Complex polymetamorphic granulites have been dated in the Santa Catarina gr
anulite complex of southern Brazil through SHRIMP study of zircon. This com
plex is dominated by intermediate-acid plutonic rocks and contains small vo
lumes of mafic and ultramafic rocks, and minor quartzite and banded iron fo
rmation. Porphyroblasts of orthopyroxene, clinopyroxene and plagioclase in
mafic and acid rocks are interpreted as magmatic remnants in a volumetrical
ly dominant granoblastic aggregate (M-1) of the same minerals and hornblend
e. Hornblende formed during a later M-2 metamorphic event constitutes rims
around pyroxene, but the hornblende is also rimmed by granoblastic simplect
ites of orthopyroxene, clinopyroxene, hornblende and plagioclase in a secon
d granulite facies event (M-3) Chlorite and epidote occur in shear zones (M
-4) This granulite terrain is Dart of a Neoproterozoic craton, because it w
as little affected by the Brasiliano Cycle. The two granulite-facies events
(M-1 and M-3) are dated by U/Pb zircon SHRIMP at about 2.68 and 2.17 Ga, w
hile the magmatic protoliths formed at about 2.72 Ga. The amphibolite facie
s event (M-2) probably occurred close to the 2.17 Ga granulitic metamorphis
m.