Isochron radiometric dating wikipedia X cam chat
However, methods using extinct radionuclides give only relative ages and have to be calibrated with radiometric dating techniques based on long living radionuclides like Pb-Pb-dating to give absolute ages.
Isochron dating is useful in the determination of the age of igneous rocks, which have their initial origin in the cooling of liquid magma.
There are over forty such techniques, each using a different radioactive element or a different way of measuring them.
It has become increasingly clear that these radiometric dating techniques agree with each other and as a whole, present a coherent picture in which the Earth was created a very long time ago.
Whole rock isochron dating uses the same ideas but instead of different minerals obtained from one rock uses different types of rocks that are derived from a common reservoir; e.g. It is possible to date the differentiation of the precursor melt which then cooled and crystallized into the different types of rocks.
One of the best known isotopic systems for isochron dating is the rubidium-strontium system.
Thus, at the moment of crystallization, the ratio of the concentration of the radiogenic isotope of the daughter element to that of the non-radiogenic isotope is some value independent of the concentration of the parent.
As time goes on, some amount of the parent decays into the radiogenic isotope of the daughter, increasing the ratio of the concentration of the radiogenic isotope to that of the daughter.
Radiometric dating--the process of determining the age of rocks from the decay of their radioactive elements--has been in widespread use for over half a century.
The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions are needed about the initial amount of the daughter nuclide in the radioactive decay sequence.
Indeed the initial amount of the daughter product can be determined using isochron dating.
It is also useful to determine the time of metamorphism, shock events (such as the consequence of an asteroid impact) and other events depending of the behaviour of the particular isotopic systems under such events.
Wiens has a Ph D in Physics, with a minor in Geology.
Other systems that are used for isochron dating include samarium-neodymium, and uranium-lead.