Paleo- and Mesoproterozoic Complexes of the Ulutau Terrane (Central Kazakhstan): Structure, Age Substantiation and Position in the Nuna Supercontinent

The article presents the results of studying and substantiating the age (SHRIMP II, LA-ICP-MS) of Paleo- and Mesoproterozoic sedimentary and volcanogenic-sedimentary complexes of the Ulutau Terrane in the west of Central Kazakhstan. Paleoproterozoic formations are represented by quartzites and shales of the Kumolinskaya Formation with a maximum sedimentation age of 2.03 Ga. These formations, including the terrigenous sequences of the Chuy-Kendykas and Issykul terraces, mark the oldest stage of accumulation of mature sedimentary sequences in the western part of the Central Asian belt, associated with the opening of rift basins within the Nuna Supercontinent during the post-collisional stretching stage. The Mesoproterozoic formations include the bimodal volcanic-sedimentary association of the Zhidinsky Series (~1326–1367 Ma), which is associated with the Ectasian stage of rifogenic magmatism that accompanied the breakup of the Nuna supercontinent. The data obtained suggest that in the Paleo- and Mesoproterozoic, the Ulutau Terrane, the Tarim Craton, and the Yangtze Craton had a similar evolution related to intra-plate tectono-magmatic processes in the western and northwestern parts of the Nuna Supercontinent.