Methodology: Sr-Nd-Hf Isotope Analysis

Pretreatment

Strontium, neodymium and hafnium are separated from the matrix elements by means of extraction chromatography using Eichrom cation exchange resin following the methods of Pourmand and Dauphas (2010) and Pourmand et al. (2014).

Sample types available for Sr-Nd-Hf analysis: igneous rocks, marine sediments, lacustrine sediments, mineral dust.

More information on Sample Types and Selection for Sr-Nd-Hf analysis.

Isotope Measurement

Device: Neptune Plus multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) with an Apex-Q desolvation nebulizer following Pourmand et al. (2014).

Results

Strontium isotope ratio data are reported as 87Sr/86Sr ratios. The analytical accuracy and precision were assessed by multiple measurements of certified reference material (SRM 987) during the analysis. Uncertainties for each sample measurement is presented as the 95% confidence interval (CI).

Neodymium isotope ratio data are reported as 143Nd/144Nd ratios and also expressed in the epsilon notation (εNd). The analytical accuracy and precision were assessed by multiple measurements of certified reference material (JNdi-1) during the analysis. Uncertainties for each sample measurement is presented as the 95% confidence interval (CI).

Hafnium isotope ratio data are reported as 176Hf/177Hf ratios and also expressed in the epsilon notation (εHf). The analytical accuracy and precision were assessed by multiple measurements of certified reference material (JMC-475) during the analysis. Uncertainties for each sample measurement is presented as the 95% confidence interval (CI).

Sr-Nd-Hf report

All results are also presented graphically on a series of plots which illustrates the range of measured isotopic ratios of tested samples.

Nd-Hf plot

An example plot of εHf versus εNd for the tested samples.

References

Pourmand, A. and Dauphas, N., (2010). Distribution coefficients of 60 elements on TODGA resin: application to Ca, Lu, Hf, U and Th isotope geochemistry. Talanta, 81(3), pp.741-753. DOI: 10.1016/j.talanta.2010.01.008

Pourmand, A., Prospero, J.M. and Sharifi, A., (2014). Geochemical fingerprinting of trans-Atlantic African dust based on radiogenic Sr-Nd-Hf isotopes and rare earth element anomalies. Geology, 42(8), pp.675-678. DOI: 10.1130/G35624.1