Access
To read this story in full you will need to login or make a payment (see right).
Letters to Nature
Nature 432, 91-94 (4 November 2004) | doi:10.1038/nature03026; Received 8 March 2004; Accepted 17 September 2004
Open Innovation Challenges
-
Optimizing Sub-cellular Localization Tags
The Seeker is looking for methods to optimize sub-cellular localization tags for protein expression....
-
Direct Molecular Detection of Proteins and Nucleic Acids
This Challenge is looking for novel approaches to protein and nucleic acid detection. This is an Id...
nature jobs
Manager Brand Solutions
- Indegene Lifesystems Pvt. Ltd
- Bengaluru 560 071 India
Post-Doctoral Associate (2) in Nanotechnology
- Cornell University
- Ithaca, NY
Contrasting origins of the upper mantle revealed by hafnium and lead isotopes from the Southeast Indian Ridge
Barry B. Hanan1, Janne Blichert-Toft2, Douglas G. Pyle3 & David M. Christie4
- Department of Geological Sciences, San Diego State University, 5500 Campanile Drive, San Diego, California 92182-1020, USA
- Ecole Normale Superieure de Lyon, Laboratoire des Sciences de la Terre, CNRS UMR 5570, 46 Allee d'Italie, 69364 Lyon Cedex 7, France
- School of Ocean and Earth Science Technology, University of Hawaii, 1680 East-West Road, POST 612A, Honolulu, Hawaii 96822, USA
- College of Oceanic and Atmospheric Sciences, Oregon State University, 104 COAS Admin Bldg, Corvallis, Oregon 97331-5503, USA
Correspondence to: Barry B. Hanan1 Email: Barry.Hanan@sdsu.edu
Abstract
The origin of the isotopic signature of Indian mid-ocean ridge basalts has remained enigmatic, because the geochemical composition of these basalts is consistent either with pollution from recycled, ancient altered oceanic crust and sediments, or with ancient continental crust or lithosphere. The radiogenic isotopic signature may therefore be the result of contamination of the upper mantle by plumes containing recycled altered ancient oceanic crust and sediments1, detachment and dispersal of continental material into the shallow mantle during rifting and breakup of Gondwana2, or contamination of the upper mantle by ancient subduction processes3, 4. The identification of a process operating on a scale large enough to affect major portions of the Indian mid-ocean ridge basalt source region has been a long-standing problem. Here we present hafnium and lead isotope data from across the Indian–Pacific mantle boundary at the Australian–Antarctic discordance region of the Southeast Indian Ridge, which demonstrate that the Pacific and Indian upper mantle basalt source domains were each affected by different mechanisms. We infer that the Indian upper-mantle isotope signature in this region is affected mainly by lower continental crust entrained during Gondwana rifting, whereas the isotope signature of the Pacific upper mantle is influenced predominantly by ocean floor subduction-related processes.
To read this story in full you will need to login or make a payment (see right).
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Geochemistry Mantle recycled in SardiniaNature News and Views (07 Dec 2000)
Geodynamics The ups and downs of sedimentsNature Geoscience News and Views (01 Jan 2008)
See all 4 matches for News And ViewsRESEARCH
Mineralogy of the mid-ocean-ridge basalt source from neodymium isotopic composition of abyssal peridotitesNature Letters to Editor (04 Jul 2002)
Isotopic portrayal of the Earth?s upper mantle flow fieldNature Article (28 Jun 2007)
See all 63 matches for Research
