Hydrous mantle transition zone indicated by ringwoodite included within diamond
- Autor(en)
- Graham D. Pearson, Frank E. Brenker, Fabrizio Nestola, John McNeill, Lutz Nasdala, Mark T. Hutchison, Sergei Matveev, Kathy Mather, Geert Silversmit, Sylvia Schmitz, Bart Vekemans, Laszlo Vincze
- Abstrakt
The ultimate origin of water in the Earth’s hydrosphere is in the,deep Earth - the mantle. Theory1 and experiments2-4 have shown,that although the water storage capacity of olivine-dominated shallow,mantle is limited, the Earth’s transition zone, at depths between,410 and 660 kilometres, could be a major repository for water,,owing to the ability of the higher-pressure polymorphs of olivine -,wadsleyite and ringwoodite - to host enough water to comprise up,to around 2.5 per cent of their weight. A hydrous transition zone,may have a key role in terrestrial magmatismand plate tectonics5-7,,yet despite experimental demonstration of the water-bearing capacity,of these phases, geophysical probes such as electrical conductivity,have provided conflicting results8-10, and the issue of whether,the transition zone contains abundant water remains highly controversial11.,Here we report X-ray diffraction, Raman and infrared,spectroscopic data that provide, to our knowledge, the first evidence,for the terrestrial occurrence of any higher-pressure polymorph of,olivine: we find ringwoodite included in a diamond fromJui´na, Brazil.,Thewater-rich nature of this inclusion, indicated by infrared absorption,,along with the preservation of the ringwoodite, is direct evidence,that, at least locally, the transition zone is hydrous, to about 1,weight per cent. The finding also indicates that some kimberlites,must have their primary sources in this deep mantle region.
- Organisation(en)
- Institut für Mineralogie und Kristallographie
- Externe Organisation(en)
- University of Alberta, Durham University, Trigon GeoServices, Las Vegas, Nevada, Ghent University , Johann Wolfgang Goethe-Universität Frankfurt am Main, Universität zu Köln, Università degli Studi di Padova, Universität Bayreuth
- Journal
- Nature
- Band
- 507
- Seiten
- 221-224
- Anzahl der Seiten
- 4
- ISSN
- 0028-0836
- DOI
- https://doi.org/10.1038/nature13080
- Publikationsdatum
- 03-2014
- Peer-reviewed
- Ja
- ÖFOS 2012
- 1030 Physik, Astronomie, 105116 Mineralogie, 105101 Allgemeine Geologie
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/9c50316f-3632-4970-9afd-e72dd48069ff