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Monday October 25, 2010. (Why the Eons, Eras, Periods, and Epochs Changed). The Launch Pad Monday, 10/25/10. Describe the process by which continents were formed in the Precambrian Eon.
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MondayOctober 25, 2010 • (Why the Eons, Eras, Periods, and Epochs Changed)
The Launch Pad Monday, 10/25/10 Describe the process by which continents were formed in the Precambrian Eon. Volcanic island arcs and oceanic plateaus rose up in the ancient seas due to the upwelling of magma from the upper mantle. The action of plate tectonics caused the arcs to accrete into crustal provinces. The crustal provinces then accreted into cratons. The cratons then accreted to form the foundations of the modern continents.
Announcements • If you need to take or remediate Test 3, please make an appointment with me to do so ASAP.
Activity • Get your tape from the Lab on the Geologic Time Scale. • On the front side (from Part 1), divide the Precambrian Eon into Eras. • Research what caused the Eras to change and note this on the tape. • On the back side (from Part 2), if you have not done so already, divide the Phanerozoic Eon into eras, periods, and epochs. • Research what caused the all of the changes and note this on the tape.