Different Periods of the Geologic Time Scale Are Different in Length

Multiple Choice

Different periods of the geologic time scale are different in length. Why?

A) The geologists who developed the time scale did not care about absolute ages.
B) The time scale was developed ad hoc, as a relative time scale based on rocks and fossil succession with no reference to absolute time when it was developed.
C) Early geologists made mistakes, but it was easier to retain the terminology in the time scale.
D) None of the above.