Título: | The Aguablanca Cu–Ni ore deposit (Extremadura, Spain), a caseof synorogenic orthomagmatic mineralization: age and isotopecomposition of magmas (Sr, Nd) and ore (S) |
Autores: | Casquet, César ; Galindo Francisco, Mª del Carmen ; Tornos Arroyo, Fernando ; Velasco Roldán, Francisco ; Canales Gallarosa, Ángel |
Tipo de documento: | texto impreso |
Editorial: | Elsevier Science B.V., Amsterdam, 2001 |
Dimensiones: | application/pdf |
Nota general: | info:eu-repo/semantics/openAccess |
Idiomas: | |
Palabras clave: | Estado = Publicado , Materia = Ciencias: Geología: Petrología , Tipo = Artículo |
Resumen: |
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, is located 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 host igneous 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 (?Nd338= -6 to -7.5; Sr(338)=0.7082 to 0.7100; ?34(sulphides) near + 7.4‰). Assimilation–fractional crystallization (AFC) processes are invoked to explain early cumulates and immiscible sulphide-magma formation. Intrusion took place at the beginning of the type-A oblique subduction of the South Portuguese Zone under the Ossa-Morena Zone and was probably driven by transpressive structures (strike-slip faults). The mineralization is thus synorogenic. Aguablanca is probably the first case referred to in the literature of a magmatic Cu–Ni ore deposit hosted by calc-alkaline igneous rocks. |
En línea: | https://eprints.ucm.es/id/eprint/12147/1/Casquet_et_al_OGR_Aguablanca.1.pdf |
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