Monday, February 25, 2008

"What is an Index Fossil?"

Bellwork:
1) Limestone is formed in ___________.
2) _______________ breaks down rocks; _______________ moves them.
3) Would a younger fossil be found in the top or the bottom layer of rock?

- Think-Pair-Share: What do fossils help us do?
- Define index fossil
1) Give us EVIDENCE of the AGE of rock layers
2) Have to have lived a SHORT length of time
3) They let us connect rocks that exist in DIFFERENT areas as the SAME ==> If 2 rocks contain the same index fossil, they were formed at about the SAME time
- Use "Index Fossil Key" (Earth History Resources p. 41) to CIRCLE and LABEL the index fossils on pages 93, 97, and 99 in the workbooks
- Cut out the rock layers on page 103 and correlate (line-up) the fossils on page 101
- Exit Slip (page 100): ONE thing index fossils tell us about rocks is…