Axia College Material
Appendix L
Week Six Lab Report: Metamorphic Rocks
Answer the lab questions for this week and summarize the lab experience using this form.
Full Name
Date
Carefully read pages 108-116 of Geoscience Laboratory.
Complete this week’s lab by filling in your responses to the questions from Geoscience
Laboratory. Select answers are provided for you in red font to assist you with your lab work.
Although you are only required to respond to the questions in this worksheet, you are encouraged
to answer others from the text on your own.
Lab Questions
6.1.
(Ref. Figure 6.2)
A. Judging from the changes that are evident in these two before-and-after illustrations,
do you suppose that the geologic age of calcitic marble could be determined from its
fossil content (as can be done with fossiliferous limestone)?
No
B. Why or why not?
Based on the illustration, the calcite has completely recrystallized, destroying the original
structure including any fossils that had originally be deposited in the limestone.
6.2.
(Ref. Figure 6.2B) Account for the straight boundaries (that mark flat surfaces) of
individual crystals at the fracture surface of the calcitic marble. Hint: Check out the
properties of calcite in Table 3.3 on page 61.
Answer: The straight boundaries are calcite cleavage surfaces
6.3.
(Ref. Figure 6.3) Explain the difference between the fracture surface of quartz sandstone
and that of quartzite. Hint: Check out the properties of quartz in the lower one-half of
Table 3.3 on page 60.
Sandstone fractures along the line of the matrix material and between grains. Quartzite
fractures across the grains (crystals).
6.6.
2 tons
Approximately how many tons of lignite would be required to produce the amount of heat
generated by one ton of anthracite coal?
6.7.
Find the name of this iron sulfide mineral at the top of Table 3.3 on page 60.
Answer: pyrite
6.8.
Name another region, in addition to the example of South America shown in Figure 6.7B,
where one should expect to find lineated and foliated metamorphic rocks. Hint:
Topography (physiography) should be your guide here, so think of another linear (chainlike) mountain system.
The Rocky Mountains
6.9.
(Refer to Figure 6.8.)
A. What metamorphic setting appears to be reflected here—contact or regional? Hint:
Does this landscape appear to be merely baked, or does it appear to be folded
(wrinkled)?
Regional.
B. Which types of metamorphic rocks would you expect to find here?
Slate, phyllite, schist, gneiss
Lab Summary
Address the following questions in a 100- to 200-word summary:
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Summarize the general principles and purpose of the lab.
Explain how this lab helped you better understand the topics and concepts addressed this
week.
Describe what you found challenging about this lab.
Describe what you found interesting about this lab.
Write your summary here:
The purpose of this assignment was to understand how metamorphic rocks are formed, the
changes that occur to the original rocks and minerals and the settings in which the metamorphic
rocks are formed. This lab helped me better understand the concepts by presenting problems
that made me think about how pressure and heat change the rocks. The most challenging part of
the lab was thinking about why the geologic age of the calcite could not be determined using the
fossils. The most interesting was realizing that some of the same rocks could be found in South
America and in the Rocky Mountains because of the tectonic settings.