IANIGLA   20881
INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Spectral Identification of Buddingtonite and Associated Minerals at Don Sixto, A Low Sulfidation Au-Ag Deposit
Autor/es:
MUGAS LOBOS, ANA CECILIA; ORDOÑEZ, MARIANA; MÁRQUEZ-ZAVALÍA, MARÍA FLORENCIA; GALLISKI, MIGUEL ÁNGEL
Lugar:
Lima
Reunión:
Conferencia; SEG 2012 Conference; 2012
Institución organizadora:
Society of Economic Geologists (SEG)
Resumen:
Don Sixto is an epithermal low sulfidation Au-Ag deposit located in Mendoza Province, Argentina. In this area, ore minerals are disseminated, mainly in hydrothermal quartz veins and altered volcanic-pyroclastic units of Permian-Triassic age (Mugas Lobos et al., 2010, and references therein). In Don Sixto, the gold resource reaches 1,258,000 oz. In order to characterize the argillic mineral association, reflectance spectroscopy was performed. The analyzed samples reflected major amounts of illite and smectite with lesser kaolinite and chlorite; goethite and hematite were also recognized. In addition, buddingtonite, previously reported by Godeas and Rubinstein (2004), was identified. Buddingtonite (NH4)AlSi3O8, initially described by Erd et al. (1964), is an ammonium-bearing feldspar closely related to gold occurrence. This mineral has been found as a hydrothermal replacement of plagioclase, and lately in oil shales and hydrothermal deposits (Voncken et al., 1993). The buddingtonite described in this contribution has been found closely related to illite, associated with high average Au grade (1.63 g/t) ores (Fig. 1A). The presence of illite, highly crystalline illite, and illite-smectite mixture is related to an average grade of 2.51 g/t Au (Fig. 1B). Based on the spectral features of buddingtonite and illite from Banderas, a low sulfidation Au-Ag prospect in Guatemala, Harlap (2008) interpreted that illite crystallinity and ammonium alteration intensity increases toward gold mineralization. These observations are similar to the occurrence of buddingtonite at Don Sixto. Considering that the relationship between buddingtonite and gold mineralization is not totally understood, the occurrence of these minerals at Don Sixto provides more evidence about the related argillic association and gold grade for this epithermal low sulfidation deposit. The buddingtonite described in this contribution has been found closely related to illite, associated with high average Au grade (1.63 g/t) ores (Fig. 1A). The presence of illite, highly crystalline illite, and illite-smectite mixture is related to an average grade of 2.51 g/t Au (Fig. 1B). Based on the spectral features of buddingtonite and illite from Banderas, a low sulfidation Au-Ag prospect in Guatemala, Harlap (2008) interpreted that illite crystallinity and ammonium alteration intensity increases toward gold mineralization. These observations are similar to the occurrence of buddingtonite at Don Sixto. Considering that the relationship between buddingtonite and gold mineralization is not totally understood, the occurrence of these minerals at Don Sixto provides more evidence about the related argillic association and gold grade for this epithermal low sulfidation deposit. The buddingtonite described in this contribution has been found closely related to illite, associated with high average Au grade (1.63 g/t) ores (Fig. 1A). The presence of illite, highly crystalline illite, and illite-smectite mixture is related to an average grade of 2.51 g/t Au (Fig. 1B). Based on the spectral features of buddingtonite and illite from Banderas, a low sulfidation Au-Ag prospect in Guatemala, Harlap (2008) interpreted that illite crystallinity and ammonium alteration intensity increases toward gold mineralization. These observations are similar to the occurrence of buddingtonite at Don Sixto. Considering that the relationship between buddingtonite and gold mineralization is not totally understood, the occurrence of these minerals at Don Sixto provides more evidence about the related argillic association and gold grade for this epithermal low sulfidation deposit. The buddingtonite described in this contribution has been found closely related to illite, associated with high average Au grade (1.63 g/t) ores (Fig. 1A). The presence of illite, highly crystalline illite, and illite-smectite mixture is related to an average grade of 2.51 g/t Au (Fig. 1B). Based on the spectral features of buddingtonite and illite from Banderas, a low sulfidation Au-Ag prospect in Guatemala, Harlap (2008) interpreted that illite crystallinity and ammonium alteration intensity increases toward gold mineralization. These observations are similar to the occurrence of buddingtonite at Don Sixto. Considering that the relationship between buddingtonite and gold mineralization is not totally understood, the occurrence of these minerals at Don Sixto provides more evidence about the related argillic association and gold grade for this epithermal low sulfidation deposit. 4)AlSi3O8, initially described by Erd et al. (1964), is an ammonium-bearing feldspar closely related to gold occurrence. This mineral has been found as a hydrothermal replacement of plagioclase, and lately in oil shales and hydrothermal deposits (Voncken et al., 1993). The buddingtonite described in this contribution has been found closely related to illite, associated with high average Au grade (1.63 g/t) ores (Fig. 1A). The presence of illite, highly crystalline illite, and illite-smectite mixture is related to an average grade of 2.51 g/t Au (Fig. 1B). Based on the spectral features of buddingtonite and illite from Banderas, a low sulfidation Au-Ag prospect in Guatemala, Harlap (2008) interpreted that illite crystallinity and ammonium alteration intensity increases toward gold mineralization. These observations are similar to the occurrence of buddingtonite at Don Sixto. Considering that the relationship between buddingtonite and gold mineralization is not totally understood, the occurrence of these minerals at Don Sixto provides more evidence about the related argillic association and gold grade for this epithermal low sulfidation deposit.
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