Unit 9 Guide: Foundations of Earth Science
Clues to Earth’s Past and Geologic History
Key Concepts and Questions to Be Able to Explain and Answer:
1. What is the law of superposition? How can it be used to determine the relative age of rock layers?
2. What is an unconformity? Describe the formation and draw a picture of each of the following unconformities: angular unconformity, disconformity, nonconformity.
3. What is the principle of uniformitarianism? How was it used to make a more accurate prediction of Earth’s age?
4. What is a fossil? Name and describe the 2 conditions that are necessary for fossil formation.
5. What are the three characteristics of all index fossils? How are index fossils helpful in determining the age of rock layers?
6. What is the difference between absolute and relative age.
7. Describe how knowing the half life of an isotope that undergoes radiometric decay can be used to determine the absolute age of a rock. Be able to solve half life calculation problems.
8. What are the characteristics of eons, eras, periods and epochs?
9. Which era(s) are divided into periods? Which era(s) are divided into epochs?
10. Write the names of eons, eras and periods in order from the beginning of Earth’s history through the present.
11. Describe the process of natural selection. How can natural selection cause species to evolve?
12. What is the leading hypothesis for the extinction of the dinosaurs? Explain this theory.
13. During what period did the first human beings exist? Have humans been around for much of geologic history?
14. Match the following major geologic events) with the appropriate era/period:
Assessments
Quiz Date: ______
Formal Lab Report: Half Life Date: ______
Unit 9 Test Date: ______
Reading Assignments:
Students will be assigned readings from the following pages in the text book.
Chapter 13 pages 360-389
Chapter 14 pages 390-421
Vocabulary
fossil principle of superposition radioactive decay
permineralized remains relative age half life
carbon film unconformity radiometric dating
mold angular unconformity uniformitarianism
cast disconformity geologic time scale
nonconformity absolute age trace fossil
natural selection mammals index fossil
eon gymnosperms angiosperms
era trilobites species
period cyanobacteria
epoch
evolution
How to Receive up to 5 Bonus Points for Completing the Unit Guide:
1. Type or handwrite an answer to each Unit Objective Question. Unless stated in the question, all answers must be given in complete sentences.
2. Define each of the vocabulary terms. Do not just copy the definition out of the book’s glossary. Use and add on to the definition we developed in class by giving additional information and examples of each word.
3. Unit Guides must be turned in on test day and will NOT be accepted late. You must answer ALL unit objective questions and define ALL terms.
4. Mrs. Froehlich will review your Unit Guide and determine the number of bonus points to be added to your test. Bonus points will be granted based on correctness and completeness of answers and definitions.