Referring to the rocks you see here ...... 1. Which is the second-oldest sedimentary rock layer? A. B B. C C. E D. F
E. D The package of sediments C, D, E, and F is upside-down, as shown by the footprints and mud cracks, so C is the oldest one, and D is second-oldest. Points Earned: 1/1 Correct Answer: E Your Response: E 2. Which is the oldest fault: A. H B. I C. J I is cut by J, so I is older than J. And with reference to K, both I and J can be shown to be older than H. Points Earned: 1/1 Correct Answer: B Your Response: B 3. Which is older: A. Unconformity K. B. Fault I. C. Fault H. D. Unconformity L. E. Fault J. Unconformity L is cut by fault I, so is older than I. Fault I is cut by fault J, so is older than J. Fault J is cut by unconformity K so is older than K. Unconformity K is cut by intrusion G so is older than G, and intrusion G is cut by fault H so is older than H. Hence, unconformity L is the oldest on this list. Points Earned: 1/1 Correct Answer: D Your Response: D 4. Which is younger: A. Unconformity L. B. Fault J. C. Rock layer A. D. Rock layer B. E. The tree. The tree is growing on intrusion G, which can be shown to be younger than all of the others. Points Earned: 1/1 Correct Answer: E Your Response: E 5. Which is not accurate about the Grand Canyon, in Arizona:
A. The rock record of the canyon contains many unconformities. B. The youngest rock layer at the canyon slants downward to the north beneath still-younger rocks of Zion, Bryce, etc. C. The oldest rocks are on top, with younger ones beneath, as shown by all of the footprints being upside-down in the rocks of the canyon walls. D. A great thickness of sedimentary rocks exists in Death-Valley-type faulted basins, which can be seen deep in the canyon in many places. E. The walls of the Canyon include rocks deposited in many different environments. There are some folded rocks in the heart-of-a-mountain-range metamorphics at the bottom, but otherwise, everything is right-side up. All the other possible answers here are correct. Points Earned: 1/1 Correct Answer: C Your Response: C 6. The age of the Earth can be estimated in many ways. Which statement below is most accurate? A. Uniformitarian calculations show that the Earth is 4.6 billion years old. B. Annual-layer counting shows that the Earth is more than about 100 thousand years old, uniformitarian calculations show that the Earth is more than about 100 million years old, but we don’t know how to estimate how much more than 100 million years the Earth is. C. Annual-layer counting shows that the Earth is more than about 100 million years old. D. Annual-layer counting shows that the Earth is more than about 100 thousand years old, uniformitarian calculations show that the Earth is more than about 100 million years old, and radiometric techniques tell us how old the Earth is.
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- Summer '06
- Outer core, Structure of the Earth, Mantle, Death Valley