3D gravity modelling of the Aguablanca Stock, tectonic control and emplacement of a Variscan gabbronorite bearing a Ni–Cu–PGE ore, SW Iberia

The Aguablanca stock is a Variscan mafic pluton located in the Ossa-Morena zone,\udsouthern Iberian Massif, hosting an unusual Ni–Cu–PGE mineralization associated with magmatic\udbreccia pipes which intruded its northern part. The emplacement of the Aguablanca stock and the\udmineralized breccia pipes are related to the activity of the Cherneca ductile shear zone, a Variscan\udsinistral shear zone that favoured magma ascent through the upper crust. A detailed gravity study has\udbeen carried out in order to investigate the 3D geometry of the Aguablanca intrusion and to get insights\udabout the emplacement mechanism and tectonic controls of the mineralization. The three-dimensional\udgravity modelling shows that the stock has an inverted drop geometry with a feeder zone in contact\udwith the Cherneca ductile shear zone. The inferred orientation of the feeder zone suggests that the\udemplacement probably took place along an open tensional crack formed within the strain field of the\udadjacent Cherneca ductile shear zone. The modelling of the breccia pipes hosting the Ni–Cu–PGE ore\udshows that they are included inside the feeder zone, thus their emplacement is probably controlled by\udsuccessive opening events of this tensional crack