U-PB AGE OF GRANITOIDS IN THE JUNCTION ZONE BETWEEN THE OLEKMA GRANITE-GREENSTONE AND ALDAN GRANULITE-GNEISS TERRANES

Abstract

U-Pb dating of zircons from the reference granitoid complexes showed that principal thrusts in the northern flank of the junction zone between the Olekma granite-greenstone and Aldan granulite-gneiss terranes of the Aldan Shield were formed 1962 ± 5-2398 ± 4 Ma ago. The oldest structural and metamorphic transformations affected the nonstratified infracrustal complex 3005 ± 4 Ma ago. These data substantiate the reliable correlation of structural units with the geochronological scales previously elaborated for the northern flank and adjacent areas of the Olekma granite-greenstone and Aldan granulite-gneiss terranes.