Answer:
The Geological Time Scale
Step-by-step explanation:
The Geological Time Scale is the framework in which the history of the Earth is inscribed. It combines a numerical scale that uses the million years as a unit (chronometric scale) and a scale that is expressed in relative time units (chronostratigraphic scale).
The chronometric scale is based on the measurement of certain physical properties of rocks, generally the relationship between the content of stable and unstable isotopes of the same element.