VIII. Time and Earth’s History

A. Time
  1. problems and early attempts
  2. uniformitarianism
B. Relative vs. absolute ages
    1. sequences of events (layer sequence)
    1. superposition,
    2. original horizontality,
    3. lateral continuity,
    4. cross-cutting relationships,
    5. unconformitites
  1. . principle of fossil succession
    1. age range
    2. fossil assemblages (fig. 11.11)
  2. Geologic Time Scale (fig. 11.16)
      >Precambrian (>540 ma)
    1. Paleozoic (540-248 ma)
    2. Mesozoic (248 – 65 ma)
    3. Cenozoic (<65 ma)
  3. radiometric dating
    1. radioactive decay
    2. half-life
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