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Introduction to the Geologic Time Chart (6:36)

Key Ideas

As this video progresses, key ideas will be introduced to invoke discussion.

Key Ideas

Think about the following questions as you watch the video

  1. 00:25 What is periodization?
  2. 01:12 Why does Professor Alvarez call periodization in history “informal” and periodization in geology “formal”?
  3. 01:42 What are the major divisions of time geologists use?
  4. 03:32 How does the rate of change compare in the four eons?
  5. 06:00 Professor Alvarez says that each period of geologic history has a personality that is familiar to all geologists. What is it that he likes about the Ordovician period?