MetamorphicRocks-1

PRE-LAB QUESTIONS 1. Where might you find regional metamorphic rocks being formed today? (Select all that apply.) A . In the core of the Himalayas B. Adjacent to a lava flow C. Near a deep, large igneous intrusion D. In a shallow fault zone E. None of the above 2. Match the following foliated rocks with their metamorphic grade: A. Schist 1. Highest grade B. Slate 2. Second-highest grade C. Gneiss 3. Second-lowest grade D. Phyllite 4. Lowest grade 3. The parent material of a metamorphic rock is known as the __protolilth_____. 4. True or False? Regional metamorphism is a localized event. false 5. What are the three types of metamorphism? Regional (dynamothermal) Contact (Thermal) Dynamic v. SU22

DATA SHEET Table 3. Metamorphic Rock Identification Rock Sample Foliated (Yes/No) Grain Size Other Textural Features Composition Rock Name Protolith M yes medium hard quartz schist Mudstone or siltone N no coarse scaled calcite marble limestone O no fine rough plagioclase hornfels P yes medium hard feldspar gneiss Granite or siltstone Q no fine gritty quartz quartzite Standstone and quartz R yes fine Metallic graphite anthracite coal 1. How did you determine the compositions of sample N and sample Q? Rocks are made up of minerals so for samples Q and N they both are monomineralic which means they each have one mineral 2. Where might you find a rock like sample M being formed on Earth today? on the continental side of a plate boundary that is convergent 3. Sample R is highly desired in the energy industry because it is the most “clean” variety. Using your knowledge of metamorphic processes, how do you think this rock becomes so “clean” compared to its protolith? When compared to bituminous coal, anthracite rocks burn exceptionally cleanly because they contain little sulfur content and fossil fuels that generate a significant amount of heat. v. SU22

8. The central Virginia to Alabama and The Himalaya range 9. Where on Earth do we often find examples of metamorphism due to chemically active fluids? Underground or in earths crust 10. What two properties of rock change during metamorphism? texture and mineral composition. 11. What two things can happen to minerals during metamorphism? They change size and shape 12. Other than old blackboards, what can slate be used for today? Electrical panels 13. What metamorphic rock is created from sandstone? Quartzite 14. How would you tell the difference between quartzite and marble if you did not have acid available for testing? Do a scratch test 15. Is contact metamorphism likely to produce foliated rocks? Explain why or why not. The primary metamorphic force in the foliation of rocks is contact metamorphism, which happens under relatively low pressure. 16. Metamorphic rocks can be classified as low grade, intermediate grade, or high grade, based on the temperature and pressure conditions under which they form (in addition to the figure in 6.4 of the textbook, refer to supplemental images in Canvas if needed). At what grade v. SU22

(low, intermediate, or high) would you classify schist? Slate? Gneiss? What do large crystals generally indicate in terms of the metamorphic grade? Mineral crystals typically get bigger as the metamorphic grade increases. Schist is intermediate slate is low gneiss is high 17. The temperatures and pressures needed to create a particular metamorphic rock can also tell us about the tectonic environment in which it formed. Consulting the diagrams referred to in the above question, your textbook, the videos, or other sources as necessary, in what tectonic environment do serpentinite and soapstone form? What about gneiss? hornfels? Serpentinite is from fault zones, soapstone is places where tectonic plates are subducted, gneiss is from convergent plate boundaries, and hornfels is from upper or middle crust III. Reflection: this sheet was pretty simple I didn’t think it was too bad v. SU22