Question

Use Figure 6.21 to complete questions 1-8. 

.1. Place the lettered features in proper sequence, from oldest to youngest, in the space provided on the figure.

2. What type of unconformity separates layer G from layer F?

3. Which principle of relative dating did you apply to determine that rock layer H is older than layer I?   

4. Which principle of relative dating did you apply to determine that fault M is older than rock layer F? 

5. Explain how you know that fault N is older than igneous intrusion J. 

6. If rock layer Fis 150 million years old and layer E is 160 million years old, what is the approximate age of fault M? 

Approximate age of fault M: _______  million years

7. The analysis of samples from layers G and Findi- cates the following proportions of parent materi- al to daughter product. If the half-life of the parent is known to be 75 million years, what are the ages of the two layers? 

8. What time interval is represented by the discon- formity at the base of rock layer G? 

Time interval: _______ to _______  million years 

9. What fraction of time is represented by the Precambrian? 

Precambrian: _______  percent 

10. Examine the photograph in Figure 6.22. Describe, as accurately as possible, the relative geologic history of the area, using the principles of rela- tive dating covered in this exercise.  

 

Answer 1