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Index fossils are the remains or traces of organisms that existed for a short period but were widespread. Geologists use them to determine the relative age of rock layers. In this exercise, students learn to identify and correlate index fossils by comparing profiles of Bryce Canyon and Zion National Park.
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Day 37 What are index fossils? Index fossils are the remains or traces of organisms that lived for only a short time, but in many places around the world. Why are index fossils useful to geologists? When geologists find an index fossil in a rock layer, they know it is about the same age as all other rock layers that contain the same index fossil. Daily Warm-Up Exercises
Use Index Fossils(Part 1, steps 10-12) Investigation 7 Fossils and Time
Index Fossil Correlations • Turn to page 61 and cut out the profiles of Bryce Canyon and Zion National Park. • Color all the same fossils the same color. Ex: color all the Wingatea pink. • Place the two profiles on page 59 and attach them so the index fossils are aligned correctly. (Line up the layers with the same fossils.)
Same at Grand Canyon & Zion Kaibab and Z1 have the same index fossils
Same at Zion & Bryce Z7 and B5 have the same index fossils Z2 and B1 also have the same index fossils
Compare Ages -- B3 vs. Supai B3 is younger than B1 B1 is from early Triassic Supai is from late Pennsylvania Triassic is more recent than Pennsylvania B3 is younger than Supai
Compare Ages -- B2 vs. Z1 B2 is younger than B1 B1 is from early Triassic Z1 is from Permian Triassic is more recent than Permian B2 is younger than Z1
Environment for B9 Since coal forms from decayed plants, the environment must have had a lot of plants. The sandstone means that sand was present. The area was probably swampy or on a floodplain.
Labels Exercise 7.2
Captions Exercise 7.3
CaSE Book Student Resource Book, page 50
Wrap up • Turn to page 63 and complete the index-fossil correlation questions. • You will turn in yesterdays Index Fossil ws, your correlated paper that you glued the layers on and pg. 63 all at the same time. • Turn in to me in this order: • On top: Index Fossils and ID ws • Next: The 3 canyons lined up • Last page: Ws 63, Index Fossil Questions