GLG/101 Version4 / 1
Associate Level Material
Plate Tectonics Worksheet
Answer the lab questions for this week and summarize the lab experience using this form.
Carefully read Ch. 8 of Geoscience Laboratory.
Complete this week’s lab by filling in your responses to the questions from Geoscience Laboratory. 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.
Questions and charts are from Geoscience Laboratory, 5th ed. (p. 133-150), by T. Freeman, 2009, New York, NY: John Wiley & Sons. Reprinted with permission.
Lab Questions:
8.4 Which has the greater proportion of Iron, Magnetite, or Hematite?
8.7 When the reverse switch of a drill is thrown the drill rotates in the opposite direction. How does that affect the drill’s circuitry?
8.9 Name the 2 other spheres.
8.11 As Columbus’s fleet sailed westward the discrepancy between magnetic north and celestial north changed. Did it increase of decrease?
8.12 Explain the difference in the orientations of the inclined compass needles in figure 8.18. Toward which cardinal direction is the observer facing?
8.16 During which of these 5 geologic periods were Europe and North America most different in their positions with Earth’s magnetic field?
8.17 Place the 3 kinds of reefs in figure 8.26 in their order of succession from oldest first to youngest last.
8.18 What explains the shrinking of ocean crust as the crust moves away from volcanoes?
8.20 Does it appear in figure 8.29 that the reversals in Earth’s magnetic field are separated in equal periods of time, or are they random in their occurrences?
8.21 What were the three observations that Vine and Mathews made about the stripes?
- Directional trends-
- Order of the color coding on sides of the ridges-
- Widths of stripes compared to the duration of stripes-
8.25 Why doesn’t the South American plate descend beneath the Nazca plate?
8.26 How many years will it be until Los Angeles and San Francisco are side by side?
8.27 What is the average rate of northward movement of India during the past 71 million years (in centimeters per year)?
8.28 In centimeters per year, calculate the rate at which the Pacific plate is moving northwestern to the hotspot (which is marked by present day volcanoes).
8.30 Describe the direction of movement of the Pacific plate during the development of the volcanic islands that comprise the Seamounts. How has that direction changed?
Lab Summary:
Address the following in a 200-300 word summary:
- 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: