Lab # 4 (Summer ’17 version) —Earth Science
Geological Time, Fossils, and Dating
Purpose: To study the geological time scale, interpretation of the fossil record, and dating techniques for geology.
This lab relates to the currently accepted geological time scale and to fossil and other evidence that relates to that scale. Part of the study is from the Internet and part of the study is from the Mastering Geology website, which accompanies the Tarbuck text. It reinforces the material covered in the text and lecture notes relating to radiometric dating and relative dating as well as the time scale itself. There is some disagreement between the scientific community and certain religious groups relating to the length of Earth’s history, the fossil record, and dating techniques, but I want to emphasize that there is NO disagreement among the scientific community. As with the text and other materials for this course, the scientific viewpoint is supported by observed data and evidence.
1) Read the rest of the information on this exercise BEFORE starting the lab.
2) Print this page to use while doing the lab.
3) Part II of the lab uses the Mastering Geology website.
Part I—“Fossils, Rocks, and Time”
4) Go to document “Fossils, Rocks, and Time” in the publications section of the USGS (United States Geological Survey) website by clicking on the link http://pubs.usgs.gov/gip/fossils/contents.html . Click on “Introduction” below the photograph and work your way through the presentation answering the questions below as you go. At the bottom of each page, there is an icon to take you forward or back.
5) Go to the website Enchanted Learning—Dinosaur Fossils by clicking on the link http://www.enchantedlearning.com/subjects/dinosaurs/dinofossils/ . Although this website is designed for “younger” readers, we “old” people can get some good information from it. After the website’s homepage loads, click on the button that says, “How fossils form?”, and use the information to answer the next set of questions below. After completing this page, click on the button, which says “Types of Fossils”, and answer the next group of questions.
6) Go to the Arkansas Geological Commission website and read about the pseudofossils Arkansas” by clicking on the link http://www.geology.ar.gov/geology/pseudofossils.htm . Answer the related questions below.
Part II—Radiometric and Relative Dating
1) Go to the following website www.masteringgeology.com and login
2) Click on the GEODe Earth Science link on the left hand side of the screen
3) On the Main Menu click on the Relative Dating—Key Principles link.
4) Work through the frames answering the questions for this section.
5) On the Main Menu click on the Dating With Radioactivity link.
6) Work through the frames answering the question for this section.
1. What time interval is shown as the oldest and what is the youngest one?
2. What year did Neal Armstrong walk on the Moon?
3. What does the suffix –zoic (as in Cenozoic) mean?
4. What is the most obvious feature of sedimentary rocks?
5. What major life forms existed in the pre-Archean eon?
6. What dominates the great bulk of the fossil record?
7. According to the chart on fossil succession, when did pine trees begin to appear?
8. If two rocks from different regions of the Earth contain the same kind of fossils, what do we know?
9. What were Darwin’s four processes for “causing” evolution?
10. What is an index fossil?
11. What is the useful range of radiometric dating using the radioactive isotope potassium-40?
12. What is permineralization and what is another name for permineralization?
13. Why did some dinosaurs not form fossils?
14. What are fossils rock-colored?
15. What is an example of a trace fossil?
16. Why are more footprints found belonging to meat eating dinosaurs than those belonging to plant eating dinosaurs?
17. What is a coprolite? What information can they give the scientist?
18. What are the most common pseudofossils?
19. What type of formation you would find in the Fayetteville Formation in northern Arkansas?
20. How are the ‘turtle rocks’ created?
21. How are the ‘carpet rocks’ created?
(Mastering Geology – GEODe—Relative Dating)
22. In what year was plate tectonics formally proposed?
23. What is relative dating?
24. What is the law of superposition?
25. In Frame 6, what is the name of the oldest rock layer?
26. In Frame 7, what is the name of the youngest feature?
27. In Frame 9, what is the name of the youngest feature?
28. In Frame 10, did the fault occur before or after the dike was formed?
29. Answer the questions in each of Frames 11-16. Write the answers below.
30. What is the principle of original horizontality?
31. What is conformable?
32. What is an unconformity?
33. In Frame 23, between what groups does an angular unconformity exist?
34. In Frame 27, what is the proper sequence of events?
(Mastering Geology – GEODe—Dating with Radioactivity)
35. What information does the atomic number give?
36. Why do some nuclei undergo radioactive decay?
37. Answer the question in Frame 27. Write the answer below
38. How are numerical dates for sedimentary layers usually determined?
39. Answer the questions in Frames 44-46. Write the answers below.