Chapter 24, Problem AM

KEY TERMS

1. geologic time (Intro) 2. fossil (24.1) 3. paleontology 4. amber 5. replacement fossil 6. mold 7. cast 8. trace fossil 9. relative geologic time (24.2)

10. principle of original horizontality 11. principle of superposition 12. principle of cross-cutting relationships 13. unconformities 14. correlation 15. index fossils 16. eons 17. eras 18. periods

19. absolute (numerical) geologic time (24.3) 20. radiometric dating 21. carbon-14 dating 22. geologic time scale (24.5) 23. Cambrian explosion 24. Great Dying 25. epochs 26. K-T event

For each of the following items, fill in the number of the appropriate Key Term from the preceding list.

a. _____ Widespread, easily identified fossils that are typical of a particular time segment of the Earth’s history

To determine

Pick the keyword from the given list: The name of fossils that are widespread and represent a particular time segment of earth’s history.

Answer to Problem AM

The fossils that are widespread and represent a particular time segment of earth’s history are called as the index fossils.

Explanation of Solution

Some specific fossils are used to find the similarity between the rock layers of two different localities. This process of matching the rock layers of different localities is called as correlation.

The fossils used as a base in the process of correlation are called as the index fossils. Every index fossil represent a particular time period.

Therefore, if two rocks layers obtained from different localities have same index fossils then it represents that those rock layers belong from the same time period of the history.

Conclusion:

Therefore, the word index fossils can be picked from the list.