Abstract:

The authors accumulate a large amount of new data of regional geology and geochronology in recent years and makes a generalization and summation of the tectonic nature and evolution in Northeastern China. A comprehensive study indicates that the NE China continent is composed mostly of relatively stablae massifs, rather than orogenic belt since Late Paleozoic. All of these massifs include the basements of Precambrian-Early Precambrian, even Archean, and were simultaneously subjected to metamorphism and granitic magmatism in early Early Paleozoic(490-510 Ma). During 350-450 Ma, at least two stable microcontinents of Erguna-Xing’an and Songnen-Jiamusi composed of massifs solidified in 490-510 Ma existed in NE China, marked by without magmatism, which are northwards linked together with Erguna and Buriya massifs in Russia,respectively. These two microcontinents collided together along a NNE-trending Kailu-Nenjiang-Heihe(NE China)-Nora-Soukhotin(Russia) in Early Carboniferous and formed a Northeast Asia continental plate(NACP).The well-known Xilamulunhe fault is commonly referred as a final collision zone between NACP and North China plate, but the west end of the fault is cut by NNE-trending fault, and east end linked together with Kailu-Nenjiang collision zone and not stretches eastwards into Songliao basin, indicating the Xilamulunhe fault is possibly related to the formation of Kailu-Nenjiang collision zone. From Late Carboniferous to Mid Permain, the NACP on the whole was at extension setting where at least in NE China, a series of faulted basins with predominant volcanics formed in early time and a large marine sedimentary basin formed in Mid Permian. All of the Late Paleozoic volcanics and sedimentary rocks do not suffer regional metamorphisam. The transformation of Mesozoic tectonic regime in NE China is related not only to superposition and transformation of Paleo-Asia ocean tectonic system by west Pacific tectonic system, but the evolution of Mongolia-Okhotsk tectonic system plays an important role in transforming tectonic regim, especially in Mid-Late Jurassic. The evidences of geology and geophysics show that the well-known three faults of Derbugan in Da-Xinganling Mountains, Hegenshan in central part of Inner-Mongolia and Nadanhada in east part of Heilongjiang Province are not deep faults controlling tectonic units probably. The parts under Mesozoic-Cenozoic basins in NE China for the most part are not metamorphosed crystalline basement, but a large marrine sedimentary basin.

Key words: Northeastern China, Phanerozoic, tectonic evolution, tectonics