87Sr/86Sr and 143Nd/144Nd ratios of GSJ rock reference samples; JB-1a, JA-1 and JG-1a.

Sr and Nd isotope ratios of twelve GSJ rock reference samples.

“…Kurasawa (1984), Zhang Zichao (1987), Kagami et al (1989), Iizumi et al (1994) and Yamamoto and Maruyama (1996) also reported Sr isotope values of GSJ-RRS with the value of NBS987. The NBS987 values in these reports are 0.710278 ± 0.000009 (2am), 0.71030 ± 0.00003 (26m), 0.710252 ± 0.000018 (2(ym), 0.710275 ± 0.000007 (2am) and 0.710241 ± 0.000022 (2(y m), respectively.…”

“…However, there are still few isotopic data for some GSJ-RRS, and Nd isotope ratios have not yet been reported for some samples, such as JA-3 and JR-2. Also, as pointed out by some authors (e.g., Kagami et al, 1989;Arakawa, 1992), some GSJ-RRS exhibit systematic differences in Sr and Nd isotopic ratios between laboratories even if normalization has been done using standard samples of chemicals.…”

“…The standard samples of "igneous rock series" provided by the Geological Survey of Japan (GSJ rock reference samples, GSJ-RRS) are widely used for analytical references of geological samples, and their Sr and Nd isotopic ratios have been reported from several laboratories (e.g., Shibata and Adachi, 1972;Nohda and Wasserburg, 1981;Kagami et al, 1982Kagami et al, , 1987Kagami et al, , 1989Kurasawa, 1984;Zhang Zichao, 1987;Ando and Shibata, 1988;Okano et al, 1989;Arakawa, 1992;Iizumi et al, 1994Iizumi et al, , 1995Yamamoto and Maruyama, 1996). However, there are still few isotopic data for some GSJ-RRS, and Nd isotope ratios have not yet been reported for some samples, such as JA-3 and JR-2.…”

143Nd/144Nd ratios of twelve GSJ rock reference samples and reproducibility of the data.

“…The stan dard errors (2Um) of 143Nd / 144Nd ratios for each run of the standard rock samples range from 0.000006 to 0.000012 which correspond to 0.0012% to 0.0023% of the data. Kagami et al (1989) used two step normalization to reduce the dispersion of 143Nd/ 144Nd data, with 142Nd/ 144Nd =1.141827 after 146Nd /'44Nd = 0.7219. In our measurement system, however, no large variation in Nd isotope ratios was found after the normalization with 146Nd / 144Nd = 0.7219.…”

“…The determination of isotope com positions of standard rock samples is particu larly important for checking the precision of data and for interlaboratory comparison of the data. For 87Sr/86Sr ratios of the GSJ (Geological Survey of Japan) rock reference samples, many data have been accumulated and their evaluation has been made (Ando et al, 1987;Ando and Shibata, 1988;Kagami et al, 1989). However there is not enough data for 143Nd/ 144Nd ratios of the GSJ rock reference samples.…”