The late-Variscan peraluminous Valdepeñas pluton (southern Central Iberian Zone)

  1. Errandonea-Martin, J.
  2. Carracedo.Sánchez, M.
  3. Sarrionandia, S.
  4. Santos Zalduegui, J.F.
  5. García de Madinabeitia, S.
  6. Gil-Ibarguchi, J.I.
Revista:
Geologica acta: an international earth science journal

ISSN: 1695-6133

Año de publicación: 2017

Título del ejemplar: . Special Issue: Granites and Related Rocks: a tribute to Guillermo Corretgé

Volumen: 15

Número: 4

Páginas: 361-378

Tipo: Artículo

DOI: 10.1344/GEOLOGICAACTA2017.15.4.7 DIALNET GOOGLE SCHOLAR lock_openAcceso abierto editor

Otras publicaciones en: Geologica acta: an international earth science journal

Resumen

The Valdepeñas pluton is the easternmost outcrop of the Cáceres-Valdepeñas magmatic alignment (southern Central Iberian Zone). This massif is constituted by a cordierite-bearing porphyritic monzogranite and may be grouped within the so-called “Serie Mixta” granitoids. The Valdepeñas monzogranite is of magnesian [FeOt /(FeOt +MgO)~0.76], alkali-calcic [(Na2O+K2O)–CaO=7.8–8.5] and peraluminous (A/CNK=1.14–1.20) composition. Multielemental- and REE-normalized patterns are comparable to those of similar rocks in the NisaAlburquerque-Los Pedroches magmatic alignment, and slightly differ from those of the Montes de Toledo batholith, both in the southern Central Iberian Zone. The U-Pb zircon age of 303±3Ma is consistent with the late-orogenic character of the intrusion and is in accordance with most of the granitic peraluminous intrusions in the southern Central Iberian Zone. 86Sr/87Sr300Ma ratios (0.707424–0.711253), εNd300Ma values (-5.53 to -6.68) and whole-rock major and trace element compositions of the studied rocks, suggest that the parental magma of the Valdepeñas monzogranite could derive from a crustal metaigneous source. The U-Pb ages (552–650Ma) of inherited zircon cores found in Valdepeñas monzogranite samples match those often found in Lower Paleozoic metavolcanics and granitic orthogneisses of Central Iberia and, furthermore, point to Upper Neoproterozoic metaigneous basement rocks as possible protoliths at the magma source. Based on the solubility of monazite in peraluminous melts, the estimated emplacement temperature of the studied monzogranite is 742–762ºC. The results obtained in this work would contribute to a better understanding of the origin of the “Serie Mixta” granitoids.

Información de financiación

Financial support by the Spanish Ministerio de Ciencia e Innovación (grant CGL2015-63530-P) and the University of the Basque Country UPV/EHU (Grupo Consolidado project GIU15/05) is acknowledged. J. Errandonea-Martin would also like to thank the grant from the UPV/EHU 2014 program for the formation of research scientists. F. de la Cruz at the UPV/EHU, for the help in the preparation of thin sections, as well as the technical and human support provided at the Geochronology and Isotope Geochemistry-SGIker facility (UPV/EHU, MINECO, GV/EJ, ERDF and ESF), is gratefully acknowledged. Constructive criticism by F. Bea and an anonymous reviewer are also appreciated.