Garnet-spinel transition in the upper mantle: Review and interpretation
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Date
2010-10
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Earth Science
Abstract
This study carried out a comprehensive review of mantle-derived garnet peridotites on the basis of their garnet-spinel compositional relationships. The P-T estimates of the garnet peridotites of both orogenic and xenolithic derivations confirm previously established two garnet-spinel transition (GST) zones. Results of natural samples and experimental studies of all the garnet peridotites plot below the first GST at low P (<2 GPa). The second GST at high P (6-10 GPa), obtained from the experimental system (MgO-Cr2O3-SiO2), was firstly evidenced from natural samples in this study and may imply a challenge to our understanding of Cr-rich and Al-poor mineral phase transition under ultrahigh P condition. Based on the data and our estimates, we propose the existence of another GST within the garnet peridotite discontinuous zone and a potential spinel-phase peridotite zone in the upper mantle. © 2010 China University of Geosciences and Springer-Verlag Berlin Heidelberg.
Description
Keywords
Garnet peridotite, Garnet-spinel transition, Spinel peridotite, Ultra-high P-T, Upper mantle
Citation
Su, B., Zhang, H., Asamoah, S.P. et al. J. Earth Sci. (2010) 21: 635. https://doi.org/10.1007/s12583-010-0117-x