Please use this identifier to cite or link to this item:
Title: Tectonometamorphic Evolution of the Migmatitic Paragneisses of the Filali Unit (Internal Rif, Morocco)
Authors: Afiri, Abdelkhaleq
Essaifi, Abderrahim
Charroud, Ali
Aqnouy, Mourad
Abdelrahman, Kamal
Alali, Amar
Abioui, Mohamed 
Keywords: migmatitic paragneisses; sub-isothermal decompression; pseudosections; partial melting; melt reintegration; Rif belt
Issue Date: 2023
Publisher: MDPI
Project: Researchers Supporting Project number (RSP2023R351), King Saud University, Riyadh, Saudi Arabia 
Serial title, monograph or event: Minerals
Volume: 13
Issue: 4
Abstract: A lithosphere-scale extensional shear zone juxtaposes an underlying sub-continental peridotite body and overlying migmatitic paragneisses of the Filali unit in the Beni Bousera massif (Internal Rif, Morocco). Three stages are recognized in the metamorphic evolution of the aluminous paragneiss, marked by the chemical zoning of garnet porphyroblasts and the evolution of associated mineral assemblages characterized by the presence of kyanite and rutile (M1), sillimanite, k-feldspar and melt (M2), and cordierite (M3). Phase-equilibrium modeling (pseudosections) and multi-equilibrium thermobarometry point to P-T conditions of 7 kbar 750 C and 3.5 kbar 685 C for the M2 and M3 stages, respectively. M1 conditions of 9.3 kbar 660 C were inferred using modeling after the reintegration of melt lost during M2 into the bulk composition. Published geochronological data suggest a Variscan age (250–340 Ma) for the M1 event, whereas M2 and M3 are Oligo-Miocene and related to the Alpine orogeny. The recorded sub-isothermal decompression is related to significant crustal attenuation in the Oligo-Miocene and is responsible for the juxtaposition of the hot asthenospheric mantle and the crustal units, causing the melting of the paragneiss. The exhumation of the gneisses by crustal extension is associated with the westward retreat of an Alpine subduction (slab rollback).
ISSN: 2075-163X
DOI: 10.3390/min13040484
Rights: openAccess
Appears in Collections:FCTUC Ciências da Terra - Artigos em Revistas Internacionais
I&D MARE - Artigos em Revistas Internacionais

Show full item record

Page view(s)

checked on Apr 17, 2024


checked on Apr 17, 2024

Google ScholarTM




This item is licensed under a Creative Commons License Creative Commons