Radiometric dating uses what isotopes Adult friendfinder chat
Other isotopes occur naturally in the uranium and actinium decay series, and thorium is present in all uranium ores.
This then causes orthoclase and biotite, both K rich minerals into which Rb can substitute, to precipitate.Synthetic isotopes have been prepared; thorium-229 (7,880-year half-life), formed in the decay chain originating in the synthetic actinoid element neptunium, serves as a tracer for ordinary thorium (thorium-232).Thorium exhibits an oxidation state of 4 in almost all of its compounds.However, because Rb substitutes for K in minerals and these minerals have different K/Ca ratios, the minerals will have had different Rb/Sr ratios.During fractional crystallization, Sr tends to become concentrated in plagioclase, leaving Rb in the liquid phase.
The age of a sample is determined by analysing several minerals within the sample. If these form a straight line then the samples are consistent, and the age probably reliable.