SHRIMP-zircon U–Pb dating of the Ni–Cu–PGE mineralized Aguablanca gabbro and Santa Olalla granodiorite: Confirmation of an Early Carboniferous metallogenic epoch in the Variscan Massif of the Iberian Peninsula

SHRIMP U–Pb zircon dating of the Valencia del Ventoso plutonic complex, Ossa-Morena Zone, SW Iberia: Early Carboniferous intra-orogenic extension-related ‘calc-alkaline’ magmatism

“…In addition we summarize published ages for the Early Carboniferous magmatism. Detailed information summarizes the published ages for the Olivenza-Monesterio antiform pluton facies: 1 -Brovales pluton (Kober method, Montero et al, 2000); 2 -Burguillos del Cerro plutonic complex (amphibolitic gabbro, diorite and Q-monzodiorite dated by amphibole Ar-Ar, Dallmeyer et al, 1995; leucogranite dated by WR RbSr, Bachiller et al, 1997); 3 -Valencia del Ventoso plutonic complex (U-Pb SHRIMP, present work); and 4 -the Santa Olalla pluton (tonalite and monzogranite by U-Pb TIMS, Romero et al, 2006; gabbro and granodiorite dated by U-Pb SHRIMP, Ordoñez-Casado et al, 2008). In addition, information for other plutonic and metamorphic rocks includes: 5 -Reguengos de Monaraz Massif; 6 -Aracena Belt norites; 7, 8, 9, 10 -Beja-Acebuches amphibolites and gabbros, note that Ar-Ar ages indicate the age of metamorphism whereas U-Pb SHRIMP ages indicate the protolith age; 11 -Beja igneous complex; 12 -North Sevilla batholith, emplaced in the South Portuguese Zone; 13 and 14 -Pedroches Batholith, emplaced in the Central Iberian Zone.…”

“…1B). This c. 350-330 Ma Carboniferous magmatism (e.g., Dallmeyer et al, 1995;Montero et al, 2000;Ordoñez-Casado et al, 2008;Pin et al, 2008) is composed of ultramafic to felsic, metaluminous alkaline-calc-alkaline plutons and peraluminous dykes ).…”

“…The only other suggestion, to date, that the IRB is connected with the OMZ Carboniferous magmatism came from Tornos et al (2005Tornos et al ( , 2006 and Ordoñez-Casado et al (2008). They proposed that the IRB was key in the development of the mineralization of the alkaline-calc-alkaline Santa Olalla plutonic complex, that includes the Aguablanca mafic-ultramafic stock, some 35 km to the south-east of Valencia del Ventoso (Fig.…”

“…Cambeses et al / Gondwana Research xxx (2014) xxx-xxx 2002; Simancas et al, 2003;Pereira et al, 2007;Rosas et al, 2008;Pereira et al, 2009), c. 350-330 Ma. At the same time there was: sedimentary basin development Giese et al, 1994;Simancas et al, 2003); mid-crustal intraplating of the 'IBERSEIS Reflective Body' of ultramafic-mafic sills Carbonell et al, 2004;Palomeras et al, 2009;Brown et al, 2012); extensive mineralization (Romero et al, 2006;Tornos et al, 2006); medium to high temperature low-pressure metamorphism (cf., Bard, 1969;Ordoñez-Casado, 1998;Pereira et al, 2003;Díaz-Azpiroz et al, 2004Pereira et al, 2007Pereira et al, , 2009; and the main OMZ OlivenzaMonesterio antiform magmatism (Dallmeyer et al, 1995;Montero et al, 2000;Ordoñez-Casado et al, 2008). The Olivenza-Monesterio Variscan plutons are typically compositionally diverse comprising gabbros and diorites through quartzdiorites to granodiorites and granites (e.g., Pons, 1982;Casquet and Galindo, 2004;Ordoñez-Casado et al, 2008) suggesting complex interplay of magmas derived from mantle and crustal sources.…”

Exhuming a cold case: The early granodiorites of the northwest Iberian Variscan belt—A Visean magmatic flare-up?

“…This early Carboniferous suite is widely represented in other areas of the WEVB (e.g., Schaltegger, 1997Schaltegger, , 2000Schulmann et al, 2002;Eichhorn et al, 2000;Cartannaz et al, 2007;Li et al, 2014;Mezger and Gerdes, 2016;Tabaud et al, 2015;Galán et al, 1997;Ledru et al, 2001;Rossi et al, 2009;Kubínová et al, 2017;Laurent et al, 2017;Žák et al, 2017), including the Ossa Morena zone of southwest Iberia (e.g., Dallmeyer et al, 1995;Ordóñez Casado, 1998;Montero et al, 2000;Ordóñez Casado et al, 2008;Romeo et al, 2006;Jesus et al, 2007;Pin et al, 2008;Pereira et al, 2009Pereira et al, , 2015Braid et al, 2012;Dupuis et al, 2014;Gladney et al, 2014;Cambeses et al, 2015). In the Ossa Morena zone rocks belonging to this suite are the volumetrically dominant granitoids, whereas in northwest Iberia the volumetrically dominant granitoids are both the previously described syntectonic leucogranites and the postorogenic granites (Fig.…”