Isotopic variation in Semail Ophiolite lower crust reveals crustal-level melt aggregation

Jansen, M. N., Lissenberg, C. J. ORCID: https://orcid.org/0000-0001-7774-2297, Klaver, M., de Graaff, S. J., Koornneef, J. M., Smeets, R. J., MacLeod, C. J. ORCID: https://orcid.org/0000-0002-0460-1626 and Davies, G. R. 2018. Isotopic variation in Semail Ophiolite lower crust reveals crustal-level melt aggregation. Geochemical Perspectives Letters 8 , pp. 37-42. 10.7185/geochemlet.1827

Preview

PDF - Published Version Available under License Creative Commons Attribution. Download (4MB) | Preview

Abstract

The scale and magnitude of compositional heterogeneity in the mantle has important implications for the understanding of the evolution of Earth. Heterogeneity of the upper mantle is often evaluated based on mid-ocean ridge basalt compositions, despite their homogenisation prior to eruption. In this study we present Nd and Sr isotope data obtained by micro-drilling single plagioclase and clinopyroxene crystals in gabbroic cumulates of the Semail Ophiolite (Oman) and show that mantle source variability is better preserved in the lower crust than in the extrusive suite. Analysis of sub-nanogram quantities of Nd in plagioclase revealed a range in 143Nd/144Ndi in the Wadi Abyad crustal section that is three times greater than recorded in the extrusive suite. The isotopic variability is preserved in plagioclase, whereas clinopyroxene is isotopically homogeneous. These data imply that the mantle is heterogeneous on the scale of melt extraction, and that a significant proportion of homogenisation of erupted melts occurs in the oceanic crust, not the mantle.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Earth and Environmental Sciences
Additional Information:	This paper is published under the terms of the CC-BY licence
Publisher:	European Association of Geochemistry
ISSN:	2410-339X
Date of First Compliant Deposit:	23 November 2018
Date of Acceptance:	10 October 2018
Last Modified:	05 May 2023 17:26
URI:	https://orca.cardiff.ac.uk/id/eprint/117054

Citation Data

Cited 5 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item