Backarc basin inversion and subcontinental mantle emplacement in the crust: kilometre-scale folding and shearing at the base of the proto-Alboran lithospheric mantle (Betic Cordillera, southern Spain)

Karoly Hidas*, Guillermo Booth-Rea, Carlos J. Garrido, Jose Miguel Martinez-Martinez, Jose Alberto Padron-Navarta, Zoltan Konc, Flavio Giaconia, Erwin Frets, Claudio Marchesi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

43 Citations (Scopus)

Abstract

To constrain the latest evolutionary stages and mechanisms of exhumation and emplacement of subcontinental peridotites in the westernmost Mediterranean, we present here a detailed structural study of the transition from granular spinel peridotite to plagioclase tectonite in the western Ronda Peridotite (Betic Cordillera, southern Spain). We show that the plagioclase tectonite foliation represents an axial surface particularly well developed in the reverse limb of a downward facing moderately plunging and moderately inclined synform at the base of the Ronda massif. The fold limbs are cut by several mylonitic and ultramylonitic shear zones with top-to-the-SW sense of shear. After restoring the middle to late Miocene vertical-axis palaeomagnetic rotation and the early Miocene tectonic tilting of the massif, these studied structures record southward-directed kinematics. We propose a geodynamic model in which folding and shearing of an attenuated mantle lithosphere occurred by backarc basin inversion during late Oligocene (23-25 Ma) southward collision of the Alboran Domain with the palaeo-Maghrebian passive margin, leading to the intracrustal emplacement of peridotites in the earliest Miocene (21-23 Ma).

Original languageEnglish
Pages (from-to)47-55
Number of pages9
JournalJournal of the Geological Society
Volume170
Issue number1
DOIs
Publication statusPublished - Jan 2013
Externally publishedYes

Keywords

  • RONDA PERIDOTITE MASSIF
  • GIBRALTAR ARC
  • RECRYSTALLIZATION FRONT
  • EXTENSIONAL EXHUMATION
  • TECTONIC IMPLICATIONS
  • ALPUJARRIDE COMPLEX
  • GARNET-LHERZOLITE
  • SPREADING CENTER
  • OMAN OPHIOLITE
  • BENI-BOUSERA

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