Geologic Time & the Geologic Time Scale

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

Geologic Time as a Linear Progression

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

Evolution of Life on Earth (in 1 hour)

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

Geologic Time as a Spiraling Line

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

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

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.

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

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

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

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

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

Stratigraphic Correlation Through… …Relative dating and Biostratigraphy

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

Surface Geology of South Carolina