The relevance of crystal transfer to magma mixing: a case study in composite dykes from the central pyrenees

Ubide, Teresa, Gale, Carlos, Larrea, Patricia, Arranz, Enrique, Lago, Marceliano and Tierz, Pablo (2014) The relevance of crystal transfer to magma mixing: a case study in composite dykes from the central pyrenees. Journal of Petrology, 55 8: 1535-1559. doi:10.1093/petrology/egu033

Author Ubide, Teresa
Gale, Carlos
Larrea, Patricia
Arranz, Enrique
Lago, Marceliano
Tierz, Pablo
Title The relevance of crystal transfer to magma mixing: a case study in composite dykes from the central pyrenees
Journal name Journal of Petrology   Check publisher's open access policy
ISSN 1460-2415
Publication date 2014-01-01
Year available 2014
Sub-type Article (original research)
DOI 10.1093/petrology/egu033
Open Access Status Not yet assessed
Volume 55
Issue 8
Start page 1535
End page 1559
Total pages 25
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Language eng
Abstract Two composite dykes containing abundant mafic enclaves within a felsic host crop out in the Maladeta Plutonic Complex, Pyrenees, Spain. Field, petrographic and geochemical criteria reveal mixing between gabbroic and aplitic magmas, giving rise to a variety of hybrid compositions. The rocks contain spongy plagioclase, quartz ocelli and amphibole-biotite clots that are interpreted as early crystals destabilized by reaction with the hybrid melts. Spongy plagioclase and quartz ocelli were mechanically transferred from the felsic to the mafic magma, whereas amphibole-biotite clots are former pyroxene crystals from the mafic magma.Multivariate statistics (principal component analysis) have been used to examine variations in the mineral trace element compositions, which are best explained by the crystal transfer process. This study shows that crystal transfer represents a mixing mechanism that can overcome some of the physical limitations of interaction between rheologically contrasting magmas and explain deviations of the hybrid compositions from the theoretical mixed chemical composition. In particular, hybrid wholerock compositions show non-linear correlations in inter-element variation diagrams for elements that are enriched or depleted in preferentially transferred crystals. This effect has been quantified by extending magma mixing modelling to include crystal transfer.The composite dykes studied could be regarded as scale models of the behaviour of larger-scale magmatic systems, so this investigation has important implications for interpreting the petrogenesis of igneous suites by magma mixing.
Keyword Composite dyke
Crystal transfer
Geochemical modelling
Magma mixing
Principal component analysis
Q-Index Code C1
Q-Index Status Provisional Code
Grant ID CGL2008-06098/BTE
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Earth Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 9 times in Thomson Reuters Web of Science Article | Citations
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