Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/276717
COMPARTIR / EXPORTAR:
SHARE CORE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Petrology and geochronology of the Porriño late-Variscan pluton from NW Iberia. A model for post-tectonic plutons in collisional settings |
Autor: | González Menéndez, Luis; Gallastegui Suárez, Gloria; Cuesta, A.; Montero, Pilar; Rubio Ordóñez, A.; Molina, J. F.; Bea, F. | Palabras clave: | post-orogenic magmatism Variscan orogeny post-tectonic granites monzogranites enclaves provincia Pontevedra |
Fecha de publicación: | dic-2017 | Editor: | Universidad de Barcelona | Citación: | Geológica Acta, vol.15, n.4, 283-304 | Resumen: | The Variscan orogen of NW Iberia contains abundant syn- and post-tectonic granitoids. The post-tectonic granitoids are metaluminous to slightly peraluminous, I-type granites, monzogranites ± granodiorites ± tonalites. The Porriño pluton studied here is a representative example. It consists of two units: i) a pink-red, peraluminous, biotite granite and ii) a gray, metaluminous to peraluminous, biotite (± amphibole ± titanite) monzogranite, including maficintermediate enclaves. SHRIMP U-Pb dating yielded 290-295Ma ages for all the units. The mineralogy and geochemistry show that the pink-red granite has features of I- and A-type granites, whereas the gray monzogranite and enclaves are I-types. Sr isotopes show scattered values for the pink-red granite (87Sr/86Sr295Ma ≈ 0.702-0.710) and uniform values for the gray monzogranite and enclaves (87Sr/86Sr295Ma≈ 0.705-0.706). Geochemical results indicate a peritectic entrainment of clinopyroxene + orthopyroxene ± Ca-plagioclase ± ilmenite ± garnet, and minor accessory phases (± zircon ± titanite ± apatite) into a melt similar to the leucocratic gray monzogranite. A mafic-intermediate source is proposed for the gray monzogranite and its enclaves. Restitic protoliths generated granitic melts with A-type features such as the pink-red granite. The I-type nature of many post-tectonic granitoids could be explained by the previous extraction of S-type syn-tectonic granites that left restites and less fertile rocks. Late orogenic new melting affected the previously unmelted and more mafic lithologies of the lower-middle crust, and gave rise to I-type granitoids. Repeated melting events affecting such lithologies and previous restites could have generated granitic melts with A-type features. | Descripción: | Número especial "Granites and Related Rocks. A tribute to Guillermo Corretgé" | Versión del editor: | https://revistes.ub.edu/index.php/GEOACTA/article/view/17607/22461 | URI: | http://hdl.handle.net/10261/276717 | DOI: | https://doi.org/10.1344/GeologicaActa2017.15.4.3 | ISSN: | 1695-6133 |
Aparece en las colecciones: | (IGME) Artículos |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
---|---|---|---|---|
petrology_geochronology_porriño_2017.pdf | Artículo principal | 3,04 MB | Adobe PDF | Visualizar/Abrir |
CORE Recommender
Page view(s)
18
checked on 27-abr-2024
Download(s)
8
checked on 27-abr-2024
Google ScholarTM
Check
Altmetric
Altmetric
NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.