Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, Spain
22 páginas, 14 figuras, 8 tablas.
| Autores: | , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 2009 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/29227 |
| Acceso en línea: | http://hdl.handle.net/10261/29227 |
| Access Level: | acceso abierto |
| Palabra clave: | Ammonium-rich mica Annite Betic Cordillera Exsolution Muscovite Phengite Spain Mica riche en NH4 Cordillères Bétiques Espagne |
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oai:digital.csic.es:10261/29227 |
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España |
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Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, SpainRuiz Cruz, María DoloresSanz de Galdeano, CarlosAmmonium-rich micaAnniteBetic CordilleraExsolutionMuscovitePhengiteSpainMica riche en NH4Cordillères BétiquesEspagne22 páginas, 14 figuras, 8 tablas.[EN] Variably sized lamellae of annite within muscovite crystals and lamellae of muscovite within annite crystals from gneissic rocks of the Torrox area in the Betic Cordillera, Spain, are interpreted as formed by exsolution of NH4-bearing micas present in the earliest metamorphic assemblage. The NH4-rich white mica, identified only in the overlying schists, was formed during the first diagenetic-to-metamorphic episode, with N derived from the maturation of organic matter. Initially contained in white mica, the NH4 was redistributed between white mica and annite, probably at conditions of increasing metamorphism. In the current assemblage of gneisses, NH4 is preferentially concentrated in annite, especially in the composite Ms+Ann grains. This assemblage, which consists of muscovite in homogeneous grains + muscovite in exsolved grains + annite in homogeneous grains + annite in exsolved grains, was probably derived from the lower-temperature four-mica assemblage: muscovite + NH4-rich white mica + annite + NH4-bearing annite. Exsolution as temperature increased explains the presence of NH4-rich micas in the overlying schists and the presence of exsolved grains in gneisses. The exsolution process occurred at ~450°C and ~3 kbar, physical conditions characterizing the first metamorphic episode affecting this formation.[FR] Nous interprétons la présence de lamelles d’annite de tailles différentes dans les cristaux de muscovite, et les lamelles de muscovite au sein des cristaux d’annite, dans les roches gneissiques de la région de Torrox, Cordillères Bétiques, en Espagne, en termes d’une exsolution de micas contenant NH4 présents dans l’assemblage métamorphique précoce. Le mica blanc enrichi en NH4, identifié uniquement dans les schistes de la séquence supérieure, a été formé au cours du premier épisode de recristallisation diagénétique à métamorphique, l’azote ayant été dérivé par maturation de la matière organique. Quoique initialement incorporé dans le mica blanc, le NH4 fut redistribué entre mica blanc et annite probablement lors d’une augmentation du degré de métamorphisme. Dans l’assemblage actuel des gneiss, le NH4 est de préférence incorporé dans l’annite, et surtout dans les grains composites à Ms + Ann. Cet assemblage, qui contient la muscovite en grains homogènes + la muscovite en grains exsolvés + l’annite en grains homogènes + l’annite en grains exsolvés, a probablement été dérivé à partir de l’assemblage à quatre micas stables à faible température: muscovite + mica blanc enrichi en NH4 + annite + annite enrichie en NH4. Une exsolution à mesure que la température a augmenté expliquerait la présence de micas riches en NH4 dans les schistes de la séquence supérieure et la présence de grains exsolvés dans les gneiss. Le processus d’exsolution a eu lieu à environ 450°C et 3 kbar, conditions qui ont caractérisé le premier épisode métamorphique affectant cette formation.This study has received financial support from the Project CGL 2006–02481 (Ministerio de Educación y Ciencia) and from the Research Group RNM–199 (Junta de Andalucía).Peer reviewedMineralogical Association of Canada201020102009info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501http://hdl.handle.net/10261/29227reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttp://dx.doi.org/10.3749/canmin.47.1.107info:eu-repo/semantics/openAccessoai:digital.csic.es:10261/292272026-05-22T06:33:51Z |
| dc.title.none.fl_str_mv |
Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, Spain |
| title |
Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, Spain |
| spellingShingle |
Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, Spain Ruiz Cruz, María Dolores Ammonium-rich mica Annite Betic Cordillera Exsolution Muscovite Phengite Spain Mica riche en NH4 Cordillères Bétiques Espagne |
| title_short |
Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, Spain |
| title_full |
Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, Spain |
| title_fullStr |
Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, Spain |
| title_full_unstemmed |
Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, Spain |
| title_sort |
Exsolution microstructures in NH4-bearing muscovite and annite in gneisses from the Torrox area, Betic Cordillera, Spain |
| dc.creator.none.fl_str_mv |
Ruiz Cruz, María Dolores Sanz de Galdeano, Carlos |
| author |
Ruiz Cruz, María Dolores |
| author_facet |
Ruiz Cruz, María Dolores Sanz de Galdeano, Carlos |
| author_role |
author |
| author2 |
Sanz de Galdeano, Carlos |
| author2_role |
author |
| dc.subject.none.fl_str_mv |
Ammonium-rich mica Annite Betic Cordillera Exsolution Muscovite Phengite Spain Mica riche en NH4 Cordillères Bétiques Espagne |
| topic |
Ammonium-rich mica Annite Betic Cordillera Exsolution Muscovite Phengite Spain Mica riche en NH4 Cordillères Bétiques Espagne |
| description |
22 páginas, 14 figuras, 8 tablas. |
| publishDate |
2009 |
| dc.date.none.fl_str_mv |
2009 2010 2010 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/article http://purl.org/coar/resource_type/c_6501 |
| format |
article |
| dc.identifier.none.fl_str_mv |
http://hdl.handle.net/10261/29227 |
| url |
http://hdl.handle.net/10261/29227 |
| dc.language.none.fl_str_mv |
Inglés |
| language_invalid_str_mv |
Inglés |
| dc.relation.none.fl_str_mv |
http://dx.doi.org/10.3749/canmin.47.1.107 |
| dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess |
| eu_rights_str_mv |
openAccess |
| dc.publisher.none.fl_str_mv |
Mineralogical Association of Canada |
| publisher.none.fl_str_mv |
Mineralogical Association of Canada |
| dc.source.none.fl_str_mv |
reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC instname:Consejo Superior de Investigaciones Científicas (CSIC) |
| instname_str |
Consejo Superior de Investigaciones Científicas (CSIC) |
| reponame_str |
DIGITAL.CSIC. Repositorio Institucional del CSIC |
| collection |
DIGITAL.CSIC. Repositorio Institucional del CSIC |
| repository.name.fl_str_mv |
|
| repository.mail.fl_str_mv |
|
| _version_ |
1869417899134812160 |
| score |
15,81155 |