This document provides information on geological time periods from the Precambrian Era to the present. It outlines the main eras of the geologic time scale including the Paleozoic Era (Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian periods), Mesozoic Era (Triassic, Jurassic, and Cretaceous periods), and Cenozoic Era (Tertiary and Quaternary periods). It also describes methods for determining absolute and relative ages of rocks, including radiometric dating techniques using radioactive isotopes and their half-lives.

4. Cenozoi
c Era
Mesozoi
c Era
Paleozoi
c Era
Precambr
ian Era

5. (Precambrian Era)




4,600-545

6. Paleozoic Era)


(Cambrian)
(Ordovician)
(Silurian)
(Devonian)
(Carboniferous)
(Permian)

7. Paleozoic Era)
(Cambrian)

8. Paleozoic Era)
Ordovician)

9. Paleozoic Era)
Silurian)

10. Paleozoic Era)
Devonian)

11. Paleozoic Era)
Carboniferous)

12. Paleozoic Era)
Permian)

13. Era)


Mesozoic
Triassic)
Jurassic)
Cretaceus)

14. Era)
1.
Mesozoic
(Triassic)

15. Era)
Mesozoic
Jurassic)

16. Era)
Mesozoic
Cretaceus)

17. Era)


Period)
2.
Period
Cenozoic
Tertiary
Quaternary

18. Era)

Cenozoic
Tertiary Period)

19. Era)

Period)
Cenozoic
Quaternary

20. 1.
2.
3.

22. age)
relative

23. absolute
age)
Half life)”

24. 87
232
238
- 40
– 50
-
13.90
–
4.51
1.30

25. absolute
age)
C-14
C-14
1
5,730
C-14
5,730
C-14
C-14

26. absolute
age)

27. 1.
2.
3.
20 g
2
1.25 g
10 g
-131
8
-131
2.5 g
Tc-99
10
Tc-99
24

30. Fossil)

35. Fossil)

36. Fossil)
Index

37. 1.
2.

41. -

45. 


47. (Bedding)