Stable Neodymium Isotope Ratios of Geological Reference Materials

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 delta Nd-146/144 values relative to the reference material JNdi-1 was greater than 0.030 parts per thousand (2s). Measurements of five previously analysed RMs yielded delta Nd-146/144 values that were consistent with those obtained using the double-spike method. The igneous rocks showed minimal variations in their delta Nd-146/144 values, which ranged from -0.039 parts per thousand to +0.015 parts per thousand. The sediments displayed large stable Nd isotopic fractionations ranging from -0.099 parts per thousand to +0.057 parts per thousand, implying differences in their sources. The soil RMs showed a range of -0.093 parts per thousand to -0.010 parts per thousand, likely owing to complex geological processes such as the degree of chemical weathering. The sedimentary rock dolomite had the heaviest delta Nd-146/144 values at +0.147 +/- 0.032 parts per thousand (2s, n = 3). Of the analysed RMs, the delta Nd-146/144 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.