ID-TIMS Sm-Nd and Sr isotopic composition of reference material Basalt Ribeirão Preto (BRP-1)

The reference material BRP-1 ("Ribeirão Preto Basalt") was produced by the Brazilian Geological Survey and derived from a 130 Ma within-plate basalt collected in a quarry near the city of Ribeirão Preto, in the Paraná basin. This study presents the Sm-Nd and Sr isotopic ratios of the RM BRP-1 obtained through repeated TIMS measurements spanning twelve years at the LAGIR laboratory in Brazil. Isotopic ratios were determined using a TRITON mass spectrometer, with corrections for instrumental bias and fractionation based on repeated measurements of the certified RMs JNdi-1 and NIST SRM 987. No significant difference between measurements was observed, whether digesting samples in single or batch mode, using metal-jacketed PTFE bombs or PFA vials, or with or without the addition of spike. The measured Nd and Sr isotopic ratios for BRP-1 are: 143Nd/144Nd = 0.512408 ± 0.000010 (2s), and 87Sr/86Sr = 0.706011 ± 0.000017 (2s). The mass fractions (in µg/g) of Sm and Nd are 11.0 ± 0.2 and 51.9 ± 0.6, respectively, indicating no significant differences from accepted literature values.