In the Bug granulite-gneiss domain of the Ukrainian shield, a composite tectono-magmatic brec-
cia including enderbites and various mafic rocks was studied in the gneiss-enderbite complex. Based on the
assessment of the thermodynamic conditions of rock and mineral formation and the analysis of the U–Pb
and Lu–Hf isotope systems of zircon, the endogenous history of the gneiss–enderbite complex is deciphered.
The predominant rocks are enderbites with numerous enclaves of two-pyroxene and pyroxene–amphibole
crystalline schists that were deformed under granulite facies metamorphism. The oldest zircons have a con-
cordant U-Pb age of 3.6–3.7 Ga, which is close to the age of the protolith of the Bug enderbites. The zircons
are characterized by a heterogeneous structure, negative Hf(t) values from –1 to –38, and a variation in
176Hf/177Hf(0) isotope ratios from 0.28035 to 0.28095, which is consistent with their different ages and origins.
Based on the age, geochemistry, and isotope composition of zircon from composite breccia rocks, following
geological events from Archean to Proterozoic are distinguished: (1) 3.67–3.60 Ga stage of magmatic crys-
tallization of early mineral associations; (2) 3.0‒2.8 Ga stage of granulite metamorphism and partial melting
(2.9 Ga) of the enderbites with the preservation of melt mineral phases in zircons, but with a strong distur-
bance of its U-Pb isotope system; (3) 2.0–1.9 Ga stage of Proterozoic granulite metamorphism with the reor-
ganization of cation and isotope systems of rock-forming and accessory minerals. The obtained data are con-
sistent with the model of polychronous evolution of the continental crust of the Ukrainian Shield in the
Paleo- and Mesoarchean with its strong reworking in the Paleoproterozoic.