Metamorphic Rock Analysis and Interpretation Activity 7 Name: Course/Section: Da
ID: 115764 • Letter: M
Question
Metamorphic Rock Analysis and Interpretation Activity 7 Name: Course/Section: Date: A Analyze the samples of sedimentary limestone and metamorphic marble in Fig. A7.3.1 1. These rocks are both composed of the same mineral. Wha is it? What test could you perform on the rocks to be sure? 2. How is the textue of these two rocks differen? limestone marble Figure A7.3.1 Figure A7.3.2 shows three metamorphic rocks that had a mudstone or shale protolith and that display excellent foliatie The three specimens represent different metamorphic grades. Higher-grade types can also be formed from protoliths other than mudstone, but we are going to think about a progression from mudstone through successively more intense metamorphism 1. Describe the change in grain size from slate to schist 2. How does the texture of phyllite differ from that of schist? 3. Why do you think that the micas (flat minerals) in these rocks are all parallel, or nearly so, to one another? slate phyllite schist cm 1 cm cm A7.3.2 Analyze the rock sample in Fig. 7.5A. The white layers in this metamorphic rock--a gneiss-were originally flat, parallel layen that were later folded during metamorphism. Describe a process that could account for how this strong, dense gneiss was folded without breaking during regional metamorphism. (Hint How could you bend a brittle candlestick without breaking it Analyze the foliated metamorphic rock sample in Fig. A7.3.3. 1. What mineral defines the foliation in this rock? 2. Notice that the rock consists mostly of muscovite but also contains scattered garnet crystals. What is the name for this kind of texture? 19Explanation / Answer
A.1.As given one is limestone and other is marble rock so we can say one is the metamorphic equivalent of other that means marble formed due to metamorphism of limestone so both are composed of calcium carbonate(CaCO3).
We will do carbonate test for confirmation .
2.Limestone is sedimentary rock and marble is metamorphic and in this rock sample of limestone we can see the fossil presence like gastropods but in metramophic marble in obvious case we could not find fossil .
B.1.Slate:It fully fine grained and no foliation is there.
Phyllite:- It also fine grained but it has foliation .
Schist :-It is medium grained with mixture of foliation .
2.As the textures described above phyllite shows the foliation clearly and schist has a mixed type texture
3.As per the texture of all three rocks we can not say micas are parallel but they are nearly parallel in phyllite but to one another in other rocks.