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The time frame and detailed tectonic processes during the transition from the Paleo-Asian Ocean to the Paleo-Pacific Ocean regimes have long been controversial. The Jiamusi Block, which is located in the eastern margin of the Eurasia, is a transitional zone between the Paleo-Asian Ocean and the Paleo-Pacific Ocean regimes. The Jiamusi Block has been considered to be the last unit collaged to the Central Asian Orogenic Belt (CAOB) but also influenced by subsequent westward subduction and accretion of the Paleo-Pacific plate. Abundant geological units in the Jiamusi Block provide key insights into the final amalgamation of the CAOB and the onset of the Paleo-Pacific Ocean regime. This paper presents a review on the tectonic affinity and origin linkage of the Jiamusi Block based on detailed characterization of both the granulite facies basement and the Phanerozoic sedimentary cover, as well as the surrounding Mesozoic accretionary complexes. From these analyses, we develop an integral tectonic model for the Jiamusi Block aiming to better constraining the evolution history from the final amalgamation of the eastern CAOB to the onset of the Paleo-Pacific Ocean regime. We found that the tectonic history of the Jiamusi Block can be divided into at least four stages: (1) prior to the Early Paleozoic, the Jiamusi Block was conterminous with the other mirco-continents in NE China as a large combined block, which originated from the Sayang–Baikal orogenic belt within the Siberia Craton and experienced the Pan-African metamorphism (ca. 500 Ma); (2) along the tectonic evolution of the CAOB, those blocks in NE China drifted south to the eastern CAOB in some time after ca. 500 Ma; (3) during the Late Paleozoic, the subduction of the Mongol-Okhotsk Ocean or the Panthalassa induced back-arc extension and eventually the opening of the Heilongjiang Ocean, which ripped off the Jiamusi Block and drove it eastward away from the CAOB; (4) during the period from the Late Triassic to the Early Jurassic, following the closure of the Heilongjiang Ocean and the subduction of the Paleo-Pacific Ocean in the east, the Jiamusi Block was reunited with the contiguous CAOB, marking the final amalgamation of the CAOB and tectonic shift to a dominance by the Paleo-Pacific Ocean tectonic regime in the region. • Jiamusi Block is a hinge of tectonic transition between the Paleo-Asian Ocean and the Paleo-Pacific Ocean regimes. • Jiamusi Block together with the other parts of NE China was more likely originated from the Sayang–Baikal orogenic belt. • Jiamusi Block experienced eastward rift away during the Early Permian and reunion to the CAOB during the Late Triassic. [ABSTRACT FROM AUTHOR]

[Display omitted] • The west Jiamusi-Khanka Block in a passive continental margin setting by 300 Ma but an active continental margin by 270 Ma. • The Heilongjiang Ocean account for the transition from a passive to an active continental margin setting. • A new essential tectonic framework for the composite orogenic metallogenic system in the east of North China. Since the Paleozoic, the composite orogenic belt in the east of North China (the eastern Central Asian Orogenic Belt) has undergone multiple stages of subduction-accretion, tectonic superposition and destruction driven by multiple tectonic domains, e.g., the Paleo-Asian Ocean, the Panthalassa, and the Paleo-Pacific Ocean. Multiple episodes of tectono-magmatic activities and associated composite orogenic metallogenic systems have also been occurred. However, the tectonic affinities of these composite orogenic metallogenic systems are still not well understood, due to the poor knowledge of the temporal and spatial transitions among the three tectonic domains. Recently, a regional ocean, namely the Heilongjiang Ocean, has been proposed to be a critical link among the three tectonic domains that drove the Paleozoic tectonic evolution of the eastern Central Asian Orogenic Belt. To constrain the tectonic history of the Heilongjiang Ocean, here we reported new petrological, whole-rock major and trace elemental, and zircon U-Pb geochronological data of sedimentary and magmatic rocks from the western edge of the Jiamusi-Khanka Massif in the east of Heilongjiang Province. Integrating our new results with previous studies in the region, we established a novel tectonic framework for the eastern Central Asian Orogenic Belt: (1) During 380–310 Ma, a