In situ Sr–Nd isotope analysis of vesuvianite by LA-MC-ICP-MS: methodology and application

Abstract

Vesuvianite is a common accessory mineral that usually occurs in metamorphosed and metasomatised, argillaceous carbonate rocks (i.e., skarn rocks) and as a late crystallising phase in igneous rocks such as nepheline syenites. Vesuvianite is a Ca-rich mineral that preferentially incorporates Sr and light rare earth elements (LREEs). Given that vesuvianite is susceptible to alteration and commonly contains inclusions, in situ laser ablation analysis is the preferred approach for measuring its Sr–Nd isotopic compositions. The use of matrix-matched and homogeneous reference materials is a prerequisite for laser ablation isotope analyses. Two in-house vesuvianite standards M6635 and M659 were used for external correction during in situ laser ablation analysis for Sr and Nd isotopic compositions, respectively. In this paper, we apply in situ Sr and Sm–Nd isotope analyses for 11 vesuvianite samples (M6635, M784, M1377, M660, M1439, M1450, M6601, 13MDL176, Wilui, Hazlov, and Goodall) from different locations. The obtained Sr and Sm–Nd isotopic compositions for these vesuvianite samples are consistent with those obtained by solution-based methods using MC-ICP-MS, which demonstrates the robustness of our analytical methods. We recommend that samples M6635, M784, M1377, and M1450 are suitable vesuvianite reference materials for in situ Sr isotope analyses, and sample M659 is a potential vesuvianite reference material for in situ Sm–Nd isotope analyses.