Petrografia aplicada ao potencial ornamental de cornubianitos e granitos a SE da Vila do Ibaré, Lavras do Sul, RS

Abstract

Brazil plays an important role in the ornamental rock market as one of the world's leading exporters of this material, which causes an improvement in demand all the time, as the country looks for new areas with economic potential based on colors, patterns, and preferences. The goal of this work was to map and detail a petrográfic area with potential for ornamental rock exploration, where there had previously been exploration without strong geophysical controls, and where we are now dealing with an inactive quarry. The area of study is located in the interior of Lavras do Sul municipality in the region of Ibaré, approximately 365 kilometers from Porto Alegre, including the Granito Jaguari and the Complexo Ibaré, on the southeast of Riograndense Escudo Sul. The mineralogy of the Granito Jaguari is typical, consisting primarily of alkaline feldspar, quartz, and biotite in large granulometry. Cornubianito's mineralogy is made up of actinolite, biotite, quartz, and, in some places, plagioclase, which can only be identified microscopically. There were no microcracks found in either rock, and the degree of change was low. The area was divided into two parts: the northeast region, which possessed the most evident folds, and the southeast region, which did not have folds. With the petrográfic study and mapping of these geophysical units, it was discovered that there are new areas to explore, as well as significant differences in the studied region's southeast and northeast.