1. Open Socrative. Type the room number: 246449
Enter your name. Write answers to the questions on the board.

2. Open Socrative. Type the room number:
Enter your name. Write answers to the questions on the board.

3. 1.State one piece of evidence that indicates basalt is the youngest rock unit in the cross section.
Cut through EVERYTHING. After the basalt intrusion the Fault cut through all the layers and the Basalt. The Fault split the basalt and other layers!

4. 2. You MUST use your?
ESRT

5. 3. State one reason why certain species of graptolites are used as an index fossil.
Lived everywhere and for a short time period

6. 4. The index fossil Eurypterus is found in the limestone layer
4. The index fossil Eurypterus is found in the limestone layer. What trilobite index fossil could be found in the shale layer?
Elliptocephala or Cryptolithus. They are OLDER than Eurypterus (below)

7. 5. The granite intrusion is 54 million years old and the vesicular basalt is 1.2 million years old. The rock layers have not been overturned. During which geologic time period did the shale layer form?
Neogene

8. 6. Order from Oldest to Youngest:A d B C d d D E d
Contact metamorphism has occurred on the Brunswick Sandstone.

9. 7. State one piece of evidence that supports the fact that the Palisade Sill is younger than the Brunswick sandstone.
Contact metamorphism has occurred on the Brunswick Sandstone.

10. 8. Identify the geologic feature represented by boundary X
8. Identify the geologic feature represented by boundary X Identify by name one index fossil that existed when the limestone rock shown in the cross section was being formed
Unconformity. E H M P U Y

11. 9.During which geologic time period was rock layer C deposited?
10. Identify two processes that produced the unconformity in outcrop I.
Cambrian. Uplift and erosion. Lived for a short time period and wide geographic location. C14 has a short half life, these animals are TOO OLD.

12. 11.Describe one characteristic a fossil must have in order to be considered a good index fossil.
12.Explain why carbon-14 can not be used to find the geologic age of these index fossils.
Cambrian. Uplift and erosion. Lived for a short time period and wide geographic location. C14 has a short half life, these animals are TOO OLD.

13. 13. The index fossil Dicellograptus was found in the shale layer
13.The index fossil Dicellograptus was found in the shale layer. During which geologic time period did this shale layer form?
Ordovician

14. 14.What geologic time period is missing?
Devonian or Silurian or Ordovician

15. 15.Which Graph is correct?
The one on the LEFT. U238 is the radioactive isotope that is DECAYING into Pb206.

16. 16. Which layer is the youngest? Oldest
Glacial Deposits-Youngest. Gray sandstone-Oldest

17. 17. Put in order: Oldest to Youngest A, B, C, D
Sandstone Limestone Shale Sandstone. Tilt. Unconformity. Shale Limestone Intrusion of Igneous Rock B. Erosion.

18. 18. Where did earth’s early oxygen come from?
19. Where did gases in earth’s early atmosphere come from?

19. 20. Which letter best represents an index fossil?

20. 21. Why is volcanic ash a good time marker?

21. 22. When did a rock form that contains the index fossil Lichenaria ?
23. What group of organisms does Lichenaria belong to?
24. Are those organisms still alive today?

22. 25. What index fossil lived during the breakup of pangaea?
26. When did the Archean Eon end?
27. List in order from oldest to youngest:
Earliest birds
Earliest fishes
Earliest insects

23. 28. After two half-lives, what percent of the original sample of uranium-238 remains?
29. If 100 grams of pure C 14 starts to decay, how much N 14 will be created after 11,400 years?
30. How many ½ lives is that?
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