For questions 11 through 20 please refer to Figure 3 Cliff Exposures at Vaes Dat
ID: 120697 • Letter: F
Question
For questions 11 through 20 please refer to Figure 3 Cliff Exposures at Vaes Dathrak.:
https://drive.google.com/file/d/1lwAo5sUnBys7uxBiUWpITMEyqs4Dv8g_/view?usp=drivesdk
Questions 11 through 17: Multiple Choice: Mark the best answer for each question posed below.
11. What type of contact exists between Unit 11 and Unit 10?
a. a comforable depositional contact
b. an intrusive contact
c. a noncoformity
d. a disconformity
e. an angular unconformity
12. A fault cuts the lowest portion of the northern section of this outcrop. What type of
fault is this?
a. a right-lateral strike-slip fault
b. a left-lateral strike-slip fault
c. a normal fault
d. a reverse (thrust) fault
13. What type of contact exists at the base of unit 9 south of the fault?
a. a comforable depositional contact
b. an intrusive contact
c. a noncoformity
d. a disconformity
e. an angular unconformity
14. There are two contacts between the limey-shale unit 1 and the breccia unit 2 at the
bottom of the cliff-exposure. This other type of contact is an example of a(n):
a. nonconformity.
b. angular unconformity.
c. disconformity.
d. intrusive contact.
e. fault (tectonic) contact.
15. The oldest rock type exposed in this outcrop is a(n):
a. shale.
b. breccia.
c. sandstone.
d. chert.
e. basalt.
16. What principle best supports the answer to the question 15 above? Hint: how did
you determine the oldest rock type from the next oldest?
a. The principle of original horizontality.
b. The principle of stratigraphic superposition.
c. The principle of original continuity.
d. The principle of inclusion.
e. The principle of cross-cutting relationships.
Questions 17 through 20: True/False
form).
17. Faulting within the cliff exposures at Vaes Dathrak is still active.
18. The fault within this cliff exposure is the product of tension.
19. The contact at the base of the basalt (unit 1) is an intrusive contact.
20. Units 11 and 12 could have been depsoited in a shallow marine environment in a
passive continental margin setting.
Explanation / Answer
11. The contact is a conformable deposition contact. Unit 11 gets deposited over Unit 10.
12. The fault is a reverse fault, where one side of the fault gets displaced upwards with respect to the other side.
13. Below Unit 9, the contact is disconformity, the units below and above it are parallel to the unconformity surface.
14. The other type of contact is the fault or the tectonic contact. The contact where the Unit 1 of the footwall touches the Unit 2 of the hanging wall.
15. The oldest rock unit is the shale, which lies at the bottomost part of the sequence.
16. The principal of Stratigraphic superposition states that in an undeformed sequence of rock, the lowest unit is the oldest unit.
17. False. The fault is not active.
18. False. Reverse faults form as a result of compression.
19. False. The contact at the base of the basalt is not an intrusive contact.
20. This can be true. Because of the overlying sedimentary beds above 11 and 12.