The beginning and end points of eras, epochs, and periods on the geologic time scale are set by __________ ages.
A)relative
B)systematic
C)numerical
D)isotrophic

Question

Quizplus · Accepted Answer

The beginning and end points of eras, epochs, and periods on the geologic time scale are set by numerical ages, which are obtained through radiometric dating of rocks and fossils. This involves measuring the decay of radioactive isotopes within the rocks or fossils, which allows scientists to determine the age of the material. Relative ages are used to establish the sequence of events within a particular time period, but they do not provide actual numerical ages. Systematic and isotrophic are not relevant terms in this context.

The Beginning and End Points of Eras, Epochs, and Periods