Helium and carbon isotopes in fluorites: implications for mantle carbon contribution in an ancient subduction zone

Citation
J. Yamamoto et al., Helium and carbon isotopes in fluorites: implications for mantle carbon contribution in an ancient subduction zone, J VOLCANOL, 107(1-3), 2001, pp. 19-26
Citations number
41
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
ISSN journal
0377-0273 → ACNP
Volume
107
Issue
1-3
Year of publication
2001
Pages
19 - 26
Database
ISI
SICI code
0377-0273(200106)107:1-3<19:HACIIF>2.0.ZU;2-B
Abstract
The concentrations of helium and carbon in fluorite associated with Cretace ous to Neogene (90-13 Ma) granitic magmatism in the Japanese are have been measured. Concentrations of Li, U, Th and Gd were measured to correct for s econdary generated He-3. The CO2/He-3 of fluorites are almost uniform (1.5 x 10(10)-4 x 10(10)) and in fair agreement with the range of present island are volcanic gases. The calculated mantle C contribution in the Mesozoic s ubduction zone appear to have been identical to the present one (7-19%) ind icating that the C flux from the mantle in supra-subduction zone environmen ts has remained fairly constant during the past 70 million years. (C) 2001 Elsevier Science B.V. All rights reserved.