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Migmatitic Gabbros From a Shallow-Level Metamorphic Contact Aureole, Fuerteventura Basal Complex, Canary Islands: Role of Deformation in Melt Segregation

  • Alice Hobson
  • François Bussy
  • Jean Hernandez
Chapter
Part of the Petrology and Structural Geology book series (PESG, volume 11)

Abstract

Partial melting and deformation-assisted melt segregation, resulting in migmatization, has occurred in a shallow-level gabbroic metamorphic contact aureole, in the roots of a volcanic edifice. Melt segregated into small tension gashes and larger conjugate veins leading to unusual “zebra” and “striped” structures. In areas preserved from deformation, melt did not segregate and froze as small leucocratic pods. Geometry of the network of leucosome veins allows reconstruction of a transtensional stress field at time of melting; which can be related to large-scale regional tectonic activity. Mass transfer processes resulting in the stromatic structures involved small-scale melt segregation, input of allochtonous melts and pervasive circulation of high-temperature fluids. Deformation triggered and enhanced these processes by opening fractures into which the melts could migrate, and by promoting the percolation of fluids in the contact aureole.

Key words

gabbro partial melting migmatite melt segregation microstructures 

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Copyright information

© Springer Science+Business Media Dordrecht 2000

Authors and Affiliations

  • Alice Hobson
    • 1
  • François Bussy
    • 1
  • Jean Hernandez
    • 1
  1. 1.Institut de Minéralogie et PétrographieUniversité de Lausanne, BFSH2LausanneSwitzerland

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