@misc{10481/78039,
year = {2022},
month = {10},
url = {https://hdl.handle.net/10481/78039},
abstract = {Under modern oxidising Earth surface conditions, dehydrated subducted slabs show
Mo isotope compositions as low as δ98/95Mo = −1.5 ‰, compared to the depleted
mantle δ98/95Mo = −0.2 ‰. Such light Mo isotope compositions reflect the redoxdependent
aqueous mobility of isotopically heavy Mo associated with slab dehydration.
Here we analysed basaltic glasses from the South-Mid Atlantic Ridge, whose
parental melts are influenced by the enriched Discovery and Shona mantle plumes.
We report increasingly higher δ98/95Mo of up to −0.1‰from the most depleted samples
towards those tapping more enriched mantle sources. δ98/95Mo values correlate
with radiogenic Sr and Nd isotopes, which indicates the recycling of Proterozoic sediments
with a Mo isotopic composition that was not affected by subduction-related,
oxic dehydration. We propose that the Mo isotope signatures were retained during subduction and reflect anoxic conditions
during deep sea sedimentation in the mid-Proterozoic. Finally, Mo isotope fractionation between different terrestrial reservoirs
likely depends on the slab redox budget, and therefore on the timing of subduction with regard to Earth’s surface oxygenation.},
organization = {Swiss National Science Foundation (SNSF)	1NF40-141881	
Swiss National Science Foundation (SNSF)},
organization = {European Commission	636808},
organization = {European Research Council (ERC)	RYC2020-030014-I},
organization = {Spanish Government		
182508},
publisher = {European Association of Geochemistry},
title = {Molybdenumisotopes in plume-influenced MORBs reveal recycling of ancient anoxic sediments},
doi = {10.7185/geochemlet.2236},
author = {Ahmad, Q. and König, S.},
}