Postaccretionary Granitoids in the Structure of Dzabkhan Terrain of the East Siberian Platform Early Caledonian Framing
The Paleozoic granitoids of the Urgamal pluton in the structure of the crystalline basement of the north-western part of the Dzabkhan terrain are considered. The age of these granitoids is 463 ± 2 MA (U–Pb method, ID-TIMS). Urgamal pluton is located on the border of Dzabkhan terrain with Early Caledonian formations of the Lake zone. The intrusion of the pluton took place after the junction of the Dzabkhan terrain with paleooceanic and island-arc complexes of the Lake zone. By their position, these granitoids are postaccretionary formations in the Early Caledonian superterrain of Central Asia. Similar in age and structural position intrusive complexes are known in the Early Caledonian Lake zone, Sangilen Block of Tuva-Mongolian terrain, as well as in the Olkhon terrain framing the East Siberian platform. Data on the features of the geological position of these complexes allow us to estimate the time of articulation of the Early Caledonian superterrain of Central Asia and the Siberian platform.