Late Cretaceous granitoids of the Sikhote–Alin orogenic belt, southeastern Russia: implications for the Mesozoic geodynamic history of the eastern Asian continental margin

New U-Pb age data from granitoids in the Central Sikhote-Alin orogenic belt, southeastern Russia, challenges the long-held belief that Late Cretaceous magmatism was absent at the eastern margin of the Palaeo-Asian continent. The study identifies three distinct plutonic rock suites with ages ranging from 105 to 73 million years, indicating active post-orogenic magmatic activity during this period. This contradicts previous assumptions about a magmatic quiescence phase (88–50 Ma) and suggests that tectonic changes, such as a slab tear in the subducted Palaeo-Pacific plate, triggered asthenospheric upwelling and partial melting of the overlying crust. The findings provide critical insights into the Mesozoic geodynamic history of the eastern Asian continental margin, with implications for understanding plate convergence dynamics.

Kemkin, I. V., Grebennikov, A. V., Ma, X.-H., & Sun, K.-K. (2022). Late Cretaceous granitoids of the Sikhote–Alin orogenic belt, southeastern Russia: implications for the Mesozoic geodynamic history of the eastern Asian continental margin. Journal of the Geological Society, 179(4). https://doi.org/10.1144/jgs2021-109