Presentation on theme: "Geologic Time 1 Add this unit to your Table of contents!"— Presentation transcript:
Geologic Time 1 Add this unit to your Table of contents!
A timeline of your education If we made a timeline of your education, where would you fall?? What would we use as the scale? Grade level K123456789101112 K Where would you fall on the timeline of the Earths history?? 4.6 billion years agoPresent day
Fossils and Geologic Time The geologic time scale organizes geologic and evolutionary events. It is based on evidence in the fossil record and has been shaped by mass extinctions.
How do extinctions shape Geologic Time? Mass extinction- A large number of species become extinct After a mass extinction, opportunities open for new life-forms to emerge.
Geologic Time Scale Divisions of the Geologic Time Scale Precambrian Era Paleozoic Era Mesozoic Era Cenozoic Era
The Precambrian Era 4.6 billion years ago – 542 million years ago ~88% of the earths history
Major Events Formation of the Earths crust from molten rock First appearance of life --- bacteria! First organisms could photosynthesize---- Oxygenated atmosphere First multi-cellular organisms
Major Events MASS Extinction- widespread glaciation Geologists compared the Earth to a giant snowball during this time
DOMINATE ORGANISMS Bacteria Multicellular organisms Fossils found in South Australia Cyanobacteria and stromatolites