Wikipedia ar ar dating
The multiple checks verify that the rate of isotope decay does not change over time, and it verifies the accuracies of the methods.For dating back to about 35,000 years, sediment layers are precise. Sediments include different types of pollen depending upon the season.For example, potassium decays into two different isotopes of argon having different half-lives.
Measuring the ratio of C14 to C12 and C13 therefore dates the organic matter for periods back to about eight half-lives of the isotope, 45,000 years.
To take this into account, a calibration curve is developed using other dating methods to establish the C14 levels over time.
Other methods do not require knowing the initial quantities.
Navnet Holocæn kommer af græsk og betyder "den helt nye tid" (af holos 'hel' og kainos ny).
Starten af Holocæn er defineret i en iskerneboring på Grønlands indlandsis, NGRIP2, i 1492,45 m dybde.