Among the several outcrops of the mainly Palaeoproterozoic igneous-metamorphic basement of the Tandilia System exposed near the Estación Pablo Acosta, a quartz body, associated to a NE-SO shear zone, was identified. Field work, petrologic and geochemical studies revealed that it was formed from a siliceous fluid generated by metamorphic differentiation during the Transamazonian orogeny. On the other hand, the high degree of quartz purity together with the estimated outcropping volume points out a potential importance for industrial commercialization of the mineralization. In addition, this research provides valuable information to the geological-genetic model for the Tandilia System of the Buenos Aires Province.