Skip Navigation

This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Azor, A.
Right arrow Articles by Ballèvre, M.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Journal of Petrology | Volume 38 | Number 1 | Pages 35-64 | 1997
© Oxford University Press 1997

Low-Pressure Metamorphism in the Sierra Albarrana Area (Variscan Belt,Iberian Massif)

A. Azor1,* and M. Ballèvre2

1 Departamento De Geodinámica Universidad De Granada, Facultad De Ciencias,Campus Fuentenueva S/N, E-18002 Granada, Spain
2 Laboratoire De Pétrologie–Géochimie Géosciences Rennes (UPR–CNRS 4661), Université Rennes I,F-35042 Rennes Cedex, France

Received February 2, 1996; Revised typescript accepted August 2, 1996


  Abstract

A low-pressure metamorphic zonation ranging from biotite to migmatite zones occurs in the Sierra Albarrana area (Variscan Belt of southwestern Iberian Peninsula) in uppermost Precambrian to Lower Palaeozoic metasedimentary rocks. The principal deformation in this area is related to a major ductile shear zone whose central part is localized immediately to the southwest of the Sierra Albarrana Quartzites. The metamorphism is synchronous with respect to this deformation. The metamorphic zones are symmetrically distributed with respect to the Sierra Albarrana Quartzites. Pressure–temperature (P–T) conditions are ~3.5–4 kbar and range from ~400°C (biotite zone) to 500°C (staurolite–garnet zone) up to 650–700°C (migmatite zone). We have not detected pressure variations along the different metamorphic zones. Relic kyanite is observed in the form of inclusions in andalusite within veins in the lower-grade part of the staurolite–andalusite zone. The low-pressure metamorphism of the Sierra Albarrana area arises from a two-stage history including moderate crustal thickening followed by subsequent localization of deformation in a transcurrent shear zone during peak P–T conditions. Channelized fluid flow within the major ductile shear zone may have contributed to the heat budget of the low-pressure metamorphism.

KEY WORDS: fluid flow; Iberian Massif; low-pressure metamorphism; shear zone; Sierra Albarrana area

* Corresponding author. Telephone: (34) 58 24 29 00. Fax: (34) 58 24 33 52. e-mail: azor{at}platon.ugr.es


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.