Relative age dating vs absolute age dating
The comparison helps establish the relative age of these remains.
Bones from fossils absorb fluorine from the groundwater.
Absolute dating is distinguishable from relative dating.
Absolute dating tells us exactly how old a material or object is, while relative dating tells us how much older or younger the material or object is as compared to another.
Relative dating is determined by comparing its placement with that of fossils in other layers of rock.
Tools like radiometric dating allow some samples to be assigned a certain age to within some accuracy.
Assigning a certain age or date is a form of absolute dating.
Over time, mare volcanism waned, and the Moon entered a period called the Eratosthenian -- but where exactly this happened in the record is a little fuzzy.
Tanaka and Hartmann lament that Eratosthenes impact did not have widespread-enough effects to allow global relative age dating -- but neither did any other crater; there are no big impacts to use to date this time period.
Absolute dating tells when the fossil was formed, relative dating compares fossils to other fossils, some fossils cannot se absolute dating so they have to use both relative and absolute dating together.