1) Why do the different rocks exposed in the Grand Canyon appear in layers for the most part?
Where are the oldest layers of rock found? Where are the youngest rocks found? Explain in 2-4
sentences (4 points)
2) Why do you think geologists are especially interested in contacts (where two different rocks
come together) when trying to piece together the history of the Canyon’s formation? Explain in
2-4 sentences (4 points)
3) What are some specific rocks found in Grand Canyon (for example, the Tapeats Sandstone)?
NAME and DESCRIBE at least 3 examples in at least 3 sentences each. Be sure to indicate
whether each rock is sedimentary, metamorphic or igneous. You can also mention the age of
the rock, how it was formed/deposited, where it is found in the Canyon with respect to other
rocks, colors, grain/crystal sizes, types of minerals found within the rock, cross-bedding features,
clasts, fossils present, banding/layering, geometric orientation (angle), etc. (9 points)
Rock 1:
Rock 2:
Rock 3:
4) What is an unconformity? Where can you find one in the Grand Canyon? What types of rocks
contact at the “Great Unconformity,” and about how old is each type of rock? What does the
missing time between the two rock formations mostly likely represent? Explain in 3-5 sentences
(5 points)
5) What type of environment do sedimentary rocks form in? Where do metamorphic rocks form?
Keep in mind the rocks at the Great Unconformity when answering. Explain in 2-4 sentences (4
points)
6) Where are fossils from the “Cambrian Explosion” found in the Grand Canyon? What type of
environment did the organisms live in and how do we know? Describe what these creatures
may have looked like. Explain in 2-4 sentences (4 points). These 2 videos will help if you’re
stuck:
Where are the oldest layers of rock found? Where are the youngest rocks found? Explain in 2-4
sentences (4 points)
2) Why do you think geologists are especially interested in contacts (where two different rocks
come together) when trying to piece together the history of the Canyon’s formation? Explain in
2-4 sentences (4 points)
3) What are some specific rocks found in Grand Canyon (for example, the Tapeats Sandstone)?
NAME and DESCRIBE at least 3 examples in at least 3 sentences each. Be sure to indicate
whether each rock is sedimentary, metamorphic or igneous. You can also mention the age of
the rock, how it was formed/deposited, where it is found in the Canyon with respect to other
rocks, colors, grain/crystal sizes, types of minerals found within the rock, cross-bedding features,
clasts, fossils present, banding/layering, geometric orientation (angle), etc. (9 points)
Rock 1:
Rock 2:
Rock 3:
4) What is an unconformity? Where can you find one in the Grand Canyon? What types of rocks
contact at the “Great Unconformity,” and about how old is each type of rock? What does the
missing time between the two rock formations mostly likely represent? Explain in 3-5 sentences
(5 points)
5) What type of environment do sedimentary rocks form in? Where do metamorphic rocks form?
Keep in mind the rocks at the Great Unconformity when answering. Explain in 2-4 sentences (4
points)
6) Where are fossils from the “Cambrian Explosion” found in the Grand Canyon? What type of
environment did the organisms live in and how do we know? Describe what these creatures
may have looked like. Explain in 2-4 sentences (4 points). These 2 videos will help if you’re
stuck:
