Coastline Community College - GEOLOGY 105

Lab Lesson 9: Geologic Time

Questions 1 through 3 are based on the Lab Exercise, Step 2.

Questio1)Record your answer to Lab Exercise, Step 2, Question 11. How long ago was the igneous rock in rock unit B formed?

Question 2

Record your answer to Lab Exercise, Step 2, Question 12. How long ago was the igneous rock in rock unit C formed?

Question 3

Record your answer to Lab Exercise, Step 2, Question 13.

How long ago was the metamorphic rock in rock unit G formed?

Questions 4 through 8 are based on the Lab Exercise, Step 3. 4.

Question 4

Record your answer to Lab Exercise, Step 3, Question 14. How long ago were the fossils found in Layer A formed?

Question 5

During what period were the fossils in Layer A formed?

Question 6

Record your answer to Lab Exercise, Step 3, Question 15. How long ago were the fossils found in Layer D formed?

Question 7

During what period were the fossils in Layer D formed?

Question 8

Record your answer to Lab Exercise, Step 3, Question 16. How long ago were the fossils found in Layer E formed?

Question 9

During what period were the fossils in Layer E formed?

Question 10

Record your answer to Lab Exercise, Step 3, Question 17. How long ago were the fossils found in Layer F formed?

Question 11

During what period were the fossils in Layer F formed?

Question 12

Record your answer to Lab Exercise, Step 3, Question 18. What is the least amount of

time that could have passed during the hiatus represented by younger unconformity seen in Figure 9.12?

Question 13

Record your answer to Lab Exercise, Step 3, Question 19. What is the least amount of time that could have passed during the hiatus represented by the older unconformity seen in Figure 9.12?

Question 14

Which of the following principles is NOT used in determining the relative age of rocks?

Question 15 through 19 are based on Figure 9.17 on page 208 of your lab book.

Questions 15

Determine the relative age each of the geologic structures shown in the geologic cross section in Figure 9.17, from youngest to oldest; then answer the questions below. As before, a wiggly line running across the geologic cross section indicates an unconformity and a fault is indicated with a bold straight line.

Which is the youngest geologic structure in Figure 9.17?

Question 16

Which is the oldest geologic structure in Figure 9.17?

Question 17

Which letter represents an unconformity in Figure 9.17?

Question 18

Which letter represents a fault in Figure 9.17?

Question 19

What is the proper order of geologic structures B, C, D, and F in Figure 9.17 from oldest

to youngest?

Question 20

What relative dating principle states that in a sequence of sedimentary rocks, unless

overturned, the oldest beds are at the bottom and the youngest beds are at the top?

Question 21

What relative dating principle states that fossils in a sequence of sedimentary rock layers succeed one another in a definite, recognizable order?

Question 22

The Principle of Cross-cutting Relationships states that                                  .

Question 23

The Principle of Lateral Continuity states                            .

Question 24

What type of unconformity appears between two parallel sedimentary layers?

Question 25

What type of unconformity appears between a sedimentary layer and an igneous or

metamorphic rock body?

Question 26

What type of unconformity appears between a tilted sedimentary strata and a horizontal overlying layer?