Abstract
The work plan aims obtaining 40Ar/39Ar data in minerals concentrates of representative key-samples of alkaline rocks from the Poços de Caldas Alkaline Massif (MG/SP) to determine their crystallization/emplacement ages with precision. This massif is the largest Brazilian (ca. 800 km2) and one of over a hundred alkaline occurrences that cut across the Brazilian platform, emplaced along the …