Modern geochronology techniques have become indispensable resources for basic geological cartography, having been used systematically for some decades by geological surveys across the globe.

Over the past decade, the Geological Survey of Brazil started using the conventional TIMS U-Pb geochronological technique and SHRIMP, as well as the Pb-Pb by evaporation and Sm-Nd techniques in its geological cartography studies.

Carlos Eduardo Ganade de Ara˙jo