Journal of Maps (Mar 2023)

Structure of a Variscan migmatite-granite transition zone (N Sardinia, Italy)

  • M. De Luca,
  • N. Ruberti,
  • G. Oggiano,
  • Ph. Rossi,
  • V. Pascucci,
  • L. Casini

DOI
https://doi.org/10.1080/17445647.2023.2182721

Abstract

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ABSTRACTThis paper presents the structural map of the Barrabisa Complex, an E-W ribbon-like migmatitic massif exposed in the northern part of Sardinia. The migmatites consist of metatexites and diatexites with variable melt proportion, grading in the central part of the complex to a foliated peraluminous granodiorite. Xenotime/monazite dating indicates that the foliated granodiorite pluton emplaced in upper Carboniferous times (≈307–313 Ma) within a narrow E-W ductile top-to-the east shear zone cutting through a Variscan high-grade metamorphic basement composed of orthogneisses, metasedimentary-derived migmatites and subordinate amphibolites. Field geological mapping, coupled with structural and micro-structural analysis, allowed us to distinguish the granodioritic pluton and three metamorphic units characterized by variable melt to protholith ratio, that represent a continuous transition from metatexite to diatexite with high melt concentration, to foliated granodiorite.

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