Meter-scale Nd isotopic heterogeneity in pyroxenite-bearing Ligurian peridotites encompasses global-scale upper mantle variability

Abstract

Research Article| October 01, 2013 Meter-scale Nd isotopic heterogeneity in pyroxenite-bearing Ligurian peridotites encompasses global-scale upper mantle variability Giulio Borghini; Giulio Borghini 1DISTAV, Università di Genova, corso Europa 26, 16132 Genoa, Italy2Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, New York 10964, USA3Dipartimento di Scienze della Terra, Università di Milano, via Botticelli 23, 20133 Milan, Italy Search for other works by this author on: GSW Google Scholar Elisabetta Rampone; Elisabetta Rampone 1DISTAV, Università di Genova, corso Europa 26, 16132 Genoa, Italy Search for other works by this author on: GSW Google Scholar Alberto Zanetti; Alberto Zanetti 4Istituto di Geoscienze e Georisorse, CNR, via Ferrata 1, 27100 Pavia, Italy Search for other works by this author on: GSW Google Scholar Cornelia Class; Cornelia Class 2Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar Anna Cipriani; Anna Cipriani 2Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, New York 10964, USA5DSCG, Università degli Studi di Modena e Reggio Emilia, Piazza S. Eufemia 19, 41100 Modena, Italy Search for other works by this author on: GSW Google Scholar Albrecht W. Hofmann; Albrecht W. Hofmann 2Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, New York 10964, USA6Max Planck Institute for Chemistry, P.O. Box 3060, 55020 Mainz, Germany Search for other works by this author on: GSW Google Scholar Steven L. Goldstein Steven L. Goldstein 2Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, New York 10964, USA7Department of Earth and Environmental Sciences, Columbia University, 61 Route 9W, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar Geology (2013) 41 (10): 1055–1058. https://doi.org/10.1130/G34438.1 Article history received: 31 Jan 2013 rev-recd: 30 May 2013 accepted: 31 May 2013 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Giulio Borghini, Elisabetta Rampone, Alberto Zanetti, Cornelia Class, Anna Cipriani, Albrecht W. Hofmann, Steven L. Goldstein; Meter-scale Nd isotopic heterogeneity in pyroxenite-bearing Ligurian peridotites encompasses global-scale upper mantle variability. Geology 2013;; 41 (10): 1055–1058. doi: https://doi.org/10.1130/G34438.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Pyroxenites embedded in peridotite are often invoked as a major cause of short-length scale isotopic heterogeneities in the upper mantle, but there has been little direct evidence. We report spatially controlled chemical and Sr-Nd isotopic compositions of pyroxenites and their host peridotites from an ophiolitic mantle sequence in the Northern Apennines, Italy, with depleted mantle compositions, representing a surface exposure of veined upper mantle, a potential source for mid-oceanic-ridge basalts (MORB). Interaction between pyroxenites and adjacent mantle rocks results in centimeter-scale chemical modifications in the host peridotites, systematically lowering their Sm/Nd ratios. Over time, this interaction causes the host peridotite at >0.1 m scale to acquire an isotopic heterogeneity larger than the range defined by the peridotite and pyroxenite end-members. Moreover, the 143Nd/144Nd variation of a single outcrop covers most of the global Nd isotopic variability documented in abyssal peridotites. Such pyroxenite-peridotite veined mantle domains may represent the enriched component rarely found in abyssal peridotites, but often invoked to account for the low end of 143Nd/144Nd variations in MORB. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.