1. Geologic Time & the Geologic Time Scale

2. How do we make sense out of a 1000 foot-thick rock sequence?
Rock Units:
Supergroup
Group
Formation
Member
Bed
Time Units:
Eon
Era
Period
Epoch
Stage

3. Geologic Time as a Linear Progression

4. Geologic Time in one Hour
Hadean – Proterozoic eons
Proterozoic & Phanerozoic eons

5. Evolution of Life on Earth (in 1 hour)

6. Earth’s Geologic Time in 100 Yards
Phanerozoic Eon begins between 12 and 11 yard lines

7. Geologic Time as a Spiraling Line

8. 2009 Geologic Time Scale
Subdividing 4.6 billion years into smaller, more “manageable” intervals

9. Time-rock Time vs. Phanerozoic Cenozoic Neogene Eocene Bartonian Eon
Era
Period
Epoch
Age
Eonothem
Erathem
System
Series
Stage

10. Rocks Don’t mix time units with rock units! Late Fossils Eocene Time
vs.
vs.
Upper
Meaning: Late Eocene fossils are found in Upper Eocene rocks.
So Periarchus lyelli (sand dollar) lived during the Priabonian age and fossils occur in rocks from the Priabonian stage.

11. Time-Rock and Rock-Rock Units
Time Units
Pennsylvanian rocks in SE Kansas

12. What’s in a Name?
Paleozoic rocks of Europe
Western England

13. Evolution of Western Interior Seaway, North America (Cretaceous Period)

14. goodbye Tertiary, hello Paleogene/Neogene
2009
Cenozoic Era –
goodbye Tertiary, hello Paleogene/Neogene
1980s
Subdivisions were based on fossil content…

15. If the type section for the Ordovician is in western England, how do we know rocks in Eastern USA are the same age?

16. Stratigraphic Correlation Through…
…Relative dating and Biostratigraphy

17. Index fossils are: • Common • Widespread • Lived during a relatively
short interval of time

18. Surface Geology of South Carolina