Publication Date:
2013-01-25
Description:
Although initial studies have demonstrated the applicability of Ni isotopes for cosmochemistry and as a potential biosignature, Ni isotope composition of terrestrial igneous and sedimentary rocks, and ore deposits remains poorly known. Our contribution is four-fold: (1) to detail an analytical procedure for Ni isotope determination, (2) to determine the Ni isotope composition of various geological reference materials, (3) to assess the isotope composition of the Bulk Silicate Earth relative to the Ni isotope reference material NIST SRM 986, and (4) to report the range of mass-dependent Ni isotope fractionations in magmatic rocks and ore deposits. After purification through a two-stage chromatography procedure, Ni isotope ratios were measured by MC-ICP-MS and were corrected for instrumental mass bias using a double-spike correction method. Measurement precision (two standard error of the mean) was between 0.02 and 0.04‰ and intermediate measurement precision for NIST SRM 986 was 0.05‰ (2 s ). Igneous and mantle-derived rocks displayed a restricted range of δ 60/58 Ni values between -0.13 and +0.16‰ suggesting an average BSE composition of +0.05‰. Manganese nodules (Nod A1; P1), shale (SDO-1), coal (CLB-1) and a metal-contaminated soil (NIST SRM 2711) showed positive values ranging between +0.14 and +1.06‰, whereas komatiite-hosted Ni-rich sulfides varied from -0.10 to -1.03‰. © 2013 The Authors. Geostandards and Geoanalytical Research © 2013 International Association of Geoanalysts
Print ISSN:
1639-4488
Electronic ISSN:
1751-908X
Topics:
Geosciences
Permalink
