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Relative Dating Lab- KEY. 1. # of Events. 1. # of Events. B= 9. 1. # of Events. C = 9. 1. # of Events. C = 9. 1. # of Events. D = 18. 2. Figure A: The erosion occurred between which 2 events?. 12 erosion. 9. 13 last deposit. 8. 7. Angular Unconformity. 6. 5. 4. 3. 2.
E N D
1. # of Events B= 9
1. # of Events C= 9
1. # of Events C= 9
1. # of Events D= 18
12 erosion 9 13 last deposit 8 7 Angular Unconformity 6 5 4 3 2 10-intrusion of magma 1 Uplift = 11
The erosion occurred between the intrusion of the magma and the deposition of the top layer of sedimentary rock. Or…… • The erosion occurred between the tilting of the older rocks, and the deposition of the top layer of sedimentary rock.
3. Figure B: Did the faulting occur before of after the erosion?
3. • The faulting occurred before the erosion, since it is cut by the erosion boundary. • Law of Cross Cutting Relationships.
4. Figure C. If the igneous rock is 10 million years old, how can you describe the age of the fault?
4. The fault must be older than 10 MYBP since it is cross cut by the igneous rock that is 10 MYBP
5. Figure D • Which igneous dike came first, the black one or the one with the dashes? How do you know?
erosion 5. The black igneous dike came first since it is cross cut by the dike with the dashes.
6. Figure E • A. How old is the fault. Give a range of years.
40 MYBP 80 MYBP 100 MYBP A. The fault occurred between 40 and 80 MYBP
40 MYBP 80 MYBP 100 MYBP B. The sandstone must be older than 100 MYBP since it is cut by the 100 MYBP black igneous dike.
40 MYBP 80 MYBP 100 MYBP C. The pluton must be younger than 40 MYBP since the pluton cross cuts the erosional boundary, and the erosional boundary is cut by the 40 MYBP dike with the plus signs.