GEOCRONOLOGIA DO CENTRO-OESTE BRASILEIRO

In this paper the Authors present the results of 81 K-Ar age determinations, involving samples from West Central region (Goias and Mato Grosso States) and west part of Minas Gerais State. Brazil. Sample are related to the several stratigraphic and tecto-orogenic units, and the results are discussed under the light of modern knowledge about that region. For each geologic unit, higher numbers are interpreted as related with major tecto-orogenic events; smaller ages may indicate various thermotectonic stages and regional uplifts, not yet well known. Rb-Sr analysis reported by HURLEY in 1968 are included in the dicussion. Two major events are infered and their significance is discussed.