1. The Geologic Time Scale Geologic Time Scale

2. Geologic Time Scale: Subdivisions of Earth's history by pure Time and by Rocks deposited during an interval of time Geologic Time Scale

4. Divisions: Eons (largest) Phanerozoic ------ “shelly fossils” 542 my Proterozoic ------ modern tectonics 2.5 by Archean ------ oldest rocks 4.0 by Hadean ------ origin of Earth 4.6 by Geologic Time Scale

5. “Precambrian” is an informal term for everything prior to the Cambrian

6. Divisions: Eras only Phanerozoic subdivided based on appearance of fossils bounded by mass extinctions Geologic Time Scale

7. Divisions: Eras (largest) Cenozoic - new life Mesozoic - middle life Paleozoic - ancient life Geologic Time Scale

8. Periods (fundamental unit) Geologic column originally divided as Time-Rock units. Geologic Time Scale

9. Periods (fundamental unit) Geologic Time units bear the names of their corresponding Time-Rock units. Geologic Time Scale

10. Time Scale was developed piece-meal Units were recognized locally Bounded by regional unconformities Based on fossil assemblages Named for local geography (tribes) Geologic Time Scale

11. 19th C Naturalists Characterized their own rocks

12. Geologic Time Scale 19th C Naturalists Characterized their own rocks “Wataugan” “Catawbian” “Allegheny”

13. Type section: where the unit was originally defined. Independent workers Around Europe 19th Century Geologic Time Scale

14. Type sections: Geologic Time Scale Cambrian Ordovician Devonian Silurian

15. Time scale assembled by: Geologic Time Scale Principle of Superposition Principle of Fossil Succession Correlation

16. Characteristics of the Time Scale: There is not a single, complete section anywhere! Scale was originally all relative. Absolute time was added later. Geologic Time Scale

17. Same principles applied for Epochs & Ages Biologic component more important Cenozoic Epochs were originally based on % of modern mollusc species. Work on Series & Stages continues today Geologic Time Scale

18. What to know. Geologic Time Scale from class web page Practice on Blank Eons (dates) Eras (for Phanerozoic & dates) Periods (Miss, Penn, & Tertiary) Do not have to know who, where & when of naming. Geologic Time Scale

19. What to know. Geologic Time Scale from class web page Practice on Blank Eons (dates) Eras (for Phanerozoic & dates) Periods (Miss, Penn, & Tertiary) Do not have to know who, where & when of naming. Geologic Time Scale My personal guarantee Question #1 on Test 1

20. Queens Two Cover Jacks Three Poker Play Maybe Day Some Over Come Honey Please Plate My On Eggs Put

21. Grand Canyon Zion Complete Geologic Section can be assembled though correlation. For example: Arizona - Utah Bryce Canyon

22. http://3dparks.wr.usgs.gov/coloradoplateau/images/bryce_strat.jpg Grand CanyonZion

23. http://3dparks.wr.usgs.gov/coloradoplateau/images/bryce_strat.jpg Grand CanyonZion

24. http://3dparks.wr.usgs.gov/coloradoplateau/images/bryce_strat.jpg Grand Canyon Zion Cambrian - Jurassic

25. http://3dparks.wr.usgs.gov/coloradoplateau/images/bryce_strat.jpg Brice Canyon Zion

26. http://3dparks.wr.usgs.gov/coloradoplateau/images/bryce_strat.jpg Grand Canyon Zion Cambrian - Quaternary Bryce Canyon