tectonic switch occurred in the region from weakened influence of the Paleo-Asian Ocean domain in the south to enhanced influence of the westward subduction of the Panthalassa into the eastern Jiamusi-Khanka Massif; the latter induced back-arc extension and eventually the opening of the Heilongjiang Ocean, which drove the Jiamusi-Khanka Massif to drift eastward away from the Central Asian Orogenic Belt; (2) during 300–270 Ma, subduction of the Heilongjiang Ocean was triggered in its eastern margin, producing arc-type magmatism in the west edge of the Jiamusi-Khanka Massif; by 270–210 Ma, subduction of the Heilongjiang Ocean expanded to its west margin (beneath the Songliao Massif); (3) following the eventual closure of the Heilongjiang Ocean in ~ 180 Ma and subduction of the Paleo-Pacific Ocean in the east, the Jiamusi-Khanka Massif rejoined the conterminous Central Asian Orogenic Belt, marking the final amalgamation of the Central Asian Orogenic Belt; since then, the tectonic history of the composite orogenic metallogenic systems in the east of North China was taken over by the Paleo-Pacific domain. This new tectonic model not only links the evolution of the three tectonic domains, but also provides a vital basis for the geodynamic framework of the contemporary endogenetic metallogenesis in this region. [ABSTRACT FROM AUTHOR]

Northeast (NE) China is located in the eastern Central Asian Orogenic Belt (CAOB) and evolved from the amalgamation of several microcontinental blocks, which, from west to east, include the Erguna, Xing'an, Songliao, and Jiamusi-Khanka blocks. Since the Paleozoic, NE China has undergone multiple stages of subduction–accretion and tectonic destruction under the tectonic domains of the Paleo-Asian Ocean, Panthalassa, and the Paleo-Pacific Ocean. This complexity has resulted in uncertainty surrounding the amalgamation processes of the various microcontinents. Fortunately, several suture zones in NE China, including the Toudaoqiao–Xinlin Suture, the Hegenshan–Heihe Suture, the Solonker–Xar Moron–Changchun Suture, and the Jilin–Heilongjiang High-pressure Belt contain information that provides key constraints on the tectonic evolution of NE China. This paper reviews the spatial distribution, composition, and formation ages of these suture zones based on published geological records. Our temporal and spatial analyses of these suture zones enable the evolution of NE China to be assigned to those three tectonic domains: (1) In the earliest of these, the Paleo-Asian Ocean tectonic domain (650–250 Ma), the Erguna Block amalgamated with the Xing'an Block along the Toudaoqiao–Xinlin Suture during the Late Cambrian (ca. 500 Ma); the Erguna–Xing'an Block then collided with the Songliao Block along the Hegenshan–Heihe Suture during the Late Carboniferous (ca. 300 Ma), whilst the combined Erguna–Xing'an–Songliao Block amalgamated with the North China Craton along the Solonker–Xar Moron–Changchun Suture at the End-Permian (ca. 250 Ma). (2) in the Panthalassa tectonic domain (315–230 Ma), the subduction of Panthalassa (or locally, the Mongol-Okhotsk Ocean) was initiated in the eastern Jiamusi-Khanka Block during the Late Carboniferous (ca. 315 Ma), resulting in back-arc extension in the western Jiamusi-Khanka Block, which evolved into the Heilongjiang Ocean separating the Jiamusi-Khanka and Songliao blocks during the Late Permian to Late Triassic (260–230 Ma). (3) in the Paleo-Pacific Ocean tectonic domain (230–130 Ma), the first stage of westward subduction of the Paleo-Pacific oceanic plate occurred during the Late Triassic (ca. 230 Ma), causing the Jiamusi-Khanka Block to amalgamate with the North China Craton during the Late Triassic (ca. 230 Ma) and subsequently with the Songliao Block during the Late Triassic to Early Jurassic (210–180 Ma), forming the Jilin–Heilongjiang High-pressure Belt, whereas the second stage of subduction induced the emplacement of the Nadanhada Terrane during the Early Cretaceous (ca. 130 Ma). This represented the final assembly of NE China in the eastern CAOB. • NE China can be divided into three tectonic domains of the Paleo-Asian Ocean, the Panthalassa, and the Paleo-Pacific Ocean. • The assembly of NE China was accomplished through the generation of five suture zones, which formed from ∼500 Ma to ∼130 Ma. • NE China recorded multiple stages of activity of the Paleo-Asian, Panthalassa (Mongol-Okhotsk), and the Paleo-Pacific oceans. [ABSTRACT FROM AUTHOR]