Contributions to Mineralogy and Petrology

, Volume 104, Issue 4, pp 453–462

Oxidation state of mantle xenoliths from British Columbia, Canada

  • Dante Canil
  • David Virgo
  • Christopher M. Scarfe
Article

DOI: 10.1007/BF01575622

Cite this article as:
Canil, D., Virgo, D. & Scarfe, C.M. Contr. Mineral. and Petrol. (1990) 104: 453. doi:10.1007/BF01575622

Abstract

Mössbauer spectra for 17 spinels separated from mantle xenoliths from six different eruptive centers in southern British Columbia, Canada were measured in an effort to accurately determine their Fe3+/total Fe ratios, and to examine lateral and vertical variations in oxygen fugacities (fo2's) calculated for these samples using published thermobarometric methods. Spectra acquired at 298 and 77 K suggest that both Fe2+ and Fe3+ are tetrahedrally coordinated in lherzolite spinels from this alkaline province. Calculatedfo2's for spinel lherzolites from British Columbia range from about 0.5 to 1.5 log units below the fayalite-magnetite-quartz (FMQ) oxygen buffer at 15 kbar using the thermobarometric method of O'Neill and Wall. Thesefo2's are on average more reducing than those reported for the upper mantle beneath the Massif Central and Japanese Arc and fall within the range for fresh MORB glasses and for lherzolite xenoliths from the southwestern United States and Mongolia. Significant variations info2 between samples from different eruptive centers with varying ages are absent, indicating that the oxidation state of the upper mantle was not affected by Cenozoic magmatism within this alkaline province.

Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • Dante Canil
    • 1
  • David Virgo
    • 2
  • Christopher M. Scarfe
  1. 1.Experimental Petrology Laboratory, Department of GeologyUniversity of AlbertaEdmontonCanada
  2. 2.Geophysical LaboratoryCarnegie Institution of WashingtonWashington DCUSA
  3. 3.Bayerisches GeoinstitutUniversität BayreuthBayreuthFederal Republic of Germany