Revisiting the Late Paleozoic–Mesozoic tectonic evolution of epicontinental eastern Central Asian Orogenic Belt on the basis of detrital zircon

Abstract

The eastern Central Asian Orogenic Belt (CAOB) is a natural laboratory for studying and interpreting the evolution of accretionary collages. The CAOB contains several micro-landmasses whose tectonic evolution during the Late Paleozoic–Mesozoic is a matter of debate. Here, we revisited detrital zircon data in relevant areas and present new detrital zircon U–Pb age data from the Hulin Complex and Wandashan Accretionary Complex (consisting of the Raohe and Yuejinshan complexes) in the eastern CAOB. The youngest zircon peak age of mica-quartz schist from the Hulin Complex constrains the timing of deposition to after ∼153.5 Ma. Sandy slate and fine sandstone from the Wandashan Accretionary Complex have youngest ages of ∼135.7 and ∼254.7 Ma, respectively. These data, together with detrital zircon data in the epicontinental eastern CAOB, suggest that there was a transformation from an extensional to convergent tectonic setting in the eastern CAOB around the Late Permian–Early Triassic. The Khanka Massif may have been adjacent to the Songnen and Jiamusi massifs to the west and north respectively, during the Late Paleozoic–Mesozoic. Between the Songnen and Jiamusi massifs, the Mudanjiang Ocean initially opened in the Late Paleozoic and closed after the Late Jurassic (∼153.5 Ma) and produced the Heilongjiang Complex. The Paleo-Yuejinshan back-arc basin underwent extension in the Permian and finally closed after ∼216 Ma, forming the Yuejinshan Complex at ∼210–180 Ma. The Raohe Complex was accreted at ∼169–133 Ma and emplaced at ∼133–131 Ma. The large-scale sinistral strike-slip movement of the Dunmi Fault started later than ∼153.5 Ma and partially displaced the Heilongjiang Complex from the Mudanjiang area to the present-day Hulin Complex. The eastern CAOB was under a superimposed tectonic regime of the Paleo-Pacific Ocean and Paleo-Asian Ocean in the Late Paleozoic.