Metamorphic Rocks ( Definition - Classification - Common Rocks )

presented for Dr | Magdy Basta
Faculty of petroleum and mining engineering, Suez University
Physical Geology Course ( 2016 - 2017 )
presented by : G7 - Members

1. METAMORPHIC ROCKS G7-MEMBERS Suez University Faculty Of Petroleum & Mining Engineering Petroleum Engineering Depatment

2. Definition & Formation They are formed in the solid state as in response to pressure, temperature and chemical active fluids. They are formed within the earth crust below the zone of weathering and cementation ,however above the zone of re-melting. The process of forming metamorphic rocks is called metamorphism .

3. Metamorphism (from the Greek words for “ changing form ”) is the process by which rising temperature and changes in other environmental conditions transforms rocks and minerals. Metamorphism can change any type of parent rock : sedimentary, igneous, or even another metamorphic rock . The acting agents of metamorphism are; heat, pressure and chemically active fluid.

4. Heat Heat increases with depth. It is the most important factor in metamorphism. Metamorphism can take place at temperatures between ( 150 : 800 ) C

5. Pressure Pressure increases with depth. At about 40,000 psi rocks become plastic. Confining pressure : reduces the space between the grains leading to re-crystallization and forming anew mineral with a closer atomic packing. Differential pressure : simply causes shear stresses resulting in movement in the planes of the material and re-orientation of grains.

6. Chemically active fluids Water with its dissolvent is the most active of chemical agents.

7. Metamorphic Changes Metamorphism commonly alters both the texture and mineral content of a rock.

8. TEXTURAL CHANGES As a rock undergoes metamorphism , some mineral grains grow larger and others shrink. The shapes of the grains may also change . Fossils give this limestone its fossiliferous texture. (Marble)Metamorphism has destroyed the fossiliferous texture of the limestone

9. Texture In Metamorphic Rocks Which Deals with the arrangements of grains . In metamorphic rocks , we have just two types.

10. Texture In Metamorphic Rocks

11. Types Of Foliated Rocks Is Based upon the coarseness or fineness of the foliation & the thicknes s

12. Composition Of metamorphic Rocks

13. GRADE OF METAMORPHISM Pressure increases (Force acting upon the rock) Temperature Increases

14. 1 ) CONTACT METAMORPHISM occurs where hot magma intrudes cooler country rock. The country rock may be of any type sedimentary , metamorphic, or igneous. The highest-grade metamorphic rocks form at the contact, closest to the magma. Lower-grade rocks develop farther out. Contact metamorphism commonly occurs without deformation . As a result, the metamorphic minerals grow with random orientations.

15. 2 ) Regional Metamorphism Develops over extensive area. It is associated with the building of some mountain ranges. Many new minerals are developed in response to high pressure and temperature.

16. Important Metamorphic Rocks Slate Phyllite Schist Gneiss Marble Hornfels Quartzite

17. Slate Low grade metamorphism of Shale. Finegrained Caused By Regional Me tamorphism . Composed mostly of colorless Mica and Small amounts of chloride of different colors

18. Phyllite Higher grade metamorphism of Shale. Caused By Regional Me tamorphism . Composed mostly of Muscovite and Chlorite. Formed between [ 250 – 300 ] C

19. Schist Intermediate grade metamorphism. Caused By Regional Me tamorphism . Composed of clearly visible flakes of Mica, Talc, Chlorite and Hematite.

20. Gneiss high grade metamorphism. Caused By Regional Me tamorphism . Composed of Granite, Diorite.

21. Marble Caused By Regional Metamorphism of Limestone and dolomite. (more often) Or caused by contact Metamorphism of Calcite Or dolomite.

22. Quartzite Any grade metamorphism . The metamorphic product of quartz-rich sandstone. Mostly white color.

23. Question : What is The Difference Between …? Gneiss Quartzite Metamorphic Rock (comes from shale) Metamorphic Rock (Comes from Sandstone) Un-Foliated Foliated high grade metamorphism. Any grade metamorphism

24. Question : What is The Difference Between …? Sandstone Quartzite Sedimentary Rock Metamorphic Rock Quartz Quartzite Mineral Metamorphic Rock

25. Question : What is The Difference Between …? limestone Marble Sedimentary Rock Metamorphic Rock Calcite Marble Mineral Metamorphic Rock

26. Question : What is The Difference Between …? Phyllite Slate High-Grade Metamorphism Of Shale Low-Grade Metamorphism Of Shale

27. Rock Cycle Magma Igneous rocks sediments Sedimentary Rocks Metamorphic Rocks Heating Cooling Weathering Pressure+Heat Pressure + Cementation Erosion Erosion Heat+Pressure

28. G7-MEMBERS محمد خالد وهبة محمد ممدوح محمود محمود جميل عبدالفتاح بيومي حمدي أحمد