Clumped isotope calibration data for dolomite and apatite; non-InterCarb carbonate standard data

Here we report I-CDES standardized values for a suite of 11 carbonates that are commonly measured by the clumped isotope community to aid future comparisons of non-I-CDES datasets. In addition, seventeen dolomite samples (25–1200°C) and five apatite samples (1–38°C) of known precipitation temperature were measured using carbonate-based standardization. Excellent agreement between calcites and dolomites heated to similar temperatures (1100–1200°C) suggests no mineral-specific differences in absolute acid fractionation factor. We show that calcite and dolomite regressions largely agree, but are sensitive to sample characteristics, regression method, and how equations are statistically compared. We suggest that there is no need for a dolomite-specific clumped isotope calibration, although our results suggest further work is necessary to determine the influence of sample characteristics on this relationship. The apatite calibration equation defined in this study is statistically indistinguishable from calcite-based calibrations; we corroborate previous findings that an apatite-specific calibration is unnecessary.

本报告揭示了由群集同位素社群普遍测量的11种碳酸盐的I-CDES标准化值，旨在辅助未来对非I-CDES数据集的比较。此外，通过对已知沉淀温度（25–1200°C）的17个白云石样本和5个磷灰石样本（1–38°C）进行基于碳酸盐的标准化测量，我们观察到在相似温度（1100–1200°C）下加热的方解石与白云石之间表现出卓越的一致性，这表明在绝对酸度分配因子上不存在矿物特有的差异。我们指出，方解石与白云石之间的回归关系基本一致，但对样本特性、回归方法以及统计比较方程式的处理十分敏感。我们建议无需针对白云石进行特定的群集同位素校准，尽管我们的研究结果暗示了有必要进一步研究样本特性对该关系的影响。本研究中定义的磷灰石校准方程式在统计学上与基于方解石的校准方程式不可区分；我们证实了之前的发现，即无需针对磷灰石进行特定的校准。