Geologic Time Scale What is the geologic time
- Slides: 13
Geologic Time Scale
What is the geologic time scale? n Time-line of Earth’s history n Breaks down Earth’s history into units of time
Eras are the largest unit of time. Precambrian Paleozoic Mesozoic Cenozoic Eras are divided into smaller parts called periods. Periods are then divided into even smaller parts called epochs.
Precambrian Era Earliest span of time in Earth’s history. n No life for a long time and then very simple life appears. n Early life influenced by volcanoes and mountain building n
Precambrian (cont. ) Oldest rock 4 bya n Single-celled organisms 3. 6 bya n Canadian Shield formed 3. 6 bya n n (bya= billion years ago)
Paleozoic Era n n n Took place after Precambrian Era “Age of Fishes”: living organisms only existed in the seas Early invertebrates and amphibians (first animals to live on land) Tropical climates allowed growth of new species Forests of trees developed
Paleozoic Era (cont. ) n n n Formation of Appalachian Mountains in eastern Canada Mass extinction at end of era when 80% of marine invertebrates disappeared Cause of extinction is not clear, but may be related to formation of Pangaea
Mesozoic Era n n Beginning of the break up of Pangaea North American plate collides with Pacific Plate: formation of Coast Range, then Rocky Mountains “Age of Reptiles” Reptiles, small mammals, dinosaurs and small birds
Mesozoic Era (cont. ) n n Warm climate in Canada Creation of coal, oil and gas in western Canada Era ended with mass extinction by asteroid or climate change 50% of all plant and animal species (including dinosaurs) became extinct.
Cenozoic Era n n n The Era we are currently in!!! “Age of Mammals” Mammals, flowering plants Canada experienced an Ice Age with four periods of glacial activity First humans
Cenozoic Era n We still have much diversity but could there be a mass extinction to come? ? ?
Formation of Canada n Let’s draw…
- Compare geologic time with the geologic column.
- How is the geologic time scale organized
- Geologic time scale graphic organizer
- Geologic time scale in a calendar year
- Geologic time scale animals
- The longest subdivision of the geologic time scale is the
- Moth scale
- Geologic time
- Nonconformity
- Geologic time scale poem
- Geologic time scale
- Geologic time scale drawing
- Brainpop geologic time
- Geological time scale graphic organizer