The Khanka Massif: The Heterogeneity of its Basement and Regional Correlations

This paper reports new geochronological data on metagranitoids (U–Pb SIMS) and ophiolites (Sm–Nd) from the Khanka massif. New and published data define the Early Neoproterozoic Matveevka–Nakhimovka terrane with 935- and 915-Ma early suprasubduction magmatism, 850–880-Ma and 757-Ma withinplate and Pacific-type transform margin magmatism, as well as the Late Neoproterozoic–Early Cambrian Dvoryan and Tafuin terranes with 543, 520, 517, and 513-Ma suprasubduction magmatism. These two terranes are separated by a suture (Voznesenka and Spassk terranes) formed by Ediacaran–Cambrian shelf deposits and a Cambrian accretionary wedge with ophiolites older than 514 Ma. The greater part of the Khanka massif formed in the late 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 the Early Cretaceous strike-slip movements. Heterogeneous structures of the main part of the Khanka massif can be traced to the north based on 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. These blocks are separated by the Spassk–Wuxingzhen–Melgin suture formed by their collision in the Late Cambrian. The Bureya–Songnen–Jiamusi–Khanka superterrane formed as a part of the Gondwana supercontinent approximately 500 Ma ago through orogeny and accretion of the Rodinia supercontinent fragments.