Caracterização das rochas vulcânicas da área 1 do depósito polimetálico de Santa Maria, Caçapava do Sul - RS

Abstract

Intense prospective research is being carried out in the mining district of Minas do Camaquã in recent years. The district belongs to the city of Caçapava do Sul, located in the state of Rio Grande do Sul and hosts the Zn-Pb- (Cu-Ag) Santa Maria polymetallic deposit. This deposit is characterized by sedimentary rocks of the Santa Bárbara Group and volcanic rocks that occur in the area in the form of dikes and sills. The region has been studied from the petrographic, mineralogical, geochemical and petrological point of view for decades, however there are still controversies regarding the information of mineralizing fluids, genetic correlations and parental origin of the igneous lithologies. In this sense, the proposed study included a macroscopic and microscopic petrographic analysis of the volcanic rocks associated to the mineralization and its geochemical classification by larger elements from analyzes of Atomic Emission Sprectometry by Inductively Coupled Plasma (ICP-AES). The studied volcanic rocks considered trachyandesites, andesite basalts and andesites have a calcium-alkaline character and when compared with other volcanics of the Camaquã Basin, presented strong similarity with the rocks of the Rodeio Velho Member and the Acampamento Velho Formation.