Sulfur isotopic composition of the Tristan-Gough plume source

A new study reveals distinct sulfur isotopic signatures in the Tristan-Gough plume system, offering insights into Earth's mantle heterogeneity. The research analyzed 46 mineral-hosted sulfide inclusions from Tristan and Gough islands, part of a long-lived EMI-type plume with roots at the core-mantle boundary. Findings show that Gough exhibits positive mass-independent fractionated sulfur (MIF-S) averaging Δ33S = +0.25‰, while Tristan shows no clear MIF-S indication. This suggests that recycled surface material older than 2.45 billion years is present in the EMI-type sources of both Pitcairn and Gough plumes, despite their distinct isotopic characteristics. The study highlights the potential for MIF-S to serve as a tracer for ancient recycled crustal material in mantle plumes.

Class, C., Thomassot, E., le Roex, A., & Chauvel, C. (2021). Sulfur isotopic composition of the Tristan-Gough plume source. Goldschmidt2021 Abstracts. https://doi.org/10.7185/gold2021.6599