title: Evidence for primordial water in Earth's deep mantle.
abstract: The hydrogen-isotope [deuterium/hydrogen (D/H)] ratio of Earth can be used to constrain the origin of its water. However, the most accessible reservoir, Earth's oceans, may no longer represent the original (primordial) D/H ratio, owing to changes caused by water cycling between the surface and the interior. Thus, a reservoir completely isolated from surface processes is required to define Earth's original D/H signature. Here we present data for Baffin Island and Icelandic lavas, which suggest that the deep mantle has a low D/H ratio (δD more negative than -218 per mil). Such strongly negative values indicate the existence of a component within Earth's interior that inherited its D/H ratio directly from the protosolar nebula.
authors.affiliation: NASA Astrobiology Institute, Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Drive, Honolulu, HI 96822-1839, USA. Hawai'i Institute of Geophysics and Planetology, Pacific Ocean Science and Technology (POST) Building, University of Hawai'i, 1680 East-West Road, Honolulu, HI 96822, USA. lydia.hallis@glasgow.ac.uk.
authors.forename: Lydia J
authors.initials: LJ
authors.lastname: Hallis
authors.affiliation: NASA Astrobiology Institute, Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Drive, Honolulu, HI 96822-1839, USA. Hawai'i Institute of Geophysics and Planetology, Pacific Ocean Science and Technology (POST) Building, University of Hawai'i, 1680 East-West Road, Honolulu, HI 96822, USA.
authors.forename: Gary R
authors.initials: GR
authors.lastname: Huss
authors.affiliation: Hawai'i Institute of Geophysics and Planetology, Pacific Ocean Science and Technology (POST) Building, University of Hawai'i, 1680 East-West Road, Honolulu, HI 96822, USA.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Nagashima
authors.affiliation: NASA Astrobiology Institute, Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Drive, Honolulu, HI 96822-1839, USA. Hawai'i Institute of Geophysics and Planetology, Pacific Ocean Science and Technology (POST) Building, University of Hawai'i, 1680 East-West Road, Honolulu, HI 96822, USA.
authors.forename: G Jeffrey
authors.initials: GJ
authors.lastname: Taylor
authors.affiliation: Scripps Institution of Oceanography, University California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0244, USA.
authors.forename: Sæmundur A
authors.initials: SA
authors.lastname: Halldórsson
authors.affiliation: Scripps Institution of Oceanography, University California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0244, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Hilton
authors.affiliation: Department of Oceanography, University of Hawai'i, Marine Sciences Building 304, 1000 Pope Road, Honolulu, HI 96822, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mottl
authors.affiliation: NASA Astrobiology Institute, Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Drive, Honolulu, HI 96822-1839, USA. Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Drive, Honolulu, HI 96822, USA.
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Meech