1. Earth Exact Age of Earth: _______

2. Geologic Dating Methods I: Radioactive Decay http://www.btinternet.com/~j.doyle/SR/Emc2/decay_a-decay.gif

3. Geologic Dating Methods II: Known Rates of Radioactive Decay http://people.hofstra.edu/j_b_bennington/2cnotes/halflife.J PG

4. Geologic Dating Methods III: Ratios of Parent : Daughter Atoms Radiocarbon half-lifes

5. EARTH’S OLDEST ROCKS 4.03 BYA (Acosta Gneisses) 3.7 – 3.8 BYA 3.4 – 3.5 BYA http://pubs.usgs.gov/gip/geotime/age.html 3.4 – 3.6 BYA

6. Earth’s Oldest Known Rocks (Probably do NOT date to Earth’s Formation)

7. Geologic Forces (e.g., Plate Tectonics)

8. Origin of Solar System

9. IRON METEORITES (Canyon Diablo) Age: 4.53-4.58 BYA (U > Pb) http://pubs.usgs.gov/gip/geotime/age.html

10. Canyon Diablo Crater (Near Flagstaff AZ)

11. LUNAR ROCKS Oldest Moon Rocks: 4.4-4.5 BYA http://pubs.usgs.gov/gip/geotime/age.html

12. Earth’s Origin (~ 4.5-4.6 BYA)

13. 500 Million Years After Origin of Earth (Artistic Rendition) http://www.arcadiastreet.com/cgvistas/earth/images/earth_ancient_volcano_60 0.jpg

14. The Earth Cools (Artistic Rendition) http://www.cartage.org.lb/en/themes/Sciences/Paleontology/Paleo zoology/Precambrian/Precambrian.htm

15. Ancient Evidence for Free Oxygen Isua Rock (Greenland): ~ 3.7 Billion Years Old Metamorphosed Sediments Abundant Free Uranium – Likely Only in Oxidizing Environment

16. Oxygen Liberating Process?

17. Ancient Fossil “Cyanobacteria” (3.47 BYA) http://marsfossil.home.netcom.com/images/pilbara_detail.jpg Apex Chert in Western Australia (Pilbara Formation)

18. Fossil Stromatolites (3.5 BYA)

19. Living Stromatolites (Shark Bay Australia)

20. Fig. 2.8 in Willis and McElwain 2002 Stromatolite Formation

21. Living Stromatolites (Cross-Section)

22. Fossil Stromatolites (with Fossil Microorganisms) Gunflint Chert – Ontario, Canada (2 BYA)

23. Origin of the Cell?

24. Origin of Organic Macromolecules?

25. Hypothesis I: Terrestrial Accretion (Miller – Urey Experiments 1950s)

26. Origin of Cell Membrane?

27. Fig. 2.4 in Willis and McElwain 2002 Hypothesis: Drying, Rehydrating of Tide Pools

28. Hypothesis II: Meteoric and Cometary Infall of Organic Molecules formed Elsewhere (Present Day Meterites can contain 1% Organic Molecules)

29. Hypothesis III: Meteoric and Cometary Infall of Cells formed Elsewhere (e.g., Mars)

30. Predominantly Non-Oxidized Sediments Reduced Rocks

31. Ancient Evidence for Free Oxygen Isua Rock (Greenland): ~ 3.7 Billion Years Old Metamorphosed Sediments Abundant Free Uranium – Likely Only in Oxidizing Environment

32. Banded Iron Formations (Up to 3.7-3.8 Billion Years Ago) Evidence for Pulses of Free Oxygen

33. Red Beds (Up to 2.3 Billion Years Ago) Evidence for Free Oxygen Accumulation

34. Heterocysts (Up to 2.1 Billion Years Ago) Microbiology 155 (2009), 1418-1426

35. Atmospheric Oxygen Levels http://ncbi.nlm.nih.gov

36. Fossil Eukaryotic Cells Grypania ciliaris (Alga) in Northern Michigan (2.1 – 1.1 BYA)

37. Fossil “Red Alga” in Arctic Canada (1200 MYA) “Bangia” Figs. 2.12 in Willis and McElwain 2002

38. Fossil “Green Alga” in Spitsbergen (800-700 MYA) “Cladophora” Fig. 2.14 in Willis and McElwain 2002

39. Fossil Tetrads (> 470 MYA) Bitter Springs Formation, Australia

40. Cooksonia (420 MYA)