Name Date Period ______
Chapter 4 Lesson 4: Geologic Time
1. The geologic time scale is a record of ______and ______.
2. Number the following periods in order from earliest to latest.
Neogene ___ Quaternary ___ Cretaceous ___ Jurassic ___ Triassic ___
3. Refer to My Planet Diary and Figure 2. During which period did modern humans arise? ______
4. How does uniformitarianism help scientists who are studying Earth’s past?
______
5. ______Mesozoic Era
6. ______Precambrian Time
7. ______Cenozoic Era
8. ______Paleozoic Era
9. _____the geologic principle that the same geologic processes that operate today operated in the past to change Earth’s surface
10. _____a unit of geologic time that subdivides eras
11. _____a long unit of time used to divide the time between
Precambrian Time and the present
12. _____a record of the geologic events and the evolution of life forms as shown in the fossil record / A. period
B. geologic time scale
C. era
D. uniformitarianism
Fill in the blank to complete each statement.
13. Because the time span of Earth’s past is so great, geologists use the ______time scale to show Earth’s history.
14. Scientists chose where units of geologic time began and ended based on major changes in ______at certain times.
15. The long span of time that begins geologic time is called ______.
16. Geologists divided the time between Precambrian Time and the present into three long units of time called ______.
17. The Triassic Period, the Jurassic Period, and the Cretaceous Period occurred in the ______Era.
18. Weathering, erosion, and ______are the processes scientists infer to have shaped Earth’s surface in the past.