Journal article

Using calculated chemical potential relationships to account for replacement of kyanite by symplectite in high pressure granulites

JA Baldwin, R Powell, RW White, P Stipska



Calculated mineral equilibria are used to account for the formation of sapphirine-plagioclase, spinel-plagioclase and corundum-plagioclase symplectites replacing kyanite in quartz-plagioclase-garnet-kyanite granulite facies gneisses from the Southern Domain of the Athabasca granulite terrane, a segment of the Snowbird tectonic zone in northern Saskatchewan, Canada. Metamorphic conditions of >14 kbar and 800 °C are established for the high pressure, garnet-kyanite assemblage using constraints from P-T pseudosections and Zr-in-rutile thermometry. Replacement of kyanite by symplectites reflects the reaction of kyanite with the matrix following near-isothermal decompression to <10 kbar. The chem..

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Awarded by Australian Research Council

Awarded by Ministry of Education of the Czech Republic

Funding Acknowledgements

M. Williams and M. Jercinovic provided the Zr-in-rutile analysis. RP acknowledges support from Australian Research Council grants DP0451770 and DP0987731, and the hospitality of ETH, Zurich in 2014, courtesy of Prof. L. Tajcmanova where some of the ideas presented here took shape. PS acknowledges the Ministry of Education of the Czech Republic (grant LK11202). We thank K. Evans and an anonymous reviewer for comments that greatly improved the manuscript.