL ALIGNMENT BAND- ING Scheme for Metamorphic Rock Identification Slate Phyllite Gneiss Schist

10. Progression of Metamorphism Start with a shale and then hit it with heat and pressure! Rock NameRock Type Grade of Metamorphism ShaleSedimentary----- SlateMetamorphicLow PhylliteMetamorphic Low/Intermediate SchistMetamorphic Intermediate/High GneissMetamorphicHigh Molten Rock Cools into Igneous Rock ----- More Heat & Pressure

11. Shale (Sedimentary Rock) Slate (Metamorphic Rock) Heat & Pressure

12. Slate (Metamorphic Rock) Heat & Pressure Phyllite (Metamorphic Rock)

13. Phyllite (Metamorphic Rock) Schist (Metamorphic Rock) Heat & Pressure

14. With even more heat & pressure (High-Grade Metamorphism) … you end up with something that is really Gneiss!

15. Scheme for Metamorphic Rock Identification TextureComposition Type of Metamorphism CommentRock Name Variable Contact (Heat) Various rocks changed by nearby magma/lava Quartz Metamorphism of Quartz Calcite and/or Dolomite Metamorphism of Various minerals in particles and matrix Pebbles may be distorted or stretched NONFOLIATED Regional (Heat & Pressure) Sandstone Limestone or Dolostone Hornfels Quartzite Marble Metaconglomerate

16.  ESRT p. 7  Animation: Metamorphic Rock Scheme Animation: Metamorphic Rock Scheme

17. Where are metamorphic rocks found?  At the interface between igneous and sedimentary rocks Mountainous regions

18. THE ROCK CYCLE How are rocks classified?

19.  By their origin (the way they are formed)

20. Major Rock Groups  Sedimentary  Formed at the Earth’s surface  Clastic (Mineral Fragments or grains, clays)  Crystalline (chemical precipitates and evaporites)  Bioclastic (formed organically from shells or plants)  Igneous  Formed from magma (molten rock)  Plutonic (intrusive):slow cooling, coarse/very coarse crystals  Volcanic (extrusion): quick cooling at the surface, glassy/fine crystals  Metamorphic  Changed by heat and pressure

21. Rock Cycle Conclusion

22. Fig. 2.9 MAGMA

23. Solidification IGNEOUS

24. MAGMA IGNEOUS Plutonic Solidification

25. MAGMA Volcanic IGNEOUS Plutonic Solidification

26. MAGMA Volcanic IGNEOUS Plutonic Uplift Solidification Weathering & Erosion

27. MAGMA Volcanic IGNEOUS Plutonic SEDIMENT Solidification Weathering & Erosion SEDIMENT

28. MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY Solidification Weathering & Erosion Erosion Transport Deposition

29. MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY Solidification Weathering & Erosion Deposition Burial/Compaction Cementation

30. MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY METAMORPHIC Increased P&T Solidification Weathering & Erosion Deposition Burial/Compaction Cementation

31. MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY METAMORPHIC Increased P&T Melting Solidification Weathering & Erosion Deposition Burial/Compaction Cementation Can you see any shortcuts?

32. MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY METAMORPHIC Increased P&T Melting Solidification Weathering & Erosion Deposition Burial/Compaction Cementation

33. MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY METAMORPHIC Increased P&T Melting Solidification Weathering & Erosion Deposition Burial/Compaction Cementation

34. Citations  Slide 6 (Progression of Metamorphism of Shale) http://physics.uwstout.edu/geo/_derived/sect4.htm_txt_sect4.2.gif  Slide 10  Shale: http://library.thinkquest.org/06aug/02459/rocks/sedimentary/Shale.jpg  Slate: http://www.global-b2b-network.com/direct/dbimage/10260661/Grey_Slate.jpg  Slide 11:  Phyllite: http://www.bedford.k12.ny.us/flhs/science/geoscience/images/phyllite.jpg  Slide 12:  Schist (1) http://www.randall.k12.wi.us/rocks/images/schist-with-garnet.jpg  Schist (2) http://www.es.ucl.ac.uk/schools/Glossary/schist.jpg  Slide 13:  Gneiss (1) http://hyperphysics.phy-astr.gsu.edu/hbase/geophys/geopic/gneiss2.jpg  Gneiss (2) http://www.cropsoil.uga.edu/soilsandhydrology/images/Gneiss.jpg  Gneiss (3) http://upload.wikimedia.org/wikipedia/commons/6/60/Gneiss.jpg  Slide 16:  8/16/2006 Physical Setting Regents Earth Science Exam p. 18  Slide 17:  Earth Science Reference Tables p. 6