Stable Neodymium Isotope Ratios of Geological Reference Materials
Jianghao Bai, Jinlong Ma, Gangjian Wei, Le Zhang, Chengshuai Liu, Ting Gao, Yuhui Liu, Yufei Liu
Abstract
Here, we report the stable Nd isotopic compositions of twenty‐seven widely available geological reference materials (RMs) including silicates, sediments, soils and carbonates. Nd was purified from geological samples using a single TODGA resin column. The Nd isotopic ratios were determined via MC‐ICP‐MS using the combined standard‐sample bracketing and internal normalisation method. The (long‐term) intermediate measurement precision of δ 146/144 Nd values relative to the reference material JNdi‐1 was greater than 0.030‰ (2 s ). Measurements of five previously analysed RMs yielded δ 146/144 Nd values that were consistent with those obtained using the double‐spike method. The igneous rocks showed minimal variations in their δ 146/144 Nd values, which ranged from ‐0.039‰ to +0.015‰. The sediments displayed large stable Nd isotopic fractionations ranging from ‐0.099‰ to +0.057‰, implying differences in their sources. The soil RMs showed a range of ‐0.093‰ to ‐0.010‰, likely owing to complex geological processes such as the degree of chemical weathering. The sedimentary rock dolomite had the heaviest δ 146/144 Nd values at +0.147 ± 0.032‰ (2 s , n = 3). Of the analysed RMs, the δ 146/144 Nd values of thirteen of them are being reported for the first time. The datasets presented here should play fundamental role in quality assurance and allow for universal comparisons for stable Nd isotope systematics.