The Earth Has a History Questions

GLS100 Evolving Earth Prof. Cullen Shown below is the reconstructed cross-section of sedimentary rock layers through the Boulder, Colorado area discussed in the video “The Earth Has a History”. Use this cross-section to answer the questions that follow. (can’t insert table) 1. How many unconformities are shown in the cross-section? Three What important geologic process(es) was/were primarily responsible for producing these features? processes: Erosion and stream deposits, then overtime cemented together 2. Which numbered rock layer is the oldest ? rock layer : 2 3. What two simple Principles of stratigraphy were needed by the narrator of the video to correctly describe the geologic history of this area? Principle of superposition Principle of cross-cutting relationships 4. Which of the following event(s) must have occurred between the deposition of beds 1 through 2 and the deposition of beds 3 through 6? A. deposition of pebbles in Boulder Creek B. erosion C. uplift D. tilting E. intrusion of crystalline basement rock F. none of the listed events occurred between the deposition of beds 1-2 and beds 3-6 Your choice(s) (letters): A and B and C 5. How many times were beds 1 and 2 tilted? 0 1 2 3 4 times. Your choice: 3 Explain your choice below. If it was 4, it might be vertical, but it’s definitely at least 3 times because they are at such a high angle. 6. What is the most recent geologic event recorded in the cross-section? Event: 7 7. Was the Principle of Uniformitarianism at all useful to the narrator when attempting to understand the geologic history recorded in the rocks near Boulder, Colorado? Answer: Yes Explain your answer