X-ray fluorescence and isotope dilution analyses establish the NBS 70a K-feldspar as sufficiently homogeneous after regrinding to serve as an interlaboratory Rb-Sr age reference sample. Similar coefficients of variation at approximately 0.2% for a single analysis using 0.1 g samples are obtained for Rb (530 ppm), Sr (65.1 ppm) and radiogenic Sr (3.0 ppm), both between bottles and within bottles.
|Number of pages||5|
|Journal||Geochimica et Cosmochimica Acta|
|Publication status||Published - Jun 1969|