Age of the Vishnyakovskoe Deposit of Rare-Metal Pegmatites (East Sayan):U-Pb Geochronological Study of Manganotantalite

摘要

The U—Pb age of the manganotantalite from rare-metal pegmatites of the Vishnyakovskoe deposit (East Sayan Belt) has been assessed at 1838 + 3 Ma. The acquired data indicate the pegmatites of this deposit and associated granites of the Sayan complex belong to the postcollision South Siberian igneous belt (1.88-1.84 Ga), which stretches along the southwestern frame of the Siberian Craton by more than 2500 km, from the Yenisei Ridge to the Aldan Shield. Formation of this igneous belt is related to joining (starting from about 1.9 Ga BP) of the series of continental microplates and island arcs to the Siberian Craton; this led to final stabilization of the craton at about 1.8 Ga BP.