Week Six Lab Report: Metamorphic Rocks
Answer the lab questions for this week and summarize the lab experience using this form.
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.
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)? Yes
B.Why or why not?
Because it remains a solid when it goes through metamorphism and solids retain clues to the events that change them.
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.
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.
The sandstone will fracture in the softer stone of the matrix and the quartzite will fracture through the original sand grains, rather than around them.
6.6.Approximately how many tons of lignite would be required to produce the amount of heat generated by one ton of anthracite coal?
About two tons since lignite only produces about half the heat of anthracite.
6.7.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 (chain-like)...