%0 Journal Article
%A Casquet Martín, César
%A Galindo Francisco, María Del Carmen
%A Tornos Arroyo, Fernando
%A Velasco Roldán, Francisco
%A Canales Gallarosa, Ángel
%T The Aguablanca Cu–Ni ore deposit (Extremadura, Spain), a caseof synorogenic orthomagmatic mineralization: age and isotopecomposition of magmas (Sr, Nd) and ore (S)
%D 2001
%@ 0169-1368
%U https://hdl.handle.net/20.500.14352/56996
%X The Aguablanca Cu–Ni orthomagmatic ore deposit is hosted by mafic and ultramafic rocks of the Aguablanca stock,which is part of the larger, high-K calc-alkaline Santa Olalla plutonic complex. This intrusive complex, ca. 338 Ma in age, islocated in the Ossa-Morena Zone (OMZ) of the Iberian Variscan Belt. Mineralization consists mainly of pyrrhotite,pentlandite and chalcopyrite resulting from the crystallization of an immiscible sulphide-rich liquid. Isotope work on the hostigneous rocks (Sr, Nd) and the ore (S) suggests that contamination with an upper-crustal component took place at some depth before final emplacement of the plutons (εNd338= -6 to -7.5; Sr(338)=0.7082 to 0.7100; δ34(sulphides) near + 7.4‰). Assimilation–fractional crystallization (AFC) processes are invoked to explain early cumulates and immisciblesulphide-magma formation. Intrusion took place at the beginning of the type-A oblique subduction of the South PortugueseZone under the Ossa-Morena Zone and was probably driven by transpressive structures (strike-slip faults). The mineralizationis thus synorogenic.Aguablanca is probably the first case referred to in the literature of a magmatic Cu–Ni ore deposit hosted by calc-alkalineigneous rocks.
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