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The Late Paleozoic–Mesozoic tectonic evolution in the northeastern (NE) Asian continental margin has been a controversial issue. Accretionary complexes (ACs) and sedimentary formations, as the direct material records of the reconstruction of plate subduction history and surface response, respectively, are the categorically ideal indicators to explore tectonic evolution of the NE Asian continental margin. This study reviews recent geological and geophysical advances about the crustal structures beneath the massifs and ACs such as the Yuejinshan and Raohe ACs and conducts a detailed dissection on lithology, degree of metamorphism and deformation, deep crustal structure, and formation time of these fossil ACs. These results, together with the coeval sedimentary formations and igneous rock associations, provide new insights for Late Paleozoic-Mesozoic tectonic evolution of NE Asian continental margin, i.e., the NE Asian continental margin experienced the evolution of two tectonic regimes during the Late Paleozoic–Mesozoic: 1) the stage of the Paleo-Asian Ocean tectonic regime, including a passive continental margin in the early stage of the Late Paleozoic, an active continental margin in the early Permian, and tectonic transition in the Triassic. A paleo-ocean occurred between the Jiamusi Massif and an unnamed massif during the Late Devonian–late Permian; and 2) the stage of the Paleo-Pacific tectonic regime, including the subduction onset of the Paleo-Pacific Plate beneath Eurasia in the Early Jurassic, the accretion and emplacement of the Jurassic ACs during the Late Jurassic–early Early Cretaceous, and the continuous westward subduction during the Late Mesozoic. The Yuejinshan AC was the product of the Paleo-Asian Ocean tectonic regime and formed during the Late Devonian–early Permian. Its final emplacement occurred in the late Permian. The Raohe AC was the product of the Paleo-Pacific tectonic regime and experienced the following stages: 1) the formation of seamounts and deposition of the terrigenous clastic sediments in the Middle–Late Jurassic; 2) the seamount–Eurasia collision in the Late Jurassic; 3) the northward migration of the embryo of the Raohe AC during the Late Jurassic–early Early Cretaceous (160–140 Ma); 4) the deposition of the early Early Cretaceous sediments; and 5) the final emplacement of the Raohe AC in the late Early Cretaceous (140–130 Ma). • Sedimentary strata and accretionary complex reveal the evolution of the NE Asia. • NE Asia was in a passive continental margin setting in the early Late Paleozoic. • E Asia was an active continental margin setting in the early Permian. • The subduction of the Paleo-Pacific Plate beneath Eurasia began in the Early Jurassic. • The Yuejinshan and Raohe accretionary complexes formed in different tectonic [ABSTRACT FROM AUTHOR]

A big mantle wedge (BMW) is an important deep Earth structure that has implications for our understanding of geodynamic processes. The eastern and northeastern Asian BMWs have been extensively studied in the past two decades. This paper reviews evidence for the age, formation, spatial extent, and geodynamic effects of BMWs, with the aim of distinguishing between two BMWs. The eastern Asian BMW initially formed in the late Early Cretaceous and was active from 110 to 55 Ma due to rollback of the subducted Paleo-Pacific Plate and eastward-directed deep mantle flow. This BMW affected the entire eastern Asian continental margin and controlled the late Mesozoic–early Paleogene tectonic evolution of the margin, including destruction of the North China Craton and reworking of continental crust in South China. The northeastern Asian BMW has been active from 20 Ma to the present-day due to rollback of the subducted Pacific Plate and eastward mantle flow. It has mainly affected northeast Asia and resulted in different types of Cenozoic intraplate volcanism and occurrence of earthquakes with deep epicenters. • Eastern (E) and northeastern (NE) Asian big mantle wedges (BMW) are identified. • E Asian BMW formed in late K1 and controlled late Mesozoic-early Cenozoic evolution. • NE Asian BMW formed at ca.20 Ma and controlled intraplate volcanism and earthquakes. [ABSTRACT FROM AUTHOR]

The timing and mantle processes of the Cenozoic transition from an active continental margin to a trench–arc–basin system in northeast Asia remain controversial. Here we present major and trace element, and Sr–Nd–Pb–Hf isotope data for Cenozoic basaltic rocks from the Russian Far East, which provide new constraints on the deep mantle processes during the transition. The basaltic rocks formed mainly in four stages. The results show that middle Eocene basaltic rocks have arc-like geochemical features, such as depletions in high-field-strength elements, indicating an origin by partial melting of a mantle wedge that had been modified by slab-derived fluids and recycled sediments. Early and middle Miocene basaltic rocks also have arc-like geochemical features, and have relatively low contents of fluid-mobile elements and high contents of fluid-immobile elements, as compared with the middle Eocene basaltic rocks. This suggests that these magmas were derived by the melting of previously melted lithospheric mantle that had been modified by slab-derived fluids. In contrast, late Miocene basalts have ocean island basalt-like geochemical features, such as enrichments in high-field-strength elements, indicating their derivation by partial melting of the asthenospheric mantle. The temporal variations in the mantle sources of the Cenozoic basaltic rocks in the Russian Far East, along with an abrupt change in Sr Nd isotopic compositions at ca. 20 Ma, demonstrate that the transition from an active continental margin to a trench–arc–basin system in northeast Asia occurred at ca. 20 Ma. • The basalts in the Russian Far East formed mainly at ca. 45, 20, 13, and 7 Ma. • The temporal variations in the sources of the Cenozoic basalts were determined. • Transition from active continental margin to trench-arc-basin occurred at 20 Ma. • The rollback of Pacific Plate and trench retreat control the tectonic transition. [ABSTRACT FROM AUTHOR]