Don Barrie, Geoscience Educator

Homework Assignment #2 Geology 100

Due several days before each exam (consult syllabus for due date).                                                                 Submit your typed assignment via WebCT by 11:59 PM Pacific Standard Time on the due date.

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Type out complete responses to each question.  Then, copy the questions and your responses, paste them into a Microsoft Word document, and submit your assignment via WebCT (see WebCT login instructions, above).  Save your Word document as follows:  Last Name_GEOL100_Hmk2 (e.g., Barrie_GEOL100_Hmk2). 

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While oral collaboration is encouraged (i.e, talking out homework answers with other students), you must complete this homework assignment on your own.  This means: do not share homework answers electronically with another student so that your work cannot be copied without your knowledge.

Your instructor may submit student homework assignments to www.turnitin.com for a plagiarism check.  Two or more students who turn in identical or nearly identical homework answers may receive a score of zero if evidence of electronic answer sharing is found.

Homework #2 Questions

1. Explain how the principle of uniformitarianism applies to the study of sedimentary rocks.

2. How are sedimentary rocks classified? 

3. Describe the common detrital, inorganic, and organic (biochemical) sedimentary rocks. 

4. How does a detrital sediment change with transport distance in terms of rounding, sorting, and average grain size? 

5. What is a depositional environment?  Describe at least two marine and two non-marine depositional environments.

6. What factors/agents contribute to the formation of metamorphic rocks? 

7. How are metamorphic rocks classified?

8. Describe the basic differences between regional, contact, hydrothermal, and dynamic metamorphism.

9. Distinguish different metamorphic textures, including slaty, phyllitic, schistose, and gneissic textures. 

10. In which plate tectonic setting do most foliated metamorphic rocks form? 

11. Describe the textural characteristics of the following metamorphic rocks: slate, schist, phyllite, gneiss, marble, quartzite. 

12. Explain how the rock cycle works in terms of what processes convert each rock type into the two others. 

13. How old is the Earth?

14. What is the difference between relative and absolute dating?

15. Summarize the six principles of relative dating.

16. What are the time boundaries between the Cenozoic, Mesozoic, and Paleozoic Eras and between the Paleozoic Era and Precambrian time? 

17. What types of fossils are dominant within each Era? 

18. Explain the processes of radioactive decay, specifically alpha decay, beta decay, and electron capture. 

19. A hypothetical parent element has a half-life of 1,000,000 years.  If a radioactive mineral contains 25% parent and 75% daughter product, how old is the mineral (and thus the igneous rock containing the mineral?) 

20. What is the difference between an earthquake focus and epicenter? 

21. Describe the various types of seismic wave and the elastic deformation they cause.

22. Describe how to distinguish P, S, and Surface waves on a seismogram. 

23. Explain how to distinguish seismic wave amplitude, seismic wave period, and S-P time difference (delta t) on a seismogram record.

24. What is the minimum number of seismogram records (each from a different location) needed to locate the origin of an earthquake?

25. For each increase of 1 point on the Richter scale, by how much does wave amplitude change?

26. For each increase if 1 point on the Richter scale, how much more energy is released?  

27. What factors contribute to earthquake damage?   

28. Explain the difference between compressional stress, tensile stress, and shear stress. 

29. Describe  elastic strain, plastic (ductile) strain, and brittle strain.   

30. Describe the following geologic structures: (1) normal fault, (2) reverse fault, (3) thrust fault, (4) strike slip fault, (5) anticline, (6) syncline. 

31. What stress/strain conditions produce normal faults, reverse and thrust faults, and strike-slip faults. 

32. Which types of geologic structures would you expect to find along convergent, divergent, and transform plate boundaries? 

33. What is the difference between joints and faults? 

Important Vocabulary (for reference only; not part of homework assignment)