ХАНКАЙСКИЙ МАССИВ: ГЕТЕРОГЕННОСТЬ ФУНДАМЕНТА И РЕГИОНАЛЬНЫЕ КОРРЕЛЯЦИИ

Abstract

The results of geochronology studies on metagranitoids (U-Pb SIMS) and ophiolites (Sm-Nb) from the Khanka massif are considered. New and published data define the Early Neoproterozoic Matveevka-Nakhimov terrane with early suprasubduction magmatism of 935 and 915 Ma, intraplate and Pacific-type transform margin magmatism of 850-880 and 757 Ma, and the Late Neoproterozoic-Early Cambrian Dvoryan and Tafuin terranes with suprasubduction magmatism of 543, 520, 517 and 513 Ma. Between these two parts of the massif there is a suture (Voznesenka and Spassk terranes) formed by Ediacaran-Cambrian shelf deposits and a Cambrian accretionary prism with ophiolites older than 514 Ma. The greater part of the Khanka massif formed late in the Cambrian with the Kordonka island arc terrane accreted at the end of the Silurian. The Sergeevka terrane of the Ordovician island arc joined it through Early Cretaceous strike-slip movements. Heterogeneous structures of the main part of the Khanka massif can be traced to the north by the analogous stages of magmatism and metamorphism, where the Jiamusi massif (including the East Bureya terrane) is an Early Neoproterozoic block and the eastern Songnen massif (including the West Bureya terrane) is a Late Neoproterozoic-Cambrian block. Between these two blocks is the Spassk-Wuxingzhen-Melgin suture formed by their collision late in the Cambrian. The Bureya-Songnen-Jiamusi-Khanka superterrane formed as a part of the Gondwana supercontinent about 500 Ma ago through orogeny and accretion of the Rodinia supercontinent fragments.