**4. Tectonic position of the Bureya-Jiamusi superterrane**

Ideas about the location of the Bureya-Jiamusi superterrane in the Late Mesozoic-Cenozoic are quite various. Thus, according to [33] the joining of Bureya-Jiamusi superterrane to Argun superterrane (through South Mongolian-Khingan belt or Sungliao block according to the views of the Chinese geologists) occurred in the second half of Paleozoic. It accreted to the Chinese-Korean craton in late Permian [46]. And later, being a part of Amur plate, together with the Chinese-Korean craton, superterrane moved north and accreted to Siberian platform, forming Mongol-Okhotsk orogenic belt and provoking closure of Mongol-Okhotsk basin. Different authors suggest various time stages of the process of the basin closure: in the early Cretaceous [32], in the Late Jurassic [46], or at the end of the Paleozoic [26].

It is known that the union of large geological objects, as a rule, is accompanied (fixed) by magmatic manifestations. The following stages of volcanic activity are set for the northern flanks of the Argun superterrane and the South Mongolian-Khingan (Sunglao) orogenic belt: 147– 138 Myr—volcano-plutonic complex of adakite granites—trachyriolites; 140–122 Myr—differentiated calc-alkaline volcano-plutonic complex; 119–97 Myr—bimodal volcano-plutonic complex; 94-cognac (88?)—absarokite-trachyandesite intraplate [3, 6, 37]. Absolutely other age sequence of Bureya-Jiamusi superterrane magmatic activity is noted in late Mesozoic.

In the author's opinion, the final closure of the Mongolian-Okhotsk basin occurred in the interval 119–97 Myr and was accompanied by the formation of bimodal volcano-plutonic complexes in the frames of the Mongolo-Okhotsk belt [3]. So far, it can be stated that an entirely different age sequence of magmatic activity is noted in the late Mesozoic within the Bureya-Jiamusi superterrane. And the magmatites formed at the same time have disparate material characteristics with late Mesozoic volcanites of the Argun superterrane and the South Mongolian orogenic belt. The fact that the closure of Mongol-Okhotsk orogenic belt was accompanied by the formation of riftogenic structures in its frames, made by the bimodal complexes formations, is confirmed by the evolution of the western flank of the Mongol-Okhotsk orogenic belt [1]. The absence of bimodal complexes in the territory of Bureya-Jiamusi superterrane [4, 5] can be an evidence of the fact that the studied superterrane did not participate in the closure of the Mongol-Okhotsk basin, that this geological object represented an independent structure in the late Mesozoic.

The idea of the tectonic boundary of the Bureya-Jiamusi superterrane with the Badzhal and Honshu-Sikhotealin orogenic belts is almost unambiguous for all authors. And the ideas of the researchers of the eastern structures and the Bureya-Jiamusi superterrane collision time, which fits into the interval 155–125 Myr [16], are close.
