questions from the accompanying video about rocks of the Grand Canyon in Arizona (given at the bottom of this page). You may begin watching the video at the 2:45 minutes mark. You will use this video in conjunction with concepts about geologic time and sedimentation given in Chapter 5 (Links to an external site.) and Chapter 7 (Links to an external site.) of the OER textbooks (Salt Lake Geology).
https://opengeology.org/textbook/7-geologic-time/#712_Grand_Canyon_Example
Answer the following questions related to Grand Canyon’s sedimentation and erosional history.
- The Colorado River has been eroding the region since the last 5.5 million years. This prolonged erosion has created a 1 mile deep canyon. The question you will answer is this: What is the rate of erosion of the Grand Canyon by the Colorado river? Give your answer in ft/year. Show your work. [Hint: Rate = distance/time]
- Geologist Dave tells Dr. Michio Kaku: "as you walk down this trail……….for every step you take, you go about 20,000 years into the past". Explain what the geologist means by this statement.
- Based on the geologic explanations presented in the video, how would you explain to someone who insists that the age of the Earth is about 6,000? Explain your answer by giving at least two supporting evidence from the video.
Please follow the below instructions when you post your replies to the above questions.
- Answer each question in a separate paragraph and always identify the question number you are answering. You can’t answer ALL questions in one paragraph in the form of an essay.
https://youtu.be/NpW_Q_J4HF4
Testimonials
The Grand Canyon in Arizona