Changes in the earth's magnetic field from normal polarity to reversed polarity or vice versa reversed polarity:
Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.
The absolute dating is more precise than relative dating because it tells the exact age of the fossils.
Rocks and structures are placed into chronological order, establishing the age of one thing as older or younger than another.
There is an enormous body of science on the age-dating of Apollo samples and Moon-derived asteroids.
Lunisolar Solar Lunar Astronomical year numbering.
These changes typically occur so slowly that they are barely detectable over the span of a human life, yet even at this instant, the Earth's surface is moving and changing.
Others measure the subatomic particles that are emitted as an isotope decays.
Relative dating instead allows for identifying the sequential order of geological events one relative to the other.
Relative dating is based on super imposition and fossils.