Isotope dating of rocks
The isotopes are then measured within the same machine by an attached mass spectrometer (an example of this is SIMS analysis).
This is a common dating method mainly used by archaeologists, as it can only date geologically recent organic materials, usually charcoal, but also bone and antlers.
This system is highly favoured for accurate dating of igneous and metamorphic rocks, through many different techniques.This technique uses the same minerals and rocks as for K-Ar dating but restricts measurements to the argon isotopic system which is not so affected by metamorphic and alteration events. The decay of 147Sm to 143Nd for dating rocks began in the mid-1970s and was widespread by the early 1980s.It is useful for dating very old igneous and metamorphic rocks and also meteorites and other cosmic fragments.those that form during chemical reactions without breaking down).The unstable or more commonly known radioactive isotopes break down by radioactive decay into other isotopes.