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Eastern basins in Heilongjiang Province include rudimental Sanjiang Basin, Boli Basin, J ixi Basin, Hulin Basin and Ning’an Basin. According to stratigraphic unconformity, the LateMesozoic basins would be sub-divided into four structural layers, which experienced some extension stages in three different tectonic settings and three tectonic inversion stages. Structural layer I ( Suibin and Dongrong Formations) developed in NS oriented rift trough; structural layer II (Didao, Chengzihe andMuleng Formations) developed in back-arc extension slip set-tingwith NE-NNE trend; during the depositional period of structural layer III (Dongshan Formation ) , this area extended again; while structural layer IV (Houshigou, Hailang, Qixinghe and Yanwo Formations) developed in NW-NNW oriented comp ressional setting, filling with coarse sediments. The formation and evolution of the eastern basins in Heilongjiang were impacted by the collision and closure ofMongolia—Okhotsk Sea, and controlled by the subduction of the eastern Pacific Plate and the matching function of some foreign bodies. The localmantle convection and significant lithospheric thinning caused by the subduction from the Pacific Plate to the mainland are the main dynamic mechanisms of basin-formed.

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