1. Welcome To Class

2. Agenda Turn in homework Geologic time scale Fossil Reading 2
Notes
Fossil Reading 2
Review for test

3. Geologic Time If time was a 30 day month
Recorded human history would be .18 minutes or 10.8 seconds
First Homo sapiens would be .013 days or minutes or seconds
Cenozoic would be .42 days or 604 minutes
Mesozoic would be 1.18 days or 1700 minutes
Paleozoic would be days or 2808 minutes
Precambrian would days or minutes

4. In a day… Human history = 2.5 seconds Home sapiens = .6 minutes
Cenozoic = 20.2 minutes
Mesozoic= 56.5 minutes
Paleozoic= 93.6 minutes
Precambrian= minutes

5. Geologic Time Scale
Geologic time scale – chart that divides Earth’s history into units of time
Divisions based on geologic events and major changes in living things

6. Geologic Time Scale
Divided into eons, eras, and periods

7. PRECAMBRIAN TIME
Length– beginning of time (4.6 billion yrs) – 542 million years ago
Makes up 88% of Earth’s history

8. Precambrian Time Major Events Earth forms Rocks and minerals form
Stromatolites (algae) are most common fossils

9. PALEOZOIC ERA

10. Paleozoic Era Length – 542 – 251 million years ago Major Events
Supercontinent, Pangea, formed
Shelled marine animals common
Land Plants and animals appear
Fish, amphibians, reptiles appear
Permian mass extinction

11. Paleozoic Broken Down Cambrian Ordovician Silurian Devonian
Carboniferous
Mississippian
Pennsylvanian
Permian

12. MESOZOIC ERA

13. Mesozoic Era Length – 251-65 million years ago Major Events
Age of the Dinosaurs
Major Events
Pangea broke up
Dinosaurs
First Birds
First flowers
Dinosaur extinction

14. Mesozoic Broken Down Periods in the Mesozoic Triassic Jurassic
Cretaceous

15. CENOZOIC ERA

16. Cenozoic Era Length – 65 million years ago-present Major Events
Age of mammals
Major Events
Mammals appear
Continents in current places
First humans

17. Cenozoic Broken Down Tertiary Quaternary Paleocene Eocene Oligocene
Miocene
Piliocene
Quaternary
Pleistocene
Holocene

18. Fossil Reading
Due today

19. Review
Worksheet due on test day
Create a Note card (tomorrow)

20. Which are the oldest? Remember the laws/principles/unconformities
Law of Superposition
Principle of Original Horizontality
3 Unconformities
Law of Cross Cutting Relationships

25. Absolute Age
Radiometric/carbon dating
Half life

26. Interpret a half life graph
5.8 days

27. .25 half lives

28. 28 years

29. Review Work on the worksheet Due on the TEST!! Create a note card