New observations by X-ray fluorescence microscopy provide insights for the origin of Aguablanca sulfide-matrix breccias in SW Spain
- Stephen J. Barnes
- Rubén Piña
- Margaux LeVaillant
- Lorena Ortega
- Rosario Lunar
ISSN: 1885-7264
Año de publicación: 2019
Número: 24
Tipo: Artículo
Otras publicaciones en: Macla: revista de la Sociedad Española de Mineralogía
Resumen
Sulfide-matrix breccia ores are common features of deposits hosted within mafic conduit-style intrusions. They account for a large proportion of Ni-Cu sulfiderich ores in a number of deposits including the sub-layer and offset dyke deposits at Sudbury (Lightfoot, 2016), deep portions of the feeder dyke system and margins of the Ovoid and Eastern Deeps orebodies at Voisey’s Bay, (Barnes et al., 2017), Nebo-Babel (Seat et al., 2007) and particularly in the subject of this contribution, the Aguablanca deposit in SW Spain (Piña, 2019). Genetic interpretations of sulfide matrix breccias have fallen into four main categories (Barnes et al. 2019): tectonic “durchbewegung” origins, upward emplacement of sulfide-rich slurries due to late stage compression in intrusive complexes, downward emplacement as sulfiderich gravity flows during backflow in sill-dyke complexes or into footwall offset dykes, and gravity-driven downward percolation of sulfide liquid through the matrix of original silicate-matrix intrusion breccias. This study presents microbeam XRF mapping to reveal petrographic features, textures and chemical zoning patterns in Aguablanca sulfide-matrix breccia ores at a scale of mm-cm.