Bacia do Paraná, vulcanismo ácido, ignimbritos, geoquímica
Abstract
Geological mapping on a scale of 1:50,000 was carried out in an area of 1800 km2, located in the central part of the Videira and Barracão Sheets in the Campos Novos, Celso Ramos and Anita Garibaldi municipalities, Santa Catarina. Five basic flows followed by six acidic units, similar to ignimbrites, were recognized and comprise a 500- to 600- m thick pile. Petrographic and major element geochemical data reveal the tholeitic character of the association and its relationship with low-titanium basalts and Palmas-type acidic rocks. Preliminary petrogenetic study suggests that the acid rocks originated by partial melting of a gabbroic parent which may be the intrusive equivalent of the basic flows of the study area.
