Sr and Nd isotope ratios of twelve GSJ rock reference samples

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., 1982, 1987, 1989; Kurasawa, 1984; Zhang Zichao, 1987; Ando and Shibata, 1988; Okano et al., 1989; Arakawa, 1992; Iizumi et al., 1994, 1995; Yamamoto 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. 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. We measured 87Sr/86Sr and 143Nd/144Nd ratios for JB-l a, JB-2, JB-3, JA-1, JA-2, JA-3, JG-1 a, JG-3, JGb-1 and JR-l, 87Sr/86Sr ratios for JF-1 and JF-2, and 143Nd/144Nd ratios for JG-2 and JR-2. Strontium and Nd isotopic ratios were measured for five to nine separate aliquots of each GSJ RRS. These data were compared with previously reported data which were normalized chemical standards. using