Química mineral com ênfase em ETR na porção noroeste do complexo intrusivo Lavras do Sul/RS

Abstract

The growing demand for studies related to Rare Earth Elements (REE) is evident in almost all countries, due to the great discoveries about new applications of these elements in various industrial sectors. These elements have specific properties that optimize various processes and products, thus obtaining great economic importance. Therefore, the search for new information about these elements is constant, as well as the investigation for places where their concentration would be possible. The REE are present, in larger quantities, in minerals associated with alkaline rocks, mainly carbonatites, but studies have revealed significant concentrations in different rocks with alkaline affinity such as granites, rhyolites and aplites. In the study area, located in the municipality of Lavras do Sul, the outcropping rocks belonging to the Lavras do Sul Intrusive Complex (LSIC) present these characteristics and previous studies have shown the existence of a hydrothermal system that acted on these rocks, thus generating the possibility of concentration of REE elements in some portions of the area. The focus of this work is to analyze the behavior of the REE from petrographic and petrological data of the alkaline rocks collected in the area, aided by mineral chemistry studies in SEM-EDS and electron microprobe, identifying the main minerals that contain these elements, quantifying these possible concentrations and relating them to the probable concentrating processes. The results revealed minerals with concentrations of REE, such as allanite, thorite, barite and apatite.