1. Fossils Mr. Skirbst Earth Science Topic 24

2. Fossils The preserved remains or evidence of a living thing

3. Types of Fossils 1.Petrification

4. Types of Fossils 1.Petrification minerals replace organic material Ex. Petrified wood

5. Types of Fossils 2.Molds

6. Types of Fossils 2.Molds empty space left by plant of animal buried in sediment

7. Types of Fossils 2.Molds empty space left by plant of animal buried in sediment 3.Casts

8. Types of Fossils 2.Molds empty space left by plant of animal buried in sediment 3.Casts a filled in mold

9. Types of Fossils Molds & Casts CAST MOLD

10. Types of Fossils 4.Imprints

11. Types of Fossils 4.Imprints impression in soft sediment

12. Types of Fossils 5.Preservation

13. Types of Fossils 5.Preservation entire specimen preserved (hard and soft parts)

14. Types of Fossils 5.Preservation entire specimen preserved (hard and soft parts) Freezing – trapped in ice

15. Types of Fossils 5.Preservation entire specimen preserved (hard and soft parts) Freezing – trapped in ice Amber – trapped in sap

16. Types of Fossils 5.Preservation entire specimen preserved (hard and soft parts) Freezing – trapped in ice Amber – trapped in sap Tar pit – trapped in tar

17. Types of Fossils 5.Preservation entire specimen preserved (hard and soft parts) Freezing – trapped in ice Amber – trapped in sap Tar pit – trapped in tar Peat pit – trapped in peat / bog

18. Types of Fossils 6.Trace Fossils

19. Types of Fossils 6.Trace Fossils tracks, trails, footprints

20. Age of Fossils

21. 1.Relative Age:

22. Age of Fossils 1.Relative Age: - determining age relative to others

23. Age of Fossils Law of Superposition

24. Age of Fossils Law of Superposition in sedimentary rock layers, older rocks are beneath younger rocks

25. Age of Fossils Law of Superposition YOUNG OLD

26. Age of Fossils Index Fossils

27. Age of Fossils Index Fossils - layers of rock with index fossils are close in age to other layers with the same kind of fossils

28. Age of Fossils Index Fossils 1 1 2 2 3 3 4

29. Age of Fossils 2.Absolute Age

30. Age of Fossils 2.Absolute Age determining the actual age of fossils

31. Age of Fossils Radioactive Dating

32. Age of Fossils Radioactive Dating - radioactive elements decay at a constant rate

33. Age of Fossils Radioactive Dating - radioactive elements decay at a constant rate Half-life – time it takes for ½ of element to decay