Ik. Kozakov et al., CRUSTAL GROWTH IN THE GEOLOGIC EVOLUTION OF THE BAIDARIK BLOCK, CENTRAL MONGOLIA - EVIDENCE FROM SM-ND ISOTOPIC SYSTEMATICS, PETROLOGY, 5(3), 1997, pp. 201-207
The Sm-Nd isotopic systematics of supracrustal sequences and intrusive
granitoid complexes of the Baidarik block in the Bayan-Khongor zone o
f Early Caledonides of Central Mongolia (Dzabkhan microcontinent of th
e Central Asian foldbelt) were used to recognize the principal periods
of crustal growth: no earlier than 1.7 Ga, Early Proterozoic (1.8-2.5
Ga), and Archean (2.9-3.3 Ga). The isotopic structure of the continen
tal crust of the Baidarik block is characterized by a vertical heterog
eneity: the modern erosion level exposes rocks of the Archean continen
tal crust, which rest on analogous rocks of mainly Riphean and, probab
ly, Early Proterozoic age.