Metamorphic Rock Inquiry Activity 7.1 Name: Course/Section: Date: Analyze the me
ID: 115763 • Letter: M
Question
Metamorphic Rock Inquiry Activity 7.1 Name: Course/Section: Date: Analyze the metamorphic rocks in Fig. A7 1.1 and actual rock samples of them·if available Beneath or ente ea describe the rock's composition (what it is made of) and texture (the size, shape, and arrangement of its you can, using your current knowledge and observational skills picture 2 4 6 Figure A7.1.1 B REFLECT & DISCUSS Reflect on your observations and d how you would classify the rocks into groups. Be prepared to discuss your classification with your classmates or teacher. tions and descriptions of metamorphic rocksin part A. Then describe 197Explanation / Answer
A) 1. By observing the sectional part we can conclude the following points:
Composition : The rock is composed of alternating light color and dark color layerings. Light color layer may be composed of quartz, feldspar minerals while the dark color layers are composed of biotite or amphibole.
Texture : The light-colored layers are showing interlocking texture. The size of the light-colored minerals are larger than the dark-colored minerals. However, the dark-colored banding is much thinner. The two colored bands are arranged alternately.
Conclusion : The rock is Gneissic metamorphic rock.
2. Composition : The rock is composed of quartz grains identified by white color and might be amphibole(green colored) and biotite (dark colored).
Texture : The rock is highly foliated. The drak colored minerals are forming the foliation plane. The quartz grain sizes are larger than the dark-colored minerals.
Conclusion: The rock may be phylllite or schist.
3. Composition : The rock is totally composed of quartz grains. Color of the rock is brownish white.
Texture : the rock is non-foliated. Quartz grains are showing interlocking texture.
Conclusion : The rock is Quartzite (metamorphosed sandstone).
4. Composition : The rock is very fine-grained. Foliation plane is seen from the section. The rock is composed of chlorite(green colored), muscovie and may be quartz at some places. The inclusion is seen at two places. The inclusion is the garnet mineral.
Texture : The rock is foliated indicates it will break along the foliation planes. The grains are fine to medium sized.
Conclusion : The rock is phyllite (metamorphosed slate).
5. Composition : The rock is composed of chlorite, muscovite and biotite minerals.
Texture : Foliation plane is seen.
Conclusion: The rock is Phyllite.
6. Composition: Quartz, feldpar and mica minerals are present.
Texture : The rock is highly foliated. Grains are medium-sized.
Conclusion : The rock is Schist rock.
B) On the basis of above observation, we can classify the rocks as follows :
The metamorphic grade is increasing from Phyllite to Quartzite.
Rock Name Texture Grain Size Parent Rock Phyllite Foliated Fine-grained Slate Schist Fine to medium grained Phyllite Gneiss Fine to medium grained Schist Quarztite Non-foliated Coarse-grained Quartz Sandstone