This is different to relative dating, which only puts geological events in time Most absolute dates for rocks are obtained with radiometric methods.These use radioactive minerals in rocks as geological clocks.
And, what about other findings like fossil fish, plants and insects?
The atoms of some chemical elements have different forms, called isotopes.
These break down over time in a process scientists call radioactive decay.
In historical geology, the primary methods of absolute dating involve using the radioactive decay of elements trapped in rocks or minerals, including isotope systems from very young (radiocarbon dating with Radiometric dating is based on the known and constant rate of decay of radioactive isotopes into their radiogenic daughter isotopes.
Particular isotopes are suitable for different applications due to the type of atoms present in the mineral or other material and its approximate age.