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Journal of Geological Research
Volume 2012 (2012), Article ID 723839, 8 pages
http://dx.doi.org/10.1155/2012/723839
Research Article

3 H e / 4 H e Ratio in Olivines from Linosa, Ustica, and Pantelleria Islands (Southern Italy)

1LSCE, CEA-CNRS-UVSQ, Centre de Saclay, 91191 Gif-sur-Yvette, France
2IPGP, CNRS, 75005 Paris, France
3CFTA, Università di Palermo, 90123 Palermo, Italy

Received 5 August 2011; Accepted 5 December 2011

Academic Editor: Steven L. Forman

Copyright © 2012 Elise Fourré et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We report helium isotope data for 0.03–1 Ma olivine-bearing basaltic hawaiites from three volcanoes of the southern Italy magmatic province (Ustica, Pantelleria, and Linosa Islands). Homogenous 3 H e / 4 H e ratios (range: 7.3–7.6  R a ) for the three islands, and their similarity with the ratio of modern volcanic gases on Pantelleria, indicate a common magmatic end-member. In particular, Ustica ( 7 . 6 ± 0 . 2 R a ) clearly differs from the nearby Aeolian Islands Arc volcanism, despite its location on the Tyrrhenian side of the plate boundary. Although limited in size, our data set complements the large existing database for helium isotope in southern Italy and adds further constraints upon the spatial extent of intraplate alkaline volcanism in southern Mediterranea. As already discussed by others, the He-Pb isotopic signature of this magmatic province indicates a derivation from a mantle diapir of a OIB-type that is partially diluted by the depleted upper mantle (MORB mantle) at its periphery.