What is the difference between geochronologic division and chronostratigraphic division?
Chronostratigraphic divisions of the geologic timescale are in
units of geological material, while geochronologic divisions are
periods of time. It is important to make this distinction because
while you can visit a deposit of fossils from a certain time period
(the geological material; chronostratigraphy), you can visit the
actual time period (geochronology).