Answer:
Major divisions in the sedimentary rick layers.
Explanation:
Geologic time scale refers to a system of chronological dating which relates geological strata to time. Geologic time scale is used by scientists to describe the timing of the events that had occurred in the past, thus the scale divides the earth history into units of varying magnitude. There are four basic block of time, these are eons, eras, periods and epochs.
In determine geological time, rock records provide evidence of past geological events and life forms.
