Composition, age, and tectonic position of granitoids of the Shmakovka complex

Abstract

The geological, geochemical, and geochronological data on the granitiods of the Shmakovka massif, which represents a petrotype of the synonymous complex (southern Russian Primorye), show that the granitoid intrusions of the Shmakovka Complex play a “coupling” role, occurring in different blocks of the Khanka composite terrane. The geochemical and isotopic features of the granitoids indicate that their formation resulted from melting of a “mixed,” substantially metapelite, source similar to the most intensely metamorphosed rocks of the Khanka massif. According to U–Pb measurements, the granitoids are 490 ± 1 Ma old. The analysis of the distribution of Early Paleozoic I-, S-, and A-type granitoids in southern Primorye reveals that Late Cambrian–Early Ordovician endogenic events marked the amalgamation of Precambrian–Early Paleozoic blocks and the eventual formation of the Bureya–Jiamusi superterrane (Bureya–Khanka orogenic belt).