Earth’s History How the earth works. How the earth has changed over time. Earth timeline activity. California geology.
Earth Structure
How the Earth Works: Plate Tectonics
The Earth’s Plates
Themes for Today The earth is very old. The earth is always changing.
Ages to Note 14 billion years - age of universe 4.5 billion years - age of earth 3.5 billion years - oldest know life on earth 544 million years - explosion of life 65 million years - dinosaur extinction 1.5 million years - first homo sapiens
Geologic Time Scale
Cambrian 540 Ma
Permian 270 Ma
Cretaceous 60 Ma
Present
North America: Plate Tectonics at Work
Timeline Activity Divide into groups of 2. Collect 4.5m of adding tape. Using the worksheet provided, measure out each time. Note that each time is the time from the present, not the previous time. Have fun!!