Tracing subducted black shales in the Lesser Antilles arc using molybdenum isotope ratios

Heye Freymuth, Tim Elliott, Matthijs van Soest, Susanne Skora

Research output: Contribution to journalArticle (Academic Journal)peer-review

29 Citations (Scopus)
297 Downloads (Pure)

Abstract

Lesser Antilles arc lavas have trace element and radiogenic isotope characteristics indicative of a continent-derived contribution. It is hotly debated whether this continental signature represents terrigenous sediment that has been subducted with the Atlantic plate and added to the magma sources in the mantle wedge or portions of the sub-arc crust that are assimilated during magma ascent. Here we present Mo isotope data for Lesser Antilles arc lavas and sediments off-board the Lesser Antilles trench. Sequences of black shales, present in the subducting sediment piles, are highly enriched in Mo and have unusually high 98Mo/95Mo. Despite their low mass fraction in the sediment package (<10 % in DSDP Site 144), they dominate the Mo content and isotopic composition of the bulk sediment subducting at the Lesser Antilles trench. We show that lavas from the southern part of the Lesser Antilles arc also have high 98Mo/95Mo ratios, implicating the addition of Mo derived from the subducted black shales to their mantle sources. This establishes a new link between the composition of subducted material and the arc lava output.
Original languageEnglish
Pages (from-to)987-990
Number of pages4
JournalGeology
Volume44
Issue number12
Early online date1 Oct 2016
DOIs
Publication statusPublished - Dec 2016

Fingerprint Dive into the research topics of 'Tracing subducted black shales in the Lesser Antilles arc using molybdenum isotope ratios'. Together they form a unique fingerprint.

Cite this