The Geologic Time Scale

1 The Geologic time ScaleA history of the earth How old is the earth ? billion years! 4,600,000,000 Divided into eras : Precambrian Paleozoic Mesozoic Cenozoic million years 4 x million years How long was the Paleozoic?544 MYA - 245 MYA How long was the Paleozoic?544 MYA - 245 MYA 299 million years How long was thePrecambrian?299 million years 4,056 million years299 million years Warning:Not to Scale !! To Scale ? To Scale ? How big was a a Sauroposeidon? A Scale timeline To appreciate the times involved in earth s history, we will make two Scale timelines A set distance on the timeline represents the same amount of time ( 1 cm = 1 year) Example: If this line represents your K-12 school career, where would you be now?

2 K12 K123456789101112A Scale timeline To appreciate the times involved in earth s history, we will make two Scale timelines A set distance on the timeline represents the same amount of time ( 1 cm = 1 year) Example: If this line represents your K-12 school career, where would you be now? Scale Timeline of earth s HistoryPart I: Outdoor Timeline How old is earth ? 4,600,000,000 years old ( billion years) Today s time line Scale : 1m = 100 million years billion years = 46 meters Ground Rules We stay together - no stragglers!

3 When I talk, you listen Stay with your table partner and make decisions as a pair Scale Timeline of earth s HistoryPart II: Paper Timeline Today, you will create a Scale timeline of earth s history on a long sheet of adding machine paper Scale : 1 inch = 100,000,000 years billion years = 46 inches Mr. Inman s mother was born 1,625,000,000 years ago. Where would this be on the time line? Scale Timeline of earth s HistoryPart II: Paper TimelineYou may use: Meter sticks (even though we re using inches) Decimal inch rulers Your textbooks Copies from other textbooks The internet You may compare your timeline to my sample, but you can t take a pencil there when you go!

4 Scale Timeline of earth s HistoryPart II: Paper TimelineTo clean up: Return Meter sticks (even though we re using inches) Decimal inch rulers Your textbooks Copies from other textbooks Leave the computers running and open, but shut down the internet One member of each pair will keep the timeline until tomorrow Go back to original seats