Lu-Hf method

Applications of the Lu/ Hf method and of the Re/ Os method have no advantages over the methods mentioned previously. For simultaneous determination of the mother and daughter nuclide by MS, suitable non-radiogenic nuclides have to be selected as reference nuclides. In the case of Hf, the use of Hf is preferred for this purpose. However, the main drawbacks of the Lu/ Hf method are the low concentration of Lu in minerals (< 1 mg/kg) and the difficulties in measuring Hf by MS due to the low ionization yield. In the Re/ Os method, Os is used as reference nuclide. As in the case of dating by the Lu/ Hf method, the low concentration of Re in minerals (on the average 1 ng/kg) is a basic drawback with respect to broad application. The method has been used for dating of meteorites and... 

Patchett, P J. and Tatsumoto, M. (1980) A routine high-precision method for Lu-Hf isotope geochemistry and chronology. Contrib. Mineral. Petrol, IS, l i-l. 

The physical methods of geochronology are based on the radioactive decay of unstable (parent) radionuclides into stable (daughter) isotopes such as Rb to Sr to ° Pb Th to 208pb 235pj jQ 207p(j. Rc to Os Lu to Hf and to °Ar. There are... 

The decays of " Sm (Samarium) to " Nd (Neodymium), Lu (Lutetium) to Hf (Hafnium), and Re (Rhenium) to Os (Osmium) all have long parental half-lives and very low natiual abimdances of the parent isotopes which means that the radiogenic daughter isotopes accumulate very slowly. Before about 1980 these decay schemes were of little value as radiometric dating methods. However, improvements in analytical techniques have permitted geochronologists to apply these three dating methods to certain types of problems. 

---