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An Early Ordovician tonalitic–granodioritic belt along the Schistose-Greywacke Domain of the Central Iberian Zone (Iberian Massif, Variscan Belt)

Published online by Cambridge University Press:  16 January 2012

A. RUBIO-ORDÓÑEZ ,
P. VALVERDE-VAQUERO ,
L. G. CORRETGÉ ,
A. CUESTA-FERNÁNDEZ ,
G. GALLASTEGUI ,
M. FERNÁNDEZ-GONZÁLEZ  and
A. GERDES
A. RUBIO-ORDÓÑEZ
Affiliation:
Área de Petrología y Geoquímica, Departamento de Geología, Universidad de Oviedo, c/ Arias de Velasco s/n, Oviedo (Asturias), 33005, Spain
P. VALVERDE-VAQUERO*
Affiliation:
Área de Laboratorios, Instituto Geológico y Minero de España (IGME), c/ La Calera 1, 28760, Tres Cantos (Madrid), Spain
L. G. CORRETGÉ
Affiliation:
Área de Petrología y Geoquímica, Departamento de Geología, Universidad de Oviedo, c/ Arias de Velasco s/n, Oviedo (Asturias), 33005, Spain
A. CUESTA-FERNÁNDEZ
Affiliation:
Área de Petrología y Geoquímica, Departamento de Geología, Universidad de Oviedo, c/ Arias de Velasco s/n, Oviedo (Asturias), 33005, Spain Unidad de Microsonda Electrónica, Centro Cientifico Técnico ‘Severo Ochoa’, Universidad de Oviedo, Campus ‘El Cristo’, 33006, Oviedo (Asturias), Spain
G. GALLASTEGUI
Affiliation:
Instituto Geológico y Minero de España (IGME), c/ Matemático Pedrayes 25, 33005, Oviedo (Asturias), Spain
M. FERNÁNDEZ-GONZÁLEZ
Affiliation:
Unidad de Microsonda Electrónica, Centro Cientifico Técnico ‘Severo Ochoa’, Universidad de Oviedo, Campus ‘El Cristo’, 33006, Oviedo (Asturias), Spain
A. GERDES
Affiliation:
Institut für Geowissenchaften, Goethe Universität, Altenhöferallee 1, 60438, Frankfurt, Germany
*
†Author for correspondence: p.valverde@igme.es
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Abstract

The Zarza la Mayor and Zarza de Montánchez tonalites and Arroyo de la Luz granodiorite are part of a tonalitic–granodioritic belt located along the Schistose-Greywacke Domain of the Central Iberian Zone. These intrusions are also part of the Central Extremadura Batholith, a set of plutons ranging from tonalite to leucogranite that have been considered a prime example of Variscan syn-kinematic plutonism. New LA-ICP-MS and CA-ID-TIMS U–Pb dating reveals that the Zarza la Mayor tonalite–granodiorite is an Early Ordovician intrusion. The LA-ICP-MS data show that there is an absence of inherited cores, despite some complex internal zoning with obvious resorption features in some of the zircon crystals. Dating of monazite and zircon by CA-ID-TIMS provides a concordant age of 478.1 ± 0.8 Ma. This age coincides with electron microprobe analysis (EMPA) monazite chemical ages for the Zarza de Montánchez (482 ± 10 Ma) and Arroyo de la Luz (470 ± 15 Ma) intrusions. These new data indicate the presence of an Early Ordovician belt of calc-alkaline tonalite–granodiorite in the Schistose-Greywacke Domain – the Beira Baixa–Central Extremadura tonalite–granodiorite belt – which resembles a continental magmatic arc. This belt is contemporaneous with the Ollo de Sapo magmatic event further north in the Central Iberian Zone.

Keywords

Early Ordoviciantonalite–granodioriteU–Pb geochronologyIberian MassifLA-ICP-MSID-TIMSEMPA
Type
Rapid Communication
Information
Geological Magazine , Volume 149 , Issue 5 , September 2012 , pp. 927 - 939
Copyright
Copyright © Cambridge University Press 2012

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