Abstract
Heating experiments were carried out, at 1100°C and 1200°C under controlled oxygen fugacity, on olivine-spinel assemblages from New Caledonia. This mineral pair constitutes a perfect experimental material for such studies. The result was a marked change in chemical composition of the minor phase, olivine: it becomes enriched in iron and chromium and the magnesium and nickel contents decrease. Careful studies of the influence of oxygen fugacity show that, though it has a strong effect on the rate of re-equilibration, it does not affect the equilibrium composition of the phases. The stability limits of the mineralogical assemblage used are also examined. Our results show the possibility of an important subsolidus re-equilibration in natural assemblages containing olivine and spinel. A new equation for the geothermometer based upon Fe 2+-Mg 2+ partitioning between olivine and spinel is proposed and some applications discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
