Astrochronology is the dating of
sedimentary
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
units by calibration with
astronomically tuned timescales, such as
Milankovic cycles
Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypot ...
,
or even
sunspot cycles. When used in concert with
radiometric dating
Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares ...
, it allows the resolution of timescales to a high degree of accuracy. If
orbital precession cycles are identified, the dating error can be as low as 21,000 years.
References
Geochronological dating methods
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