Light stable isotopic compositions of enriched mantle sources: Resolving the dehydration paradox

Volatile compositions of enriched mid-ocean ridge basalt are presented, including water concentrations (FTIR and TC/EA) and isotopic ratios of hydrogen (Conventional and TC/EA), boron (laser ablation ICP-MS), lithium (MC-ICP-MS) and oxygen (laser fluorination). Of special significance, we performed an interlaboratory comparison between conventional and TC/EA techniques for hydrogen isotopic ratios in basaltic glasses, resulting in revisions to the mica standardization protocol for the TC/EA method. Glasses from the Arctic and South Atlantic were analyzed for deltaD SMOW using stepped-heating manometry/mass spectrometry at the University of Miami Stable Isotope Laboratory. Water contents and hydrogen isotope ratios of glasses from the Azores Platform and EPR 6° to 17°N were measured by continuous flow via the High Temperature Conversion / Elemental Analyzer (TC/EA) technique at the University of Oregon. In situ boron isotopic compositions were measured by laser ablation, multiple-multiplier ICP-MS at the Department of Terrestrial Magnetism, Carnegie Institute of Washington. Lithium concentrations and isotopic compositions were measured by MC-ICP-MS at Lamont-Doherty Earth Observatory using chemistry and column procedures following Tomascak et al. [1999], with minor modifications. Oxygen isotopes from Arctic ridge samples were measured by J. Eiler at the California Institute of Technology as described in Cooper et al. [2004].

Dixon, J., Bindeman, I., Kingsley, R., Simons, K., le Roux, P., Hajewski, C., Swart, P., Langmuir, C., Ryan, J., Walowski, K., Wada, I., Wallace, P. 2017. Light stable isotopic compositions of enriched mantle sources: Resolving the dehydration paradox, Version 1.0. Interdisciplinary Earth Data Alliance (IEDA). https://doi.org/10.1594/IEDA/100728. Accessed 2020-09-20.

2017-11-14

Light Stable Isotopic Compositions of Enriched Mantle Sources: Resolving the Dehydration Paradox. Geochemistry, Geophysics, Geosystems, 18.

Creative Commons Attribution-NonCommercial-Share Alike 3.0 United States [CC BY-NC-SA 3.0]

volatiles, enriched MORB, stable isotopes, mantle metasomatism

2017-11-05